w/ 2- HARVARD UNIVERSITY LIBRARY OF THE Museum of Comparative Zoology ': • • • • The Library Museum of Comparative Zoology Harvard University University of Kansas Publications museum of natural history VOLUME 16 • 1964-196 8 EDITORS E. Raymond Hall, Chairman Frank B. Cross Theodore H. Eaton, Jr. Henry S. Fitch J. Knox Jones, Jr. Museum of Natural History UNIVERSITY OF KANSAS LAWRENCE 1972 NA - L[avore*\cej Museum of Natural History university of kansas lawrence PRINTED BY UNIVERSITY OF KANSAS PRINTING SERVICE LAWRENCE CONTENTS OF VOLUME 16 1. Distribution and taxonomy of mammals of Nebraska. By }. Knox Jones, Jr. Pp. 1-356, pis. 1-4, 82 figs. October 1, 1964. 2. Synopsis of the lagomorphs and rodents of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 357-407. February 12, 1965. 3. Mammals from Isla Cozumel, Mexico, with description of a new species of harvest mouse. By J. Knox Jones, Jr., and Timothy E. Lawlor. Pp. 409-419, 1 fig. April 13, 1965. 4. The Yucatan deer mouse, Peromyscus yucatanicus. By Timo- thy E. Lawlor. Pp. 421-438, 2 figs. July 20, 1965. 5. Bats from Guatemala. By J. Knox Jones, Jr. Pp. 439-472. April 18, 1966. 6. Evolution and classification of the pocket gophers of the sub- family Geomyinae. By Robert J. Russell. Pp. 473-579, 9 figs. August 5, 1968. 7. Revision of pocket gophers of the genus Pappogeomys. By Robert J. Russell. Pp. 581-776, 10 figs. August 5, 1968. 8. Systematics of megachiropteran bats in the Solomon Islands. By Carleton J. Phillips. Pp. 777-837, 17 figs. December 16, 1968. Index, pp. 839-860. University of Kansas Publications Museum of Natural History Volume 16, No. 1, pp. 1-356, pis. 1-4, 82 figs. October 1, 1964 Distribution and Taxonomy of Mammals of Nebraska BY J. KNOX JONES, JR. MUS. COMP. ZOOL LIBRARY i*ov j 0 ib64 HARVARD university: University of Kansas Lawrence 1964 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 16, No. 1, pp. 1-356, pis. 1-4, 82 figs. Published October 1, 1964 University of Kansas Lawrence, Kansas PRINTED BY HARRY (BUD) TIMBERLAKE. STATE PRINTER TOPEKA, KANSAS 1964 29-6532 Distribution and Taxonomy of Mammals of Nebraska BY J. KNOX JONES, JR. CONTENTS PAGE INTRODUCTION 5 ENVIRONMENT 8 Climate 8 Soils 10 Geology and Physiography 12 Vegetation 1 5 Effects of Man on the Environment 19 FACTORS INFLUENCING DISTRIBUTION AND SPECIATION .... 20 Wisconsin Glaciation and Post- Wisconsin Climates 20 Emigration of Recent Mammals to Nebraska 31 Some Effects of the Environment 35 The Missouri River as a Barwer to Dispersal 39 Geographic Variation and Speciation 42 Mammalian Distributional Areas 45 Summary 48 TREATMENT AND ACKNOWLEDGMENTS 49 CHECKLIST (with page references) OF MAMMALS OF NEBRASKA. . 54 ACCOUNTS OF SPECIES 58 INTRODUCED MAMMALS 330 SPECIES OF UNVERIFIED OCCURRENCE 337 TYPE LOCALITIES 339 LITERATURE CITED 341 (3) INTRODUCTION Nebraska (area 77,227 square miles) extends from the oak- hickory forest along the Missouri River in the southeast, where the elevation is less than 900 feet, to the pine-clad hills and ridges of the Panhandle, some of which exceed 5000 (the highest is 5340) feet in elevation and are outlying foothills of the Rocky Mountain system. Interposed between these two extremes are the prairies — the true prairie, or tall-grass prairie, of the Central Lowlands and the mixed prairie of the Great Plains, including the unique Sand Hills that occupy more than 18,000 square miles to the north of the Platte River in the central part of the state. In Nebraska, there- fore, mammals of the eastern part of temperate North America mingle with those of the grasslands, and to a lesser extent with species having northern, western or southern affinities. Con- sequently it is not surprising that 54 of the 81 species of native mammals occurring in the state reach distributional limits there. The earliest published references to mammals in Nebraska are in the accounts of explorers, fur traders and missionaries who visited the plains region in the 17th and 18th centuries, but it was not until the 19th Century that systematic biological exploration of the state was really begun. Notable among the explorers and naturalists who visited Nebraska between 1800 and 1850, most of whom traversed the Missouri River, were Captains Lewis and Clark in 1804 and 1806, John Bradbury and Henry M. Brackenridge in 1811, Maximilian ( Wied-Neuwied ) in 1833-34, and John J. Audubon in 1843. By far the most important of the early explorations of Nebraska, however, was that of Major Stephen H. Long in 1819 and 1820. His party, which included naturalists Thomas Say and Edwin James, spent the winter at the so-called Engineer Canton- ment, along the Missouri River in what is now southeastern Wash- ington County, and in the spring of 1820 crossed Nebraska along the Platte River on the way to the Rocky Mountains. James' ( 1823) account of this expedition includes descriptions of six mammals from Nebraska in footnotes by Say and also a synoptic list of mam- mals found by the group. This report and others are of special interest also because they describe the then existing biotic condi- tions, which differed greatly from those prevailing today. After the discovery of gold in California in 1849, the Platte Valley became one of the principal routes of travel to the west, leading to increased military activity there for the protection of travelers. (5) 6 University of Kansas Publs., Mus. Nat. Hist. Also, survey parties were active seeking the best routes for military wagon roads and later for railroads. The specimens accumulated through the efforts of F. T. Bryan, J. G. Cooper, F. V. Hayden, G. K. Warren, and W. S. Wood, to name a few who were associated with the various military enterprises, were reported by Baird ( 1858 ) and Coues and Allen (1877) among others. Unfortunately, the localities of capture of some of these valuable specimens were only vaguely defined, and others have been incorrectly located by mam- malogists owing to changes in political boundaries after the collec- tions were made. Nebraska Territory was created as a result of the Kansas-Nebraska Act of 1854, and from 1854 to 1861 included all lands between the 40th parallel and the Canadian boundary that were west of the Missouri River and east of the crest of the Rocky Mountains — in other words, what is now Nebraska, northeastern Colorado, and most of the Dakotas, Wyoming and Montana. With the establish- ment of Dakota Territory in 1861, Nebraska Territory was reduced to Nebraska proper and that part of Wyoming between the 41st and 43rd parallels and east of the 110th meridian. In March, 1863, the present boundaries of Nebraska were fixed. Many specimens obtained in the period 1854-63, properly labeled at the time as from '"Nebraska," came from places in other states as their boundaries currently are recognized. Specimens labeled as from "Ft. Pierre" [South Dakota], "Ft. Buford" [North Dakota], "Milk River" [Mon- tana], or "Ft. Laramie" [Wyoming], for example, pose no problem because the localities are well known; specimens from places less well known, such as "Deer Creek" (Jones, 1958&), or that were labeled with reference to a general locality, such as "Platte River," do pose problems and require the routes and dates of travel by the parties concerned in order to place them accurately on modern maps. Insofar as was possible I have admitted for Nebraska only those records that I could convince myself actually originated there. More than 200 books and scientific papers have been published in which reference was made to mammals in Nebraska, most of which are listed at the end of this account. The first published list of mammals of the state was by Samuel Aughey (1880) in his "Sketches of the physical geography and geology of Nebraska." But this list contained little original information, being mostly a compilation, with liberal extrapolation, from the compendia of Baird and of Coues and Allen cited previously. The only other Mammals of Nebraska 7 paper treating mammals on a state-wide basis, except the four check- lists of Myron Harmon Swenk (1915c, 1918, 1919, and 1920b) and one of my own (1957), was Swenk's "A preliminary review of the mammals of Nebraska, with synopses," which appeared in 1908 and in which 92 kinds were listed. Of the serial publications in which papers dealing with Nebraska have appeared, three, the North American Fauna series (1889-present), the Journal of Mam- malogy (1919-present) and the University of Kansas Publications, Museum of Natural History (1946-present), are of particular note. In addition to published sources I have had available two un- published manuscripts of considerable import. One, "The mam- mals of Nebraska" by the late Merritt Cary, written about 1905, was made available to me in Washington, D. C, by Stanley P. Young of the U. S. Fish and Wildlife Service. The other, a collection of notes on Nebraskan mammals compiled over a period of more than 50 years by the late Myron H. Swenk, is now in my possession through the courtesy of Edson H. Fichter. A number of citations have been taken from each manuscript. My own work in Nebraska began in the summer of 1946 and, save for 1954 when military service took me out of the country, I collected at least some mammals in the state in each year through 1961. Principal collections were made in the summers of 1947, 1948, 1952, and 1957, and by J. R. Alcorn in the spring of 1958. In the course of this study, nearly all specimens of Nebraskan mam- mals in North American museums that came to my attention prior to March 31, 1962, were examined— a total of 10,339. The few specimens of which I was aware that, for one reason or another, were not personally examined generally are duplicated among specimens in other collections. It is axiomatic that a study of the kind here reported on is but a progress report. Much remains to be learned concerning the distribution and speciation of mammals in Nebraska and mention is made in the text beyond of some remaining problems. Lest I be criticised for preparing this report mainly from the taxonomic and distributional approach, I would remind the reader that little pre- cise information currently is available concerning the ecology of Nebraskan mammals (the studies of Fichter et at, 1955, Mohler et ah, 1951, and Sather, 1958, being notable exceptions), and it is hoped that this work will stimulate biologists to undertake such studies. 8 University of Kansas Publs., Mus. Nat. Hist. ENVIRONMENT Climate The climate of Nebraska is typical of that of the interior of large continents and is characterized by sparse to moderate rainfall, low humidity, hot summers, cold winters, wide variations in tempera- ture and rainfall from year to year, and not infrequent drastic changes in weather from day to day. The two major factors in- fluencing climate in the state are (1) its interior location con- tinentally, far distant from large bodies of warm water, and (2) its situation in the rain shadow to the east of a high, north-south moun- tain system. Short-period changes in weather are influenced by the invasion of large masses of air: warm, moist air from the Gulf of Mexico; hot, dry air from the southwest; cool, usually dry air from the north Pacific Ocean; or cold, dry air from interior Canada. Masses of air over Nebraska generally are associated with the eastward movement of high and low pressure systems (cyclones and anticyclones), which are influenced by the Rocky Mountains. Many cyclonic storms pass either to the north or the south of Nebraska. Air cross- ing the mountains at the latitude of Nebraska looses most of its Table 1. — Mean Temperature and Precipitation Values, 1905-1960, for Seven Selected Weather Stations, Arranged from East to West (Data from "Local Climatological Data" Sheets, 1960, for the Stations Listed). Temperature in Degrees Fahrenheit; Precd?itation in Inches. Station (and altitude) Temperature Precipitation Jan.* max. Jan.* min. July* max. July* min. Average annual Average annual Average snow- fall** Omaha (978 ft.) 31.0 33.3 29.5 34.1 33.1 36.0 39.8 13.3 14.7 8.0 12.9 9.2 11.7 11.9 87.5 89.0 87.0 90.6 85.2 87.6 89.2 67.4 66.6 63.4 64.8 59.0 62.2 57.4 51.2 51.8 48.3 50.9 47.2 49.4 48.5 28.05 27.62 23.56 24.61 18.61 18.42 15.30 29.15 Lincoln (1166 ft.) 29.83 Norfolk (1544 ft.) Grand Island (1841 ft.) 28.93 28.80 Valentine (2587 ft.) North Platte (2779 ft.) 28.90 31.64 Scottsbluff (3950 ft.) 39.68 * Average daily minima or maxima. ** Average 10 seasons (1950-51 to 1959-60). Mammals of Nebraska 9 moisture on the windward side of the Rockies and becomes warmer and drier as it descends the eastern slopes onto the plains. Most (nearly 80 per cent) of the precipitation that falls on Nebraska comes in the six warm months of the year (April -Sep- tember) and originates in warm, moist air from the Gulf of Mexico. However, much air moving north from the Gulf is deflected to the east by the eastward movement of air over the Rockies, with the result that the easternmost part of the state receives more than twice as much precipitation as the westernmost part, and much Gulf air that originates at the longitude of Nebraska misses the state altogether. Average annual precipitation decreases rather uniformly from more than 34 inches in the southeast (34.51 at Falls City, 1931-1955) to about 13 inches in the western part of the Panhandle (12.88 at Mitchell, 1931-1955). Thundershowers in spring and summer ac- count for a large part of the rainfall. In some years thundershowers are numerous and well distributed but more often than not they are infrequent and scattered. The result is a great variability in monthly or annual (or both) rainfall from year to year. A few hailstorms are recorded each year in Nebraska, mostly in June, July, and August. Snowfall generally is heavier in the east, north, and northwest than in the central and southwestern parts of the state and averages about 29 inches annually. Precipitation at Nebraskan weather stations was officially recorded as early as 1876 and since that time a succession of wet and dry periods have occurred as follows (Blair, 1941; Stevens, 1959): 1876-1892. Wet period with one dry year. 1893-1901. Dry period with one rather wet year. 1902-1909. Wet period with one rather dry year. 1910-1920. Irregular precipitation; most years dry, but 1915 wettest year on record. 1921-1940. Dry period with one wet year; especially dry after 1930. 1941-1951. Wet period with one dry year. 1952-present. Moderately dry period. Mean annual temperature varies from between 53° and 54° F. along the southern border of Nebraska (54.0 at Pawnee City, 53.7 at Fairbury, 53.6 at Beaver city, and 53.3 at Benkelman, all 1931-1955 averages) to 45.8° F. (1931-1955) at Harrison in the northwestern corner of the state. Maximal summer temperatures in excess of 100° F. occur regularly throughout the state in June, July, August, and September, 118° F. recorded at Geneva, Hartington, and Minden being the record high. Minimal temperatures of 0° F. 10 University of Kansas Publs., Mus. Nat. Hist. or colder occur on the average in 10 days of the year in the south- east and in 25 days in the northwest. Minima lower than — 40° F. have been recorded on several occasions; the record low for the state is — 47° F., recorded at Camp Clarke on February 12, 1899. The average date of the last freeze in spring ranges from April 25 in the extreme southeast to May 21 in the northwestern part of the Panhandle, and the average date of the first freeze of autumn from about October 6 to September 20 in the same areas. The growing season, therefore, ranges on the average from 164 days in the south- east to 122 days in the northwest, but is subject to considerable variation from year to year. The relative humidity varies on the average from about 60 per cent in the warm months to 70 per cent in the colder parts of the year. Soils Three of the major soil divisions of North America are found in Nebraska in the form of six general soil associations. Three of the associations, brunizem, chernozem, and chestnut, are among the dark-colored soils that developed under prairie vegetation; two, regosol and lithosol, are immature, shallow soils; the sixth, alluvium, is a soil of stream bottomlands (see especially "Soils of the north central region of the United States," Bull. Univ. Wisconsin Agric. Exp. Sta., 554:1-192, illustrated, June, 1960). Each of the soil associations needs to be thought of in relation to climate, vegetation, physiography, and geologic history, because all influenced soil formation. Brunizem. — This soil association owes its existence to tall-grass prairie. Brunizem (or prairie) soils developed under tall grass in a temperate, relatively humid climate, and occupy an extensive area in the central United States that now corresponds closely to the so- called "com belt." Brunizem soils generally form a dark grayish brown, thick, slightly acid upper horizon that is underlain by dark yellowish brown or grayish brown subsoils. Brunizems can form from materials that vary from sand to clay (but form mostly from loess, glacial outwash or glacial till) and are among the most agri- culturally productive soils known. Humic-gley soils, known also as wet meadow soils, are found extensively throughout this soil association. Humic-gley forms under grasses and sedges on sites that are poorly drained but not wet enough to support formation of organic soils, is thick, blackish, usually non-calcareous, and is underlain by grayish subsoils. Mammals of Nebraska 11 Chernozem. — Chernozem covers the loess plains of eastern and central Nebraska; it developed under the drier, western part of the tall-grass prairie and adjacent parts of the mixed prairie. The color is grayish brown, paler than brunizem, the amount of water moving downward is less than in brunizem, and the upper horizon is slightly acidic to mildly alkaline. Chernozem soils occupy well-drained sites, the gentle slopes and rolling hills, of the loess plains and intergrade on steep slopes with regosols and in swales and lowlands with planosols. Chestnut. — Soils of this association are present on the High Plains of western Nebraska and in adjacent regions. Chestnut soils are associated with mixed-grass prairie. They grade westwardly into the brown soils of the disclimax short-grass prairie, are char- acteristic of semi-arid areas ( less than 20 inches of annual precipita- tion), brownish, and relatively thin. This soil association borders the Sand Hills on the west and south, and south of the Platte River in central Nebraska grades eastward into the darker chernozem. Small areas of immature, shallow soils are completely surrounded by elements of the chestnut soil zone in the Panhandle, including the lithosols of the rough, broken lands of the Pine Ridge and of the hills and breaks along the North Platte River, and some isolated areas of Valentine sand (a regosol). Also of especial note are the Badlands to the north of the Pine Ridge escarpment in Dawes and Sioux counties. This rugged section, mostly Pierre Shale of Cre- taceous age and a part of the Missouri Plateau, has clayey shales (gumbo) exposed over wide areas along with some lithosols on the more rugged slopes. Regosol. — This soil association in Nebraska is composed entirely of sands and fine sandy loams of the Valentine series. It is mostly confined to the Sand Hills proper, north of the Platte River in the central part of the state, but occurs also in isolated patches along the Platte farther to the east, south of the Platte in the southwest, and on the High Plains. The Valentine sands are composed mostly of the coarser materials of the Tertiary peneplain that once covered much of central and western Nebraska and were developed through eolian action. In addition to sand, some humic-gley soil is found in the Sand Hills around the many lakes and marshes. Lithosol. — Lithosols are thin, immature soils that develop over rock. No true subsoil is present. In Nebraska, lithosols occur on the Pine Ridge and in the rough country along the North Platte River in the western Panhandle. 12 University of Kansas Publs., Mus. Nat. Hist. Alluvium. — This soil association is found in Nebraska in the bot- tomlands of the larger rivers and their major tributaries. It is a poorly defined association because it frequently combines elements from two or more other soil associations. In the western part of the state, alluvial soils tend to be darker and more humic than soils of adjacent uplands and frequently support a riparian plant community notably different from that of uplands. The soils of the general associations described above are divisible into soil series, which themselves may be subdivided into soil types. For detailed information of this sort, the reader is directed to the soil surveys of individual counties that, beginning in 1913, have been issued by the U. S. Department of Agriculture for all but six (Arthur, Grant, Hooker, Logan, McPherson, and Thomas) of Ne- braska's 93 counties. Reference to these surveys and especially their accompanying maps is useful in the selection of collecting sites for mammals and may be useful also in locating place names that do not appear on maps of larger scale. Some relationships of soils to distribution and speciation of mammals in Nebraska are discussed in a following chapter. Geology and Physiography Geology "The geological formations of Nebraska occur as (1) unconsoli- dated sediments called mantelrock, shaped by wind, streams and glaciers, (2) widespread sedimentary bedrock known as shale, mud- stone, sand, sandstone, and limestone, and (3) deep-seated granite and granite-like rocks. Much of the state is mantled with rock debris beneath which bedrock outcrops in places" (Condra and Reed, 1943:1). The mantle is mostly of Pleistocene age and the bedrock ranges in age from early Paleozoic to late Tertiary — see Condra and Reed, op. cit.: figs. 1 and 3, for maps showing location and extent of mantlerock and bedrock in Nebraska. The Quaternary mantle, frequently 100 to 300 feet thick, con- sists mostly of the dune sand of the Sand Hills and some small, isolated areas adjacent thereto, and loess, deposits of which cover that part of Nebraska situated to the east and south of the Sand Hills (the Loess Plains, Loess Hills, and Loess on Glacial Drift areas of some topographic classifications). West of the Sand Hills, on the High Plains, the mantle, partly loess, is thin or absent. Bedrock outcrops in Nebraska principally in the southeast (Meso- zoic and Paleozoic rocks) and in the Panhandle (Tertiary rocks Mammals of Nebraska 13 and Pierre Shale of Cretaceous age ) . Outcroppings of pre-Tertiary rocks in the southeast and elsewhere usually are thinly exposed, generally along water courses, but the Tertiary rocks of western Nebraska (Pliocene, Miocene and Oligocene) are exposed over wide areas and provide important habitats for some mammals. Hydrography The surface drainage of Nebraska falls entirely within the Mis- souri River system and direction of drainage, therefore, is generally eastward to the Missouri, which forms the eastern border of the state. Excepting the immediate vicinity of the Missouri itself, Nebraska has eight major drainage basins. North of the Pine Ridge in the northwest, the Hat Creek and White River basins drain northwardly into South Dakota. The Niobrara River, flowing east- ward the entire length of the state, drains all but a small part of northern Nebraska and empties into the Missouri in Knox County. The Platte River also courses the breadth of Nebraska, through the central part of the state, its basin receiving the southeastward-flow- ing Loup River (in Platte County) and Elkhorn River (in Sarpy County); the Platte is the longest of the Missouri's tributaries. In southern Nebraska, the Republican and Blue basins drain away to the southeast, eventually to reach the Missouri via the Kansas River system. Much of the water in Nebraska's streams and rivers comes from surface run-off, but a significant portion comes from under- ground sources, especially from the area under the Sand Hills. Aside from streams and rivers, Nebraska has about 2500 lakes, marshes and artificial reservoirs containing 15 acres or more of water. Most of the natural lakes and marshes are in the Sand Hills where, counting bodies of standing water of all sizes, the number exceeds 3000. Physiography According to Frye and Schoewe (1953:246), the "problem of de- fining 'physiographic subdivisions' is a difficult one in any region, and particularly so where the region to be so subdivided is a plains country." They went on to point out (p. 247) that "all aspects of the flora, fauna, climate, soil, geology, and topography should be considered in erecting a physiographic unit and each such unit should possess some degree of internal homogeneity." With this definition in mind, and using Fenneman ( 1931 ) as a starting point, the general physiographic regions of Nebraska can be defined as follows: 14 University of Kansas Publs., Mus. Nat. Hist. Central Lowlands Province This province includes approximately the eastern fourth of Nebraska — all within Fenneman's Dissected Till Plains section. The border between the Central Lowlands and the adjoining Great Plains, marked by a series of low hills or an eastward-facing escarp- ment in other places, is poorly defined in Nebraska because the original border is buried under loess. The boundary in Nebraska is taken to be the westernmost extension of glacial (Kansan) till. The Central Lowlands Province occupies roughly the same area in Nebraska as does the tall-grass prairie and the brunizem soil group, and includes as districts the Drift-Loess Hills in the northeast, Loess Hills south of the Platte River in the southeast, and the Missouri River Lowlands. Great Plains Province The western three-fourths of the state falls within this province; three different sections, the Plains Border, High Plains, and Mis- souri Plateau, are recognized, each having well-marked districts. Missouri Plateau Section. — This section is found in two disjunct areas in the northern part of the state. In the northwest, the Pierre Plains (including the Badlands) to the north of the Pine Ridge form one distinct unit, and the Niobrara District, including the unglaciated tablelands and plains to the northeast of the Sand Hills in Boyd, Keya Paha, and parts of Antelope, Brown, Cherry, Holt, Knox, and Rock counties, forms a second. Whereas the boundary of the Pierre Plains is well marked by the Pine Ridge, the Niobrara District merges gradually with the Sand Hills to the southwest and with the Drift-Loess Hills of the Central Lowlands to the east. Plains Border Section. — The Plains Border includes the central part of the state south of the Sand Hills. Mantled with loess or sandy loess, it grades into the Central Lowlands eastwardly, the High Plains westwardly, and the Sand Hills northwardly. The boundary with the High Plains is marked in several places by isolated areas of dune sands that are here regarded as belonging to the Plains Border. Two distinct units of this section, divided by the Platte River, are recognized, the Loess Hills and Plains to the north and the Loess Plains to the south. High Plains Section. — Being the most diverse of the sections of the Great Plains in Nebraska, the High Plains includes the following districts: Sand Hills, including approximately 18,000 square miles Mammals of Nebraska 15 of dune sands of precisely the same area described in relation to soils and vegetation; Pine Ridge, a rugged, pine-covered escarp- ment in the northwest that separates the High Plains from the Missouri Plateau; the High Plains proper (Western Nebraska- Eastern Wyoming Upland of Fenneman), including the tablelands both north and south of the North Platte River in the Panhandle and the rough, broken country along (and south of) that river in Banner, Morrill, and Scotts Bluff counties; and the deeply eroded Goshen Hole Lowland, which encompasses the western part of the North Platte Valley. The "topographic regions" of Nebraska, more precisely denned and limited than the physiographic areas recognized here, have been mapped previously by Condra (1934:2) and Lugn (1935:16). Vegetation The vegetation of Nebraska probably is better known than that of any other plains state, as illustrated by the following selected references: Rydberg (1895); Pound and Clements (1900); Pool (1914 and 1957); Aikman (1929); Winter (1936); Weaver (1954); Weaver and Albertson ( 1956 ) . Pound and Clements ( op. cit. ) , in their "The Phytogeography of Nebraska," were first to propose a system of vegetative zonation for the state, wherein they recognized four major "regions" as follows: Wooded Bluff and Meadow Land ( confined to the extreme eastern part of the state); Prairie (tall-grass prairie); Sand-hill (including Sand Hills proper and adjacent areas of mixed-grass prairie to the south of the Platte River; and Foot-hill (High Plains, Pine Ridge, and adjacent areas of the Panhandle). Each region was subdivided into two or more "districts." In addition, nine "general classes or formations" of plant life were proposed, not necessarily limited to a particular region or district. This work, despite the short-comings resulting from its appearance at a time when the science of plant geography was in its infancy, remains the basic reference on Nebraskan phytogeography. Pool (1914: frontispiece) recognized six "phytogeographic re- gions" in the state as follows: Broadleaf Woods; Yellow Pine; Prairie; Short Grass; Sandhills; and Badlands. Inasmuch as Pool's study dealt only with the Sand Hills, there was no elaboration in text concerning his arrangement. Utilizing the two works last cited, supplemented by additional published information (see among others Braun, 1950; Kellogg, 1905; Weaver, 1954; Weaver and Albertson, 1956), the vegetation 16 University of Kansas Publs., Mus. Nat. Hist. of Nebraska can be divided into two basic segments, forest and grassland, the former having two major associations and the latter three. Forests Deciduous Forest. — The deciduous forest of this classification is restricted to the oak-hickory association (Braun, 1950:181-184) oc- curring along the Missouri River and its major tributaries in the southeastern part of the state. The northern limit is reached along the Missouri approximately at the southern border of Washington County, although some species of trees characteristic of this as- semblage extend no farther northward than the mouth of the Platte, if that far. On the other hand, several important species ( red oak, bur oak, and bass wood, for example) occur much farther northward or westward than the boundary of the association as here de- limited. Unfortunately, much of the oak-hickory woodland that once occurred in southeastern Nebraska has been destroyed by man. Aikman (1927) recognized three major communities in the de- ciduous woodlands of eastern Nebraska, bur oak-bitternut hickory, black oak-shellbark hickory, and red oak-basswood; the first two are limited to the oak-hickory association. About 43 species of deciduous trees are native to southeastern Nebraska (see Pool, 1957), of which 20 are more or less restricted to the oak-hickory as- sociation. Characteristic trees of this area are as follows (those marked by an asterisk do not occur elsewhere in the state) : Black Walnut (Juglans nigra) * Bitternut Hickory (Carya cordiformis) * Shellbark Hickory ( Carya ovata) Hop-hombean (Ostrya virginiana) Red Oak ( Quercus borealis var. maxima ) * Black Oak ( Quercus velutina) Bur Oak ( Quercus macrocarpa) * Yellow Oak (Quercus muehlenbergii) Red Elm ( Ulmus rubra) Kentucky Coffee Tree ( Gymnocladus dioica ) Silver Maple (Acer saccharinum) Basswood ( Tilia americana) Eastern deciduous trees occur, of course, far to the west in Ne- braska (mostly along rivers) of the limits of the oak-hickory as- sociation, but the deciduous flora becomes increasingly depauperate in number of species westwardly, until only a few kinds (several willows, cottonwood, ash, boxelder, American elm) remain. These dendritic extensions of deciduous vegetation into grasslands are Mammals of Nebraska 17 properly regarded as communities of the major plant association in which they occur. Coniferous Forest. — As here understood, the coniferous forest association now is limited to the slopes of the Pine Ridge of the northwestern part of the state and to smaller, less densely forested areas on the Bighorn and Wildcat ridges to the south of the North Platte River in Banner and Scotts Bluff counties. Although these two areas have no connection in Nebraska, they are connected farther to the west in Wyoming according to R. Kellogg (1905:12). The only dominant is western yellow pine (Pinus ponderosa); in fact, only one other native conifer, western red cedar (Juniperus scopulorum ) , occurs in the two areas and it is not limited thereto. The yellow pine occurs in Nebraska also in some places along the Niobrara River as far east as Keya Paha County, and within historic time occurred in several isolated areas in other parts of central and western Nebraska (see Kellogg, loc. cit., and Pool, 1957:172, map 1). The species probably occurred widely over much of the western part of the state in post- Wisconsin times and the areas remaining when white man first reached western Nebraska were relics of this former widespread distribution. The montane floral affinities of the Pine Ridge are strengthened by the occurrence there, in addition to yellow pine, of quaking aspen (Populus tremuloides) , narrow-leaved cottonwood (P. an- gustifolia ) , balsam poplar ( P. halsamifera ) , and western black birch ( Betula fontinalis ) . Only one of these four species ( narrow-leaved cottonwood) occurs also in Banner and Scotts Bluff counties but Rydberg's cottonwood (P. acuminata), a western species which does occur there, is lacking in the Pine Ridge area. Grasslands Tall-grass Prairie. — The tall-grass prairie, or true prairie as it often is called, originally occupied the vast region of the central United States that lies between the deciduous woodlands and the mixed prairie of the Great Plains. In Nebraska, typical tall-grass prairie covered that part of the state east of approximately the 99th meridian, excepting the area occupied by deciduous forest. "The transition zone from the true to the mixed prarie is very gradual and the corresponding ecotone unusually broad. The best limit is set by the disappearance of Stipa spartea [needlegrass] and Sporo- bolus asper [tall dropseed], which are replaced in the mixed prairie by very closely related species, S. comata and S. cryptandrus. In 2—6532 18 University of Kansas Publs., Mus. Nat. Hist. Nebraska the relation is further disturbed by the extensive sand-hill region, in which the high chresard favors a postclimax of tall grasses far beyond their proper climate" (Weaver and Clements, 1938:524). The ecotonal area between tall grass and mixed grass was displaced eastward 100 to 150 miles in Nebraska as a result of the "great drought" (1933-1941) according to Weaver and Bruner (1954:122). Tall-grass prairie grows mostly on brunizem soil, but the western part of the region in Nebraska is on chernozem soil. The western border of tall grass approximates the line of 23 inches of annual precipitation. Most of the original tall-grass prairie in Nebraska (and elsewhere) has been turned for agricultural purposes; only small, mostly isolated areas remain. Weaver ( 1954 ) , whose "North American Prairie" is recommended to the reader, recognized six plant communities of the tall-grass prairie (dominated by 10 grasses). Lowland communities noted were: big bluestem (Andropogon gerardi and the introduced blue- grass, Poa pratensis ) ; sloughgrass ( Spartina pectinata ) ; and switch- grass (Panicum virgatum) — Canada wild-rye (Ely mus canadensis). Communities of uplands listed were: little bluestem (A. scoparius along with side-oats grama, Bouteloua curtipendula, and Junegrass, Koeleria cristata ) ; needlegrass ( Stipa spartea ) ; and prairie dropseed ( Sporobolus heterolepis ) . Mixed Prairie. — The mixed prairie covers the largest area of any of the grassland associations of North America; it is the grassland of the Great Plains. This association owes its name to the fact that its climax vegetation is comprised both of mid grasses and short grasses, on more or less equal tenns (Weaver and Clements, 1938:523). In Nebraska, the mixed prairie is underlain by cher- nozem and chestnut soils, and originally covered that part of the western two-thirds of the state not included within the Sand Hills. The so-called short grass plains of western Nebraska and adjacent regions, once thought a distinct grassland association, now are known to represent only a disclimax of the mixed prairie, resulting primarily from overgrazing (Weaver and Clements, loc. cit.). Major dominants among grasses in mixed prairie are: needle- and-thread (Stipa comata); western wheatgrass (Agropyron smithii); sand dropseed (Sporobolus cryptandrus) ; Junegrass (Koeleria cristata); buffalo grass (Buchloe dactyloides); and blue grama (Bouteloua gracilis). In the short-grass disclimax, blue grama, buffalo grass, and cactus (Opuntia) prevail; sages (espe- cially Artemisia tridenUita) are not uncommon in some areas. Mammals of Nebraska 19 Significant areas of mixed-grass prairie remain in Nebraska, albeit frequently overgrazed by cattle, but some parts have been converted to croplands. Sand Hills. — The vegetation of the Sand Hills is a combination of tall grasses, mid grasses, and species dominant on sandy soils. The result is a vegetative assemblage so unique that it deserves separate treatment among the grassland types of Nebraska. The high water table of the Sand Hills favors a postclimax segment of tall grasses in the many meadows and around the many lakes; three different plant communities occur on uplands (Weaver and Albertson, 1956). In addition to overgrazing, drought and fire, which affect drastically the conditions in all grassland areas, wind- blown sand is a major factor affecting plant cover on the Sand Hills. For botanical studies concerning this interesting area, the reader is directed to Rydberg (1895), Pool (1914), Tolstead (1942), and Weaver and Albertson (op. cit .: 163-192 ) . According to Weaver and Albertson ( loc. cit. ) , plant communities of the Sand Hills (and dominant species) are: blowout (blowout grass, Redfieldia flexuosa, and a legume, Psoralea lanceolata) , which becomes established first at the bottoms or on the lower slopes of barren blowouts after sand stops shifting there; sandhill muhly (Muhlenbergia pungens), which occurs on upland areas of rela- tively stable dune sands; bunch grass (little bluestem, sand blue- stem, A. Iwllii, sand reed, Calamovilfa longifolia, needle-and-thread, and frequently soapweed, Yucca glauca), the widespread, char- acteristic upland vegetation of the Sand Hills; and the lake and wet meadows, in which a transition occurs from numerous sedges and certain tall forbs in the wettest places through a distinctive middle zone (big bluestem, sloughgrass, switchgrass, and other species) to the upper portion of wet meadows where postclimax true prairie obtains (little bluestem, tall dropseed, Junegrass, and western wheatgrass ) . It is well to note that deciduous trees occur in the Sand Hills along the major streams, and ponderosa pine is found at certain places along the Niobrara and some of its tributaries. The grass- land of the Sand Kills is devoted almost exclusively to grazing of livestock. Effects of Man on the Environment Since the settlement of Nebraska by European man, principally in the last century, he has changed tremendously the pristine en- vironment. Changes wrought by man have been detrimental to 20 University of Kansas Publs., Mus. Nat. Hist. some mammalian species and advantageous to others. Directly, man extirpated some large ungulates and carnivores and drastically reduced populations of some other species. Indirectly, for example by cutting timber, turning prairie sod, and diverting or polluting streams, he endangered, at least in some areas, survival of other mammals. On the other hand, man controlled prairie fires that long had restricted woodlands, planted trees where none had grown previously, created artificial bodies of water that soon acquired riparian plant communities, brought food (cultivated grains) to areas where food previously had been scarce, and even introduced some mammals at places where they had not occurred naturally. In the accounts of species beyond, I have attempted, where appro- priate, to mention specific effects resulting from the activities of man. For an account of Nebraska as the white man found it, and some of the changes that followed his emigration, the reader is directed to R. H. Wolcott's "Biological conditions in Nebraska" (Proc. Ne- braska Acad. Sci., 8(2):23-34, 1906). FACTORS INFLUENCING DISTRIBUTION AND SPECIATION Wisconsin Glaciation and Post-Wisconsin Climates The Pleistocene Epoch, comprising four, vast continental glaciers (Nebraskan, Kansan, Illinoian, and Wisconsin), each followed by a comparatively warm, dry period (Aftonian, Yarmouth, Sangamon, and Recent), obviously affected markedly the distribution and speciation of organisms in boreal and temperate regions. Although details of the distribution of some species in the Pleistocene are conjectural, it is known that biotic assemblages were displaced, not necessarily intact, southward on the North American continent ahead of advancing glaciers, and that they shifted northward again, probably beyond their limits as we now know them, in interglacial times. Important as these massive shifts in response to changing climates may have been in the speciational and distributional his- tories of the elements of boreal and temperate biotas, it is necessary to look no farther back than the last continental glacier (Wisconsin) and subsequent post-glacial events for an explanation of the com- position of the Recent mammalian fauna of Nebraska. At its maximum, some 18,000 years BP (before the present), the edge of the Wisconsin glacier rested nearest Nebraska immediately north of the Missouri River in extreme southeastern South Dakota Mammals of Nebraska 21 as evidenced by accumulation there of drift deposits (Flint, 1957: 338, fig. 20-1), but according to Schultz et al. (1951:6) actually did reach what is now the northeastern edge of Nebraska. From southeastern South Dakota, the glacial border generally extended northwestward toward North Dakota, roughly paralleling the pres- ent course of the Missouri, and east-southeastward across northern Iowa. At the same time, isolated but relatively extensive montane glaciers, the so-called Cordilleran glaciers, rested on the Rocky Mountains to the west. Exactly what the conditions at the latitude of Nebraska were at the time of maximal extent of the Wisconsin and Cordilleran glaciers is unknown, but most authorities (Clements and Chaney, 1937, Deevey, 1949, Dillon, 1956, Dorf, 1959, Martin, 1959, for example) agree that the climate was cooler than now, and that general biotic assemblages characteristic today of more northerly areas prevailed in at least some regions. Dillon ( op. cit. ) attempted to reconstruct Wisconsin climates and life-zones, and suggested that the mean maximum temperature under which a continental glacier could con- tinue to grow was 45° F.; therefore he postulated (p. 167) a de- pression of 25° F. ( as compared with temperatures in the same areas today) in mean annual temperature at the edge of the ice sheet decreasing to a drop of about 5° F. at the Equator. With this as a guide, he suggested (p. 174, fig. 10) that conditions in Nebraska at the height of the Wisconsin approximated those of the present-day Arctic, Hudsonian and Canadian life-zones, all of which now occur far to the north and west of the state. Cold-adapted animals and plants certainly occurred to the south of the glaciated region in Wisconsin times. Among mammals, caribou in Nebraska (Schultz et ah, 1951: table 1), Iowa and New Mexico (Banfield, 1962:40), the collared lemming and heather vole in Pennsylvania (Guilday and Doutt, 1961:249), the masked shrew (Findley, 1953:645) and southern bog lemming (Jakway, 1958:321) in Nuevo Leon, Mexico, and the masked shrew, Richardson's ground squirrel and meadow vole in southwestern Kansas (Hibbard, 1949:86) attest to this, as do relict populations of montane species on the Black Hills of South Dakota and elsewhere on the Great Plains. At or about the same time warmth-adapted species (Blair, 1959) were displaced southward to refugia in peninsular Florida and eastern Mexico. Elements of the boreal forest, too, occurred far south of the glacial boundary (Blair, op. cit., Deevey, 1949, and others), but in some instances northern floral elements may 22 University of Kansas Publs., Mus. Nat. Hist. have existed as isolated, marginal stands amid otherwise temperate floras; in the Rocky Mountains, coniferous forest existed at much lower elevations than now. In the Plains region, hemlock and other conifers grew near the glacial border in Iowa and South Dakota (Flint, 1957:323). Further, according to Clements and Chaney ( 1937:24) : "There is good evidence from relict trees that the boreal forest of climax conifers and subclimax hardwoods moved south- ward over the Great Plains in front of the ice, since the white spruce persists today in the higher parts of the Black Hills of South Da- kota, and the aspen and paper birch survive in northern Ne- braska . . . ." Also, the occurrence of ponderosa pine at scattered localities in Nebraska as far south as the Kansas border (Pool, 1957:172, map 1) when white man first reached the state suggests a more widespread and continuous distribution of that species in past times. On the other side of the ledger, Braun (1950 and elsewhere), Kendeigh ( 1961 ) and others have argued for relatively little change, vegetationally at least, to the south of the glacial boundaries. Ken- deigh (p. 286) reviewed the evidence supporting four separate refugia (rather than widespread southward displacement) for the boreal forest, and suggested ( p. 287 ) that the Floridian and Mexican refugia for many vertebrates owed existence not to colder climate but to the southward extension of relatively dry grassland to the Gulf of Mexico. He noted also ( p. 286 ) that the formation of loess on the Great Plains ( both Peorian and Bignell loess formed in Wis- consin times) was indicative of the then existing vegetation: "This buff-colored, homogeneous, porous, calcareous, non-stratified de- posit forms only in arid or semi-arid regions, and is indicative of grassland abutting directly on the glacial front. There is no evi- dence that extensive coniferous forest existed in front of the glacier during any of its advances in this area." Schultz et al. (1951:28) suggested also that the formation of loess indicated a time of "desiccation" and "reduced vegetative covering." Insofar as mam- mals are concerned, the presence in Nebraska in Wisconsin times (Schultz et al., 1951: table 1) of grassland types such as ground squirrels, prairie dogs, two genera of pocket gophers, pocket mice, two kinds of lagomorphs, and pronghorn, along with extinct horses and bison, strongly suggests a prairie-plains environment, at least in part. Unfortunately, few Wisconsin faunal and floral assembledges have yet been discovered near the glacial border on the Great Mammals of Nebraska 23 Plains; perhaps few will be found. Until such time as more com- plete evidence is available, no conclusive statement can be made concerning character of the biota in Wisconsin times. It is well to remember also that the period of "maximal" extent of the ice sheet, covered perhaps 10,000 years or more, and produced several regionally important retreats and readvances of ice (substages and interstadial periods ) that may have affected profoundly local condi- tions near the southern boundary of the glacier. In other words, minor shifts in the climate and in the biota can be inferred as having taken place in this period. On the basis of the evidence presently available, it seems reason- able to postulate that a kind of azonal, ecotonal plant and animal community existed in Nebraska at the height of Wisconsin glacia- tion. Where conditions of slope, soil and drainage permitted, coni- fers and other boreal species prevailed; in river valleys and other favored areas, especially in the eastern part, elements of the eastern deciduous forest may have occurred; and grassland occupied still other areas. Perhaps the landscape had a parklike appearance as do some present-day areas on the western slopes of the Rocky Mountains. The climate probably averaged somewhat cooler than now. The mammalian fauna may have been a mixture of boreal species and relatively cold-tolerant temperate species — especially wide-ranging kinds and those of grassland affinities — that were distributed ecologically in accordance with local conditions at any one time and place. Such an hypothesis is generally in accord with the ideas advanced by Smith (1957:207), who wrote: "No definite evidence is contributed by the distributional patterns of terrestrial vertebrates as to what the biota to the south of the Wisconsin glacier may have been, and a compromise on the extent of biological dis- placement seems advisable. This intermediate viewpoint recognizes that the fauna of the glaciated territory was forced southward or eliminated but does not imply that the boreal fauna completely re- placed a more southern faunal type or that the area south of the ice front was appreciably colder than at present. This view holds that an admixture of ecologically segregated boreal and austral ele- ments existed, possibly almost side by side, near the ice front but within unglaciated territory." With the foregoing as a background, we can discuss some biotic changes that may have occurred in the post- Wisconsin era. After maximal advance of the glacier, there followed the "late-glacial period," a time of stagnation, retreat, and periodic readvance of 24 University of Kansas Publs., Mus. Nat. Hist. the ice, culminating with the Valders readvance about 10,700 years BP. It is reasonable to envision a general withdrawal from the Nebraskan region of some boreal elements, accompanied by in- vasion of an increasing number of temperate species in those times. Subseqeunt to the Valders, which advanced no nearer than 500 miles to what is now Nebraska, there ensued a series of post-glacial climatic shifts, usually reckoned as within Recent time, that played a major role in influencing the composition of the modern mam- malian fauna of the state. The major climatic periods of the post- Wisconsin in North America, which are correlated with known climates of the same stages in Europe, have been the subject of a number of recent papers (see especially Deevey, 1949, Deevey, 1961, Deevey and Flint, 1957, Martin, 1959, Martin et al, 1961, Sears, 1961, Smith, 1957). From several sources, the approximate chronology of events since maximal Wisconsin glaciation is as follows: 17,000-18,000 BP Maximal advance of Wisconsin ice sheet 11,000-17,000 BP Stagnation, retreat, and periodic readvance of ice 10,000-11,000 BP Valders readvance 9,000-10,000 BP Post-Valders phase 2,500- 9,000 BP Hypsithermal Interval 4,000- 9,000 BP Warm, wet (Climatic Optimum) 2,500- 4,000 BP Warm, dry ( Xerodermic Period) After 2,500 BP Sub-Atlantic or Becent phase In pre-hypsithermal time, after the Valders readvance, climate of the central grasslands may have approximated that of the region today. At such a time, invasion by temperate species would have been accelerated and some remaining boreal elements excluded, but the more tolerant boreal kinds probably remained relatively widespread, some more or less continuously distributed and others in scattered relict areas. One faunal assemblage from this period (Schultz and Frankforter, 1948), from three sites associated with remains of early man in Frontier County and having an average C-14 date of 9,524 BP, yielded the following mammals (specific determinations not given): Blarina; Lepus; Sylvilagus; Cynomys; geomyid; Perognathus; Castor; Peromyscus; Synaptomys; Microtus; Canis; Procyon; Taxidea; Odocoileus; large cervid; Antilocapra; Bison. Considering the time factor, I assume that these remains are, at least in the majority of instances, referable to Recent species. Most are wide-ranging or grassland kinds, but Synaptomys and possibly the Microtus (identification to species needed) are boreal elements, and Blarina is an animal of the eastern deciduous forests, iMammals of Nebraska 25 reflecting a westward extension of that faunal and floral assemblage in the Post-Valders phase. Hypsithermal Interval With the advent of the warmer, relatively moist Climatic Op- timum (9,000-4,000 BP) of the Hypsithermal Interval, I imagine a westward extension far onto the plains of elements of the eastern deciduous forest and probably also tall-grass prairie — forest species along the river systems and on favored drier sites, and tall grasses on the uplands. Climatic conditions at this time would not have been unfavorable for the hardier boreal elements still remaining, and such trees as ponderosa pine (Pinus ponderosa) and such mammals as Microtus pennsylvanicus, Sorex cinereus and Sijnap- tomys cooperi probably occurred in relatively undisturbed, albeit possibly disjunct, areas. Sears' (1961:2038-2039) report of a pollen profile from Hackberry Lake, Cherry County, bears on the point. In sediments from the lake bottom having a C-14 date of 5040 ± 95 years BP, he found a "minimum of grass and maximum of forest." Subsequently, trees became few and grasses abundant for a time, corresponding roughly to the Xerothermic Period, but in relatively recent time (after 1110 ± 75 years BP) trees in- creased in abundance at the expense of grasses. In the sediments dated 5040 ± 95 years, Sears found roughly 25 per cent of the pollen to be that of trees, which he interpreted as indicative of a "humid interlude," but more than half of the tree pollen was pine, which he interpreted as possibly indicating that the period was cool, not warm. A different explanation occurs to me for the relatively large amount of pine pollen, namely that many of the hardier boreal animals and plants that remained after glaciation survived most or all of the Climatic Optimum, only to be eliminated or re- duced to relict status in the following hot, dry Xerothermic Period. Smith (1957) analyzed the post-Wisconsin biogeography of the Prairie Peninsula and noted evidence from recent distributional pat- terns that four species of amphibians and five of reptiles having southern affinities dispersed northward well beyond the limits of their presently continuous ranges during the Climatic Optimum. An undated occurrence of the rice rat (Oryzomys palustris) in Indian mounds near Peoria, Illinois (Smith, loc. cit.), far north of the present range of the species, may reflect a northward shift of O. palustris in the warmer, wetter period of the Hypsithermal, and the specimen said to have been taken at Neosho Falls, Kansas, 26 University of Kansas Publs., Mus. Nat. Hist. in 1859 (Cockrum, 1952:281) could represent a relict population, now extirpated, resulting from the same northward dispersal. On the plains, evidence of dispersal of mammals in the Climatic Optimum is scanty but the present distribution of at least two species is instructive. The white-footed mouse, Peromyscus leu- copus, typically an inhabitant of deciduous woodlands in the northern part of its range, presently occurs in a number of scattered, relatively or actually isolated localities (where stands of deciduous timber also are isolated) on the Great Plains from northwestern Nebraska to southeastern Alberta. If these relict populations had resulted from dispersal in the wake of the retreating Wisconsin ice sheet, it would be expected that P. leucopus now would have a more northerly distribution in the plains region. The only logical explanation, therefore, is that the species dispersed northwestward along river systems in company with deciduous timber during the Climatic Optimum. The following Xerothermie Period destroyed the continuous dendritic extensions of eastern woodland but left isolated patches in certain favored areas, in some of which white- footed mice also survived. Relict populations of the meadow jump- ing mouse, Zapus hudsonius, in the same region, on the other hand, most likely date not from the Climatic Optimum but from the time following glacial retreat. The second species, Neotoma floridana, has a relict population (N. /. baileyi) in northern Nebraska that apparently is restricted to the relatively cool canyons of the Niobrara River and a few of its tributaries. This woodrat could have reached this area only at a time when deciduous woodlands were more extensive, both geo- graphically and in number of species, than now — in other words, during the Climatic Optimum. The ensuing Xerothermie Period excluded this rat from other parts of northern and eastern Nebraska that formerly were occupied, leaving the relict subspecies, baileyi, stranded along the Niobrara (see Fig. 1). Presumably the relict distribution of the cork elm (Ulmus Thomasi) in the same area supports this explanation. The more westerly distribution of another subspecies of N. floridana (N. f. campestris), which occurs today in southwestern Nebraska and adjacent parts of Colorado and Kansas, is more difficult to explain; the distribution of campestris is spotty and irregular throughout its range and a few small popu- lations that were isolated in xeric times may have dispersed since then to a greater or lesser degree. It can be postulated that other species having eastern and southern affinities spread also to Nebraska in the Climatic Optimum Mammals of Nebraska 27 and, finding no suitable refugia in the warm, dry part of the Hypsi- thermal Interval, were subsequently excluded — but no additional evidence of such dispersal is available. In Xerothermic time (4,000-2,500 BP) the climate was consider- ably more arid than now. In this period, the much-discussed 102 Fig. 1. Present distribution of Neotoma floridana in the region of Nebraska (diagonal lines) and postulated extent of distribution in the Climatic Optimum (outer black line). 28 University of Kansas Publs., Mus. Nat. Hist. Prairie Peninsula extended eastward to the region south of the Great Lakes, affording entry to that area for many prairie species (see Smith, 1957) — among the mammals, for example, the plains pocket gopher, Geomys bursarius, and two ground squirrels, (Spermophilus franklinii and S. tridecemlineatus) . The prairie subspecies of the spotted skunk ( Spilogale putorius interrupta ) , now restricted to the western side of the Mississippi River, ranged across the Mississippi as evidenced by remains found in an Indian rock shelter in Illinois (Parmalee and Hoffmeister, 1957:261). As pre- viously noted, the Xerothermic Period seemingly had a marked effect on the distribution of at least some mammals of eastern and southern affinities that had spread westward during the Climatic Optimum. Another probable effect concerns the present distribu- tion of the short-tailed shrew, Blarina brevicauda. This eastern species early invaded the plains region as noted by remains found in association with early man in southwestern Nebraska in sites dated prior to 9,000 BP. In the warm, wet interlude of the Hypsi- thermal, B. brevicauda may have had a more extensive distribution on the plains than at present. In any event, probably then as now there was a cline of decreasing size from north to south in this species (Jones and Glass, 1960). In some manner, the central portion of the cline was obliterated in the western part of the range of this shrew, and two markedly different subspecies, the larger B. b. brevicauda and the smaller B. b. carolinensis, now meet along a fairly well-defined line in Nebraska with little intergrada- tion between them. In the Xerothermic Period the short-tailed shrew, essentially a species of eastern forests, may have been eliminated from all but a few especially favorable areas in the central grasslands by the hot, dry climate and attendant changes in the vegetational complex (see Fig. 2), thus destroying in that region the middle part of the mentioned cline. When reinvasion took place following the Hypsithermal Interval, populations of this shrew dispersed to Nebraska from the southeast and the northeast in a kind of a "pincers movement," winning the "race" of resettle- ment as it were from elements within the contiguous range of the species directly east of Nebraska (Fig. 2). Large shrews invaded northeastern Nebraska, spreading out westward along river systems as far south as the Platte; small shrews invaded from the southeast, up the Missouri and out the Republican rivers. The two invading segments met just south of the Platte River excepting near the western extent of the range of the species where carolinensis, moving Mammals of Nebraska 29 36 — SCALE OF, MILES Fig. 2. Possible changes in the distribution of Blarina brevicauda in the grass- lands region in response to post-Wisconsin shifts in climate. 1. Site in south- western Nebraska where Blarina was found in association with early man. 2. Hypothetical western extent of the range of B. brevicauda in the Climatic Optimum. 3. Hypothetical western boundary of the continuous range of the species in the Xerothermic Period. 4. Site in Kansas River Valley where one isolated population may have existed in the Xerothermic Period. Large arrows indicate general direction of post-Hypsithermal dispersal of invading stocks from the continuous range of B. brevicauda; small arrows in Nebraska indicate dispersal routes therein. For present distribution of the species in Nebraska see Fig. 7. 30 University of Kansas Publs., Mus. Nat. Hist. out the Republican, breached the narrow gap between that drainage and the drainage of the Platte in Lincoln County and turned east- ward, only to meet brevicauda, which was moving westward along the Platte. But what of the isolated populations of B. brevicauda that must have been left scattered in favorable places in the eastern part of the grasslands in the Xerothermic Period? Some probably did not survive the duration of the Hypsithermal Interval; some that did were swamped, genetically speaking, by invading stocks from the main segment of the range of the species; but remnants of a few probably survive today. One such instance may be in the Kansas River Valley of northeastern Kansas where shrews from Douglas County and surrounding areas average appreciably larger cranially than shrews either to the north or south of them, and fit nearly perfectly as the missing middle segment into the otherwise sharply stepped north-south cline (Jones and Glass, 1960: fig. 1). Logically, the Xerothermic Period was a time of extirpation over wide areas of the boreal elements that survived on the plains into Hypsithermal times. Only the hardiest remained, and these prob- ably only in small, relatively or actually isolated areas in most or all instances. One imagines it was in this period when most of the unique boreal elements of the Black Hills were restricted thereon, and that the present relict populations of Microtus pennsylvanicus in southwestern Nebraska and Synaptomys cooperi in western Kan- sas and Nebraska were isolated. The present rather wide distribu- tion in Nebraska of boreal species such as Sorex cinereus, M. penn- sylvanicus, S. coopeii, Zapus hudsonius, and Mustela nivalis prob- ably can be accounted for by limited post-Hypsithermal dispersal, for each occurs only where local conditions favor existence and each is absent from many apparently suitable areas in southern Nebraska and adjoining Kansas to which dispersal evidently has been pre- vented by intervening inhospitable terrain. Admittedly, evidence of the effects of post-Wisconsin climatic shifts on mammals in Nebraska is scanty, the only real indication being in the distributional patterns previously discussed, but is, I think, significant. When one considers that many mammals (bats, most carnivores, ungulates) are readily mobile, that the biotic changes accompanying the climatic shifts discussed must have been exceedingly slow, that Nebraska lacks any real physical barriers to dispersal of most terrestrial organisms, and that suitable relict areas probably were few, it is surprising that any geographic evidence at Mammals of Nebraska 31 all remains. Future analyses of distributional patterns of plants and other animals may well shed additional light on this problem. Also, floral and faunal assemblages associated with dated archeological sites may come to light, and late Pleistocene and early Recent paleontological finds could help. Changes since 2,500 BP After the Hypsidiermal Interval, the climate in the central United States cooled and became more humid, culminating in the condi- tions of the present (possibly it was somewhat cooler during the Little Ice Age than at present). Some minor fluctuations, to be sure, took place but none was so marked as in previous times. According to present evidence (Dorf, 1959, and others) there has been a gradual warming trend on the North American con- tinent in the last 100 years, response to which is seen in several species of mammals. The opossum has extended its range north- ward and westward notably in the last century and the range of the white-tailed jackrabbit has shifted northward on the plains in the last 50 years, in both instances probably relating, at least in part, to rising temperatures. The northward movement recorded in recent years of the pygmy mouse (Baiomys taylori), armadillo (Dasypus novemcinctus) , ring-tailed cat (Bassariscus astutus), and hispid cotton rat (Sigmodon hispidus) also reflects this present warming trend. Of these, the cotton rat, which dispersed north- ward in Kansas in this century at an average rate of seven miles per year (Cockrum, 1948), finally was taken in Nebraska in the autumn of 1958 (Jones, 1960&), and the armadillo may reach the state in the next few years if it has not already done so. It is of in- terest to note that Pleistocene precursors of the cotton rat dispersed northward also in both the Aftonian and Yarmouth interglacial periods ( Hibbard, 1958 ) . Emigration of Recent Mammals to Nebraska Discounting the five introduced species and, for the moment, the 12 species of bats, the 69 native, non-volant species of Recent mam- mals in Nebraska fall more or less into five faunal units as regards their probable late Pleistocene and Recent geographic origin. The five units are Eastern, Grasslands, Soudiern-Southwestern, Northern - Western, and Widespread. Insofar as Nebraska is concerned, these faunal units indicate the geographic regions whence mammals reached the state, but not necessarily the areas of their ultimate origin. The gray fox, for example, would not be regarded as an 32 University of Kansas Publs., Mus. Nat. Hist. eastern species if its origin were considered, but is listed among eastern species in the arrangement beyond because it probably reached Nebraska from that general direction. Nebraska's posi- tion as a plains state that nearly bridges the gap between the eastern deciduous forests and the Rocky Mountains is, of course, reflected in the composition of its mammalian fauna, and accounts in part for the fact that so many as 45 (65 per cent) of the 69 species reach their distributional limits in the state. Eastern Species A relatively large segment of Nebraska's mammalian fauna in- vaded the state from the southeast, principally along the Missouri River. Many of the species are typical of the eastern deciduous forest and probably few or none of them lived in Nebraska at the time of maximal advance of the Wisconsin ice sheet. Some invaded the state early in post- Wisconsin time only to be displaced eastward in the wake of the xeric part of the Hypsithermal Interval or, in several instances, to remain in isolated populations, but others may be only post-Hypsithermal immigrants. Several (opossum, fox squirrel, gray fox, spotted skunk) are known to have extended their ranges westward in the state within historic time. All but the spotted skunk, and possibly the eastern cottontail and eastern mole^are thought to reach distributional limits in Nebraska (if the geographic limits of the ranges of two species last-named are not reached in parts of the Panhandle, they are reached just west of the Nebraska-Wyoming border). Didelphis marsupialis Sciurtis carolinensis Marina brevicauda Sciurus niger Cryptotis parva Glaucomys volans -^. Scalopus aquaticus Peromyscus leucopus X) Sylvilagus floridanus Neotoma floridana Marmota monax Microtus pinetorum Tamias striatus i Urocyon cinereoargenteus (-ppilogale putorius Grassland Species Sixteen of the state's native, terrestrial mammals have definite affinities with the central North American grasslands — the tall-grass and mixed-grass prairies. All but one, the bison, are more or less restricted to this region, although the thirteen-lined ground squirrel and prairie vole presently occur as far east as Ohio, and several Mammals of Nebraska 33 species have invaded lower elevations in the Rocky Mountains or have crossed the mountains. The majority are characteristic in- habitants of the Great Plains, and not of the Central Lowlands to the east. Twelve (marked with an asterisk) reach distributional limits in Nebraska. Lepus townsendii * Perognathus hispidus * Cynomys ludovicianus * Reithrodontomys montanus * Spermophilus franklinii * Onychomys leucogaster * Spermophilus richardsonii * Microtus ochrogaster Spermophilus tridecemlineatus -— Vulpes velox * Geomysbursarius Mustela nigripes * Perognathus jasciatus * Antilocapra americana * Perognathus flavescens * Bison bison The grasshopper mouse, Onychomys leucogaster, is questionably placed in this grouping because its distribution suggests to me that it is typically a grassland species that has secondarily moved west- ward, but a case could be made for its inclusion in the following category. Southern-Southwestern Species Most of the mammals comprising this element are characteristic of the arid southwestern United States and adjoining Mexican Plateau, and probably moved northward on the Great Plains to Nebraska in the warmer, drier post- Wisconsin periods. All but the western harvest mouse and the badgerv-whieh is questionably identi- fied with this element, reach distributional limits in the state. The cotton rat, a species having tropical affinities, reached Nebraska, probably within the last ten years, directly from the south. Sylvilagus audubonii Spermophilus spilosoma Lepus californicus Perognathus fiavus Dipodomys ordii Sigmodon hispidus Reithrodontomys megalotis Taxidea taxus Northern-Western Species Eleven species seem to owe their presence in Nebraska to dis- placement southward or eastward (or both) during Wisconsin glaciation. Each exists (or existed in historic time) either in re- stricted areas or, if widespread, in restricted habitats. All reach distributional limits in Nebraska, and in the broad sense can be regarded as "glacial relics." Three of the species, the northern pocket gopher, bushy-tailed 3—6532 34 University of Kansas Publs., Mus. Nat. Hist. woodrat, and mountain sheep, clearly are of western origin. The others evidence northern or widespread boreal affinities. Sorex cinereus Synaptomys cooperi Eutamias minimus Zapus hudsonius Thomomys talpoides Mustela nivalis Neotoma cinerea Gulo luscus Microtus pennsylvanicus Lynx canadensis Ovis canadensis Widespread Species Species in this category have widespread distributions in North America and their origins are obscure insofar as Nebraska is con- cerned. Most or all probably occurred in suitable habitat in what is now Nebraska at the height of Wisconsin glaciation; only the four mentioned below possibly reached distributional limits in the state. Three species included herein, the porcupine, grizzly bear, and mule deer, probably have western affinities but their Recent distri- butions are broad and do not necessarily suggest that they are "relics" of eastward movement in Wisconsin times. The red fox may have reached Nebraska from the east but the species now has a broad distribution in boreal and temperate North America and hence is tentatively listed here. Castor canadensis Procyoii lotor Peromyscus maniculatus Mustela jrenata Ondatra zibethicus Mustela vison Erethizon dorsatum Mephitis mephitis Canis latrans Lutra canadensis Cants lupus Felis concolor Vulpes vulpes Lynx rufus Ursus americanus Cervus canadensis Ursus horribilis Odocoileus hemionus Odocoileus virginianus Bats Being volant, and thus exceedingly mobile, bats sometimes are difficult to categorize as to faunal relationship. Nevertheless, rela- tionships are apparent for most of the 12 species occurring in Nebraska. Five kinds, Myotis lucifugus, Myotis subulatus, Ep- tesicus fuscus, Lasionycteris noctivagans, and Lasiurus cinereus are widely distributed in North America and indicate no particular faunal affinities, although M. subulatus is distributed principally in the temperate region of the west and L. noctivagans evidently occurs in Nebraska only as a migrant, breeding to the north of the Mammals of Nebraska 35 state, but wintering mostly to the south. Myotis keenii, Pipistrellus subflavus, Lasiurus horealis, and Nycticeius humeralis reached Ne- braska from the east, although M. keenii has a disjunct subspecies on the west coast, possibly resulting from isolation in glacial times, and L. borealis, which is widespread in temperate and tropical areas of the New World, is represented in temperate North America by two subspecies (L. b. borealis in the east and L. b. teliotis in the west) that evidently do not meet geographically. Myotis evotis and Myotis volans clearly are species of the intermountain west and in Nebraska occur only in the extreme northwestern part of the state where suitable habitat prevails. Tadarida brasiliensis, known only by three isolated occurrences in Nebraska, is a straggler of tropical affinities from the south. Some Effects of the Environment Some effects of the environment on the geographic distribution of organisms are easily understood because a single, obvious factor limits a given species. In other instances the effect of the environ- ment is poorly understood because the limiting factor is obscure or, more frequently, because a combination of environmental factors interact to limit distribution. Some apparent correlations between mammalian distribution and the environment in Nebraska are men- tioned, by way of example, below. Edaphic factors Some species of mammals prefer, or are limited to, certain types of soil. Rodents of the families Geomyidae and Heteromyidae well illustrate this point in Nebraska. The plains pocket gopher ( Geomys barsarius), while state- wide in distribution, seems to prefer loose soils, is most abundant in sand or sandy loam, and is common in certain areas of silt loam (loess). It avoids rocky soils and gen- erally is rare or absent in hard, clayey substrates. The northern pocket gopher (Thomomys talpoides), on the other hand, occurs only in areas of the Panhandle where soils are mostly thin and the substrate, in general, compact and hard. Among the pocket mice, Perognathus fasciatus seems to occur only on thin, hard soils that in many places contain rock, P. flavus and P. flavescens prefer pliable soils of high sand content, although both occur in some other types as well, and P. hispidus shows no marked predilection for any particular substrate, but may prefer sandy loess to other types. The kangaroo rat (Dipodomys ordii) mostly occurs on 36 University of Kansas Publs., Mus. Nat. Hist. loose, predominately sandy soils; it is commonest on the Sand Hills and in areas where loess and sand are mixed, is relatively rare on the harsh, thin soils of the Panhandle, and is limited eastwardly by the deep loess soils on which tall-grass prairie grows. The easternmost occurrences of D. ordii (Antelope, Knox and Platte counties) are at places where loose, relatively sandy soil intrudes locally into loess. Along with soil, tall-grass prairie itself may well play a part in limiting the kangaroo rat because the saltatorial mode of locomotion of thij species would be greatly hindered by thick, tall vegetation of any kind. Vegetation Vegetation is an important limiting factor because it provides both food and cover for some mammals. Some kinds occur only in deciduous timber, some only where tall grasses prevail, some only in wet, marshy areas, and still others only on arid grasslands that are partly denuded of vegetation. In many areas of western Ne- braska, for example, the eastern cottontail (Sylvilagus floridanus) occurs only in the relatively lush vegetation along streams, and the desert cottontail (S. audubonii) occurs only on relatively barren uplands. The local distribution of the two species overlaps only narrowly along the edges of valleys. As a group, members of the family Sciuridae illustrate well the effect of vegetation on distributional limits of mammals in Ne- braska. Five species, the eastern chipmunk (Tamias striatus), woodchuck (Marmota monax), gray squirrel (Sciurus carolinensis) , fox squirrel (Sciurus niger), and southern flying squirrel (Glauco- mys volans) are kinds associated with eastern deciduous forests. One, the least chipmunk (Eutamias minimus), is generally as- sociated with coniferous forest. The remainder, the black-tailed prairie dog (Cynomys ludovicianus) and four species of ground squirrels, are grassland inhabitants. The eastern chipmunk, gray squirrel, and flying squirrel all are limited to dense stands of deciduous timber in extreme eastern Nebraska. For the gray squirrel, incident light during periods of activity (related to cover) may be the limiting factor (Packard, 1956:32), whereas availability of favored homesites or foods, or both, may limit the other two species. The woodchuck occurs west- ward some distance from continuous stands of deciduous trees, generally following along wooded valleys of streams. Possibly the Mammals of Nebraska 37 availability of preferred den-sites, on wooded hillsides and at the border of copses, limits this rodent. The fox squirrel, by far the most tolerant of environmental conditions of any of the five eastern kinds, occurs all the way to the western border of the state in the Platte Valley and in the Pine Ridge area. This species has ex- tended its range westward in historic time, both through natural dispersal and through introduction, and seemingly is limited only by the limit of deciduous timber itself. In western valleys, where nut- and fruit-producing trees are rare or absent, corn and other cultivated grains are the principal foods. The least chipmunk is restricted to the Pine Ridge and Badlands of the northwestern part of the state where it frequently, but not always, is associated with conifers (Pinns or Juniperus). Actually, the availability of rocky areas for homesites may be the principal factor limiting E. minimus. Of the grassland species, four (C. ludovicianns, S. spilosoma, S. townsendii and S. tridecemlineatus) are typically species of the Great Plains, but the fifth (S. franklinii) is an inhabitant of the tall- grass prairie and has spread westward along river valleys in recent years as a result of agricultural practices. The prairie dog occurs principally in areas where grasses and other plants are short as a result of overgrazing (formerly by bison, presently by cattle), fire, or other factors; the species seems not to survive long in climax associations of grasses. S. tridecemlineatus, which now occupies a broad distribution in the central United States, occurs within the original confines of tall-grass prairie principally in disturbed areas where relatively short vegetation now prevails. Several mammals that are typical inhabitants of the arid Great Plains occur farther to the eastward in Nebraska than in neighbor- ing states — some well into the tall-grass prairie. Possibly this is because no marked physiographic break is present, as elsewhere, between the Great Plains and the Central Lowlands. Watson E. Beed (1936) studied ecological conditions on the Ft. Niobrara National Wildlife Refuge in the only study of its kind in Nebraska of which results have been published. He divided the area studied into nine "biotic communities," and the list of mammals found in these communities, summarized here in tabular form ( Table 2 ) , illustrates the occurrence of mammals locally in different vegetative associations. 38 University of Kansas Publs., Mus. Nat. Hist. Table 2. — Distribution of Mammals in Biotic Communities on the Ft. Niobrara National Wildlife Refuge (after Beed, 1936). Communities Species •s 00 a, o o "3 +3 CD o o CO t-. o 45 3 o M o o >H u 2 CD • X CO o3 c3 o (-1 o 02 b! § oj.S HI H .a 3 « CO CO cp cu ^ +3 CO >> Q CD ft a 02 CO ct> O +» -3 a g a O Sorex cinereus Blarina brevicauda Scalopus aquaticus Sylvilagus floridanus Lepus californicus Lepus townsendii Cynomys ludovicianus Spermophilus tridecemlineatus . Sciurus niger Geomys bursarius Perognathus fasciatus Perognathus flavescens Perognathus flavus Perognathus hispidus Dipodomys ordii Castor canadensis Reithrodontomys montanus. . . Peromyscus leucopus Peromyscus maniculatus Onychomys leucogaster Microtus ochrogaster Microtus pennsylvanicus Ondatra zibethicus Zapus hudsonius Erethizon dorsatum Canis latrans Procyon lotor Mustela frenata Mustela nivalis Mustela vison Taxidea taxus Spilogale putorius Mephitis mephitis Lynx rufus** Cervus canadensis* Odocoileus hemionus* Antilocapra americana* Bison bison* X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X ? ? ? ? X X X X X X X X X X X X X X * Introduced, but originally occurred in this area. ** Not recorded from any particular community, but noted (p. 19) as occurring in the area. Climate Direct effects of climate on distributional patterns of mammals sometimes are difficult to perceive. Indirect effects, on the other Mammals of Nebraska 39 hand, are easily perceived and underscore the contention that inter- action of environmental factors, more frequently than one factor, limits the distribution of mammals. The shift eastward of the mixed-grass prairie during the "great drought" (1933-41) by as much as 150 miles (Weaver and Bruner, 1954:122), for example, certainly affected some kinds of mammals; probably it is significant that the easternmost occurrences in Nebraska of two species having affinities in the arid southwest (Perognathus flavus and Sylvilagus audnbonii) were recorded in that period. Climatic shifts of this kind could destory important relict habitats as well. One species that climate does seem to affect directly is the hispid cotton rat (Sigmodon hispidus). In four of the last 14 winters at Lawrence, Kansas, prolonged periods of low temperatures or a heavy ground-cover of ice and snow, or both, have drastically reduced numbers of S. hispidus and are thought to be the principal factors limiting continued northward dispersal of the species. The mole (Scalopus aquaticus) also is affected direcdy by climate in that in many areas, especially in the drier parts of the state, in- dividuals are active only in moist soils. Increased rainfall, then, leads to greater dispersal of moles, and could result in movement to suitable habitats formerly isolated and unoccupied. Conversely, extreme aridity excludes moles from areas that at other times are inhabited. Topography Nebraska lacks striking topographic barriers to dispersal of mam- mals. Nevertheless, topographic features (or their absence) in- fluence in one way or another the distribution of many species. The rocky areas of the Panhandle, for instance, provide the only suitable habitat for the least chipmunk (Eutamias minimus) and the bushy-tailed woodrat (Neotoma cinerea), and provide also places of retreat for several species of bats that do not occur else- where in the state. The lakes of the Sand Hills and other bodies of water provide, indirectly, suitable habitat for many riparian species; the vast areas in Nebraska where permanent water is lacking are devoid of aquatic and semi-aquatic species and generally lack those kinds that occupy riparian situations. The Missouri River as a Barrier to Dispersal As noted previously, the deciduous riparian association along the Missouri River probably served as a pathway for invasion of the Central grasslands by some eastern mammals. This same associa- tion or the river itself (or both) have prevented the dispersal east- 40 University of Kansas Publs., Mus. Nat. Hist. ward of at least nine other species at the latitude of Nebraska. The nine, all typical of arid or semi-arid grasslands, are Lepus cali- fornicus, Lepus townsendii, Cynomys ludovicianus, Perognathus flavescens, Perognathus hispidus, Onychomys leucogaster, Vulpes velox, Mustela nigripes, and Antilocapra americana. For all but P. hispidus, the deciduous woodlands that border the river probably served as the barrier. The ranges of several of these species ap- proach (or formerly approached) the Missouri near the Nebraska- South Dakota border, and farther north in the Dakotas, where the deciduous vegetation thinned and become discontinuous in some sections, some crossed the river and expanded their ranges into the tall-grass prairie to the east. In this manner, Lepus townsendii, Perognathus flavescens, Onychomys leucogaster and Antilocapra americana came to occupy geographic areas to the east of Nebraska even though the area along the Missouri was a barrier to them at that latitude. Perognathus hispidus presents a somewhat different problem. The species probably occupies favorable habitats all along the western side of the river in Nebraska. It has even been taken on the flood plain (in Richardson County), a habitat possibly oc- cupied only recently, but is not known east of the river except at one place in central South Dakota. Because it now occupies the flood plain, P. hispidus might be expected soon to gain access to the eastern side, except that the Missouri itself now may be an effective barrier for reasons outlined beyond. Deciduous trees along the Missouri may have been a barrier also, or at least partly so, to the mule deer (Odocoileus hemionus) in historic time, but in recent years individuals have been taken along parts of the river on both the Iowa and Nebraska sides, and recent records place marginal occurrence of the species far eastward in Iowa. The kangaroo rat (Dipodomys ordii) might be mentioned also in this connection. The eastern margin of its range occurs, for the most part, far to the west of the Missouri, where it is limited by other factors, but in northeastern Nebraska and adjacent parts of South Dakota this species reaches, but does not cross, the river. For mammals that could pass through the deciduous woodlands, the Missouri has proved to be no barrier at all. The list of sub- species occurring on both sides of the river is impressive, and in- cludes both semi-fossorial and fossorial kinds. The partial list be- low of subspecies that occur on both sides of the river suffices to establish the point: PLATE 1 ■ i^viT' ' l Fig. 1. Upland habitat in eastern Nebraska (north edge of Lincoln, Lancaster County). Formerly grazed, this area had not been disturbed for six years at the time this photograph was taken. Photograph courtesy of the University of Nebraska State Museum. Fig. 2. Hills above the Missouri in northern Knox County. The photograph shows native prairie in foreground, deciduous timber ( mostly oak ) in draws, and floodplain of the river in the distance. PLATE 2 Fig. 1. Shallow, sandy-bottomed Middle Loup River in Sand Hills, 1 mi. N and 4 mi. W Halsey, Thomas County. Note thin border of deciduous trees. Fig. 2. Watt's Lake, Valentine National Wildlife Refuge, Cherry County. Typical of the lake region of the Sand Hills, this photograph shows recently mowed hay, lake-side vegetation, open water, and sand hills in distance. PLATE 3 Fig. 1. Pond and associated vegetation at Rock Creek Fish Hatchery, Dundy County. This interesting area in southwestern Nebraska provides suitable habitat for many riparian mammals, including relict populations of two microtines. I H - Fig. 2. Pine-capped Wildcat Hills in southern Scotts Bluff County PLATE 4 Fig. 1. Typical view (at Fort Robinson, Dawes County) of Pine Ridge. Note cliffs and rocky slopes, which provide important habitats for some mammals. Fig. 2. Deciduous timber along Soldier Creek in Pine Ridge area of eastern Sioux County. Mammals of Nebraska 41 Cryptotis parva parva Scale-pus aquations machrinoides Sylvilagus floridanus mearnsii Spermophilus tridecemlineatus tridecemlineatus Geomys bursarius majusculus Reithrodontomys megalotis dychei Peromyscus maniculatus bairdii Microtus ochrogaster ochrogaster Microtus pinetorum nemoralis Mustela nivalis campestris The boundary line between subspecies of four species currently is drawn along the Missouri at the latitude of Nebraska. In the northeast, the nominal subspecies Onychomys leucogaster breviau- ritus occurs to the south and west of the river, whereas O. I. leuco- gaster occurs to the north and east of the river in South Dakota. For the remaining three species, Marmota monax, Ereihizon dor- satum and Canis latrans, the Missouri provides a boundary of con- venience between subspecies and in each instance the line prob- ably reflects lack of precise knowledge as much as anything. I cannot conceive of the river as an effective barrier to any of these three species. How do mammals cross large rivers that present potential bar- riers to dispersal? Principally in one of three ways: 1) swim; 2) cross on ice in winter if the river freezes over; and 3) cross as a result of flooding, either by rafting or by climbing to safety in tall vegetation, which, owing to changes in the channel that so often result from floods, ends up with its occupant on the opposite side after the water has receded. All of these methods are important, the first two especially to larger mammals and the last to smaller species. (Occasionally mammals cross rivers as a result of acts of man — by direct transport or on man-made structures such as bridges and dams — but known crossings of this kind are relatively few and of little concern here.) Because of recent changes wrought by man on the Missouri to make it more useful and reliable for river transportation, and to prevent flooding (by equalizing the flow), it perhaps now is more of a barrier than in the past, at least to small mammals. The channel has been straightened and deepened and is kept partly ice-free in winter, thus reducing the chances of a mammal successfully swim- ming the river and the opportunity of crossing on ice. The series of dams in the Missouri from the Nebraska-South Dakota line north into Montana have considerably reduced flooding north of the 42 University of Kansas Publs., Mus. Nat. Hist. mouth of the Kansas River, thereby all but preventing crossing by that means at the latitude of Nebraska. For these reasons, the river now may provide an effective barrier to P. hispidus (whereas it would not have done so in the past) and may reduce considerably gene-flow between populations of species now occurring on both sides. The Missouri River is by far the largest body of flowing water that touches Nebraska. Other rivers in the state, except as they have provided avenues of dispersal for species utilizing riparian associations, seem not to have affected the distribution or speciation of mammals. Geographic Variation and Speciation Geographic variation among Nebraskan mammals mirrors fairly well that found in other plains states at the same longitude, namely variation in color of pelage from east (dark) to west (pale) in many species, sometimes accompanied by variation in size, and clinal north-south variation in size in a few species, in general accordance with several zoogeographic rules pertaining to infraspecific varia- tion. Color of pelage in mammals oftentimes reflects the color of the substrate on which they live. Some species in Nebraska having dark subspecies in the east and pale subspecies in the west that serve to illustrate this point are the following: „ Dark, Eastern Pale, Western bPEciEs Subspecies Subspecies Scalopus aquations machrinoides caryi Sylvilagus floridanus mearnsii similis Spermophilus tridecemlineatics . . tridecemlineatus pallidus Geomys bursarius majusculus lutescens Perognathus flavescens perniger flavescens Peromyscus maniculatus bairdii luleus and nebrascensis Onychomys leucogasler breviaurilus arcliceps Microtus ochrogaster ochrogaster haydenii Mustela frenata primulina and spadix longicauda Species in which east-west variation in color of pelage is lacking, or of such minor slope as not to be recognized subspecifically, are mostly 1 ) kinds that can move readily over broad areas ( bats, un- gulates and carnivores, for example), or 2) species that, although relatively widespread, are narrowly limited ecologically in areas where differentiation might be expected. Examples of the latter are found among some rodents and insectivores that occur only in riparian communities in the western part of the state where ecologi- cal conditions approximate those under which the mammal lives Mammals of Nebraska 43 in the east (Microtus pennsylvanicus, Blarina brevicauda, and Reithrodontomys megalotis, for example). For those species in which color of pelage varies from east to west and provides charac- ters separating subspecies, the change in color ordinarily is gradual (as is the change in color of soil), resulting in relatively broad zones of intergradation between most subspecies. Significantly, boundaries between the eastern and western subspecies of most species fall in the same general area. Most specimens from Neligh, Antelope County, at the easternmost edge of the Sand Hills, for example, are intergrades regardless of the species concerned; speci- mens from Neligh of some species are assignable to an eastern sub- species, but in more species individuals resemble to a greater degree a western subspecies. Geographic variation in color of pelage in Peromyscus maniculatus, one of the most geographically variable of the mammals occurring in Nebraska, is illustrated, by way of example, in Fig. 3. More often than not the eastern of two subspecies is the larger ( in Scalopus aquaticus, Spermophilus tridecemlineatus, and Geomys bursarius, for example), but sometimes the opposite is the case (in Peromyscus maniculatus, for example ) , and in some instances there is little or no difference in size between the two. If eastern and western subspecies differ in size, the changes are gradual, as are changes in color, but changes in size and color ordinarily do not occur at the same rate or at the same places — in other words they are not ordinarily concordant. Because the zones of intergradation between eastern and western subspecies usually are broad, assign- ment of specimens from some localities therein is difficult, especially where small series or single specimens are involved, and on oc- casion must be made solely on geographic grounds. North-south variation in mammals in Nebraska is marked only in a few species. In Blarina brevicauda for example, the northern subspecies (B. b. brevicauda) is strikingly larger than the southern race (B. b. carolinensis) , but this results from peculiar circum- stances, previously noted, associated with shifts in range of this species in response to post-Wisconsin climates. Of the two sub- species of the kangaroo rat that occur in the state, the northern one (D. o. luteolus) is supposedly the larger (Setzer, 1949:512), but the differences are slight because Nebraska lies in the zone of in- tergradation between the two. In several species (Sylvilagus audubonii, Zapus hudsonius, Vulpes vulpes, and Mephitis mephitis, for example) size increases northwardly but the same subspecific name is applied throughout the range in Nebraska. 44 University of Kansas Publs., Mus. Nat. Hist. J03 OQ 97 _J — 1 — \ . i .1 ■' 1 ,H e |-W-h-\ «r> 1 © kw^®I_ i r— j*' to v4 «j- \ I t -riLJL-J — t — J — -! — j — 4 !_ j i Museum of Natural H alary ■ I "' uMIItt UnhrtnJty of Karaa T T Till 1952 _l 1 "(08 WO 97 Fig. 3. Schematic representation of color of pelage in Peromyscus maniculatus in Nebraska showing changes from east (dark) to west (pale). To arrive at color designations five specimens were selected as "guides" as follows: an average specimen from among the darkest-colored individuals was designated no. 1; an average specimen from among the palest available was designated no. 9; specimens of appropriate intermediate colors were designated nos. 3, 5, and 7. Adults from the localities represented in the figure were compared with the numbered specimens and assigned a color designation of from 0 to 10. Averages, all of which fell between 1 and 8, are indicated above for the samples treated. If the average from any locality had been 1 the symbol representing that locality would have been entirely black; if the average had been 8 the symbol would have been entirely white. Some series from the Panhandle have approximately the same color rating as do series from more easterly localities, but individuals from the Panhandle are slightly more grayish in most instances than those of approximately the same color rating to the east. Dice (1941) and Blair (1953) are among those who previously have studied variation in color in this species in Nebraska. In the western harvest mouse, Reithrodontomys megalotis dychei, there is a general increase in length of tail and length of ear from northeast to southwest in the state, in accord with Allen's Rule, and an increase in length of rostrum as well (Jones and Mursaloglu, 1961 :fig. 1). Nebraska has but two endemic subspecies, Neotoma floridana baileyi and Synaptomys cooperi relictus. Each occurs in an iso- lated, relict area and each possibly occurs in adjoining parts of another state. Another relic, Microtus pennsylvanicus finitus, oc- curs with S. c. relictus along Rock Creek in Dundy County but is known also from along the North Fork of the Republican River in adjacent Yuma County, Colorado. It is somewhat surprising that the Sand Hills of Nebraska, oc- cupying some 18,000 square miles, not including isolated outliers, Mammals of Nebraska 45 have produced no endemic subspecies of mammals. Some kinds, it is true, are somewhat paler there than elsewhere within their geographic distribution (Dipodomys ordii luteolus and Peromyscus maniculatus luteus, for example), but on the whole populations of mammals on the Sand Hills closely resemble in color those on ad- jacent pale-colored soils. The Sand Hills have served as a kind of a filter zone to distribution of mammals. Some eastern species reach the area along rivers but do not pass through it and, similarly, some species of arid regions range eastward into the Sand Hills but do not occur east of them. Mammalian Distributional Areas No one of the arrangements devised to categorize North America biotas, of which the Life-zones of C. H. Merriam, the Biotic Provinces of L. R. Dice, and the Biomes of Clements and Shelford are the most widely cited, corresponds, except in a most general way, with the patterns of distribution of Nebraskan mammals. I have, therefore, divided the state into four mammalian distributional areas, two of which are subdivided into two distributional districts each. It is my hope that the provision of a suitable arrangement for mammals may aid persons who study other animals in Nebraska and that one day, when other organisms are as well known as mammals, one of the major systems mentioned, or some other, can be applied to them all. Of the three systems noted above, Biotic Provinces appeal to me as possibly being most useful in a plains state, because they are contiguous and can readily be subdivided into Biotic Districts, which themselves can be subdivided into eco- logical associations or some other arrangement if need be. The student interested in the various schemes proposed to classify eco- logically the floras and faunas of North America is directed to Kendeigh's ( 1954 ) valuable review of the subject. Wolcott (1906), Swenk (1908), and Wolcott (1909) each divided Nebraska into five faunal areas. The three divisions generally were in accord, differing in some instances only in names used for the faunal units recognized, as seen below: Wolcott (1906) Swenk (1908) Wolcott (1909) Wooded bluffs and bottoms of the Missouri and its tributaries Prairie Sand-hill Plains or plateau Coniferous wooded region of the northwest, extending eastward north of the Niobrara Missouri Missouri Prairie Prairie Sandhill Sand-hill Plateau Plains Pine Ridge Pine Ridge 46 University of Kansas Publs., Mus. Nat. Hist. The mammalian distributional areas here recognized (see Fig. 4) are Missouri, Eastern Grassland, Central Grassland, and Pan- handle. The Central Grassland Area is divided into a Sand Hill District and a Southwestern District, and the Panhandle Area is divided into a Plains-Plateau District and a Pine Ridge-Badlands District. These several areas correspond roughly with the major soil, vegetational and physiographic areas of the state. Fig. 4. Mammalian distributional areas in Nebraska. 1. Missouri. 2. East- ern Grassland. 3. Central Grassland (Sand Hills District, 3a, Southwestern District, 3b). 4. Panhandle (Pine Ridge-Badlands District, 4a, Plains-Plateau District, 4b). Missouri Distributional Area This area approximates the former extent of climax oak-hickory forest along the Missouri River in extreme eastern Nebraska. Six kinds of mammals (Myotis lucifugus lucifugus, Pipistrellus sub- flavus subflavus, Tatnias striatus griseus, Sciurus carolinensis penn- sylvanicus, Glaucomys volans volans, and Microtus pinetorum nemo- ralis) are more or less restricted thereto. Other kinds character- istic of this area include Didelphis marsupialis virginiana, Nycticeius humeralis humeralis, Sciurus niger rufiventer, and Peromyscus leuco- pus noveboracensis. Eastern Grassland Distributional Area The tall-grass prairie and part of the ecotonal area between tall- and mixed-grass prairie are included in this distributional area. It is bounded on the east by the wooded areas along the Missouri. Mammals of Nebraska 47 The western margin, which approximates the 99th meridian in the extreme north and to the south of the Platte River, bends eastward in the middle of the state to skirt the eastern edge of the Sand Hills and adjacent relatively sandy areas. Subspecies of several grass- land species (Perognathus flavescens perniger, Reithrodontomys montanus griseus, and Onychomys leucogaster breviauritus, for example) are restricted to this area. Cryptotis parva parva, Spermophilus franklinii, Synaptomys cooperi gossii, Vulpes vulpes regalis, and Spilogale putorius interrupta are among the characteris- tic inhabitants, along with eastern subspecies (Spermophilus tride- cemlineatus tridecemlineatus and Microtus ochrogaster ochrogaster, for example) of some wide-ranging species. There are a few faunal differences between the northern and southern parts of this area but these do not to my mind justify the creation of two districts. Central Grassland Distributional Area This faunal unit comprises the Sand Hills and adjacent areas of sandy soil north of the Platte River and sandy outliers and adjacent areas to the south of the Platte. The western border north of the river is the border of the Sand Hills; south of the Platte, the isolated areas of dune sand between the 101st and the 102nd meridians form the western boundary. Only a few mammals are restricted to this area. Mostly it serves to filter western species moving east and, in part, eastern species moving west, although some of the latter have passed through the area along the riparian community bordering the Platte River. Two faunal districts are recognized, one divided from the other by the Platte. Sand Hills District. — Included herein are the Sand Hills proper, areas of sandy loess to the south of them, and the tablelands north of the Niobrara in northeastern Cherry, Keya Paha, and western Boyd counties. Only two mammals, Neotoma floridana baileyi and Perognathus fasciatus fasciatus, are peculiar to this district and both of these occur only in restricted areas therein. Mostly the district is characterized by the abundance of Geomys bursarius lutescens, Perognathus flavescens flavescens, Dipodomys ordii luteolus, Pero- myscus maniculatus luteus, and some other upland kinds, and the abundance of certain riparian mammals (such as Sorex cinereus haydeni, Zapus hudsonius pallidus, Microtus pennsylvanicus penn- sylvanicus, and Ondatra zibethicus cinnamominus) along the rivers and around the many Sand Hill lakes and marshes. 48 University of Kansas Publs., Mus. Nat. Hist. Southwestern District. — That part of the Central Grassland Area lying to the south of the Platte River comprises this district. It is characterized by lacking generally the conditions described above for the Sand Hills District and by the presence of Dipodomys ordii richardsoni, Neotoma floridana campestris, Microtus pennsijlvanicus finitus, and Synaptomys cooperi relictus. Panhandle Distributional Area That part of Nebraska lying west of the Sand Hills is included in this area. Mammals characteristic of this faunal unit as a whole, some nearly or absolutely limited to it, are Myotis subulatus subu- latus, Eptesicus fuscus pallidus, Sylvilagus audubonii baileyi, Perog- nathus fasciatus olivaceogriseus, Peromyscus maniculatus nebrascen- sis, Neotoma cinerea rupicola, Gulo luscus luscus, and Ovis canaden- sis auduboni. Pine Ridge-Badlands District. — This district is confined to the Pine Ridge in Sioux, Dawes, and northwestern Sheridan counties and to the Badlands north of Pine Ridge, mostly in parts of Sioux County. Mammals peculiar to this area are Myotis evotis evotis, Myotis volans interior, and Eutamias minimus pallidus. Myotis lucifugus carissima and Erethizon dorsatum bruneri are character- istic inhabitants but are not limited to this district. Plains-Plateau District. — That area of the Panhandle not included in the Pine Ridge-Badlands District is included here. Spermophilus richardsonii elegans and two subspecies of Thomomys talpoides, T. t. cheyennensis ( south ) and T. t. pierreicolus ( north ) occur only in this district. It is characterized additionally by lacking those kinds limited to the district previously mentioned. Summary At the height of Wisconsin glaciation, the mammalian fauna of what is now Nebraska probably was composed of boreal species, wide-ranging species, and some of the more cold-tolerant temperate species, including kinds hav- ing grassland affinities. With the retreat of the Wisconsin ice sheet, boreal elements became fewer and temperate species increased in number. It is postulated that post- Wisconsin climatic shifts, especially the Hypsithermal In- terval, with its warm, humid Climatic Optimum (9,000-4,000 BP) and suc- ceeding warm, dry Xerothermic Period (4,000-2,500 BP), played an im- portant role in the establishment of the present distributional patterns of some species (Neotoma floridana and Blarina brevicauda, for example). The Xerothermic Period probably was a time when the boreal elements still re- maining were extirpated or drastically restricted geographically. Five faunal units are recognizable among Nebraska's 69 Recent, native, non- Mammals of Nebraska 49 volant species as follows: 1) northern and western species that were forced southward or eastward by continental or montane glaciation during the Wis- consin and that now occur in the state mostly in restricted areas; 2) a group of species that invaded the state from the east, principally along the Missouri River; 3) grassland species, which are characteristic of (and many endemic to) the central North American grasslands; 4) southern and southwestern species, most of which are characteristic of the Sonoran region, that invaded the state from the southern Great Plains; and 5) a large group of wide-ranging species of undetermined origin insofar as Nebraska is concerned. Of the 12 species of bats, five are widespread, four appear to have invaded the state from the east, two are species characteristic of the intermountain west, and one ( Tadarida brasiliensis ) is a wanderer from the south. Environmental conditions control distribution of many mammals in Ne- braska. The presence or absence of certain plant associations seems to be most important in this regard but edaphic, climatic, and topographic factors also serve to limit distribution of mammals, and sometimes a combination of factors involving more than one of the major environmental categories is operative. The Missouri River and especially its deciduous riparian associa- tion have been barriers to eastward dispersal of at least nine plains species (and possibly several more), although the river and its riparian association have not been barriers to many small mammals judging from the impressive number of subspecies that occur both to the east and west of the river. The predominant geographic variation among Nebraskan mammals is in color of pelage from east (dark) to west (pale) and accords with Gloger's rule. No fewer than 15 species have pale western and dark eastern sub- species; variation in color in the same direction is apparent in a number of other species but is not of a magnitude that warrants subspecific recognition. East-west variation in size occurs in some species but is lacking in many others. Clinal variation in size from north to south is apparent in a few species and is in general accordance with Allen's and Bergmann's rules. Considering climate, soil, vegetation, and topography along with distribu- tion and speciation among mammals in Nebraska, the state can be divided into four mammalian distributional areas (see Fig. 4) as follows (from east to west): Missouri; Eastern Grassland; Central Grassland (having the Sand Hills and Southwestern districts); and Panhandle (having the Pine Ridge- Badlands and Plains-Plateau districts). Each of these distributional areas is characterized by the presence (or absence) of mammals in unique combina- tions. TREATMENT AND ACKNOWLEDGMENTS The aims of the present report have been the following: 1) to determine the kinds of Recent mammals occurring (or that oc- curred within historic time) within the political boundaries of Nebraska; 2 ) to ascertain for each the extent of geographic distribu- tion in the state; 3) to provide keys for ready identification of species; 4) to provide, insofar as I was able, a complete synonymy with reference to Nebraska for each of the subspecies and monotypic 4—6532 50 University of Kansas Publs., Mus. Nat. Hist. species treated; 5) to assess taxonomically, and to record if ap- propriate, variations of all kinds — specific, subspecific, geographic, and individual — found in the mammals studied; and 6) to relate, whenever possible, distribution and speciation of Nebraskan mam- mals to the late Pleistocene and Recent changes in the environment. Methods The arrangement of major taxonomic categories (from order to genus) in the accounts of species beyond follows Hall and Kelson (1959). Species of each genus and subspecies of each species are entered alphabetically for con- venience of the reader. Each of the seven orders of Nebraskan mammals is discussed briefly. The names of the 23 families to which the 86 mammalian species of the state belong are appropriately placed in the text. A given vernacular name is applied to the species and is intended to apply to all of its subspecies. The reader is reminded again that the study here reported on was mainly from the systematic, not the ecologic, viewpoint. I have, neverthe- less, attempted to summarize some data on reproduction for each species, be- cause such information frequently is available only on specimen labels; for the sake of consistency, brief mention is made of reproduction for each species, even if information from Nebraska is lacking. After the general discussion of a species, each subspecies or monotypic species is treated as follows: 1. The scientific name that is valid under the rules of the "International Code of Zoological Nomenclature" ( 1961 ) is followed on the same line by the name of the author. 2. The synonymy, in which the first citation is to the original description, which I have consulted in every instance, followed by designation of the type locality. The second citation is to the first use of the name-combination herein employed if it differs from the name as originally proposed. Next, in chrono- logical order, are all citations in the literature pertaining to Nebraskan mam- mals for which at least a binomial was used. By "pertaining to Nebraska" I mean one of the following: record of Nebraska-taken material (specimen or specimens); mention of a precise locality of occurrence (excepting simple listings of Nebraskan type localities); or listing of a name with reference only to Nebraska even if no specimens or precise localities were mentioned (as in the checklists of Aughey, 1880, Swenk, 1915, and Jones, 1957, for example). The word "part" appears in parentheses after a name in synonymy if that name was applied only in part, in any combination, with reference to Nebraska. 3. The geographic distribution in Nebraska stated in concise form. 4. The measurements, external and cranial, are given in millimeters. Ex- ternal measurements were read from specimen labels, are of adults unless other- wise noted, and always appear in the following sequence: total length; length of tail; length of hind foot; length of ear from notch; length of forearm (for bats only). Weights, usually given in grams, are, except as noted, of adults (females non-pregnant). Cranial measurements (also of adults unless stated otherwise) were taken by me with dial calipers in the manner described by Hall (1946:672-685) and Hooper (1952:9-11). 5. The remarks ordinarily include particular information concerning infra- Mammals of Nebraska 51 specific or other variation, along with such other notes as may apply only to a subspecies or to individual specimens. 6. The records of occurrence include both specimens examined and addi- tional records. Under specimens examined, the total number examined by me of each subspecies or monotypic species is given first, followed by a listing of the exact localities from which the specimens originated. County names are arranged alphabetically (location of Nebraska's 93 counties is shown in Fig. 82). Within each county, localities are listed from north to south; if two localities are at the same latitude the westernmost is listed first. A total of 10,339 specimens from Nebraska were examined in the course of this study. In addi- tion, many specimens from other states were examined, including topotypes or typical specimens of kinds that do not have their type localities in Nebraska. Unless otherwise noted, specimens examined are in the collection of the Museum of Natural History of The University of Kansas. Abbreviations designating specimens in other collections are as follows: AMNH — American Museum of Natural History CNHM — Chicago Natural History Museum CM — Carnegie Museum CSTC — Chadron (Nebraska) State Teachers College HM — Hastings Museum, Hastings, Nebraska MCZ — Museum of Comparative Zoology, Harvard MSU — The Museum, Michigan State University MVZ — Museum of Vertebrate Zoology, University of California NGFPC — Nebraska Game, Forestation and Parks Commission NSM — University of Nebraska State Museum RV — Collection of Ralph Velich, Omaha, Nebraska UC — Museum of Natural History, Union College, Lincoln, Nebraska UF — Department of Biology, University of Florida UI — Museum of Natural History, University of Illinois UMMZ — Museum of Zoology, University of Michigan (including specimens formerly housed in the Cleveland Museum of Natural History) UNDZ — Department of Zoology, University of Nebraska UNM — Department of Biology, University of New Mexico USNM — United States National Museum (including collections of the U. S. Biological Surveys) WFR— Collection of W. F. Rapp, Crete, Nebraska WSC — C. R. Connor Museum, Washington State College Additional records are localities reported in the literature (or field notes) from which I have not examined specimens. Records in the literature no more precise than county ordinarily are not listed if I have examined specimens from at least one place within that county or if another record from the literature is from a precise locality within the same county. If reference to the same specimen(s) appears in more than one publication, as frequently is the case, my custom has been to cite the author who last examined the specimen(s) concerned. The vast majority of place names cited in the accounts appear on any one of the commercial road maps available for Nebraska. All except nine appear on the 13 maps (nos. NK 13-6, 13-9, 14-4 through 14-12, 15-7, and 15-10) 52 University of Kansas Publs., Mus. Nat. Hist. that pertain to Nebraska in the "Western United States 1:250,000" series published by the U. S. Geological Survey. The nine that do not appear on maps of the USGS series are as follows: Bull Canyon — canyon and intermittent creek in T. 19-20 N, R. 57-58 W, northwestern Banner County. Child's Point — in Fontanelle Forest (see below), Sarpy County. Fontanelle Forest — forest reserve in T. 14 N, R. 13-14 E, northeastern Sarpy County. Homerville — town formerly in sec. 20, T. 6 N, R. 22 W, Gosper County. Kelso — railroad siding in T. 24 N, R. 31 W, northeastern Hooker County. London — town formerly in sec. 9, T. 5 N, R. 15 E, Nemaha County. Myrtle — town formerly in sec. 22, T. 16 N, R. 29 W, Lincoln County. Rockport — town formerly along Missouri River in T. 16 N, southeastern Washington County. Turlington — town formerly on C. B. and Q. Railroad approximately 4 mi. E Syracuse, Otoe County. Distribution maps accompanying accounts of the species show localities whence specimens have been examined by me or recorded by others, and my estimate of the area in the state where each species occurs. It is understood that a given species occupies only suitable habitats within the area of supposed occurrence. In plotting localities some were omitted from maps because undue crowding of symbols would have resulted; for the same reason, a few symbols are slightly offset on the maps. Also, in several instances localities were not plotted because the specimens from there were examined after maps were prepared. Localities not shown on maps are set in italic type in the lists of specimens examined and additional records. In general, a locality was not plotted if it fell within eight miles of another that was plotted. T. H. Swearingen made the finished distribution maps. Acknowledgments Completion of this paper would have been impossible without the help, direct and indirect, of many persons. I am especially mindful of the contribu- tions of those named below. For the loan of specimens, for information concerning specimens, or for permission to examine specimens at the institution concerned I am grateful to the following: S. Anderson, G. G. Goodwin, K. F. Koopman and R. G. Van Gelder, American Museum of Natural History; D. B. Gates, Chadron (Ne- braska) State Teachers College; P. Hershkovitz, Chicago Natural History Museum; J. K. Doutt and C. Heppenstall, Camegie Museum; T. Howell, Dicky Collection, University of Southern California; W. E. Eigsti and B. Nelson, Hastings Museum; B. Lawrence, Museum of Comparative Zoology, Harvard; R. H. Baker, The Museum, Michigan State University; G. J. Schildman, Nebraska Game, Forestation and Parks Commission; W. F. Rapp, Crete, Ne- braska; I. S. Wiggins, Natural History Museum, Stanford University; W. Page, A. E. Perry and N. W. Rowland, Union College, Lincoln, Nebraska; S. B. Benson and W. Z. Lidicker, Jr., Museum of Vertebrate Zoology, University of California; J. N. Layne, Department of Biology, University of Florida; D. F. Hoffmeister, Museum of Natural History, University of Illinois; W. H. Burt Mammals of Nebraska 53 and E. T. Hooper, Museum of Zoology, University of Michigan; C. B. Schultz and L. G. Tanner, University of Nebraska State Museum; T. B. Thorson, De- partment of Zoology, University of Nebraska; J. S. Findley, Department of Biology, University of New Mexico; C. O. Handley, Jr., D. H. Johnson and H. W. Setzer, U. S. National Museum; R. H. Manville, V. S. Schantz and S. P. Young, U. S. Fish and Wildlife Service (Biological Surveys Collection); R. Velich, Omaha, Nebraska; G. H. Hudson, C. R. Connor Museum, Washing- ton State College. Many persons at the Museum of Natural History of The University of Kansas participated in field work in Nebraska that resulted in specimens used in preparation of this report. Those that aided me directly are as follows: J. R. Alcorn N. L. Ford R. H. Pine Jean Alcorn E. R. Hall R. J. Russell A. H. Al-Rawi J. M. Legler R. E. Smith T. Alvarez C. A. Long H. J. Stains S. Anderson R. B. Loomis W. C. Stanley R. H. Baker W. L. Minckley H. B. Tordoff J. C. Barlow T. M. Mohler T. A. Vaughan J. B. Bowles G. J. Myers L. A. Witt W. L. Cutter R. L. Packard O. L. Webb D. W. Englert R. R. Patterson J. Zambemardi J. S. Findley A number of biologists and conservation officers of the Nebraska Game, Forestation and Parks Commission contributed specimens or provided pertinent information concerning game mammals and fur-bearers. Of these, I would mention especially P. Agee, W. J. Bailey, Jr., H. O. Compton, J. Mathisen, C. G. Pritchard, J. H. Sather (presently at Western Illinois State College), G. J. Schildman, and L. P. Vance. The continued interest of M. O. Steen, Executive Director of the Commission, who issued scientific collecting permits, is acknowledged. G. L. Wiseman and N. B. Nelson of the U. S. Fish and Wildlife Service (Valentine National Wildlife Refuge) and R. Velich of Omaha also aided in securing specimens and were helpful in other ways. I am indebted to these and the many other Nebraskans who gave of their time and assistance in connection with this work. Research grants from The Society of the Sigma Xi and the Kansas Academy of Science helped to defray part of the expenses of field work. I acknowledge my great indebtedness also to Pro- fessors A. Byron Leonard, Charles W. Pitrat and Robert W. Wilson who, as members of my doctoral committee, gave much helpful advice and counsel. In addition, Professors Leonard and Pitrat read and criticised parts of the manuscript. Finally I take great pleasure in acknowledging the following seven persons who, since the inception of my interest in Nebraskan mammals, have contrib- uted most importandy to the successful completion of this report. The seven are: my parents, Mr. and Mrs. J. Knox Jones, Sr., who encouraged my early interest in natural history and who contributed liberally toward the expenses of my formal education; my wife, Janet G. Jones, who not only typed the entire first draft of the manuscript and was helpful in many other ways, but cheerfully shouldered a disproportionate share of the responsibilities of caring for our family while the work was in progress; Professor Edson H. Fichter, now of Idaho State College, under whose tutelage my earliest work on mammals was conducted; Professor Emeritis Otis Wade of the University of Nebraska, 54 University of Kansas Publs., Mus. Nat. Hist. who served as my undergraduate advisor; Professor C. Bertrand Schultz, Direc- tor of the University of Nebraska State Museum, who early afforded me the opportunity to work with museum collections and who was instrumental in pro- viding support for field work in Nebraska in several years; and especially Pro- fessor E. Raymond Hall, who as friend and adviser on the one hand and, more formally, as chairman of my doctoral committee on the other, not only gave freely of his time and counsel during the course of this study, but placed at my disposal the many facilities of the Museum of Natural History, arranged financial support for field work that resulted in the largest collection of Nebraskan mammals housed in any museum, and read critically the entire manuscript. CHECKLIST OF MAMMALS OF NEBRASKA The 109 kinds ( subspecies and monotypic species ) of Nebraskan mammals are arranged in seven orders, 23 families and 59 genera, of which two families and five genera ( five species ) have been in- troduced from outside North America (marked by an asterisk in following checklist). A list of 12 species that have not as yet been reported from Nebraska but that may occur in the state follows the accounts of species. Order MARS UPIALI A— Marsupials Family Didelphidae — Opossums Didelphls marsupiaUs virginiana Kerr (Opossum) p. 60 Order INSECTIVORA— Insectivores Family Soricidae — Shrews Sorex cinereus haydeni Baird ( Masked Shrew ) p. 64 Blarina brevicauda brevicauda (Say) (Short-tailed Shrew) p. 66 Blarina brevicauda carolinensis (Bachman) (Short-tailed Shrew) .... p. 69 Cryptotis patva parva (Say) (Least Shrew) p. 71 Family Talpidae — Moles Scalopus aquaticus caryi Jackson (Eastern Mole) p. 74 Scalopus aquaticus machrinoides Ja"ckst>rr~tEastem Mole) p. 76 Order CHIROPTERA— Bats Family Vespertilionidae — Vespertilionid Bats Myotis evotis evotis ( H. Allen ) ( Long-eared Myotis ) p Myotis keenii septentrionalis (Trouessart) (Keen's Myotis) p Myotis lucifugus carissima Thomas ( Little Brown Myotis ) p Myotis lucifugus lucifugus ( Le Conte ) ( Little Brown Myotis ) p Myotis subulatus subulatus (Say) (Small-footed Myotis) p Myotis volans interior Miller (Long-legged Myotis) p Lasionycteris noctivagans (Le Conte) (Silver-haired Bat) p Pipistrellus subflavus subflavus (F. Cuvier) (Eastern Pipistrelle) .... p 80 81 82 83 85 87 88 89 Mammals of Nebraska 55 Eptesicus fuscus fuscus (Palisot de Beauvois) (Big Brown Bat) p. 91 Eptesicus fuscus pallidus Young ( Big Brown Bat ) p. 92 Lasiurus borealis borealis (Miiller) (Bed Bat) p. 95 Lasiurus cinereus cinereus (Palisot de Beauvois) (Hoary Bat) p. 96 Nycticeius humeralis humeralis (Rafinesque) (Evening Bat) p. 98 Family Molossidae — Free-tailed Bats Tadarida brasiliensis mexicana (Saussure) (Brazilian Free-tailed Bat) . . p. 101 Order LAGOMORPHA— Hares, Rabbits and Pikas Family Leporidae — Hares and Rabbits *Oryctolagus cuniculus (Linnaeus) (European Rabbit) p. 331 Sylvilagus audubonii baileyi (Merriam) (Desert Cottontail) p. 103 SylvUagus floridanus mearnsii (J. A. Allen) (Eastern Cottontail) p. 105 Sytvilagus floridanus similis Nelson (Eastern Cottontail) p. 107 Lepus calif ornicus melanotis Mearns (Black-tailed Jackrabbit) p. 110 Lepus townsendii campanius Hollister (White-tailed Jackrabbit) p. 113 Order RODENTIA— Rodents Family Sciurtdae — Squirrels and Allies Tamias striatus griseus Mearns (Eastern Chipmunk) p. 118 Eutamias minimus pallidus (J. A. Allen) (Least Chipmunk) p. 119 Marmota monax bunkeri Black (Woodchuck) p. 123 Spermophilus franklinii (Sabine) (Franklin's Ground Squirrel) p. 125 Spermophilus richardsonii elegans Kennicott (Richardson's Ground Squirrel) p. 128 Spermophilus spilosoma obsoletus Kennicott (Spotted Ground Squirrel), p. 129 Spermophilus tridecemlineatus pallidus J. A. Allen ( Thirteen-lined Ground Squirrel) p. 132 Spermophilus tridecemlineatus tridecemlineatus (Mitchill) (Thirteen- lined Ground Squirrel) p. 134 Cynomys ludovicianus ludovicianus (Ord) (Black-tailed Prairie Dog) . . p. 138 Sciurus carolinensis pennsylvanicus Ord (Gray Squirrel) p. 143 Sciurus niger rufiventer fi. GeofTroy St.-Hilaire (Fox Squirrel) p. 147 Glaucomys volans volans (Linnaeus) (Southern Flying Squirrel) .... p. 150 Family Geomyidae — Pocket Gophers Thomomys talpoides cheyennensis Swenk (Northern Pocket Gopher) . . p. 153 Thomomys talpoides pierreicolus Swenk ( Northern Pocket Gopher ) ... p. 154 Geomys bursarius lutescens Merriam (Plains Pocket Gopher) p. 156 Geomys bursarius majusculus Swenk (Plains Pocket Gopher) p. 160 Family Heteromyidae — Pocket Mice and Kangaroo Rats Perognathus fasciatus fasciatus Wied-Neuwied (Olive-backed Pocket Mouse ) p. 165 Perognathus fasciatus olivaceogriseus Swenk (Olive-backed Pocket Mouse) /. p. 165 Perognathus flavescens flavescens Merriam (Plains Pocket Mouse) .... p. 168 Perognathus flavescens perniger Osgood (Plains Pocket Mouse) p. 170 Perognathus flavus piperi Goldman (Silky Pocket Mouse) p. 172 56 University of Kansas Publs., Mus. Nat. Hist. Perognathus hispidus paradoxus Merriam (Hispid Pocket Mouse) .... p. 174 Perognathus hispidus spilotus Merriam (Hispid Pocket Mouse) p. 175 Dipodomys ordii luteolus (Goldman) (Ord's Kangaroo Rat) p. 179 Dipodomys ordii richardsoni (J. A. Allen) (Ord's Kangaroo Rat) .... p. 181 Family Castoredae — Beavers Castor canadensis missouriensis V. Bailey (Beaver) p. 184 Family Cricetidae — Native Rats and Mice Reithrodontomys megalotis dychei J. A. Allen (Western Harvest Mouse) p. 188 Reithrodontomys montanus albescens Cary (Plains Harvest Mouse) ... p. 192 Reithrodontomys montanus griseus V. Bailey (Plains Harvest Mouse) . . p. 193 Peromyscus leucopus aridulus Osgood (White-footed Mouse) p. 196 Peromyscus leucopus noveboracensis (Fischer) (White-footed Mouse), p. 198 Peromyscus maniculatus bairdii (Hoy and Kennicott) (Deer Mouse) .. p. 200 Peromyscus maniculatus luteus Osgood ( Deer Mouse ) p. 203 Peromyscus maniculatus nebrascensis (Coues) (Deer Mouse) p. 206 Onychomys leucogaster arcticeps Rhoads (Northern Grasshopper Mouse) p. 208 Onychomys leucogaster breviauritus Hollister (Northern Grasshopper Mouse) p. 210 Sigmodon hispidus texianus (Audubon and Bachman) (Hispid Cotton Rat) p. 214 Neotoma cinerea rupicola J. A. Allen (Bushy-tailed Woodrat) p. 215 Neotoma floridana baileyi Merriam (Eastern Woodrat) p. 217 Neotoma floridana campestris J. A. Allen (Eastern Woodrat) p. 218 Synaptomys cooperi gossii (Coues) (Southern Bog Lemming) p. 221 Synaptomys cooperi relictus Jones (Southern Bog Lemming) p. 222 Microtus ochrogaster haydenii (Baird) (Prairie Vole) p. 223 Microtus ochrogaster ochrogaster (Wagner) (Prairie Vole) p. 226 Microtus pennsylvanicus finitus Anderson ( Meadow Vole ) p. 228 Microtus pennsylvanicus pennsylvanicus ( Ord ) ( Meadow Vole ) p. 229 Microtus pinetorum nemoralis V. Bailey (Woodland Vole) p. 234 Ondatra zibethicus cinnamominus (Hollister) (Muskrat) p. 235 'Family Muridae — Old World Rats and Mice *Mus musculus Linnaeus ( House Mouse) p. 331 "Rattus norvegicus (Berkenhout) (Norway Rat) p. 333 Family Zapodidae — Jumping Mice Zapus hudsonius pallidus Cockrum and Baker (Meadow Jumping Mouse) p. 239 * Family Capromyidae — Nutria and Allies "Myocastor coypus (Molina) (Nutria or Coypu) p. 335 Family Erethizonttdae — Porcupines Erethizon dorsatum bruneri Swenk (Porcupine) p. 242 Mammals of Nebraska 57 Order CARNIVORA— Carnivores Family Canidae — Coyote, Wolves and Foxes Canis latrans latrans Say (Coyote) p. 24G Cants lupus nubilus Say (Gray Wolf) p. 251 Vulpes velox velox (Say) (Swift Fox) p. 253 Vulpes vulpes regalis Merriam ( Red Fox) p. 256 Urocyon cinereoargenteus ocythous Bangs ( Gray Fox ) p. 259 Family Ursidae — Bears Ursus americanus americanus Pallas (Black Bear) p. 262 Ursus horribilis horribilis Ord (Grizzly Bear) p. 263 Family Pbocyonidae — Raccoon and Allies Procyon lotor hirtus Nelson and Goldman ( Raccoon ) p. 265 Family Mustelidae — Weasels, Skunks and Allies Mustela frenata longicauda Bonaparte (Long-tailed Weasel) p. 268 Mustela frenata primulina Jackson (Long-tailed Weasel) p. 271 Mustela frenata spadix ( Bangs ) ( Long-tailed Weasel ) p. 272 Mustela nigripes (Audubon and Bachman) (Black-footed Ferret) .... p. 275 Mustela nivalis campestris Jackson (Least Weasel) p. 277 Mustela vison letifera Hollister (Mink) p. 280 Gulo luscus luscus (Linnaeus) (Wolverine) p. 283 Taxidea taxus taxus ( Schreber) (Badger) p. 285 Spilogale putorius interrupta (Rafinesque) (Spotted Skunk) p. 289 , Mephitis mephitis hudsonica Richardson ( Striped Skunk ) p. 292 Lutra canadensis interior Swenk (Otter) p. 297 Family Felidae — Cats Felis concolor hippolestes Merriam ( Mountain Lion ) p. 300 Lynx canadensis canadensis Kerr (Lynx) p. 303 Lynx rufus rufus (Schreber) (Bobcat) p. 305 Order ARTIODACTYLA— Even-toed Ungulates Family Cervidae — Wapiti, Deer and Allies Cervus canadensis canadensis Erxleben ( Wapiti ) p. 309 Odocoileus liemionus hemionus (Rafinesque) (Mule Deer) p. 314 Odocoileus virginianus macrourus ( Rafinesque ) (White-tailed Deer) . p. 318 "Dama dama (Linnaeus) (Fallow Deer) ./. p. 336 / Family Antilocapridae — Pronghorn/ Antilocapra americana americana (Ord) (Pronghorn) p. 323 Family Bovidae — Bovids Bison bison bison (Linnaeus) (Bison) p. 327 Ovis canadensis auduboni Merriam ( Mountain Sheep ) p. 329 58 University of Kansas Publs., Mus. Nat. Hist. ACCOUNTS OF SPECIES Key to Orders of Nebraskan Mammals 1. Hallux opposable, lacking a claw; marsupium present in females; in- cisors 5/4 MARSUPIALIA, p. 58 1'. Hallux, if present, not opposable and bearing a claw; marsupium ab- sent; incisors never more than 3/3 2 2(1'). Forelimbs modified for flight; fingers (which support a membraneous wing) longer than forearm CHIROPTERA, p. 78 2'. Forelimbs not modified for flight; fingers shorter than forearm 3 3(2'). Upper incisors absent; feet provided with hooves ARTIODACTYLA, p. 307 3'. Upper incisors present; feet provided with claws 4 4(3'). Tooth-rows continuous (no conspicuous diastema between teeth); ca- nines present 5 4'. Tooth-rows having conspicuous diastema between incisors and cheek- teeth ; canines absent 6 5(4). Canines approximately equal in size to adjacent teeth INSECTIVORA, p. 62 5'. Canines conspicuously larger than adjacent teeth . . CARNIVORA, p. 244 6(4'). Ears of approximately same length as (or longer than) tail; incisors 2/1 LAGOMORPHA, p. 101 6'. Ears conspicuously shorter than tail; incisors 1/1 ... . RODENTIA, p. 115 Order MARSUPIALIA— Marsupials Of the eight Recent families of marsupials, only one, Didelphidae, is known from North America. It is represented in the United States only by Didelphis marsupialis. Family Didelphidae — Opossums and Allies Didelphis marsupialis Opossum The opossum is widely distributed in Nebraska where it is one of the most abundant fur-bearers but, judging from the literature, the species was uncommon at the time of early settlement of the state and occurred only in the vicinity of the Missouri River and its im- mediate tributaries in southeastern Nebraska. It was not men- tioned in the historical literature that I have seen on the period of early settlement when the animals would have been of value for their pelts and more especially for food. The species seems there- fore to have increased in numbers in the slate in the past hundred years and to have expanded its range northward and westward, utilizing as avenues of travel the deciduous riparian communities of river systems. The westernmost record of occurrence in Nebraska is a specimen from Alliance obtained on November 30, 1958. Cock- rum (1952:35-37) suggested a similar westward expansion of range in Kansas. Rodeck (1952:69) reported the opossum as ". . . be- Mammals of Nebraska 59 Fig. 5. Distribution of Didelphis tnarsupialis virginiana in Nebraska. Shaded area indicates probable extent of distribution. Symbols indicate records of occurrence as follows: solid symbols, specimens examined; open symbols, records from the literature; circles, precise localities; triangles, records known only to county. coming more abundant in Colorado. A few years ago it was not even considered an inhabitant of the state, but a recent report shows it to be widespread over nearly all of Colorado east of the Divide." Certainly man is in part responsible for the westward expansion of range of the opposum into the Great Plains. He is directly re- sponsible through introduction of the species in certain places (Rees Heaton, for example, introduced "several pairs" along Medicine Creek at Curtis, Frontier County, about 1902 according to Swenk, MS). Indirectly, man created favorable deciduous habitats along water courses and elsewhere by the control of prairie fires and in some instances by plantings. Also, on vast areas he cultivated crops that provided opossums with a variety of foods, and he extirpated or reduced in numbers several large carnivores that would have preyed on opossums and that possibly in part limited their distribution to more heavily wooded areas. Lewis and Clark, who traveled up the Missouri River in 1804 and back down in 1806, recorded the opossum as "found as high [on the Missouri] as the River platt [Platte]" (Thwaites, 1905:122). Later, James (1823:369), in the account of Long's expedition to the Rocky Mountains, reported the species from the Engineer Canton- ment on the Missouri River in Washington County in the winter of 1819-20. 60 University of Kansas Publs., Mus. Nat. Hist. Aughey (1880:122) recorded D. marsupialis as "rather common in the wooded portion of the State," but listed no actual records. According to Swenk (1908:70) the opossum ". . . formerly was uncommon in this state and found only in the extreme southeastern portion, but of recent years it has extended its range along the wooded tributaries of the Missouri until it is now present along nearly the whole eastern edge of the state. In the valleys of the Blue, Platte and Elkhorn it penetrates into the Prairie region for a hundred miles or more. The most northwestern record is from Norfolk, where several have been captured in recent years. . . ." Cary ( MS ) reported the species as taken in the vicinity of Norfolk in 1896 and remarked that "previous to that year [it was] never heard of in that section." The opossum may have extended its range westward in the Re- publican River Valley of southern Nebraska in advance of westward extension in the northern and central parts of the state. Swenk (MS) recorded the species on Medicine Creek, a tributary of the Republican, in southern Lincoln County as early as 1884. The earliest known record from the northern part of the same county, in the Platte River drainage, is of an individual captured along Birdwood Creek "about 1905" (Swenk, MS). Few reports are available from the interior of the Sand Hills and the opossum seem- ingly has been less successful there than elsewhere in moving along riparian communities. Smith (1958:59), for example, reported the species as rare in Thomas County and suggested that it reached the county along the Middle Loup River "about 1930." Large litters, ability to withstand severe injury and frost-bite, and omnivorous food habits contribute to the remarkable success of this animal. It evidently is more abundant in Nebraska now than at any time in its Recent history. Females ordinarily breed in Feb- ruary and March; some may breed a second time in late spring. Reynolds (1952:229) reported an average of 8.6 young per litter for 23 litters from eastern Nebraska. Didelphis marsupialis virginiana Kerr Didelphis virgianiana Kerr, The animal kingdom . . ., p. 193, 1792 (type locality, Virginia); Swenk, Proc. Nebraska Acad. Sci., 8:70, Sep- tember, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:14, Sep- tember, 1908. Didelphis marsupialis virginiana, Chapman, Bull. Amer. Mus. Nat. Hist., 6:334, November 30, 1894 [name-combination applied to Floridian speci- mens, now the subspecies D. m. pigra, but applied prior to the original description of pigra when opossums from everywhere in the eastern United States were referred to the one subspecies, virginiana]. Mammals of Nebraska 61 Didelphius [sic] virginiana, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823. Didelphis Virginiana, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880. Didelphis virginianus virginianus, Swenk, Nebraska Blue Book, p. 851, 1915; Swenk, Nebraska Blue Book, p. 407, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:17, March 1, 1919; Swenk, Nebraska Blue Book, p. 479, December, 1920. Didelphis virginiana virginiana, Jones and Webb, Jour. Mamm., 30:313, August 17, 1949. D[idelphis]. mfarsupialis]. virginiana, Jones, Trans. Kansas Acad. Sci., 60:274, October 22, 1957. Distribution in Nebraska. — Common in eastern part of state, west certainly to Box Butte County. See Fig. 5. Measurements. — External measurements of a male and two females from 2 mi. NE Ashland are, respectively: 748, 704, 693; 310, 293, 290; 69, 65, 62; 55, 51, 47. Corresponding respective measurements of a male and female from Lancaster County are: 727, 676; 317, 294; 68, 63; 46, 47. A male from Gage County weighed 4 lbs. 9 oz., a female from Keith County, 3/2 lbs. Hamilton (1958:6) recorded the heaviest male and female examined from New York as weighing 11 lbs. 2 oz., and 7 lbs. 4 oz., respectively. Cranial measurements of two males and three females from Butler and Lancaster counties are, respectively: condylobasal length, 119.9, 118.0, 115.2, 111.3, 108.5; zygomatic breadth, 67.8, 66.6, 64.5, 60.1, 59.4; interorbital breadth, 26.1, 24.1, 24.2, 21.0, 21.5; postorbital breadth, 11.5, 10.9, 12.4, 11.1, 11.4; length of nasals, 55.4, 56.7, 53.4, 50.9, 52.2; palatal length, 71.5, 69.4, 69.5, 68.3, 65.7; length of P1-M4, 39.1, 37.8, 39.0, 38.5, 38.0. Records of occurrence. — Specimens examined, 131, as follows: Adams County: Hastings, 2 (1 HM); 5 mi. S Hastings, 4 (HM). Box Butte County: Alliance, 1 (CSTC). Brown County: Long Pine Creek, 1 (AMNH). Butler County: 3 mi. S Bellwood, 1; 4 mi. S, 4 mi. W David City, 1; 4 mi. E Rising City, 2. Cherry County: W of Crookston, 1 (NSM). Clay County: Inland, 7 (HM). Cuming County: Beemer, 1 (USNM). Douglas County: Omaha, 1 (NSM); Ralston, 1 (RV). Fillmore County: Exeter, 1 (MVZ). Franklin County: no specific locality, 1 (NSM). Frontier County: 15 mi. SE Stockville, 1 (NSM). Furnas County: Cam- brige, 1 (NSM); Republican River, 1 mi. E Cambridge, 2 (NSM). Gage County: 2 mi. W Clatonia, 1 (NSM); 1 mi. S, 1 mi. W Bamston, 1; 2 mi. S, 1/2 mi. E Barnston, 3. Hamilton County: no specific locality, 1 (HM). Hayes County: 4 mi. E Wauneta, 1 (NSM). Jefferson County: Fair- bury, 1 (NSM). Johnson County: 6 mi. ENE Cook, 1 (NSM); Cook, 4 (NSM); vicinity Cook, 2 (NSM); Sterling, 3 (NSM); 4 mi. ENE St. Mary, 1 (NSM); St. Mary, 1 (NSM); 6 mi. E Tecumseh, 1 (NSM); no specific locality, 13 (NSM). Keith County: Paxton, 1 (NSM). Lancaster County: 1 mi. E Waverly, 1 (NSM); Malcolm, 1 (NSM); Lincoln, 15 (1 NGFPC, 4 NSM, 7 UC, 3 UNDZ); vicinity Lincoln, 1 (NSM); 3 mi. W Lincoln, 1 (NSM); 3 mi. E Lincoln, 1 (UC); 1 mi. S Lincoln, 1 (UC); 3% mi. S, 2 ml E Lincoln, 1 (UC); 6 mi. S Lincoln, 1 (UC); 4 mi. NNE Bennet, 2 (NSM); no specific locality, 1 (UNDZ). Madison County: Elkhom River, 2 mi. E Norfolk, 1. Otoe County: 2 mi. S Syracuse, 1 (NSM). Richardson County: 4 mi. E Barada, 15; 2 mi. S, 4 mi. E Rulo, 1. Rock County: Skull Creek, 30 mi. S Bassett, 3 (AMNH); Johnson Ranch, Skull Creek, 2 (AMNH). Sarpy County: 2 mi. N Gretna, 1 (NSM). Saunders County: 5 mi. S Fremont, 1 (NGFPC); 2 mi. NE Ashland, 4 (NSM); 2 mi. W Ashland, 1 (NSM); Platte River, near Ashland, 5 (NSM). Seward County: 5 mi. W Seward, 1 (UMMZ); 3 mi. S, 2 mi. E Seward, 1 (UNDZ). Stanton County: 7 mi. E Norfolk, 1; 1 mi. S, 7 mi. E Norfolk, 1. Washington County: }i mi. N Blair, 1 (UC). Werster County: Bladen, 1 (AMNH). 62 University of Kansas Publs., Mus. Nat. Hist. Additional records (Swenk, MS, unless otherwise noted): Antelope County: Neligh. Cedar County: no specific locality (Cary, MS). Dodge County: Fremont. Dundy County: Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks (Jones, field notes). Gage County: Beatrice (Cary, MS). Lincoln County: Birdwood Creek; 2 mi. E North Platte; Maxwell; Medicine Creek, southern part of county. Madison County: Norfolk (Swenk, 1908:70); Battle Creek. Otoe County: Nebraska City (Cary, MS). Phelps County: Funk. Richardson County: Falls City (Cary, MS); vicinity Rulo (Jones and Webb, 1949:317). Stanton County: Pilger (Cary, MS). Thomas County: no specific locality (Smith, 1958:59). Washington County: Fontanelle; Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun] (James, 1823: 369). Fichter's (1944:18) map that records opossums taken in the 1942 trapping season has been taken into account in preparing Fig. 5. Order INSECTIVORA— Insectivores Four genera of insectivores, each represented by a single species, occur in Nebraska. One additional genus (Microsorex) and at least one additional species of Sorex may be found to occur in the state. McDowell ( 1958 ) would apply the ordinal name Lipotyphla to the Recent families of insectivores. Key to Nebraskan Insectivores 1. Total length usually more than 140; forefeet modified for digging; zygomatic arch present; condylobasal length more than 30 (family Talpidae) Scalopus aqualicus p. 73 1'. Total length usually less than 140; forefeet not modified for digging; zygomatic arch absent; condylobasal length less than 26 (family Sori- cidae) 2 2(1'). Tail long, more than 30 per cent of total length. . . .Sorex cinereus p. 62 2'. Tail short, less than 25 per cent of total length 3 3(2'). Total length more than 100; condylobasal length more than 20; usually 32 teeth (usually five unicuspids on either side of upper jaw) Blarina brevicauda p. 65 3'. Total length less than 100; condylobasal length less than 17; 30 teeth (four unicuspids on either side of upper jaw) Cryptotis parva p. 70 Family Soricidae — Shrews Sorex cinereus Masked Shrew The masked shrew is locally common, most frequently in marshy areas and lush riparian associations, in the northern part of the state south to the Platte River drainage. I know of only one record — a specimen obtained 5 mi. E Rising City on May 31, 1956 — from south of the Platte River drainage and this from but a few miles south of the divide between the drainages of the Platte and Blue rivers. No specimens are presently available from the vicinity of the Platte River proper in extreme eastern Nebraska nor from the South Platte River and Lodgepole Creek in the southern part of the Panhandle and possibly the species does not occur in these areas. Similarity, no specimens are available from the Pine Ridge Mammals of Nebraska 63 Mowwm of Natural History University of Kansas 1952 I _!05_ ^100 97 Fig. 6. Distribution of Sorex cinereus haydeni in Nebraska. For explanation of symbols see Fig. 5. area of extreme northwestern Nebraska, but I would guess that the masked shrew occurs there. In the eastern part of its range in Nebraska Sorex cinereus is often associated with Blarina brevicauda. I know of no instance, however, in which masked shrews have been taken in the state with Cryptotis parva, although the two species are sympatric over a large area. Perhaps competition between these two small shrews tends eventually to exclude one from places inhabited by the other. How- ver, Cryptotis is more an animal of upland habitats than Sorex and additional collecting may show that the two kinds live in the same areas but in different ecological niches. From C. parva, S. cinereus can be distinguished easily by longer tail, blackish or dark brown upper parts (rather than pale brown or olive brown) in summer pelage, and 32 (5 unicuspids on each side above) rather than 30 teeth. Van den Brink (1953) argued a Holartic distribution for the masked shrew and relegated Sorex cinereus to synonymy under the previously named Sorex caecutiens. He, therefore, employed the name-combination Sorex caecutiens haydeni (p. 104) for the sub- species that occurs in Nebraska. I have not had the opportunity to review critically Van den Brink's findings and consequently here retain the specific name cinereus following Hall and Kelson (1959:27). A female from Thomas County taken on July 9, 1957, was lac- tating. Asdell (1946:67) recorded the number of young as 4-10. 64 University of Kansas Publs., Mus. Nat. Hist. Sorex cinereus haydeni Baird Sorex haydeni Baird, Mammals, in Beports of explorations and surveys . . . from the Mississippi Biver to the Pacific Ocean . . .,8(1): 29, July 14, 1858 (type locality restricted to Ft. Union, just west of con- fluence of Missouri and Yellowstone rivers, Williams Co., North Dakota, by Merriam, N. Amer. Fauna, 10:60, December 31, 1895). Sorex cinereus haydeni, Jackson, Jour. Mamm., 6:56, February 9, 1925; Jackson, N. Amer. Fauna, 51:51, July 24, 1928; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 7:481, April 21, 1954; Hall and Kelson, The mammals of North America, p. 27, March 31, 1959. S[orex]. Haydeni, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880 (part). S[orex]. Cooperi, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880 (part). Sorex personatus haydeni, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 8:257, November, 1896; Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:29, October, 1936. Sorex personatus, Swenk, Proc. Nebraska Acad. Sci., 8:133, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:77, September, 1908. Sorex pfersonatus]. haydeni, Imler, Jour. Wildlife Mgt., 9:272, October, 1945. Sorex cinereus, Jones, Nebraska Bird Bev., 20:11, January, 1952. S[orexJ. cfinereus]. haydeni, Jones, Trans. Kansas Acad. Sci., 60:274, Octo- ber 22, 1957. Distribution in Nebraska. — Northern part of state, south to Platte Biver drainage; known south of Platte drainage only from one locality in Butler County. See Fig. 6. External measurements. — Measurements of a male and three females, all second year animals, from 12 mi. NNW Springview are, respectively: 94, 95, 96, 97; 35, 34, 35, 34; 13, 11, 12, 12; 6, 7, 7, 7. Average and extreme meas- urements of six young of the year (two males, four females) from Holt and Thomas counties are: 93.0 (88-97); 37.0 (36-38); 11.7 (11-12). For cranial measurements see Table 3. A male and two females from 1 mi. W Halsey weighed 3.8, 4.7, and 3.4 grams, respectively. Remarks. — Nebraskan specimens vary considerably individually in cranial dimensions. In external measurements, however, and especially in color they are fairly uniform when specimens of equal age are compared. Fresh winter pelage (seen in specimens taken in November and December ) is pale grayish brown dorsally. Sum- mer pelage of first year animals is more or less uniformly dark brown dorsally, whereas summer pelage of second year shrews is blackish brown middorsally, brownish on the sides and whitish below, imparting an over-all tricolored appearance. Aughey (1880:122) listed four shrews of the genus Sorex as oc- curring in Nebraska ("Sorex pachyurus, S. richa[rdsonii], S. Mammals of Nebraska. 65 Cooperi, S. Haydeni"). Almost certainly this resulted from guess- work; probably he projected the known ranges of the recognized "species" of the day. The last two of these names are included in the synonymy above ( Sorex cooperi Bachman is currently regarded as a synonym of Sorex cinereus cinereus). The first two names, pachyurus and richardsonii, fall in the synonymy of the species S. arcticus, which does not occur in Nebraska. Records of occurrence. — Specimens examined, 92, as follows: Butler County: 4 mi. N, Vt mi. E Octavia, 2; 5 mi. E Rising City, 1. Cherry County: Ft. Niobrara Nat'l Wildlife Refuge, 1 (NSM); 3 mi. SSE Valentine, 2; Niobrara River, 10 mi. S Cody, 1 (USNM); Two Mile Lake (sec. 12, R. 34 W, T. 31 N), 3 (2 NSM, 1 USNM); Watt's Lake, Valentine Nat'l Wildlife Refuge, 2; Hackberry Lake, Valentine Nat'l Wildlife Refuge, 2 (1 UMMZ); Dewey Lake, Valentine Nat'l Wildlife Refuge, 6; Kennedy, 1 (USNM); Pony Lake, Valen- tine Nat'l Wildlife Refuge, 1 (CNHM); Wendler's Pond, 30 mi. S Wood Lake, 9 (CNHM). Dawson County: M mi. S Gothenburg, 2. Dawes County: 20 mi. S Chadron, 1 (CSTC). Garden County: Crescent Lake Nat'l Wild- life Refuge, 1 (USNM); K mi. S Oshkosh, 2. Holt County: 1 mi. S Atkin- son, 3. Kearney County: 1%, mi. S Kearney, 1. Keya Paha County: 12 mi. NNW Springview, 4. Lancaster County: no specific locality, 1 (UNDZ). Lincoln County: 2 mi. N, 5 mi. W North Platte, 2720 ft., 1; 2 mi. N North Platte, 9. Logan County: 1 mi. NE Stapleton, 15. Platte County: Colum- bus, 1 (UNDZ). Rock County: Bassett, 4 (AMNH); Perch, 9 (AMNH). Sioux County: Agate, 4600 ft., 1. Thomas County: 1 mi. W Halsey, 3; Dismal River, 1 mi. W Thomas-Blaine Co. line, 1 (NGFPC). Valley County: 2M mi. N Ord, 2. Additional record: Cherry County: Center Lake, Valentine Nat'l Wildlife Refuge (Jones, 1952:11). Blarina brevicauda Short-tailed Shrew The short-tailed shrew occurs in a variety of habitats in eastern Nebraska and is one of the commonest small mammals in some places. In the western part of its range in the state this shrew tends to be restricted in occurrence to riparian communities, although it frequently is no less abundant therein than in similar habitats farther eastward. The known western limit of range of the species in the central Great Plains is along the Republican River just west of the Nebraska-Colorado border in Yuma County, Colorado. Two subspecies, B. b. brevicauda and the smaller B. b. caro- linensis, occur in Nebraska. The narrow zone of secondary inte- gradation between these two races and its probable origin are discussed on pp. 28-30. At the latitude of Nebraska, short-tailed shrews may breed twice yearly, once in spring and once in late summer. Each of two females taken 3 mi. SE Blair on April 24, 1958, contained 4 em- bryos. Of two pregnant females collected )i mi. W Homestead Na- 5—6532 66 University of Kansas Publs.., Mus. Nat. Hist. -az 40- Scale id o w taMIItt ' ■ I I I :» WW Muwurn of Natural H!>tory University of Knnsas 1952 Fig. 7. Distribution of Blarina brevicauda in Nebraska. 1. B. fo. brevicauda. 2. B. fc. carolinensis. For explanation of symbols see Fig. 5. tional Monument on May 8, 1959, one contained 6 embryos and the other 7. A female still in juvenal pelage, therefore a young of the year, obtained on May 1, 1958, 1 mi. S Beemer, contained 5 embryos. Lactating females have been taken in May (Gage County), July (Cedar County and Wayne County), and August (Dundy County). Blarina brevicauda brevicauda (Say) Sorex brevicaudus Say, in James, Account of an expedition from Pittsburgh to the Rocky Mountains . . .,1:164, 1823 (type locality, Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun, Washington Co.], Nebraska ) . Blarina brevicauda, Baird, Mammals, in Reports of explorations and surveys . . . from the Mississippi River to the Pacific Ocean . ., 8(1):42, July 14, 1858; Merriam, N. Amer. Fauna, 10:10, December 31, 1895; J. A. Allen, Bull. Amer. Mus. Nat. Hist., 8:257, November, 1896; Swenk, Proc. Nebraska Acad. Sci., 8:134, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:78, September, 1908. B[larina]. talpoides, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880 (part). B[larina], brevicauda, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880 (part). Blarina brevicauda brevicauda, Swenk, Nebraska Blue Book, p. 854, 1915 (part); Swenk, Nebraska Blue Book, p. 411, December, 1918 (part); Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:20, March 1, 1919 (part); Swenk, Nebraska Blue Book, p. 483, December, 1920 (part); Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:24, October, 1936; Whelan, Trans. Kansas Acad. Sci., 39:365, 1937; Bole and Moulthrop, Sci. Publ., Cleveland Mus. Nat. Hist., 5:103, September 11, 1942; Jones and Findley, Trans. Kansas Acad. Sci., 57:210, August 2, 1954; Findley Mammals of Nebraska 67 and Van Gelder, Jour. Mamm., 36:452, August 30, 1955; Hall and Kel- son, The mammals of North America, p. 52, March 31, 1959 (part); Jones and Glass, Southwestern Nat., 5:139, November 1, 1960. B[larina]. b[revicauda]. brevicauda, Jones, Univ. Kansas Publ., Mus. Nat. Hist., 7:482, April 21, 1954; Jones, Trans. Kansas Acad. Sci., 60:274, October 22, 1957. Distribution in Nebraska. — Northern and central parts of state, west cer- tainly to Cherry and Dawson counties, south certainly to Clay and Saline counties. See Fig. 7. External measurements. — Average and extreme measurements of 18 speci- mens (11 males, seven females) from the vicinity of Blair are: 132.4 ( 125-141 ) ; 26.4 ( 23-31 ) ; 17.0 ( 16-18 ) . For cranial measurements see Table 3. A male and two females from Lincoln weighed 29.5, 23.7, and 23.4 grams, respectively. Remarks. — From Blarina brevicauda carolinensis, geographically- adjacent to the south in Nebraska, B. b. brevicauda (the largest subspecies of the species) differs in being significantly larger ex- ternally and especially cranially (see measurements). The two subspecies do not differ in color. I have seen no specimens from Nebraska that can be described as exactly intermediate between brevicauda and carolinensis. Speci- mens here referred to brevicauda from Louisville and some of those from the vicinity of Lincoln are smaller externally and average slightly smaller cranially than topotypes of that subspecies and therefore approach carolinensis. Similarly, specimens here assigned to carolinensis from % mi. W Homestead National Monument and from the vicinity of DeWitt, in Gage and Saline counties, average slightly larger externally and cranially than other specimens of that subspecies from Nebraska. Two specimens from Crete that lack skulls have small external dimensions, but are referred to brevicauda because four specimens from 4 mi. NE Crete that do have skulls are typical of that subspecies. Cary (1902:69), in a paper entitled "Some general remarks upon the distribution of life in northwest Nebraska," recorded "Blarina sp." in a list of mammals restricted to the Transition Life-zone in Sioux County. Subsequently, Swenk (1908:134) listed Blarina brevicauda as occurring in Sioux County, presumably on the basis of Cary's report. Inasmuch as Cary's paper was submitted to an ornithological journal, an annotated list of mammals in his original manuscript was not published. This annotated list is preserved, however, in Swenk's collection of unpublished notes on Nebraskan mammals (Swenk, MS), and inspection reveals that the report of Blarina was not based on actual specimens but on "signs." What- ever these "signs" may have denoted, I am reasonably sure it was 68 University of Kansas Publs., Mus. Nat. Hist. not Blarina for insofar as I know the species occurs nowhere in northwestern Nebraska. Jones and Findley (1954:210) recorded B. b. brevicauda from Crescent Lake National Wildlife Refuge, Garden County, citing Imler (1945:272) as the source of the record. Subsequently, I (1957:274) mentioned Garden County as the west- ernmost record for the species in state. Perusal of Imler 's paper in connection with the present report fails to reveal mention of the species on p. 272 or anywhere else therein! Actually, the western limit of distribution of the species in the state is in Cherry, Lincoln and Dundy counties, and shrews from the last two counties are referable to B. b. carolinensis. The type locality of B. b. brevicauda (and incidently also of Cryptotis parva parva, Canis latrans latrans, and Canis lupus nu- bilus), the Engineer Cantonment where Major S. H. Long and his command, including the naturalist Thomas Say, spent the winter of 1819-1820, has been located as various places along the Missouri River by different authors (see discussion in Jackson, 1951:260-261). James (1823:146), botanist, geologist, and surgeon for the expedi- tion, and its official chronicler, entered the following concerning this locality: "The position selected for the establishment of winter quarters for the exploring party, was on the west bank of the Mis- souri [Riverl, about half a mile above Fort Lisa, five miles below Council Bluff [of Lewis and Clark, not the city of Council Bluffs, Iowa], and three miles above the mouth of Boyer's river. At this place we anchored on the 19th September 1819. . . ." This would locate the Engineer Cantonment in Washington County, Nebraska, about five miles north of the Douglas-Washington county line at a place approximately two miles east of the present village of Ft. Calhoun. Records of occurrence. — Specimens examined, 174, as follows: Antelope County: Neligh, 7 (6 NSM, 1 USNM). Boyd County: 5 mi. NNW Spencer, 1; 5 mi. S, 2 mi. E Spencer, 2. Buffalo County: Kearney, 2 (USNM). Burt County: 1 mi. E Tekamah, 2. Butler County: 4 mi. E Rising City, 2; 5 mi. E Rising City, 4. Cass County: Louisville, 5. Cedar County: 4 mi. SE Laurel, 7. Cherry County: Valentine, 3 (USNM); 4 mi. E Valen- tine, 1; 3 mi. SSE Valentine, 1; 3 mi. S Valentine, 1. Clay County: Saron- ville, 1 (UF). Cuming County: 1 mi. S Beemer, 1. Dawson County: 5 mi. S Gothenburg, 1. Douglas County: North Omaha, 1 (NSM). Hall County: 6 mi. S Grand Island, 3. Holt County: 6 mi. N Midway, 1; 1 mi. S Atkinson, 2 ( 1 NSM). Keya Paha County: 12 mi. NNW Springview, 1. Knox County: 3 mi. W Niobrara, 2; 1 mi. SE Niobrara, 1. Lancaster County: 12 mi. N Lincoln, 1 (UC); T. 10 N, R. 5 E, S of Malcolm, 1 (NSM); within 5 mi. Lincoln, 42 (1 HM, 1 NGFPC, 7 NSM, 23 UC, 5 UNDZ); 6 mi. S Lincoln, 4 (UC); % mi. W Jamaica Jet., 1 (UC); no specific locality, 1 (UNDZ). Platte County: 2 mi. N Columbus, 1 (UNDZ); 2 mi. NE Columbus, 1 (UNDZ); Columbus, 3 (USNM); 3% mi. E Columbus, 1 (UNDZ). Polk County: 15 mi. W Osceola, 2. Rock County: Perch, 4 (AMNH). Saline County: 4 mi. NE Crete, 4; Crete, 2 (WFR). Sarpy Mammals of Nebraska 69 County: Ft. Crook, 1 (AMNH); 1 mi. W Meadow, 3. Saunders County: 2 mi. NE Ashland, 4. Seward County: 1 mi. N Pleasant Dale, 4. Stanton County: 4M mi. SSE Norfolk ("on county line"), 1. Thurston County: 1 mi. S Winnebago, 3. Valley County: 2& mi. N Ord, 2. Washington County: Blair, 9 (8 UMMZ, 1 USNM); 1 mi. E Blair, 2; 3 mi. SE Blair, 2; 6 mi. SE Blair, 8. Wayne County: £ mi. W Wayne, 4; Wayne, 10. County unknown: Little Blue River, 1 (USNM). Additional records: CuMrNG County: West Point (Swenk, 1908:134). Douglas County: Omaha (Swenk, 1908:134). Lancaster County: 9 mi. NW Lincoln (Whelan, 1937:365). Seward County: Milford (Swenk, MS). Washington County: Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun], the type locality. Wayne County: 4 mi. SE Carroll (Tones, 19496:5). Blarina brevicauda carolinensis (Bachman) Sorex carolinensis Bachman, Jour. Acad. Nat. Sci. Philadelphia, 7:866, 1837 ( type locality, eastern South Carolina ) . Blarina brevicauda carolinensis, Merriam, N. Amer. Fauna, 10:13, December 31, 1895; Jones, Univ. Kansas Publ., Mus. Nat. Hist, 7:481, April 21, 1954; Jones and Findley, Trans. Kansas Acad. Sci., 57:210, August 2, 1954; Jones, Univ. Kansas Publ., Mus. Nat. Hist, 9:388, May 12, 1958; Hall and Kelson, The mammals of North America, p. 53, March 31, 1959; Jones, Jour. Mamm., 41:132, February 20, 1960; Jones and Glass, South- western Nat., 5:139, November 1, 1960. Blarina brevicauda brevicauda, Swenk, Nebraska Blue Book, p. 854, 1915 (part); Swenk, Nebraska Blue Book, p. 411, December, 1918 (part); Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:20, March 1, 1919 (part); Swenk, Nebraska Blue Book, p. 483, December, 1920 (part); Jones and Webb, Jour. Mamm., 30:313, August 17, 1949; Hall and Kelson, The mammals of North America, p. 53, March 31, 1959 (part). B[larina]. b[revicauda] . carolinensis, Jones, Trans. Kansas Acad. Sci., 60:274, October 22, 1957. Distribution in Nebraska. — Southern part of state, north along Missouri River certainly to Otoe County, north in western part of range to Platte River drainage in Lincoln County. See Fig. 7. External measurements. — Average and extreme measurements of 20 speci- mens (seven males, 12 females, one of unknown sex) from Richardson County are: 112.3 (103-121); 22.6 (19-25); 14.4 (13-16). Corresponding measure- ments of 20 specimens (11 males, nine females ) from 5 mi. N, 2 mi. W Parks are: 111.1 (106-117); 24.2 (22-27); 14.6 (13-16). For cranial measurements see Table 3. Average (and extremes) weight in grams of seven specimens (two males, five females) from the Richardson County series was 14.6 (13.4-15.5), and that of eight specimens (four males, four females) from the series from 5 mi. N, 2 mi. W Parks was 15.0 ( 13.7-16.3). Remarks. — For comparisons with Blarina brevicauda brevicauda, geographically adjacent to the north in Nebraska, see account of that subspecies. The genus Blarina is in need of taxonomic revision. When such a revision is undertaken it may be found, as Bryan P. Glass and I pointed out (Jones and Glass, 1960:140), that the subspecific name carolinensis should be restricted to the uniformly dark, small popu- lations of the species along the southern Atlantic and Gulf coasts. In that event, the name Blarina brevicauda hulophaga Elliot, 1899 (type locality, east of Dougherty, Murray Co., Oklahoma), would 70 University of Kansas Publs., Mus. Nat. Hist. be available for shrews from along the western edge of the range of the species from Oklahoma to southern Nebraska. The external and cranial measurements of Nebraskan carolinensis do not differ appreciably from those of shrews from Dorchester, Maryland, as- signed to carolinensis by Bole and Moulthrop (1942:108), nor, for that matter, from the measurements of the type specimen of Blarina brevicauda kirtlandi Bole and Moulthrop (op. cit.: 100), a sub- species characterized by its describers as constituting ". . . the central stock of the species, being intermediate in its characters and geographical distribution" ( p. 101 ) . Except for the previously mentioned specimens from )i mi. W Homestead National Monument and those from the vicinity of DeWitt in Gage and Saline counties, all the shrews from Nebraska here assigned to carolinensis are fairly uniform in external and cranial dimensions. No appreciable differences in color were noted in any of the specimens examined. Records of occurrence. — Specimens examined, 123, as follows: Dundy County: Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 44 (1 NGFPC). Furnas County: 5 mi. W Holbrook, 1 (UI). Gage County: 1 mi. SE DeWitt, 1; Y\ mi. W Homestead Nat'l Monument, 11; 1 mi. S, 1 mi. W Bamston, 1; PA mi. S, 2 mi. E Barnston, 2; 2 mi. S, & mi. E Barnston, 3. Harlan County: 1 mi. W Alma, 2; 1 mi. S Alma, 1. Hitchcock County: Republican River, Trenton, 5. Jefferson County: 7 mi. S, 2 mi. W Fairbury, 1. Johnson County: 1 mi. S, VA mi. E Burr, 1. Lincoln County: 2 mi. N, 5 mi. W North Platte, 2720 ft., 1; 2 mi. N North Platte, 5; Conroy Canyon, SW corner sec. 4, T. 11 N, R. 27 W (5 mi. S, 215 mi. W Brady), 1 (NSM). Nemaha County: Peru, 1 (NSM); 3 mi. S, VA mi. E Peru, 1. Nuckolls County: 2 mi. WSW Superior, 1; 1 mi. SSW Hardy, 1. Otoe County: 1 mi. SE Ne- braska City, 2; 3 mi. S, 2 mi. E Nebraska City, 5. Pawnee County: 4 mi. S, 8 mi. W Pawnee City, 1. Red Willow County: McCook, 1 (NSM). Rich- ardson County: 5 mi. N, 2 mi. W Humboldt, 2; 4 mi. E Barada, 5; 2 mi. N Falls City, 5; 6 mi. W Falls City, 2; 3& mi. S, 1 mi. W Dawson, 9; 8 mi. S, 1 mi. E Dawson, 2; XA mi. S, VA mi. W Rulo, 2; 2 mi. S, 4 mi. E Rulo, 1. Saline County: 1% mi. W DeWitt, 2. Additional record: Red Willow County: 9 mi. NE Bartley (Jones, 1949fc:5). Cryptotis parva Least Shrew The distribution of the least shrew is more extensive in southern Nebraska than in the northern part of the state. The species occurs all the way to the Colorado boundary along the Platte and Re- publican river systems, reaching the westernmost extent of its range in northeastern Colorado. In northern Nebraska the westernmost record is in Cherry County along Minichaduza Creek, a tributary of the Niobrara River. The range of Cryptotis parva in Nebraska is sympatric to a large degree with that of the short-tailed shrew, Blarina brevicauda. Cryptotis can be distinguished from Blarina Mammals of Nebraska 71 by the differences mentioned in the key and also by brownish (rather than grayish black) upper parts, paler venter, and in that the unicuspids gradually decrease in size posteriorly (the first two are large and the last two small in Blarina). Fig. 8. Distribution of Cryptotis parva parva in Nebraska. For explanation of symbols see Fig. 5. I have rarely found this diminutive shrew to be common in the state and have never taken more than one in the same trap line. Perhaps more would be captured if small, especially baited traps were used regularly in field work. A number have been taken in the vicinity of Lincoln in pitfalls made primarily for terrestrial arthropods. Also, I remember several times, especially in the summer of 1943, when many were found in window wells of houses on the southeastern edge of Lincoln. Asdell (1946:67) recorded the number of young as from 3-6; the species is polyestrous. Cryptotis parva parva (Say) Sorex parvus Say, in James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:163, 1823 (type locality, Engineer Canton- ment [= approximately 2 mi. E Ft. Calhoun, Washington Co.], Ne- braska). Cryptotis parva, Miller, Bull. U. S. Nat. Mus., 79:24, December 31, 1912; Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:21, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Whelan, Trans. Kansas Acad. Sci., 39:365, 1937. 72 University of Kansas Publs., Mus. Nat. Hist. B[larina], exilpes, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880. Blarina parva, Merriam, N. Amer. Fauna, 10:17, December 31, 1895; Swenk, Proc. Nebraska Acad. Sci., 8:134, September, 1908; Swenk, Univ. Ne- braska Studies, 89:78, September, 1908. Cryptotis parva parva, Bole and Moulthrop, Sci. Publ., Cleveland Mus. Nat. Hist., 5:99, September 11, 1942; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 9:388, May 12, 1958; Hall and Kelson, The mammals of North America, p. 58, March 31, 1959. C[ryptotis]. p[arva]. parva, Jones, Trans. Kansas Acad. Sci., 60:274, October 22, 1957. Table 3. — Cranial Measurements of Three Species of SoRicros. Number of specimens 13 03 jz 43 %x\ 03 £ averaged or catalogue J2A •n b^ 3^ ngth oi maxill tooth- number, and sex 1-° a o O § 1— ( Sorex cinereus haydeni, 12 mi. NNW Springview, Keya Paha County 77893 KU, 9 77894 KU, 9 77895 KU, 9 77896 KU, dV 15.5 7.6 4.4 2.9 15.7 7.7 4.4 2.8 15.8 7.6 4.4 2.9 15.8 7.6 4.4 2.8 1 mi. S Atkinson, Holt County 79247 KU, 9 79248 KU, 9 79249 KU, d1 15.5 7.7 4.2 2.8 15.8 7.6 4.2 2.8 15.7 7.7 4.2 2.7 Blarina brevicauda brevicauda, vicinity type locality Average 18 (11 cf, 7 9) Minimum Maximum 24.0 13.5 8.7 6.3 22.8 12.8 8.2 5.9 24.9 14.0 9.1 6.5 Blarina brevicauda carolinensis, Richardson County Average 20 (7c?, 12 9, 1?) . Minimum Maximum 21.1 11.5 7.610 5.7 20.1 11.0 7.3 5.3 21.9 12.2 7.9 5.9 5 mi. N, 2 mi. W Parks, Dundy County Average 20 Minimum. . Maximum . (llcf, 99). 21.2 11.6 7.8 5.7 20.7 11.3 7.5 5.5 21.9 12.2 8.1 6.0 vicinity North Platte, Lincoln County Average 5 (2d1, 2 9, 1?) Minimum Maximum 21.1 11.9 7.9 5.7 20.9 11.8 7.7 5.6 21.3 12.0 8.1 5.9 Cryptotis parva parva, Blair, Washington County 5.3 5.7 5.7 5.7 5.6 5.8 5.8 9.3 8.9 9.7 8.219 8.0 8.6 8.3 7.8 8.8 8.2 8.0 8.5 Average 5 (3 d1, 2 9 ) 15.4 14.9 15.7 7.7 7.6 7.9 5.1 4.9 5.2 3.6 3.5 3.8 5.7 Minimum 5.4 5.9 Mammals of Nebraska 73 Distribution in Nebraska. — Throughout southern part of state, west in northern part of state certainly to Cherry County. See Fig. 8. External measurements. — Average and extreme measurements of 11 speci- mens (eight males, three females) from Blair are: 79.1 (73-86); 16.4 (15-18); 10.5 ( 10-11 ). For cranial measurements see Table 3. Hamilton (1944:2) recorded the weight of adults from New York and Virginia as varying from 4.4-5.7 grams. Two females from Omaha weighed 4.1 and 4.75 grams. Records of occurrence. — Specimens examined, 45, as follows: Cherry County: W of Crookston, 1 (NSM). Douglas County: Omaha, 2; South Omaha, 1 (HM). Dundy County: 5 mi. N, 2 mi. W Parks, 1; 2 mi. SW Benkelman, 1; Haigler, 1 (USNM). Gage County: 1 mi. S, 1 mi. W Barn- ston, 1. Keith County: 4 mi. NNW Keystone, 1. Lancaster County: 1 mi. N Lincoln, 2 (NSM); Lincoln, 11 (3 AMNH, 2 NSM, 3 UC, 3 UNDZ); College View (Lincoln), 3 (1 CNHM, 2 UNDZ); between College View and Cheney, 1 (UNDZ). Lincoln County: Conroy Canyon (SW corner sec. 4, T. 11 N, R. 27 W), 5 mi. S, 2M mi. W Brady, 1 (NSM). Pawnee County: 4 mi. S, 8 mi. W Pawnee City, 1. Red Willow County: 8 mi. S, 3 mi. E McCook, 1. Sarpy County: Ft. Crook, 2 (AMNH). Washington County: Blair, 11 (USNM). Webster County: Bladen, 1 (HM). Additional records: Antelope County: Neligh (Cary, MS). Lancaster County: 9 mi. NW Lincoln (Whelan, 1937:365). Lincoln County: near North Platte (Swenk, MS). Red Willow County: 9 mi. NE Bartley (Jones, 1949^:5). Washington County: Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun], the type locality. Wayne County: 4 mi. SE Carroll (Jones, 1949fo:5). Family Talpidae — Moles Scalopus aquaticus Eastern Mole The eastern mole occurs throughout Nebraska. In the eastern part of the state the species is found in a variety of habitats and is entirely absent only from the driest places; ordinarily, however, it lives in moist, pliable soils. Marginal habitats seemingly are en- tered only in periods of relatively high rainfall. In the western part of Nebraska the distribution of S. aquaticus is limited primarily to moist soils along river systems, around lakes, in irrigated agricul- tural landu, and in lawns and gardens. There, too, excessive rainfall may lead to temporary dispersal of moles to places that are drier than those ordinarily inhabited. Along Soldier Creek in eastern Sioux County in July and August of 1957, when relatively high precipitation prevailed for the season, T. A. Vaughan and I found foraging tunnels on dry, somewhat sandy hillsides a half mile or more from the moist creek bottom. The known northwestern limit of distribution of the eastern mole is reached just beyond the borders of Nebraska. The species is known from two localities in extreme southeastern South Dakota but is not recorded from elsewhere in that state. It is known from 74 University of Kansas Publs., Mus. Nat. Hist. |03 c ■ 97 -4a 40- Fig. 9. Distribution of Scalopus aquaticus in Nebraska. 1. S. a. caryi. 2. S. a. machrinoides. For explanation of symbols see Fig. 5. only one locality in Wyoming (in the extreme southeastern part) but occurs at several places in northeastern Colorado. A female bears a single litter annually of 2-5 young in spring. A female from Neligh taken on May 3, 1958, contained 3 embryos that measured 27 mm. (crown-rump length). Males average larger than females. Scalopus aquaticus caryi Jackson Scalopus aquaticus caryi Jackson, Proc. Biol. Soc. Washington, 27:20, Feb- ruary 2, 1914 (type locality, Neligh, Antelope Co., Nebraska); Jackson, N. Amer. Fauna, 38:48, September 30, 1915; Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:21, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Beed, Bull. Con- serv. Surv. Div., Univ. Nebraska, 10:24, October, 1936; Poole and Schantz, Bull. U. S. Nat. Mus., 178:200, April 9, 1942; Hall and Kelson, The mammals of North America, p. 74, March 31, 1959. Scallops [sic] Argentatus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880 (part). Scalops argentatus, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 8:257, Novem- ber, 1896. Scalops aquaticus machrinus, True, Proc. U. S. Nat. Mus., 19:20 (specimen mentioned in footnote on p. 27), December 21, 1896 (part); Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902. Scalopus aquaticus machrinus, Swenk, Proc. Nebraska Acad. Sci., 8:135, September, 1908 (part); Swenk, Univ. Nebraska Studies, 89:79, Sep- tember, 1908 (part). Scalopus a[quaticus], caryi, Imler, Jour. Wildlife Mgt, 9:272, October, 1945. Scalopus aquaticus machrinoides, Jackson, N. Amer. Fauna, 38:45, Septem- ber 30, 1915 (part); Hall and Kelson, The mammals of North America, p. 74, March 31, 1959 (part). Mammals of Nebraska 75 S[calopus]. a[quaticus]. caryi, Jones, Trans. Kansas Acad. Sci., 60:274, October 22, 1957. Distribution in Nebraska. — Western two-thirds of state, east certainly to Antelope, Platte, and Clay counties. See Fig. 9. External measurements. — Average and extreme measurements of seven males from the vicinity of Neligh followed by measurements of a female from there are: 167.6 (157-182), 171; 31.7 (31-32.5), 28; 21.7 (20.3-23), 21. Average and extreme measurements of six males and seven females from Sioux County are, respectively: 155.4 (145-166), 150.8 (136-166); 25.8 (19-31), 25.4 (22-28); 21.3 (20-22), 20.2 (19-22). For cranial measurements see Table 4. Weight in grams of five specimens from Sioux County (three males, two females) are, respectively: 80.2, 76.5, 68.4, 54.2, 54.0. Remarks. — For comparison with Scalopus aquations machri- noides, geographically adjacent to the east in Nebraska, see account of that subspecies. The type locality of S. a. caryi (Neligh, Antelope County) is near the eastern limit of the range of the subspecies. All specimens from there possess the pale coloration diagnostic of caryi throughout its range but some individuals approach S. a. machrinoides in cranial and especially external dimensions (see external measurements and Table 4 ) . The small measurements of the holotype and two other males from Neligh listed by Jackson (1915:49) more nearly ap- proach the average of caryi from more westerly localities than do measurements of any of the other specimens that I have seen from the vicinity of Neligh. A specimen from 3 mi. S Columbus (NSM 3067) and one from Inland (HM 1861) are intermediate in coloration between caryi and machrinoides. The former specimen, a male, is larger in cranial dimensions than specimens from western Nebraska (but smaller than most topotypes ) and typical in external measurements of caryi, to which it is here referred. The specimen from Inland is mounted, has the skull inside the skin, and lacks data as to sex and measure- ments. M. H. Swenk (MS) and I independently assessed the color as nearer that of caryi than machrinoides and it is on this basis that I have assigned it to the former. The specimen from Perch (AMNH 11533/9816), assigned by Jackson (loc. cit.) to machrinoides (see also Hall and Kelson, 1959:74), is in my opinion unquestionably caryi. External and cranial measurements are typical of the latter. The color is darker than in caryi but seemingly this results from dust and dirt in the pelage, possibly acquired since the specimen was obtained. Several specimens of caryi from Nebraska have been incorrectly reported previously as concerns locality. The specimen (USNM 116363) recorded from Kennedy by Jackson (loc. cit.) is actually from 18 mi. NW of that place. His record from the "Niobrara 76 University of Kansas Publs., Mus. Nat. Hist. River" (NSM 4069) is from 10 mi. S Cody, Cherry County. Hall and Kelson (1959:73) mapped the latter locality at the mouth of the Niobrara (in Knox County). Records of occurrence. — Specimens examined, 47, as follows: Antelope County: Neligh, 4 (1 NSM, 3 USNM); 1 mi. SW Neligh, 4. Brown County: Long Pine, 1 (Stanford Univ.). Chase County: 2 mi. W Enders, 1. Cherry County: Ft. Niobrara Nat'l Wildlife Refuge, 2 (NSM); Niobrara River, 10 mi. S Cody, 1 (NSM); 18 mi. NW Kennedy, 1 (USNM); 20 mi. S Valentine, 1 (UMMZ); Hackberry Lake, Valentine Nat'l Wildlife Refuge, 1. Clay County: Inland, 1 (HM). Custer County: Victoria Springs, 1 (UMMZ). Dawes County: Chadron, 1 (CSTC); 10 mi. S Chadron, 1 (UMMZ); Crawford, 2 (NSM); 3 mi. W Crawford, 2 (1 NSM). Dundy County: 5 mi. N, 2 mi. W Parks, 4. Frontier County: 15 mi. SE Stockville, 1 (NSM). Platte County: 3 mi. S Columbus, 1 (NSM). Rock County: Perch, 1 (AMNH). Sioux County: Warbonnet Canyon, 3 (NSM); Monroe Canyon, 3 (NSM); 8 mi. N Harrison, 2 (UMMZ); 5% mi. N, 2£ mi. W Harri- son, 1 (NGFPC); 7 mi. W Crawford, 5 (NSM). Thomas County: 4 mi. W Halsey, 1; 1 mi. W Halsey, 1. Additional records: Brown County: Ainsworth (specimen catalogued in CNHM, but not now to be found). Frontier County: Curtis (Swenk, MS). Furnas County: Hendley (Gates, 1945:11). Garden County: Crescent Lake Nat'l Wildlife Refuge (Imler, 1945:272). Holt County: 10 mi. NE Stuart (Jones, field notes). Lincoln County: no specific locality (Fichter, 1941:28). Scotts Bluff County: 7 mi. S Gering (Jones, field notes). Sheridan County: 11 mi. S Gordon (Jones, field notes). County unknown: "Sand Hills" (Jackson, 1915:49). Scalopus aquaticus machrinoides Jackson Scalopus aquaticus machrinoides Jackson, Proc. Biol. Soc. Washington, 27:19, February 2, 1914 (type locality, Manhattan, Riley Co., Kansas); Jackson, N. Amer. Fauna, 38:45, September 30, 1915 (part); Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:21, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Jones and Webb, Jour. Mamm., 30:313, August 17, 1949; Hall and Kelson, The mammals of North America, p. 74, March 31, 1959 (part); Velich, Jour. Mamm., 42:92, February 20, 1961. Scalops aquaticus, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823. Scallops [sic] Argentatus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880 (part). Scalops aquaticus machrinus, True, Proc. U. S. Nat. Mus., 19:20 (specimens mentioned on p. 29), December 21, 1896 (part). Scalopus aquaticus machrinus, Swenk, Proc. Nebraska Acad. Sci., 8:135, September, 1908 (part); Swenk, Univ. Nebraska Studies, 89:79, Sep- tember, 1908 (part). S[calopus], a[quaticus]. machrinoides, Jones, Trans. Kansas Acad. Sci., 60:274, October 22, 1957. Distribution in Nebraska. — Eastern third of state, west certainly to Wayne and Fillmore counties. See Fig. 9. External measurements. — Average and extreme measurements of eight males and four females from Lincoln are, respectively: 177.7 (174-185), 171.3 (163-187); 33.6 (28.5-38), 33.5 (32-34); 22.5 (21-24), 21.5 (19-25). For cranial measurements see Table 4. A female from Lincoln weighed 99.2 grams. Mammals of Nebraska 77 Remarks. — From Scalopus aquaticus caryi, geographically ad- jacent to the west in Nebraska, S. a. machrinoides differs in being conspicuously larger externally and cranially (see measurements) and in having darker (brownish rather than silvery gray) pelage both dorsally and ventrally. All the specimens here referred to machrinoides can be clearly so assigned by virtue of large external and cranial size and relatively dark coloration with the exception of the specimen from Angus (AMNH 121617), which is an intergrade with caryi. Jackson (1915:46) remarked that "specimens from Lincoln, Nebr., [are] smaller and paler than typical machrinoides." Specimens from Table 4. — Cranial Measurements of Two Subspecies of Scalopus aquaticus. A bt) 03 03 a o 3 Number of specimens a CO -^ CO 03 Tt "3 CO 03 "3-2 tc a a CD CO 45 averaged or catalogue Greatest of sku .15 B jo u c o o -^ o m O P-, 13 PL, ■3-ii fpPn > 53 J3 ft 0) Q Scalopus aquaticus caryi, vicinity type locality 77938 KU, & 77939 KU, > is Number of specimens averaged or catalogue is* m O -P .S3 "o3 J3 3 "3 on O o of illar h-ro of dibi h-ro number, and sex $ CO c<3 o ndyl leng a g On TJ s-c c3.Q CD ngth max toot ngth man toot t-> o >> Eh 0) CD o O CSJ 1— ( PQ J 1-3 Myotis evotis evotis, 15 mi. S, 21 mi. W Cody, Wyoming 37311 KU, c? | 15.6 | 14.7 | 9.3 | 3.6 | 7.9 | 6.1 Myotis keenii septentrionalis, J^-l mi. W Meadow, Sarpy County Average 10 (5c1, 5 9). . Minimum Maximum 15.3 14.1 9.2 3.7 8.0 5.9 14.7 13.6 8.6 3.4 7.6 5.6 15.6 14.5 9.6 3.8 8.4 6.1 Myotis lucifugus carissima, 3 mi. W Crawford, Dawes County Average 10 (1>* •?" Number of specimens O m o3 o£ "cl-d 1/3 is ° _-^« averaged or catalogue -^ 3 S £ o J5 3 "2 O o number, and sex O ndyl leng si °3 03 -Q ngth max toot ngth man toot It o >> CD 0) o O CS3 « J J Lasionycteris noclivagans, Lincoln, Lancaster County 175428 AMNH, cT | 15.8 | 15.3 | .... | 4.3 | 8.6 | 5.8 | 7.2 Pipistrellus subflavus subflavus, % mi. W Meadow, Sarpy County Average 10 (6o", 4 9).. Minimum Maximum 13.1 12.0 8.0 3.6 6.9 4.3 12.6 11.7 7.5 3.4 6.7 4.1 13.4 12.4 8.4 3.8 7.2 4.5 Eptesicus fuscus fuscus, J^-l mi. W Meadow, Sarpy County Average 10 (5d\ 5 9) Minimum Maximum 19.8 18.2 13.0 4.5 10.1 7.2 18.9 17.4 12.2 4.3 9.5 7.0 21.3 19.4 13.6 4.7 10.7 7.5 Eptesicus fuscus pallidus, 5% mi. W Crawford, Sioux County Average 10 ( 9 ) . Minimum Maximum 19.0 18.0 12.4 4.4 9.8 7.0 18.3 17.6 12.0 4.2 9.5 6.6 19.4 18.5 12.9 4.7 10.3 7.4 Lasiurus borealis borealis, Butler County 12075 NSM, 9 73204 KU, 9 . . 13.2 13.8 12.5 13.1 9.9 10.1 4.3 4.4 8. 8. 5 mi. N, 2 mi. W Humboldt, Richardson County 79046 KU, 79047 KU, 9 9 13 13 12.8 13.1 10.1 9.8 4.2 4.2 8.2 7.9 4.7 4.9 4.8 4.6 5.8 5.5 6.0 8.8 8.6 9.1 8.5 8.2 8.8 6.2 6.3 6.3 6.3 Lasiurus cinereus cinereus, 1 mi. S, 4 mi. W Orella, Sioux County 12079 NSM, 9 | 18.1 | 16.9 | 13.1 | 5.3 | 10.5 | 6.4 | 8.3 Lincoln, Lancaster County 12081 NSM, 9 | 18.2 | 16.7 | 13.2 | 5.4 | 10.6 | 6.3 | 8.1 2 mi. N, 2 mi. W Bellwood, Butler County 73205 KU, 9 | 18.1 | 16.8 | 12.6 | 5.3 | 10.4 | 6.4 | 8.2 Nycticeius humeralis humeralis, 2 mi. N, 2 mi. W Bellwoca, Butler County Average 4 Minimum. Maximum (9) 14.8 13.7 10.1 4.1 8.3 5.3 14.2 13.4 10.0 4.0 8.2 5.0 15.1 14.1 10.3 4.2 8.5 5.5 6.7 6.5 6.9 Tadarida brasiliensis mexicana, Lincoln, Lancaster County 4136 NSM, 9 12437 NSM, o*.... 176105 AMNH, o» . 16.8 16.5 16.7 15.7 15.3 15.5 9.7 3.8 9.4 5.9 6.9 9.5 3.9 9.0 5.9 7.0 9.7 4.1 9.1 6.0 7.4 Mammals of Nebraska 101 Tadarida brasiliensis mexicana (Saussure) Molossus mexicanus Saussure, Revue et Mag. Zool., Paris, ser. 2, 12:283, July, 1860 (type locality restricted to Cofre de Perote, 13,000 ft., Vera- cruz, by Elliot, Field Columb. Mus., Publ. 95, Zool. Ser., 4:629, 1904— see Benson, Jour. Washington Acad. Sci., 34:159, May 15, 1944). Tadarida brasiliensis mexicana, Schwartz, Jour. Mamm., 36:108, February 28, 1955; Hall and Kelson, The mammals of North America, p. 206, March 31, 1959. Nyctinomus mexicanus, Zimmer, Science, 38 (n. s.):665, November 7, 1913; Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:21, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920. Tadarida mexicana, Webb and Jones, Univ. Kansas Publ., Mus. Nat. Hist., 5:278, May 31, 1952. T[adarida]. b[rasiliensis]. mexicana, Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Distribution in Nebraska. — Known only from Lincoln, Lancaster County; possibly occurs elsewhere in southern part of state. See Fig. 17. External measurements. — Measurements of two males and a female from Lincoln are, respectively: 101, 108, 102; 35, 30, 38; 9 (dry), 10, 10 (dry); 14 (crown), 18, 16; , 42.5, 42.8. The weight varies from 8.3-14.4 grams ac- cording to Hall (1955:51). For cranial measurements see Table 6. Records of occurrence. — Specimens examined, 3, as follows: Lancaster County: Lincoln, 3 (1 AMNH, 2 NSM). Order LAGOMORPHA— Hares, Rabbits and Pikas Four species of lagomorphs — two species of the genus Lepus and two species of the genus Sylvilagus — are native to Nebraska. Classically, the members of the genus Lepus are hares because their young are precocial whereas members of the genus Sylvilagus are rabbits because their young are altricial. Key to Nebraskan Lagomorphs 1. Ear from notch more than 90; greatest breadth of mesopterygoid fossa more than 8.5; interparietal fused with parietals 2 1'. Ear from notch less than 75; greatest breadth of mesopterygoid fossa less than 8.5; interparietal not fused with parietals 3 2(1). Dorsum of tail entirely black; mesopterygoid fossa relatively narrow, usually less than 11.0; enamel infolding on anterior face of upper incisor bifurcated or trifurcated Lepus calif ornicus, p. 109 2'. Dorsum of tail entirely white, or having thin, median pencil of black; mesopterygoid fossa relatively broad, usually more than 11.5; enamel infolding on anterior face of upper incisor a simple groove. Lepus townsendii, p. Ill 3(1'). Total length more than 460; length of ear from notch more than 71; greatest length of skull more than 80 Oryctolagus cuniculus, p. 331 3'. Total length less than 460; length of ear from notch less than 71; greatest length of skull less than 80 4 4(3'). Ear long, 62 or more from notch; auditory bullae large, length more than 11.5; external auditory meatus large, external diameter 5.2 or more (usually more than 5.5) Sylvilagus audubonii, p. 102 4'. Ear short, 61 or less from notch; auditory bullae small, length less than 10.5; external auditory meatus small, external diameter 5.3 or less (usually less than 5.0) Sylvilagus floridanus, p. 104 102 University of Kansas Ptjbls., Mus. Nat. Hist. Family Leporidae — Hares and Rabbits Sylvilagus audubonii Desert Cottontail In Nebraska the desert cottontail is typically an inhabitant of the High Plains and no records of occurrence are presently available from east of that region in southwestern Nebraska. To the north of the Platte River the species is recorded not only from the High Plains but also from southern Sheridan County and Hooker County in the western part of the Sand Hills, and from Valentine on the Crookston Table. Although audubonii has successfully penetrated the western part of the Sand Hills, it is uncommon there and the Sand Hills evidently are an effective barrier to eastward movement of the species in northern Nebraska. The loess hills and canyons south of the Platte River may provide an equally effective barrier to eastward dispersal. The absence of audubonii from most parts of the Sand Hills is especially noticeable because the eastern cotton- tail, S. floridanus, occurs there primarily in lowland habitats, leav- ing vast areas of dry, upland habitats where no members of the genus Sylvilagus occur. 97 NX i .-"V. r •_._ — ■} r-L I T « — i i -i — J-__J i \ ^L i J— )C~C i ; — ' i 4 i l JL-JL .> \ 1 — r~\ f • • ■ .JL Mima of Natural Hotaiy University of Koreas I Kg MO 97 Fig. 18. Distribution of Sylvilagus audubonii baileyi in Nebraska. For ex- planation of symbols see Fig. 5. Little is known concerning reproduction in the desert cottontail. The only breeding female from Nebraska that I know of is one taken 3 mi. N W Lisco on July 21, 1959, that contained 5 embryos. Mammals of Nebraska 103 Sylvilagus audubonii baileyi (Merriam) Lepus baileyi Merriam, Proc. Biol. Soc. Washington, 11:148, June 9, 1897 (type locality, Spring Creek, east side Bighorn Basin, Bighorn Co., Wyoming); Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902. Sylvilagus auduboni baileyi, Nelson, N. Amer. Fauna, 29:232, August 31, 1909; Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Ne- braska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920. Lepus arizonae baileyi, Swenk, Proc. Nebraska Acad. Sci., 8:115, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:59, September, 1908. Sylvilagus audubonii baileyi, Hall, Univ. Kansas Publ., Mus. Nat. Hist., 5:164, December 15, 1951; Hall and Kelson, The mammals of North America, p. 266, March 31, 1959. S[ylvilagus] '. a[udubonii]. baileyi, Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Distribution in Nebraska. — Western two-fifths of state, principally in High Plains region. See Fig. 18. External measurements. — Average and extreme measurements of eight speci- mens (four males, four females) from northwestern Nebraska (Dawes and Sioux counties) are: 413.7 (390-435); 45.0 (39-58); 96.4 (90-101); 65.6 (62-69). Average and extreme measurements of seven specimens (five males, two fe- males) from southwestern Nebraska (Chase and Dundy counties) are: 392.0 (378-409); 42.4 (36-51); 93.3 (90-96); 66.3 (62-72). For cranial measure- ments see Table 7. Respective weights in grams of three males and three females from Sioux and Dawes counties are: 940, 1040, 1090, 1090, 1230 and 1375. Remarks. — Specimens of S. a. baileyi from the southwestern part of the state average somewhat smaller than those from the north- western part but do not differ otherwise. S. a. baileyi is sympatric throughout its range in Nebraska with Sylvilagus floridanus similis, although the two species usually oc- cupy different ecological niches. S. a. baileyi differs from S. /. similis externally in having longer ears and (usually) paler upper parts, especially head, nape and middorsal region; cranially, baileyi has larger auditory bullae and external auditory meatuses, shorter tooth- rows, and ordinarily a narrower mesopterygoid fossa and shorter palatal bridge. The ears of S. a. baileyi measured from the notch in fresh specimens are usually 62 mm. or longer (see external meas- urements). Rarely an individual with ears much shorter than the average is found, as for example one from 15 mi. S Dalton on which the ears measured only 55 mm. Records of occurrence. — Specimens examined, 113, as follows: Banner County: 9 mi. N, 5 mi. E Harrisburg, 2; 10 mi. W Harrisburg, 2 (NSM); Hubbard Gap, 2 (NSM). Box Butte County: Hemingford, 17 (NSM); about 20 mi. N Bayard, 1 (NSM); no precise locality, 4 (NSM). Chase County: 3 mi. S Imperial, 1; 2 mi. W Enders, 1. Cherry County: Valentine, 2 (UMMZ). Cheyenne County: Dalton, 1 (NSM); 15 mi. S Dalton, 1. Dawes County: 10 mi. NE Chadron, 1 (USNM); 8 mi. N Crawford, 1 (NSM); Crawford, 6 (NSM); 3 mi. W Crawford, 3 (NSM); 10 mi. S Chad- ron, 10 (9 UMMZ, 1 USNM); 15 mi. S Chadron, 2 (USNM). Dundy County: 104 University of Kansas Publs., Mus. Nat. Hist. Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 6; Haigler, 1 (NSM). Gahden County: Oshkosh, 1 (NSM); no precise locality, 1 (NSM). Hooker County: Mullen, 1 (UMMZ); Kelso, 1 (UMMZ). Kimball County: 1 mi. S Bushnell, 2 (NGFPC). Morrill County: 3 mi. NW Lisco, 2. Scotts Bluff County: 2 mi. W Mitchell, 1 (NSM); Mitchell, 1 (NSM); Scotts- bluff, 1 (NSM); 6 mi. S, 2 mi. E Gering, 2 (NSM). Sheridan County: Gordon, 3 (NSM); 4-5 mi. N Antioch, 3 (UMMZ); Ellsworth, 1 (UNDZ). Sioux County: 21 mi. NW Crawford, 1 (NSM); Montrose, 1; 15 mi. N Harri- son, 1 (NSM); Orella, 1 (NSM); 1 mi. S, 4 mi. W Orella, 2 (NSM); 2 mi. S, 2 mi. W Orella, 2 (NSM); Toadstool Park, near Orella, 6 (NSM); 10 mi. N Harrison, 1 (NSM); Warbonnet Canyon, 3 (NSM); E M, sec. 21, T. 33 N, R. 54 W, 1 (NSM); head of Warbonnet Creek, 1 (CM); West Monroe Canyon, N of Harrison, 1 (NSM); Andrews, 1 (NSM); Glen, 1 (NSM); 1 mi. S, 4 mi. W Glen, 1 (NSM); 9 mi. S, 2 mi. E Harrison, 1; 6 mi. E Agate, 2 (UMMZ); 8 mi. E Agate, 1 (NSM); western part of county, 1 (NSM). Additional record: Banner County: Harrisburg (Gates, 1945:10). Sylvilagus floridanus Eastern Cottontail In eastern Nebraska this species seemingly occurs in all terrestrial habitats; ordinarily it is one of the commonest mammals and almost invariably the species most evident to man. In central Nebraska (the Sand Hills to the north and loess hills to the south) S. floridanus also is common but is somewhat restricted ecologically because it is found there principally in or near agricultural and riparian com- munities. In the western part of the state, where it is sympatric with the desert cottontail (S. audubonii), floridanus usually is re- stricted, sometimes sharply so, to riparian communities, with audu- S jp. oo 97 WilllPiiiPIIpg m 11 •.Ullti Museum of Natural Hiiiecy University of Kansas _L wo 97 Fig. 19. Distribution of Sylvilagus floridanus in Nebraska. 1. S. /. mearnsii. 2. S. /. similis. For explanation of symbols see Fig. 5. Mammals of Nebraska 105 bonii occupying adjacent uplands. Along Rock Creek in Dundy County, for example, I found floridanus restricted to the narrow valley (sometimes 100 yards or less in width) and overlapping audubonii only at the valley edges. Along Deadmans Creek in Dawes County and Soldier Creek in eastern Sioux County floridanus is similarily restricted. In other places, where a relatively broad transition exists between riparian and upland communities, for example in the Pumpkin Creek valley in Banner County and along the Platte River in the vicinity of Lisco, the two species overlap broadly in the transition area. The eastern cottontail is subject to year to year fluctuations in population levels and probably also to long-term cyclic fluctuations. Population levels may vary also in different areas at the same time. Some mammalogists have suspected (see for example Hall and Kelson, 1959:261, fig. 185) that Nuttall's cottontail, S. nuttallii, occurs in extreme northwestern Nebraska. S. floridanus and S. nuttallii have similar ecological requirements and the two species are evidently, therefore, mutually exclusive geographically. S. floridanus is widely distributed, although in restricted habitat, in Sioux County and I suspect that the western species, nuttallii, does not occur there. The eastern cottontail is polyestrous and breeds from mid-January to August according to Asdell (1946:205). Eight pregnant females from Nebraska that were obtained in the months of May through July had an average embryo count of 6.4 (3-10). Lactating females have been taken in May, July and August. Velich (1956:271-272, 1958:148, and 1961:92) reported melanis- tic S. floridanus from several places in eastern Nebraska, but espe- cially from the DeSoto Bend area of Washington County, where a population containing many melanistic individuals evidently exists. I have examined one albino eastern cottontail (from Johnson County), which had pinkish eyes according to the specimen label even though there was a small patch of buffy brown on the nose and the tail was fringed with brownish gray. Velich (1954:429) reported an albino from Sarpy County. Sylvilagus floridanus mearnsii (J. A. Allen) Lepus sylvaticus mearnsii, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 6:171, May 31, 1894 (type locality, Fort Snelling, Hennepin Co., Minnesota). Sylvilagus (Sylvilagus) floridanus mearnsi, Lyon, Smiths. Misc. Coll., 45:336, June 15, 1904. ?Lepus Americanus, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:370, 1823. 106 University of Kansas Publs., Mus. Nat. Hist. Lepus sylvaticus, Hayden, Trans. Amer. Philos. Soc. 12(n.s.):148, 1863. L[epus]. sylvaticus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880. Lepus ftoridanus mearnsii, Swenk, Proc. Nebraska Acad. Sci., 8:114, Sep- tember, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:58, Sep- tember, 1908. Sylvilagus floridanus mearnsi, Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920; Whelan, Trans. Kansas Acad. Sci., 39:366, 1937; Velich, Jour. Mamm., 35:429, August 20, 1954; Velich, Jour. Mamm., 37:272, June 9, 1956; Velich, Jour. Mamm., 39:148, February 20, 1958; Velich, Jour. Mamm., 42:92, February 20, 1961. Sylvilagus floridanus, Haecker, Nebraska Bird Bev., 9:10, 1941. S[ylvilagus]. j[loridanus] . mearnsii, Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Distribution in Nebraska. — Eastern fourth of state, west certainly to Butler, Jefferson, and Wayne counties. See Fig. 19. External measurements. — Average and extreme measurements of eight speci- mens (two males, six females) from Bichardson County are: 419.2 (408-432); 46.2 (36-65); 96.6 (90-103); 58.1 (55-61). For cranial measurements see Table 7. Two females from Bichardson County, both November-taken, weighed 2J* and 2% lbs. Four February-taken specimens from Lincoln, a male and three females, weighed respectively: 2 lbs. 1 oz., 2 lbs. 11 oz., 2 lbs. 12 oz., and 2 lbs. 7 oz. Remarks. — From Sylvilagus floridanus similis, geographically ad- jacent to the west in Nebraska, S. /. mearnsii differs in having distinctly darker upper parts, especially a middorsal suffusion of blackish, but also darker face, ears, nape (noticeably more rufous), chest, sides, flanks, rump, and upper side of tail; frequently, too, the upper surface of the feet is darker. The color differences be- tween the two subspecies are best marked in fresh winter pelage. I can detect no reliable cranial differences between mearnsii and similis and my data fail to support Nelson's (1909:173) contention that similis is smaller than mearnsii. Specimens from Butler, Jefferson, and Wayne counties are some- what paler than typical mearnsii and are intergrades with similis. A May-taken specimen from 3 mi. S and % mi. W Endicott, when compared with five May-taken similis from 4 mi. E Valentine, is darker than four and essentially the same color as the fifth; a May- taken specimen from 4 mi. E Rising City is darker than any of the five specimens from Valentine. A skull only from Columbus is provisionally assigned to mearnsii on geographic grounds. The geographic range ascribed to S. /. mearnsii in Nebraska is in accord with the range associated with that subspecies in Kansas Mammals of Nebraska 107 by Cockrum (1952:103), who assigned specimens from Washington County to mearnsii, and with Findley's (1956fo:39) assignment to mearnsii of specimens from Clay County, South Dakota. Records of occurrence. — Specimens examined, 52, as follows : Burt County : Decatur, 1 (NSM). Butler County: 4-5 mi. E Rising City, 10; 5 mi. E, % mi. S Rising City, 3. Cass County: South Bend, 1 (NSM); Murray, 1 (RV). Gage County: 2 mi. S, J£ mi. E Bamston, 1. Jefferson County: 3 mi. S, 3* mi. W Endicott, 1. Johnson County: no precise locality, 1 (NGFPC). Lancaster County: 1 mi. N Lincoln, 5 (3 NGFPC, 2 NSM); & mi. N Lin- coln, 1 (NSM); Lincoln, 7 (1 NSM, 4 UC, 2 UNDZ); 2 mi. E Lincoln, 1 (UC); 1 mi. S College View (Lincoln), 1 (UC); SY2 mi. S, 1 mi. E Lincoln, 1 (UC); 7 mi. S, 1 mi. E Lincoln, 2 (UC); Hanlon, 1 (NSM). Nemaha County: Auburn, 2 (NGFPC). Platte County: Columbus, 1 (RV). Richardson County: 5 mi. N, 2 mi. W Humboldt, 1; 4 mi. E Barada, 5; 3?2 mi. S, 1 mi. W Dawson, 2; 3 mi. S Rulo, 1. Washington County: DeSoto, 1 (RV). Wayne County: 4 mi. SE Carroll, 1 (NSM). Additional records: Cass County: Union (Gates, 1945:11). Cuming County: West Point (Swenk, MS). Douglas County: Elmwood Park, Omaha (Velich, 1958:148); near Irvington (Haecker, 1941:10). Lancaster County: Malcolm (Gates, 1945:12); 9 mi. NW Lincoln (Whelan, 1937:366); 3 mi. S, 2 mi. W Lincoln (Velich, 1961: 92). Nemaha County: 7 mi. SW Auburn (Velich, 1958:148). Otoe County: Missouri River bottoms (Velich, 1956:272). Sarpy County: Fontanelle Forest (Velich, 1954:429). Sylvilagus floridanus similis Nelson Sylvilagus floridanus similis Nelson, Proc. Biol. Soc. Washington, 20:82, July 22, 1907 (type locality, Valentine, Cherry Co., Nebraska); Lyon and Osgood, Bull. U. S. Nat. Mus., 62:36, January 28, 1909; Nelson, N. Amer. Fauna, 29:172, August 31, 1909 (part); Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:21, October, 1936; Poole and Schantz, Bull. U. S. Nat. Mus., 178:220, April 9, 1942; Hall and Kelson, Univ. Kansas Publ., Mus. Nat. Hist., 5:51, October 1, 1951; Hall and Kelson, The mammals of North America, p. 263, March 31, 1959. Lepus floridanus similis, Swenk, Proc. Nebraska Acad. Sci., 8:115, Septem- ber, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:59, September, 1908. Sylvilagus floridanus mearnsi, Nelson, N. Amer. Fauna, 29:169, August 31, 1909 (part). S[ylvilagus] '. ffloridanus], similis, Blair, Occas. Papers Mus. Zool., Univ. Michigan, 380:3, June 21, 1938; Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Sylvilagus f[loridanus]. similis, Irnler, Jour. Wildlife Mgt., 9:272, October, 1945. Sylvilagus florilanus [sic] similis, Hall, Univ. Kansas Publ., Mus. Nat. Hist., 5:159, December 15, 1951. Distribution in Nebraska. — Western three-fourths of state, east certainly to Antelope and Thayer counties. See Fig. 19. External measurements. — Average and extreme measurements of 10 speci- mens (one male, nine females) from Cherry County are: 420.3 (400-452); 50.5 (41-71); 97.5 (83-104); 55.9 (52-61). For cranial measurements see Table 7. 108 University of Kansas Publs., Mus. Nat. Hist. Five females from western Nebraska averaged 1251.2 (1000-1496) grams in weight. A male from Dawes County weighed 3& lbs. Remarks. — For comparison with Sylvilagus floridanus mearnsii, geographically adjacent to the east in Nebraska, see account of that subspecies. Specimens here assigned to S. /. similis from Clay, Hamilton, and Thayer counties are slightly darker over-all than topotypes and are intergrades with mearnsii. Nelson (1909:172) assigned three specimens from Cherry County (one from Brownlee and two from Kennedy) to S. /. mearnsii although in the same paper he listed seven specimens from the same county, including one from Kennedy, under similis. This inconsistency was first noted by Hall and Kelson (1951:51-52), who assigned the specimen from Brownlee to similis. They correctly guessed that one of the specimens from Kennedy was the one listed in the U. S. Fish and Wildlife Service files as being in the collection of the University of Nebraska State Museum; actually it is from the Snake River, 11 mi. NW Kennedy, and it is typical of similis. The second specimen from Kennedy was judged by Hall and Kelson not to exist at all, but rather that it represented a duplicated card reference to the U. S. National Museum specimen from the Snake River, 11 mi. NW Kennedy. Records of occurrence. — Specimens examined, 69 as follows: Antelope County: Neligh, 2 (USNM). Banner County: 9 mi. N, 5 mi. E Harrisburg, 1. Brown County: Johnstown, 1 (UMMZ). Cherry County: Crookston, 1 (UMMZ); Valentine, 4 (1 UMMZ, 3 USNM, including the holotype); 4 mi. E Valentine, 8; Snake River, 11 mi. NW Kennedy, 2 (1 NSM, 1 USNM); Kennedy, 1 (USNM); 11 mi. E Kennedy, 2; 20 mi. S Valentine, 1 (UMMZ); Valentine Natl Wildlife Refuge, 3 (NSM); Brownlee, 1 (USNM); 30 mi. S Wood Lake, 1 (CNHM). Clay County: Harvard, 1 (HM). Custer County: & mi. E Victoria Springs, 1 (UMMZ). Dawes County: Chadron, 2 (CSTC); 8 mi. E Chadron, 1; 10 mi. S Chadron, 5 (UMMZ); Deadmans Creek, 7 mi. S, 3)2 mi. W Crawford, 3 (NSM). Dundy County: Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 4. Frontier County: 15 mi. SE Stockville, 1 (NSM). Hamilton County: no precise locality, 1 (HM). Morrill County: 3 mi. NW Lisco, 2. Rock County: Johnson Ranch, Skull Creek, 3 (AMNH). Scotts Bluff County: 7 mi. S Gering, 1; 8 mi. S, 2 mi. E Gering, 1 (NSM). Sioux County: Warbonnet Canyon, 1 (UNDZ); 8 mi. N Harrison, 1 (NSM); West Monroe Canyon, N of Harrison, 2 (NSM); % mi. N, 10 mi. W Crawford, 1 (NSM); 5Y* mi. W Crawford, 1 (NSM); Glen, 1 (NSM). Thayer County: Davenport, 1 (UNDZ). Thomas County: 1 mi. S, 3/2 mi. W Halsey, 1. Valley County: 2 mi. S, 4 mi. E Ord, 1; 10 mi. S Ord, 4 (NGFPC). Webster County: Bladen, 1 (HM). Additional records (Swenk, MS, unless otherwise noted): Adams County: Hastings; Logan Twp. Cherry County: Cody (Cary, MS). Clay County: Inland. Garden County: Crescent Lake Nat'l Wildlife Refuge (Imler, 1945: 272); Ash Hollow, 3 mi. SE Lewellen (Champe, 1946:44, archeological site). Hitchcock County: Stratton (Seton, 1929, 4:787). Holt County: Red- bird Creek, N of O'Neill (Seton, 1929, 4:787). Lincoln County: near North Platte. Mammals of Nebraska 109 Lepus californicus Black-tailed Jackrabbit The black-tailed jackrabbit is state-wide in distribution but the species is much more abundant in the southern part of the state. Its gradual replacement of the white-tailed jackrabbit over much of Nebraska is discussed in the account of L. townsendii. Possibly L. californicus did not occur at all in Nebraska 100 years ago. Early travelers along the Platte River, where californicus is common today, collected only white-tailed jackrabbits. Even as late as 1909 Nelson, who revised the North American rabbits, had no Nebraskan specimens of californicus available for examination, al- though he (1909:127, fig. 10) mapped a large part of the state as being within the range of the subspecies L. c. melanotis. Probably the larger L. townsendii was more successful than L. californicus on the open prairie; the reverse appears true in regard to lands culti- vated for agricultural pursuits. -« Museum of Natural Hhtory Untvercity of Kama* 1MJ Fig. 20. Distribution of Lepus californicus melanotis in Nebraska. planation of symbols see Fig. 5. For ex- Merrit Cary (1902:65, 68, 69) recorded L. melanotis in the Pine Ridge country of northern Sioux County as early as 1900 and 1901 but did not record L. townsendii there. Because Cary preserved no jackrabbits as scientific specimens I cannot now verify this report. It should be noted, however, that all other available evidence sug- gests that the black-tailed jackrabbit probably had not reached the 110 University of Kansas Publs., Mus. Nat. Hist. extreme northwestern part of the state by 1900; even today the species is uncommon there, far surpassed in numbers by L. town- sendii. A female obtained 4 mi. E Rising City on June 1, 1957, contained 6 embryos. Bronson and Tiemeier (1958:411) reported pregnant females from Kansas in every month from January through August and an average of 2.6 embryos (1-5) for 32 pregnancies. Lepus califomicus melanotis Mearns Lepus melanotis Mearns, Bull. Amer. Mus. Nat. Hist., 2:297, February 21, 1890 (type locality, vicinity of Independence, Montgomery Co., Kansas — type specimen purchased in market in New York City where it had been received from Independence, Kansas, along with several hundred other jackrabbits that were probably obtained "on the northern border of Indian Territory" according to Mearns, op. cit. :298); Cary, Proc. Ne- braska Ornith. Union, 3:69, December, 1902. Lepus californicus melanotis, Nelson N. Amer. Fauna, 29:146, August 31, 1909; Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Ne- braska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:21, October, 1936; Whelan, Trans. Kansas Acad. Sci., 39:366, 1937; Hall, Univ. Kansas Publ., Mus. Nat. Hist., 5:185, December 15, 1951; Hall and Kelson, The mammals of North America, p. 284, March 31, 1959. Lepus callotis, Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880. Lepus texianus melanotis, Swenk, Proc. Nebraska Acad. Sci., 8:114, Sep- tember, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:58, Sep- tember, 1908. L[epus]. c[alifornicus] '. melanotis, Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Distribution in Nebraska. — State-wide, but more common in southern part. See Fig. 20. External measurements. — Average and extreme measurements of 10 speci- mens (four males, six females) from the vicinity of Rising City are: 568.4 (535-585); 76.3 (71-87); 130.5 (128-134); 118.5 (112-125). For cranial measurements see Table 7. Bronson (1958:109) reported the average weights of 219 adult males and 212 adult females from Kearny County, Kansas, as 90.9 oz. (5.68 lbs.) and 102.8 oz. ( 6.42 lbs. ) , respectively. Records of occurrence. — Specimens examined, 173 as follows: Antelope County: Clearwater, 1 (UMMZ). Box Butte County: 3 mi. N Heming- ford, 1 (NSM); Hemingford, 5 (NSM); about 20 mi. N Bayard, 1 (NSM). Brown County: Ainsworth, 1 (CNHM). Butler County: Rising City, 1 (RV); 4-5 mi. E Rising City, 8; 4 mi. E, 2 mi. S Rising City, 3. Burt County: Oakland, 1. Chase County: 3 mi. S Imperial, 4; 2 mi. W Enders, 4. Cherry County: Valentine Nat'l Wildlife Refuge, 1 (NSM). Cheyenne County: Dalton, 2 (NSM). Clay County: Inland, 1 (HM); 2 mi. E, 2 mi. S Clay Center, 1 (NGFPC). Custer County: 4 mi. NE Victoria Springs, 1 (UMMZ); 3 mi. NE Victoria Springs, 1 (UMMZ); 1 mi. E Victoria Springs, 1 (UMMZ); 2 mi. E Lillian, 1 (UMMZ); Comstock, 2 (1 AMNH, 1 NSM). Dawes County: Chadron, 1 (RV). Dawson County: 4 mi. E Gothenburg, 1 (UC). Dundy County: 5 mi. N, 2 mi. W Parks, 7. Fillmore County: 3 mi. N, 1 mi. E Geneva, 1. Frontier County: 15 mi. SE Stockville, 1 (NSM). Garden County: 6 mi. S Antioch, 1 (UMMZ); 5 mi. N Lisco, 1 (NSM). Hooker County: 1 mi. W Mullen, 1 (UMMZ); Kelso, 1 (UMMZ). Mammals of Nebraska 111 Kearney County: 6 mi. S Minden, 2. Knox County: Vk mi. SE Niobrara 1 (NGFPC). Lancaster County: T. 10 N, R. 5 E, near Malcolm, 1 (NSM)- Lincoln, 6 (3 NSM, 2 RV, 1 UC); 1 mi. S Lincoln, 1; 4 mi. S Lincoln, 1 (UC)-' 6 mi. SW Lincoln, 1 (UC); 7 mi. S, 1 mi. E Lincoln, 2 (UC). Morrill County: 11 mi. N Bridgeport, 73 (NSM); Bridgeport, 9 (NSM); Greenwood Canyon, S of Bridgeport, 5 (NSM). Otoe County: Unadilla, 1 (NSM). Platte County: Columbus, 1 (RV). Saline County: Crete, 3 (2 NSM, 1 RV). Seward County: 12 mi. W Seward, 1 (UC). Sheridan County' Gordon, 1 (NSM); 16 mi. NE Alliance, 1 (UMMZ); 4 mi. N Antioch, 2 (UMMZ). Sioux County: 3 mi. E Glen, 1 (NSM). Valley County- Ord 1 (NGFPC), 10 mi. S Ord, 1 (NGFPC). Webster County: Bladen, 2 (HM). Additional records: Adams County: vicinity Hastings (Swenk, MS); Logan Twp. (Swenk, MS). Antelope County: Neligh (Cary, MS). Ban- ner County: 9 mi. N, 3 mi. E Harrisburg (Jones, field notes). Cherry County: Ft. Niobrara Nat'l Wildlife Refuge (Beed, 1936:21). Cuming County: Beemer (Cary, MS); West Point (Swenk, MS). Douglas County: Omaha (Swenk, MS). Lancaster County: 9 mi. NW Lincoln (Whelan, 1937:366). Lincoln County: vicinity North Platte (Swenk, MS). Sioux County: northern part (Cary, 1902:69). Thomas County: no specific locality (Smith, 1958:61). Lepus townsendii White-tailed Jackrabbit The white-tailed jackrabbit formerly occurred over all of Ne- braska, excepting possibly the extreme southeastern part, but now is mostly limited to that part of the state north of the Platte River. The most recent record from south of the Platte in eastern Nebraska is a specimen obtained at Weeping Water in January of 1915. The most recent report from south of the Platte in central Nebraska is from Logan Township, Adams County, in 1935. I have no recent records of L. townsendii from southwestern Nebraska but local residents (in central Dundy County, for example) report that "a few" still occur there; several specimens have been taken in recent years in the parts of Colorado adjoining southwestern Nebraska. The gradual disappearance of the white-tailed jackrabbit from southern Nebraska has been accompanied by a northward spread of the smaller black-tailed jackrabbit, Lepus calif ornicus. Lawrence Bruner reported ( Swenk, MS ) that white-tails were abundant in the vicinity of Lincoln "in the early days" [probably the 1890's]; only black-tails occur in this area today. Wilson Tout reported ( Swenk, MS) that both species occurred in the vicinity of North Platte in 1915 but that L. townsendii was the more common; today the situa- tion is reversed there and black-tails are abundant whereas white- tails are uncommon. Fred Arterburn of Grant reported to Edson Fichter (interview, April 2, 1950) that white-tails were common in Chase and Perkins counties when he first arrived in 1885, that black- tails did not occur there, and that as grassland gave way to crop- land, especially corn, black-tails appeared and by 1900 outnumbered 112 University of Kansas Publs., Mus. Nat. Hist. Fig. 21. Distribution of Lepus townsendii campanius in Nebraska. For ex- planation of symbols see Fig. 5. Dashed line indicates approximate south- eastern limit of present distribution. white-tails; the latter species is rare, possibly entirely absent, in Chase and Perkins counties today. Swenk (1908:113) listed the distribution of L. townsendii as: "Entire state, but much more com- mon northwardly where the Black-tail does not occur." Now the latter species is state-wide in distribution. Cockrum (1952:98) has reported corresponding evidence of decrease of L. townsendii and increase of L. californicus in northwestern Kansas, as has Warren (1942:263, and elsewhere) in northeastern Colorado. To the north of the Platte the white-tailed jackrabbit still occurs in the loess hills of central Nebraska and in the northeastern part of the state, but in most places is less numerous than L. californicus. Even in Thomas County in the Sand Hills black-tails are reported to be more common (Smith, 1958:61). In most parts of the Sand Hills, however, in the extreme northeastern part of the state, and on the High Plains of northwestern Nebraska white-tails still out- number black-tails. Local residents of eastern Sioux County, who hunted jackrabbits for commercial purposes in the winter of 1956- 57, reported that townsendii predominated over californicus there by the approximate ratio of 10 individuals to one. My own ob- servations in central Cherry County lead me to believe that white- tails outnumber black-tails in that area by an even greater figure, perhaps as much as 20 to one. The breaking up of the prairie for Mammals of Nebraska 113 agricultural purposes has been cited previously (Brown, 1947:456, and others ) as the reason for the reduction in numbers or disappear- ance of the white-tailed jackrabbit in the southern part of its range. Unquestionably the black-tailed jackrabbit survives better in culti- vated areas. White-tails are still common, however, in northeastern Nebraska, a section of the state that has been under fairly heavy cultivation for many years. I wonder whether or not temperature has been a factor in limiting the southern distribution of L. town- sendii, because, in addition to retreat northward from the southern part of its range, the species has expanded its distribution to the north and northeast (see Scott, 1937:81, and Seton, 1929:4, 650- 652). Possibly this shift has been in part responsive to the gradual warming trend now in progress on the North American continent. The pelage of the white-tailed jackrabbit becomes nearly white in winter throughout the present range of the species in Nebraska and according to Swenk (1908:113) formerly did so even along the southern border of the state. Of two females collected 11 mi. E Kennedy on July 12, 1957, one contained 4 and the other 5 well-developed, fully-haired embryos. A female obtained 1 mi. S and 4 mi. W Crawford, in Sioux County, on August 5, 1957, carried a single embryo that measured 44 mm. in crown-rump length. As many as 6 embryos per female have been reported; only one litter per year is known. Lepus townsendii campanius Hollister Lepus campestris Bachman, Jour. Acad. Nat. Sci. Philadelphia, 7:349, 1837 (type locality, plains of Saskatchewan, probably near Carlton House), not Meyer, 1790; Baird, Mammals, in Reports of explorations and sur- veys . . . from the Mississippi River to the Pacific Ocean . . ., 8(1):585, July 14, 1858; J. A. Allen, in Coues and Allen, Bull. U. S. Geol. Surv. Territories, 11:297, August, 1877; Aughey, Sketches of the physical geography and geology of Nebraska, p. 122, 1880; Elliot, Field Columb. Mus., Zool. Ser. (Publ. 115), 8:385, 1907; Swenk, Proc. Ne- braska Acad. Sci., 8:114, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:58, September, 1908; Nelson, N. Amer. Fauna, 29:74, August 31, 1909. Lepus townsendii campanius Hollister, Proc. Biol. Soc. Washington, 28:70, March 12, 1915, a renaming of L. campestris Bachman; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:21, October, 1936. Lepus campestris campestris, Swenk, Nebraska Blue Book, p. 853, 1915. L[epus]. t[ownsendii]. campanius, Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Distribution in Nebraska. — Formerly all of state excepting extreme south- eastern part; presently occurring primarily north of Platte River. See Fig. 21. 8—6532 114 University of Kansas Publs., Mus. Nat. Hist. External measurements. — Measurements of two males and two females from Cherry County are, respectively: 632, 610, 615, 615; 85, 107, 101, 90; 161, 142, 151, 146; 110, 104, 100, 101. Measurements of a male and female from 6 mi. W Rushville are, respectively: 602, 645; 98, 115; 142, 145; 113, 118. For cranial measurements see Table 7. A male from Dawes County weighed 8 lbs. and one from Sheridan County 6.5 lbs. Two pregnant females from Cherry County weighed 9.0 and 9.25 lbs., whereas one from Sioux County weighed 8 lbs. Remarks. — Two specimens from Nebraska at the U. S. National Museum, both obtained in 1857, have uncertain data as to locality. The specimen label of one (3058) bears the locality "Platte R. 90 m. at Kearney." I interpret this specimen to be from Ft. Kearney, as did J. A. Allen (in Coues and Allen, 1877:302), but Nelson (1909:78) recorded it from "90 miles above Fort Kearney" [Lincoln County]. The other specimen (3133/4130) was recorded by Allen (op. cit.) from the "Forks of the Platte" [Lincoln County] but the label now associated with this specimen locates it only as from along the Platte River. Gates (1945:10, 11) reported (in a paper on fleas and their hosts ) L. t . campanius as taken in 1944 at Lincoln and at Huntley, Harlan County. Probably both these records relate instead to L. c. melanotis. Records of occurrence. — Specimens examined, 58, as follows: Box Butte County: Hemingford, 3 (NSM); no specific locality, 1 (NSM). Cedak County: S of Belden, 1 (NSM). Cherry County: Ft. Niobrara Nat'l Wild- life Refuge, 1 (NSM); Valentine, 1 (USNM); 5 mi. E Valentine, 1; 10 mi. ESE Gordon, 1 (CNHM); 15 mi. S Valentine, 1 (UMMZ); Kennedy, 2 (UMMZ); 11 mi. E Kennedy, 3; Valentine Nat'l Wildlife Refuge, 1 (NSM). Cheyenne County: 15 mi. S Dalton, 1. Clay County: Inland, 1 (HM). Custer County: Comstock, 1 (NSM). Dawes County: Wayside, 1; 11 mi. N Crawford, 1 (NSM); Chadron, 1 (RV); 4 mi. N, 2 mi. W Crawford, 1 (NSM); 10 mi. S Chadron, 2 (UMMZ); Crawford, 4 (NSM). Garden County: Oshkosh, 1 (NSM). Greeley County: no specific locality, 1 (HM). Kearney County: Ft. Kearney, 2 (USNM). Keha Paha County: 12 mi. N Springview, 1. Morrill County: 11 mi. N Bridgeport, 4 (NSM); Chimney Rock, 1 (RV). Rock County: Perch, 3 (1 AMNH, 2 CNHM). Sheridan County: Gordon, 3 (2 NSM, 1 UMMZ); 6 mi. W Rushville, 2 (NGFPC); 4 mi. N Antioch, 1 (UMMZ). Sioux County: Warbonnet Canyon, 1 (UNDZ); 1 mi. S Harrison, 1 (UMMZ); 1 mi. W Ft. Robinson, 1 (NSM); 1 mi. S, 4 mi. W Crawford, 1 (NSM); 6 mi. E Agate, 1 (UMMZ); Spoon Butte, 1 (USNM). Thomas County: Halsey, 1 (NSM). Valley County: 10 mi. S, 2 mi. E Ord, 1 (NGFPC). Wayne County: 1 mi. W, 2 mi. S Winside, 1. County unknown: Platte River, 1 (USNM). Additional records (Swenk, MS, unless otherwise noted): Adams County: vicinity Hastings; Logan Twp. Cass County: Weeping Water. Chase County: no specific locality ( see text ) . Lancaster County: vicinity Lincoln. Lincoln County: vicinity North Platte. Madison County: vicinity Norfolk. Perkins County: no specific locality (see text). County unknown: Loup Fork (Nelson, 1909:78). Mammals of Nebraska 115 Table 7. — Cranial Measurements of Four Species of Lagomorphs. Number of specimens c h amosals) il iction , cS (h _ s? § T3 o M ngth of tal bridge averaged or catalogue 0> '■+3 T3 S. .-SJ3 oai UfcS ° o. number, and sex 5 f-> 23 0_Q CO o to "£ C O O DO ngth max toot ngth incis fora -U CO CO lfl-2 ast le pala t- >> fe O CD 01 tn 03 o N J, Ph i-5 ►3 m >-l Sylvilagus audubonii baileyi, Dawes and Sioux counties Average 7 (3d% 4 9). Minimum Maximum 71.0 35.6 11.5 13.4 17.9 6.1 69.2 34.8 9.8 12.8 17.3 5.7 72.8 37.2 12.7 14.0 18.3 6.5 Sylvilagus floridanus mearnsii, Richardson County Average 7 (2o\ 5 9). Minimum Maximum 73.0 36.0 11.8 15.0 17.7 6.7 70.8 34.3 10.6 14.3 16.5 5.9 74.8 37.6 14.1 15.5 18.5 7.5 Sylvilagus floridanus similis, 4 mi. E Valentine, Cherry County Average 6 (Id", 5 9) Minimum Maximum 72.6 36. 05 12.5 15.0 18.2 6.6 70.8 35.6 11.4 14.3 16.6 6.5 75.3 36.4 14.8 15.8 19.2 7.1 Lepus californicus melanotis, vicinity Rising City, Butler County Average 10 (4d\ 6 9). . Minimum Maximum 98.4 44.4 11.4 17.5 25.7 10.3 95.3 41.4 10.1 16.5 23.1 9.5 101.3 45.8 12.8 18.3 27.6 11.6 Lepus toivnsendii campanius, Cherry County 73242 KU, 9 73243 KU, 9 77931 KU, & 95.8 96.7 99.8 46.3 47.1 47.2 13.2 13.1 13.2 18.4 18.3 19.3 25.1 25.1 25.6 11.7 13.1 12.8 5.4 4.5 6.0 6.8 6.2 7.6 6.5 5.9 6.9 6.3 5.9 6.6 5.5 5.0 4.7 Order RODENTIA— Rodents As a group, rodents are the most numerous of Nebraskan mam- mals, both in number of kinds (34 native species) and in number of individuals. Seven families are represented among the indig- enous rodents of the state and species of two other families ( Capro- myidae and Muridae) have been introduced in Nebraska. Key to Families of Nebraskan Rodents 1. Modified for aquatic life; hind feet webbed; lower incisor more than 6.0 in width at alveolus 2 1'. Not especially modified for aquatic life (except Ondatra); hind feet not webbed; lower incisor less than 5.5 (less than 4.0 in all except Erethizontidae) in width at alveolus 3 116 University of Kansas Publs., Mus. Nat. Hist. 2(1). Tail flattened dorso-ventrally, its breadth approximately 25 per cent its length; infraorbital canal smaller than foramen magnum. Castoridae, p. 182 2'. Tail not flattened dorso-ventrally, its breadth less than 10 per cent its length; infraorbital canal larger than foramen magnum. Capromyidae, p. 335 3(1')- Quills on dorsum and tail; infraorbital canal larger than foramen mag- num Erethizontidae, p. 241 3'. Quills lacking; infraorbital canal never larger than foramen mag- num 4 4(3'). Pelage of tail usually distichous; skull having postorbital processes. Sciuridae, p. 116 4'. Pelage of tail non-distichous (excepting Neotoma cinerea); skull lack- ing postorbital processes 5 5(4'). Cheek-teeth 4/4; external fur-lined cheek pouches present 6 5'. Cheek-teeth 3/3 or 4/3; external fur-lined cheek pouches lacking. . . 7 6(5). Tail more than three-fourths length of head and body; hind feet larger than forefeet; tympanic bullae exposed on parietal surface of skull Heteromyidae, p. 163 6'. Tail less than three-fourths length of head and body; hind feet smaller than forefeet, the latter highly modified for digging; tympanic bullae not exposed on parietal surface of skull Geomyidae, p. 151 7(5'). Cheek-teeth 4/3; tail much longer than head and body. .Zapodidae, p. 238 7'. Cheek-teeth 3/3; tail short to medium, equal to or less than length of head and body 8 8(7'). Annulations of scales on tail nearly or completely concealed by pelage (excepting Ondatra zibethicus, in which tail is laterally flattened); cheek-teeth having two longitudinal rows of cusps or prismatic. Cricetidae, p. 186 8'. Annulations of scales on tail apparent; cheek-teeth having three longitudinal rows of cusps Muridae, p. 331 Family Sciuridae — Squirrels and Allies Key to Nebraskan Sciureds 1. Total length usually more than 540; length of hind foot more than 80; greatest length of skull more than 80; postorbital processes at right angle to long axis of skull Marmota monax, p. 121 1'. Total length less than 540; length of hind foot less than 80; greatest length of skull less than 70; postorbital processes projecting back- ward and downward 2 2(1'). Total length more than 325; length of hind foot more than 50; great- est length of skull more than 50 3 2'. Total length less than 325; length of hind foot less than 50; greatest length of skull less than 50 6 3(2). Dorsal pelage yellowish brown to pale brownish; tail having distinct black tip; zygomatic arches strongly divergent posteriorly, breadth more than 40; maxillary tooth-rows strongly divergent anteriorly, length more than 15 Cynomys ludovicianus, p. 136 3'. Dorsal pelage other than yellowish brown to pale brownish; tail lack- ing distinct black tip; zygomatic arches not strongly divergent posteriorly, breadth less than 40; maxillary tooth-rows more or less parallel, length less than 12 4 4(3'). Tail less than 40 per cent of total length; P3 well developed; post- orbital breadth less than 15 Spermophilus franklinii, p. 124 4'. Tail more than 40 per cent of total length; P3 small and peglike, or absent; postorbital breadth more than 15 5 Mammals of Nebraska 117 5(4'). Tail tipped laterally with whitish; P3 usually present. Sciurus carolinensis, p. 141 5'. Tail tipped laterally with straw color to reddish orange; P3 absent. Sciurus niger, p. 144 6(2'). Dorsum striped, but lacking spots; infraorbital canal lacking, the infraorbital foramen piercing zygomatic plate of maxillary; P3 minute and peglike, or lacking 7 6'. Dorsum lacking stripes, or if striped also having spots; infraorbital canal present; P3 moderately to well developed 8 7(6). Total length more than 235; greatest length of skull more than 37; P3 absent; occurring only in southeastern Nebraska. Tamias strialus, p. 117 7'. Total length less than 235; greatest length of skull less than 37; P3 present; occurring only in northwestern Nebraska. Eutamias minimus, p. 119 8(6'). Hind foot more than 40; maxillary tooth-row more than 10; P3 nearly as large as P4 Spermophilus richardsonii, p. 127 8'. Hind foot less than 40; maxillary tooth-row less than 8; P3 one half or less as large as P4 9 9(8'). Membrane for gliding present between foreleg and hind leg; skull highly arched, highest over braincase; nasals less than 11. Glaucomys volans, p. 149 9'. Membrane for gliding lacking; skull only moderately arched, highest over orbits; nasals more than 11 10 10(9'). Dorsum having dark stripes alternating with pale stripes that con- tain dark spots; postorbital breadth less than 11.5 and less than length of nasals; length of auditory bullae less than 8.5. Spermophilus tridecemlineatus, p. 130 10'. Dorsum pale brownish gray, sometimes having indistinct white spots; postorbital breadth more than 11.5, approximately equal to length of nasals; length of auditory bullae more than 8.5. Spermophilus spilosoma, p. 128 Tamias striatus Eastern Chipmunk The eastern chipmunk occurred formerly in southeastern Ne- braska along the wooded bluffs of the Missouri River and elsewhere in wooded areas along major tributaries of the Missouri. Early accounts indicate that the species was not uncommon in some places. In the past 40 years, however, it has been taken only at two localities, each along the bluffs of the Missouri River. One of these is the Fontanelle Forest Reserve, south of Omaha in Sarpy County, where a small population of this chipmunk seemingly still persists (Velich, 1947:185-186, 1954:429); the other is Ne- braska City, from which the species has been twice recorded. Local residents at Minersville and at Peru informed me in the autumn of 1952 that "a few" eastern chipmunks were still to be found in those areas too, but that the species was seen much less frequently than in the early 1900's. Two residents of Barada reported to me in the autumn of 1956 that they had seen no chipmunks in that 118 University of Kansas Publs., Mus. Nat. Hist. vicinity for many years but that the species was "fairly common" along the bluffs of the Missouri up to about 1920. All the records from Swenk (MS) that are listed beyond, and for which a date is available, are from before the turn of the last century. 40- JAuwum of Natural History Unirurjity ol Koraat IMS Fig. 22. Distribution of two species of chipmunks in Nebraska. 1. Tamias striatus griseus. 2. Eutamias minimus pallidas. For explanation of symbols see Fig. 5. Inset map shows distribution of T. striatus in North America. Tamias striatus was first recorded from Nebraska by James (1823: 370) from the Engineer Cantonment in Washington County, the northernmost locality along the Missouri from which the species is certainly known. Hay den (1863:138) found the eastern chip- munk "abundant at Bellevue, Nebraska." He further remarked that it did "not pass above the mouth of the Niobrara; very few are seen above Council Bluffs." The northwesternmost record in the state is provided by a specimen obtained at Nickerson, along the Elkhorn River, in August of 1915. The eastern chipmunk breeds in spring and frequently again in late summer or early autumn. The number of young usually is 3, 4, or 5 (1-8). Tamias striatus griseus Mearns Tamias striatus griseus Mearns, Bull. Amer. Mus. Nat. Hist., 3:231, June 5, 1891 (type locality, Fort Snelling, Hennipen Co., Minnesota); Swenk, Proc. Nebraska Acad. Sci., 8:82, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:26, September, 1908; Swenk, Nebraska Blue Book, p. 851, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 480, December, 1920; Polder, Proc. Iowa Acad. Sci., 60:722, 1953; Velich, Jour. Mamm., 35:429, August 20, 1954; Mammals of Nebraska 119 Miller and Kellogg, Bull. U. S. Nat. Mus., 205:217, March 3, 1955; Hall and Kelson, The mammals of North America, p. 295, March 31, 1959; Velich, Tour. Mamm., 42:92, February 20, 1961. [Sciurus] striatus, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:370, 1823. Tamias striatus, Hayden, Trans. Amer. Philos. Soc, 12(n.s.) :138, 1863; Aughey, Sketches of the physical geography and geology of Nebraska, p. 120, 1880; Velich, Jour. Mamm., 24:273, June 8, 1943. [Tamias striatus] griseus, Velich, Jour. Mamm., 28:185, May 19, 1947. T[amias]. sftriatus]. griseus, Jones, Trans. Kansas Acad. Sci., 60:276, Oc- tober 22, 1957. Distribution in Nebraska. — Formerly along Missouri River and its major tributaries in southeastern part of state, north at least to Washington and Dodge counties; presently rare and limited to a few suitable areas along bluffs of the Missouri. See Fig. 22. External measurements. — No external measurements of adult eastern chip- munks from Nebraska are available. Average and extreme measurements of eleven topotypes of T. s. griseus (after A. H. Howell, 1929:20) are: 268.4 (253-299); 101.3 (93-110); 36.6 (35-38); 13.7 (12-16.5). For cranial meas- urements see Table 8. The weight in grams of four specimens (three males, one female) from St. Louis County, Minnesota, averaged 97.7 (88-110). Records of occurrence. — Specimens examined, 7, as follows: Dodge County: Nickerson, 1 (HM). Otoe County: 1 mi. S Nebraska City, 1 (RV). Sarpy County: Fontanelle Forest, 5 (1 HM, 4 RV). Additional records (Swenk, MS, unless otherwise noted): Douglas County: near Omaha; near Florence. Nemaha County: vicinity Peru. Otoe County: 5 mi. S Nebraska City (Velich, 1961:92); Minersville (see text). Richardson- County: vicinity Barada (see text); Falls City (Cary, MS); vicinity Rulo. Sarpy County: Bellevue (Hayden, 1863:138). Washington County: Engi- neer Cantonment [= approximately 2 mi. E Ft. Calhoun] (James, 1823:370); Rockport. Eutamias minimus Least Chipmunk The least chipmunk inhabits slopes and canyons of the western part of the Pine Ridge and rocky areas in the badlands to the north of the Pine Ridge. The species is common in some places. Insofar as I know it does not occur in Nebraska east of Pine Ridge, even in seemingly suitable habitat along parts of the Niobrara River, or in the southern part of the Panhandle, where Wildcat Ridge, Bighorn Ridge, and some other places offer possibly suitable habitat. The species hibernates in winter in Nebraska. Females bear a single litter annually, consisting of 2-6 young, in spring. Eutamias minimus pallidas (J. A. Allen) [Tamias quadrivitatus] var. pallidus J. A. Allen, Proc. Boston Soc. Nat. Hist., 16:289, June, 1874 (type locality restricted to Camp Thome, near Glen- dive, Dawson Co., Montana, by Gary, Proc. Biol. Soc. Washington, 19:88, June 4, 1906). 120 University of Kansas Publs., Mus. Nat. Hist. Eutamias minimus pallidus, A. H. Howell, Jour. Mamm., 3:183, August 4, 1922; A. H. Howell, N. Amer. Fauna, 52:42, November 30, 1929; White, Univ. Kansas Publ., Mus. Nat. Hist., 5:261, April 10, 1952; Hall and Kelson, The mammals of North America, p. 302, March 31, 1959. Tamias quadrivittatus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 120, 1880. Tamias minimus, Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902. Eutamias pallidus, Cary, Proc. Biol. Soc. Washington, 19:87, June 4, 1906; Swenk, Proc. Nebraska Acad. Sci., 8:82, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:26, September, 1908 (part). Eutamias pallidus cacodemus, Swenk, Proc. Nebraska Acad. Sci., 8:83, Sep- tember, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:27, September, 1908 (part); Swenk, Nebraska Blue Book, p. 851, 1915 (part); Swenk, Nebraska Blue Book, p. 408, December, 1918 (part); Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919 (part); Swenk, Nebraska Blue Book, p. 480, December, 1920 (part). Eutamias pallidus pallidus, Swenk, Nebraska Blue Book, p. 851, 1915 (part); Swenk, Nebraska Blue Book, p. 408, December, 1918 (part); Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919 (part); Swenk, Nebraska Blue Book, p. 480, December, 1920 (part). E[utamias]. m[inimus]. pallidus, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Pine Ridge and adjacent badlands of Sioux and Dawes counties, east at least to the vicinity of Chadron; known also from one locality in Box Butte County. See Fig. 22. External measurements. — Average and extreme measurements of nine speci- mens (three males, six females) from Dawes and Sioux counties are: 210.9 (204-215); 96.5 (89-100); 32.3 (31-33); 15.5 (14-17). For cranial measure- ments see Table 8. Seven specimens (two males, five females) from 3% mi. N and 1 mi. E Glen weighed an average of 45.9 grams (42.2-52.1). Remarks. — In the original description of Eutamias minimus ca- codemus of the Badlands of South Dakota, Cary (1906:90, foot- note) suggested that chipmunks from the badlands of northern Sioux and Dawes counties might be referable to cacodemus. Sub- sequently, Swenk (1908:83, and elsewhere) listed E. m. cacodemus, along with E. m. pallidus, as occurring in Nebraska. Some chip- munks from the Nebraskan badlands are somewhat paler on the head, back, and sides than chipmunks from the Pine Ridge to the south but are not nearly so pale dorsally and on the underside of the tail as specimens of E. m. cacodemus from Jackson, Pennington, and Shannon counties, South Dakota. Manuscript reports of E. m. pallidus from several places in the southern part of the Panhandle have not been admitted here. Cary (MS) recorded the species from Smeed, Kimball County, and from extreme western Banner and Scottsbluff counties, and Swenk (MS) listed it from as far east as Oshkosh, Garden County, along the Platte River. The wide distribution of ponderosa pine and red cedar in the southern Panhandle makes it tempting to assume that Mammals of Nebraska 121 E. minimus occurs there, but I know of no records of occurrence supported by specimens, nor has the occurrence of the species there been reported to me by local residents. It should be noted, how- ever, that White (1953:596) recorded the subspecies E. m. pallidus from two counties in Wyoming adjacent to the southern part of the Panhandle. Possibly the occurrence of the least chipmunk to the south of the Pine Ridge at Hemingford, based on a skull only (NSM 723), is open to question. A specimen reported by J. A. Allen (in Coues and Allen, 1877:808) from "Pole [Lodgepole] Creek" (USNM 1907/2605) originated from what is now Wyoming, as probably did another (USNM 4773) listed by him (loc. cit.) simply as from "Nebraska." Similarly, four specimens (UMMZ 62653-56) from the "Platte Valley" probably are from Wyoming. A specimen (UMMZ 62640) from the "Head of Loup Fork" almost certainly originated from some other place. The Loup Fork, or Middle Loup River, has its source in the Sand Hills, as do the other branches of the Loup River system, far to the east of the known range of E. minimus and in a habitat inhospitable to the species. Records of occurrence. — Specimens examined, 74, as follows: Box Butte County: Hemingford, 1 (NSM). Dawes County: Crawford, 2 (1 AMNH, 1 HM); 10 mi. S Chadron, 14 (UMMZ). Sioux County: Coffee Ranch, 21 mi. NW Crawford, 2 (NSM); badlands near Orella, 12 (NSM); Toadstool Park, near Orella, 2 (NSM); 2 mi. S, 2 mi. W Orella, 1 (NSM); 5 mi. S Orella, 1; 11 mi. N Harrison, 2; Warbonnet Canyon, 9 (1 CM, 8 NSM); Warbonnet Twp., 8 mi. N Harrison, 1 (UMMZ); Plunkett's Ranch, 10 mi. NE Harrison, 2 (NSM); 6 mi. NW Harrison, 3 (NSM); Monroe Canyon, 6 (2 AMNH, 3 NGFPC, 1 NSM); West Monroe Canyon, 3 (NSM); Sowbelly Canyon, 1 (NSM); 3% mi. N, 1 mi. E Glen, 7 (NSM); Smily Canyon, Ft. Robinson, 1 ( NSM ) ; Glen, 4 ( 1 AMNH, 3 NSM ) . Additional records: Dawes County: Chadron (Gates, 1945:13); Belmont (Cary, MS). Marmota monax Woodchuck The woodchuck, largest of Nebraskan sciurids, is restricted in distribution to the eastern part of the state. The species occurs largely in the Blue and Nemaha drainages but occurs also in the eastern part of the Platte drainage and north in the vicinity of the Missouri River at least as far as Dixon County. The woodchuck was first recorded from Nebraska by James (1823:369), who listed it among the mammals recorded at the Engineer Cantonment in what is now Washington County by Major Long's command in the winter of 1819-20. According to Swenk (1938:350) who reviewed the status of Marmota monax in Nebraska, the species "was originally confined 122 University of Kansas Publs., Mus. Nat. Hist. . . . to the bottom lands of the Missouri River, from about the mouth of the Platte River southward, and was decidedly uncom- mon even there." He further contended that the woodchuck began to increase in numbers and to expand its range westward in the early part of the 20th Century. Possibly this was the case, although I have no information either to corroborate or to contradict his contention. Several reports (Swenk, op. ci£.:351-353) after 1922 of woodchuck populations so high in certain areas as to create serious agricultural problems tend to support at least the thesis of increasing numbers. ► « Museum of Natural History University of Kama* 1952 Fig. 23. Distribution of two species of sciurids in Nebraska. 1. Marmota monax bunkeri. 2. Spermophilus richardsonii elegans. For explanation of sym- bols see Fig. 5. Inset map shows distribution of M. monax in North America. Possibly the planting of many hundred of miles of Osage orange hedgerows provided avenues of dispersal and sites for burrows for the woodchuck in many areas. Swenk (loc. cit.) cited several in- stances of M. monax inhabiting Osage orange hedges and it is in this habitat that I have most frequently seen the species. In the last decade, however, many farmers in southeastern Nebraska have destroyed these hedges ( 103 miles alone in Pawnee County in one year) because they sap ground water and nutritive elements from the soil of adjacent croplands. A noticeable reduction in numbers of M. monax in many places in the past 10 years or so may well be correlated with the destruction of Osage orange hedgerows. The occurrence of the species in northeastern Nebraska long has been suspected. Paul Heil of Ponca reported to me ( personal com- Mammals of Nebraska 123 munication) on July 9, 1952, that in the spring of that year he and his son caught and kept in captivity for several weeks what they believed to have been a young woodchuck. Findley (1956^:30) reported the possible occurrence of M. monax in Clay County, South Dakota, across the Missouri River from Dixon and Cedar counties. Scott (1937:68) recorded it from several places in north- western Iowa and Polder (1958:562) mentioned its occurrence in all Iowan counties bordering the Missouri from Sioux City south- ward. Not until July 1, 1960, however, was a specimen taken on the Nebraska side when George Brog killed an individual of un- known sex 6 mi. NW Wakefield. The skull alone was saved and was communicated to me by George Schildman of the Nebraska Game, Forestation and Parks Commission. This specimen tenta- tively is referred to the subspecies M. m. bunkeri; woodchucks from northwestern Iowa have been assigned to M. m. monax. No record of reproduction of this species in Nebraska is presently available. Grizzell (1955:269) reported an average of 4.6 young per litter in Maryland, the largest litter containing 8 young. The woodchuck is monestrous; the single litter is born in spring. Marmota monax bunkeri Black Marmota monax bunkeri Black, Jour. Mamm., 16:319, November 15, 1935 (type locality, 7 mi. SW Lawrence, Douglas Co., Kansas); Jones and Webb, Jour. Mamm., 30:313, August 17, 1949; Hall and Kelson, The mammals of North America, p. 321, March 31, 1959. Arctomys monax, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823; Aughey, Sketches of the physical geography and geology of Nebraska, p. 120, 1880. Marmotta monax, Swenk, Proc. Nebraska Acad. Sci., 8:87, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:31, September, 1908. Marmotta monax monax, Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 480, December, 1920. M[armota]. m[onax]. bunkeri, Swenk, Jour. Mamm., 19:349, August 18, 1938; Jones, Trans. Kansas Acad. Sci., 60:275, October 22, 1957. Distribution in Nebraska. — Eastern part of state, principally south of Platte River in Blue and Nemaha drainages, west at least to Nuckolls County, north along Missouri River at least to Dixon County. See Fig. 23. External measurements. — Average and extreme measurements of four males and four females from southeastern Nebraska are, respectively: 597.2 (579- 654), 581.5 (543-624); 142.0 (125-155), 136.8 (124-142); 93.5 (93-94), 89.3 (86-97); 24 (one specimen), 31.02 (28-34). For cranial measurements see Table 8. Two of the above-mentioned males weighed 7/2 and 9 lbs.; one of the females weighed 6 lbs. Cockrum (1952:118) reported weights of woodchucks in Kansas of up to 9 lbs. 12 oz. Records of occurrence. — Specimens examined, 15, as follows: Cass County: NE of Weeping Water, 1 (NSM); no specific locality, 1 (NSM). Dixon County: 6 mi. NW Wakefield, 1. Gage County: near Cortland, 1 (UNDZ). 124 University of Kansas Publs., Mus. Nat. Hist. Jefferson County: Plymouth, 1 (NGFPC). Johnson County: no specific locality, 1 (NSM). Lancaster County: Lincoln, 1 (UC); 8 mi. S Lincoln, 1 (NSM). Nemaha County: 7 mi. S Auburn, 1 (NSM). Nuckolls County: near Nelson, 1 (skin HM, skull KU). Richardson County: Stella, 1 (NSM); 2 mi. W Verdon, 1 (NGFPC); Rulo, 1 (WSC). Saline County: Western, 1 (NSM). Saunders County: 1 mi. S, 2K mi. E Ashland, 1 (NSM). Washington County: Blair, 1 (RV). Additional records (Swenk, 1938:350-353, unless otherwise noted): Cass County: "a few" mi. S Plattsmouth. Jefferson County: near Fairbury. Johnson County: "neighborhood" Tecumseh; "neighborhood" Elk Creek. Nemaha County: vicinity Peru; 3 mi. S, 2 mi. W Brownville; 2 mi. N, 5 mi. E Auburn. Otoe County: no specific locality. Pawnee County: J* mi. S Table Rock. Richardson County: 2 mi. SW Salem; 2 mi. S, 3 mi. W Falls City; vicinity Rulo (Jones and Webb, 1949:313). Saunders County: near Mead; near Ashland. Washington County: Engineer Cantonment ^ap- proximately 2 mi. E Ft. Calhoun] (James, 1823:369). Table 8. — Cranial Measurements of Tamias, Eutamias, and Marmota. J3 r* m ca fcfi d .2 ID c3 >> & 3 Number of specimens o3 "•3 "3.2 C a o averaged or catalogue TO " £B O o number, and sex ■S3 o o 03 -3 faB 0 ngth max toot +3 u o >> o >fc 3 Number of specimens v~2 09 03 v£ •3-S lit !3 o „ , c3 (-, A CD averaged or catalogue ■si* & a 0) O -+3 .-§^3 O °3j number, and sex ndyl leng o o 03 ,4 bD a agth max toot a u o o O) 3 p Spermophilus franklinii, Spencer, Boyd County 4290 NSM, 9 | 53.3 | 50.8 | 30.2 | 12.1 | 18.5 | 10.8 | 20.1 Verdigre, Knox County 126399 USNM, 97 1 1 I 'umr^rrMW l^^ma^J/MM/IM/IWS/1 //MmlM' Mn^ttjf nA- - - :- ^ — r- — r — T~WhrJfffMli 42 ML i " " r WmLJiWMI/iM f— ' X/77////////////////////////y/ r'~Jr'-'JWIlMlII \J n ml I ml III i — — r ">£$ i — '^EttttttUUillUUll/lllllflllllllllllllNIIIIIIJ •— ' ^^^LIJl 1 III il/ilit fnwLlJ 1 i / / 1 /I lilt III! 11/ r&\ w OO.BOv i rm^^M^/W^^W/nmrni 1 A f»0 2;m ftft~~} Kv^P-0 ■ y 71 lfilfiifotfitn /yt/ftjji/'/ 77 //J-/ ft //J/ i ^n 1 II 1 1 1 Llrll mLL14T77iirlrlhll 1 1 1 III 1 1 1 1 N WMiMlMmii IMi n — no >k»i&«L_bo 1 Scolt 10 O 90 -UlWiltt ' ■ 1 1 1 Musoum of Natural Halory UnWenify «( Kansat ^9S^ . t 1 I 103 KX> 97 Fig. 29. Distribution of Sciurus niger rufiventer in Nebraska. For explanation of symbols see Fig. 5. The fox squirrel also has moved up the Missouri River within historic time. Lewis and Clark noted upon their return down the Missouri in 1806: "In passing the Dome [or Tower, in northeastern Boyd County] and the first village of barking squirrels [prairie dogs], we stopped and killed two fox-squirrels, an animal which we had not seen on the river higher than this place" (Coues, 1893: 1199). Later, Hayden (1859:708), discussing his explorations in Nebraska and adjacent areas in the late 1850's, wrote of S. niger: "Very abundant around Council Bluffs [Iowa]. Gradually becomes rare, and ceases near the mouth of the White River [South Dakota]." Presently the fox squirrel occurs all along the Missouri in South Dakota and in much of the Missouri drainage of North Dakota. Dispersal of the fox squirrel westward along river systems in the Great Plains and successful introduction of the species in places where it did not formerly occur result largely from conditions 10—6532 146 University of Kansas Publs., Mus. Nat. Hist. created by man. Protected from prairie fires, deciduous riparian communities, consisting mostly of cottonwood and willow but hav- ing some boxelder and elm, have matured along river bottoms where only isolated stands or none at all occurred 100 years ago. Too, early settlers planted trees in newly founded towns and to create rural groves and wind breaks. Perhaps even more important to the fox squirrel was the availability of food, principally corn but also small grains, owing to cultivation of the river valleys. Hibbard (1957:525-527) in North Dakota, Hoover and Yeager (1953:359- 360) in Colorado, and Packard (1956:8) in Kansas also have re- ported westward extension of the range of the fox squirrel in recent years. As noted above, introductions are at least in part responsible for extension of range in S. niger. Hoover and Yeager {loc. cit.) sur- mised that both "stocking" and natural invasion were responsible for the establishment of fox squirrel populations along the South Platte River in Colorado. Hibbard ( loc. cit. ) attributed the spread of the species in North Dakota both to introduction and invasion. 1 know definitely of two introductions in Nebraska; probably many others occurred of which no record was kept. According to Swenk (MS), Rees Heaton introduced fox squirrels from Kansas along Medicine Creek near Curtis about 1902, where the species did not then occur. D. W. Lindeman, who farms with his brother on Dead- mans Creek, 7 mi. S and 3/2 mi. W Crawford, reported to me that his father introduced a pair of fox squirrels there in 1908 from Cass County, Iowa. Prior to that time squirrels were unknown to Linde- man along the streams of the Pine Ridge in eastern Sioux and western Dawes counties. Today S. niger is common on Deadmans Creek and other tributaries of the White River and occurs also in the Hat Creek Basin. Lindeman's dogs killed 26 squirrels in the winter of 1956-57 in one building where corn was stored. The population of S. niger in the valleys of the Pine Ridge and adjacent areas to the north could be entirely descendent from intro- duced animals. It is doubtful that fox squirrels reached the Pine Ridge along the valley of the White River of South Dakota but it is possible that individuals reached the area from the valley of the Niobrara River to the south. Females usually breed twice annually, once in late winter or early spring and again in late spring or early summer. The number of young per litter ranges from 1-6 (Asdell, 1946:220) but usually is 2 or 3. Mammals of Nebraska 147 Sciurus niger rufiventer fi. Geoffroy St.-Hilaire Sciurus rufiventer £. Geoffroy St.-Hilaire, Catalogue des mammiferes der Museum National d'Histoire Naturelle, Paris, p. 176, 1803 ( type locality, somewhere in the Mississippi Valley, probably between southern Illinois and central Tennessee according to Osgood, Proc. Biol. Soc. Washing- ton, 20:44, April 18, 1907); Swenk, Proc. Nebraska Acad. Sci., 8:80, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:24, September, 1908. Sciurus niger rufiventer, Osgood, Proc. Biol. Soc. Washington, 20:44, April 18, 1907; Swenk, Nebraska Blue Book, p. 851, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 480, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:27, October, 1936; Jones and Webb, Jour. Mamm., 30:313, August 17, 1949. Sciurus macrurus (misspelled macroura), James, Account of an expedition from Pittsburgh to the Bocky Mountains . . .,1:115, 1823 (part). [Sciurus] capistratus, James, Account of an expedition from Pittsburgh to the Bocky Mountains . . ., 1:370, 1823 (part). [Sciurus] nigra, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:370, 1823 (part). Sciurus ludovicianus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 120, 1880. S[ciurus]. n[iger], rufiventer, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Widely distributed in eastern part of state; also along major drainage systems in western part and streams of Pine Ridge area. See Fig. 29. External measurements. — Average and extreme measurements of 10 speci- mens (eight males, two females) from Lancaster and Bichardson counties are: 511.1 (490-528); 233.8 (219-245); 71.2 (67-76); 30.69 (27-32). Correspond- ing measurements for six specimens (two males, four females) from Dawes and Sioux counties are: 499.3 (490-510); 209.5 (210-225); 69.1 (64.5-73); 29.5 (25-32). For cranial measurements see Table 10. A male from Lancaster County weighed 622.3 grams. Two males and two females from the vicinity of Crawford weighed, respectively: 594.8, 690.0, 700.0, 670.0. Remarks. — Specimens from along the Niobrara River in the vicinity of Valentine and from along streams of the Pine Ridge country to the west differ in several ways from specimens of S. n. rufiventer from eastern Nebraska. The squirrels from the north- western part of the state average smaller cranially and slightly smaller externally (see measurements), and are paler over-all, but especially on the neck, feet, and tail. The latter is straw color or pale ochraceous orange ventrally rather than reddish orange. A specimen from 5 mi. WSW Ogallala (KU 76917), saved as a skull only, agrees with specimens from northwestern Nebraska in small external and cranial dimensions and perhaps small, pale-colored squirrels occur also in the western Platte Valley. The theory that fox squirrels in the western Niobrara Valley and 148 University of Kansas Publs., Mus. Nat. Hist. Pine Ridge areas represent a distinct subspecies is a tempting one, but is tempered by two major considerations. First of all, speci- mens from the western reaches of other river systems on the Great Plains differ, at least in being paler, from typical specimens of S. n. rufiventer. This is true of specimens from the Republican drainage (Cheyenne, Decatur, Rawlins, and Thomas counties, Kansas), the Arkansas drainage (Hamilton, Finney, and Kiowa counties, Kansas), the Cimarron drainage (Meade County, Kansas), and the Canadian drainage in the Texas Panhandle (W. L. Cutter, personal commu- nication). Possibly populations of fox squirrels along other river systems are pale-colored as well. Obviously these pale populations have no geographic continuity and the gene-flow of each is eastward along the rivers to the main range of S. n. rufiventer. Seemingly squirrels in the dendritic western segments of the range of rufiventer are adapting through natural selection in similar ways to similar environments. Secondly, insofar as information now available indicates, fox squirrels have only recently occupied these western areas, either through invasion or through introduction, or both. Mostly this has taken place in the last half century and one must consider the genetic basis of change in so short a period. Furthermore, few specimens are available from most of the areas mentioned. Until additional material is available from the Great Plains it seems best to refer the squirrels under discussion to the subspecies rufiventer. Records of occurrence. — Specimens examined, 119, as follows: Adams County: Ayr, 1 (HM); no specific locality, 2 (HM). Boyd County: Spencer, 1 (UNDZ). Brown County: Long Pine, 1 (Stanford Univ.). Cass County: Plattsmouth, 1 (BV); South Bend, 1 (NSM). Cherby County: Valentine, 4 ( USNM ) ; Ft. Niobrara Nat'l Wildlife Refuge, 4 ( NSM ). Cumtng County: 1 mi. S Beemer, 1. Custer County: Victoria Springs, 1 (UMMZ). Dawes County: 12 mi. E Chadron, 1 (UMMZ); Chadron, 1 (CSTC); 2 mi. W Horn, 1 (NSM); 10 mi. S Chadron, 2 (UMMZ); 3 mi. W Crawford, 3 (NSM). Dawson County: 4 mi. E Gothenburg, 1 (UC); 34 mi. S Gothen- burg, 1. Douglas County: Omaha, 1 (BV). Frontier County: 17 mi. SE Stockville, 1 (NSM). Gage County: Bamston, 1 (NSM); 2 mi. S, % mi. E Barnston, 1. Hamilton County: no specific locality, 1 (HM). Holt County: 10 mi. SE Butte, 1 (WSC). Keith County: 5 mi. WSW Ogallala, 1. Knox County: Creighton, 1 (NSM). Lancaster County: mouth of Bock Creek, Waverly, 1 (NGFPC); Woodlawn, 1 (NSM); Lincoln, 26 (1 MVZ, 1 NGFPC, 6 NSM, 2 UNDZ, 16 UC); 3 mi. E Lincoln, 1; 5 mi. E Lin- coln, 1 (UNDZ); 2 mi. S, 8 mi. E Lincoln, 1 (UC); 5 mi. S, 2 mi, E Lincoln, 1 (UC); 6 mi. S Lincoln, 1 (UC); 7 mi. S. 2 mi. W Lincoln, 1 (UC); Jamaica, 8 mi. S Lincoln, 1 (MVZ); Hanlon, 1 (NSM); Boca, 1 (NSM); no specific locality, 1 (UC). Nemaha County: 3 mi. S, Vk mi. E Peru, 1; Auburn, 1 (USNM); London, 1 (USNM). Nuckolls County: X mi. S, 2 mi. W Nelson, 1 (UNM). Otoe County: 4 mi. S, 18& mi. E Lincoln, 1 (UC); 3 mi. S, 2 mi. E Nebraska City, 3. Pierce County: 15 mi. N Norfolk, 2 (UC). Bed Wdllow County: McCook, 2 (NSM). Bichardson County: 5 mi. N, 2 mi. W Humboldt, 2; 4 mi. E Barada, 5; 4 mi. N, 4 mi. E Falls City, 1 (NGFPC); Rulo, 1 (WSC); 3 mi. SE Bulo, 3 (NGFPC). Saline County: Crete, 1 (UNDZ); 4 mi. N Tobias, 1 (MVZ); Western, 1 (UNDZ). Sarpy County: Mammals of Nebraska. 149 Bellevue, 1 (RV). Saunders County: SE comer, 5 (NSM). Seward County: 6 mi. E Seward. 1 (UC). Sioux County: Monroe Canyon, 2 (NSM); 1-VA mi. N, 10 mi. W Crawford, 2 (1 NSM); 7 mi. W Crawford, 3 (NSM); 3 mi. E Glen, 1 (NSM). Valley County: 11 mi. W North Loup, 1 (UNDZ). Washington County: Blair, 1 (RV). Webster County: Bladen, 1 (HM); Inavale, 1 (HM). Additional records: Adams County: Logan Twp. (Swenk, MS). Ante- lope County: Neligh (Cary, MS). Boyd County: Anoka (Swenk, MS); the Tower, sec. 10, T. 34 N, R. 10 W (see text). Brown County: Long Pine Canyon (Swenk, MS). Buffalo County: Kearney (Jones, fieldnotes). Cherry County: Niobrara River, S of Merriman (Cary, MS); 12 mi. S Cody (Cary, MS). Clay County: Inland (Swenk, MS). Cuming County: West Point (Swenk, 1908:80). Custer County: vicinity Broken Bow (Swenk, MS). Dakota County: no specific locality (Rapp and Gates, 1957:53). Dodge County: no specific locality (Rapp and Gates, 1957:53). Gage County: Beatrice (Swenk, 1908:80). Holt County: no specific locality (Swenk, 1908:80). Howard County: St. Paul (Swenk, MS). Jefferson County: no specific locality (Rapp and Gates, 1957:53). Knox County: Niobrara (Swenk, 1908:80). Lincoln County: 3 mi. W North Platte (Swenk, MS). Madison County: Norfolk (Swenk, 1908:80). Richardson County: Falls City (Swenk, 1908:80); vicinity Rulo (Jones and Webb, 1949:313). Scotts Bluff County: Scotts Bluff Nat'l Monument (Mattes, 1958:57). Thomas County: no specific locality (Smith, 1958:60). Wash- ington County: Engineer Cantonment [= approximately 2 mi. E Ft. Cal- houn] (James, 1823:370). Webster County: Red Cloud (Swenk, MS). Glaucomys volans Southern Flying Squirrel The southern flying squirrel is an inhabitant of the woodlands along the Missouri River in southeastern Nebraska. Probably the species was more widely distributed in the southeastern part of the state at a time when the deciduous association was more widespread [-0- \ iii • j-. r* j j ! i ! i r-LJ--^ _.^ — v— j — p-— p-j— j— j ^-T-ri-.r.js I ! ! I » | f"""L_.LJL.-i 40- Mu«um of Natural History University of Kansas 1952 L KB 100 97 Fig. 30. Distribution of Glaucomys volans volans in Nebraska. For explana- tion of symbols see Fig. 5. 150 University of Kansas Publs., Mus. Nat. Hist. than now. Although uncommon in most areas, G. volans is ap- parently relatively abundant in the vicinity of Peru where J. R. Al- corn took a specimen in 1958 and where one or more are usually captured each year on the campus of Peru State Teachers College. A farmer who lives 4 mi. E Barada informed me in 1956 that flying squirrels were still seen occasionally in that area and Velich (1954: 429) reported animals seen or taken in Sarpy County in 1950 and in Douglas County in 1952. Females may breed several times each year according to Asdell (1946:216), usually twice, and bear 1-4 young per litter. Claucomys volans volans (Linnaeus) [Mus] volans Linnaeus, Systema naturae, ed. 10, 1:63, 1758 (type locality restricted to Virginia by Elliot, Field Columb. Mus., Zool. Ser., 2:109, 1901). [Glaucomys] volans, A H. Howell, Proc. Biol. Soc. Washington, 28:109, May 27, 1915. Pteromys volucella, Aughey, Sketches of the physical geography and geology of Nebraska, p. 120, 1880. Pteromys volans volans, Swenk, Nebraska Blue Book, p. 852, 1915. Pteromys volans nebrascensis Swenk, Univ. Nebraska Studies, 15:151, Sep- tember 25, 1915 (type locality, Nebraska City, Otoe Co., Nebraska). Glaucomys volans nebrascensis, Swenk, Nebraska Blue Book, p. 408, De- cember, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 480, December, 1920. Glaucomys volans volans, A. H. Howell, N. Amer. Fauna, 44:19, June 13, 1918; Velich, Jour. Mamm., 35:429, August 20, 1954; Miller and Kellogg, Bull. U. S. Nat. Mus., 205:268, March 3, 1955; Hall and Kelson, The mammals of North America, p. 407, March 31, 1959. G[laucomys]. v[olans]. volans, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Southeastern part of state, north certainly to Douglas County and west certainly to Seward County; probably presently restricted principally to wooded areas along Missouri River. See Fig. 30. External measurements. — Measurements of an adult male from Nebraska City, followed by those of an adult female from 1 mi. NNW Peru, are: 240.5, 242; 115, 111; 30.5, 31; 18 (crown), 19. For cranial measurements see Table 10. A female from Ft. Leavenworth, Kansas, weighed 102.8 grams. Remarks. — "Pteromys volans nebrascensis" named by Swenk (1915Z?:151), was said to differ from Glaucomys volans volans in being larger, and in having a longer tail, darker feet and toes, and slightly larger and more rounded auditory bullae. I concur with A. H. Howell (1918:22-23) and Cockrum (1952:134) that ne- brascensis is a synonym of volans. Records of occurrence. — Specimens examined, 7, as follows: Nemaha County: 1 mi. NNW Peru, 1. Otoe County: Nebraska City, 2 (1 MVZ, 1 NSM); 10 mi. SE Nebraska City, 3 (HM). Saupy County: Fontanelle Forest, 1 (RV). Additional records: Douglas County: Florence (Velich, 1954:429); Omaha (Cary, MS); South Omaha Bridge (Velich, 1954:429). Nemaha Mammals of Nebraska 151 County: Peru (Swenk, 1908:88). Otoe County: near Nebraska City (Taylor, 1888:745). Richardson County: 4 mi. E Barada (see text above). Sarpy County: Bellevue (Cary, MS). Seward County: Beaver Crossing (Swenk, MS). Table 10. — Cranial Measurements of Cynomys, Sciurus, and Glaucomys. A c in 03 M e3 .2 02 03 h& 3 Number of specimens C *>3 03 og "S.8 a ,5 DO averaged or catalogue o -^ S g .-S-J3 o o number, and sex -T Ml a—1 o o m fcJD a ngth mas toot i* o >> o « (D OJ o O N Pi hJ h3 Q Cynomys ludovicianus ludovicianus, Scotts Bluff County 3277 NSM, 9 . 3280 NSM, 9 3319 NSM, dV 59.7 55.7 43.2 14.4 21.5 17.0 61.1 45.0 14.9 22.6 16.5 62.1 59.2 45.1 13.7 23.0 17.5 10 mi. S, 2 mi. E Ord, Valley County 32 NGFPC, 9 . 350 NGFPC, 9 64.5 63.3 61.3 61.3 45.0 45.1 12.5 11.9 24.5 23.6 17.1 18.0 26.1 27^6 26.3 27.7 Sciurus carolinensis carolinensis, 4 mi. E Barada, Richardson County Average 10 (5 d\ 59) 62.2 57. 39 35.0 19.0 20.8 11.3 26.0 Minimum 60.2 56.0 33.6 18.0 20.0 11.0 25.4 Maximum 63.6 58.4 36.3 19.9 21.6 11.6 26.5 Sciurus niger rufiventer, Lancaster and Richardson counties Average 10 (7d\ 3 9) Minimum Maximum 64.0 59.7 35.7 19.9 21.9 11.4 63.0 57.7 33.9 19.2 20.8 10.9 65.5 61.8 37.3 20.5 22.6 11.9 vicinity Valentine, Cherry County Average 7 (6d% 19) Minimum Maximum 61.3 56.6 34.5 19.5 21.1 11.2 60.5 56.1 33.2 19.0 20.5 10.9 62.0 57.2 35.3 19.8 21.8 11.7 Dawes and Sioux counties Average 5 (2d1, 3 9) Minimum Maximum 61.6 57.5 34.5 19.6 21.3 11.2 60.7 56.8 34.0 18.7 20.6 10.8 63.6 58.1 35.0 20.4 23.0 11.5 Glaucomys volans volans, 1 mi. NNW Peru, Nemaha County 77949 KU, 9 | 35.6 | 33.0 | 21.5 | 9.0 | 9.9 | 6.8 26.7 25.2 27.8 26.0 25.4 26.6 26.6 25.8 27.3 16.5 Family Geomyidae — Pocket Gophers Key to Nebraskan Pocket Gophers 1. Hind foot less than 30; anterior face of upper incisor smooth; enamel present on posterior occlusal face of upper premolar. Thomomys talpoides, p. 152 1'. Hind foot 30 or (usually) more; anterior face of upper incisor grooved; enamel lacking on posterior occlusal face of upper premolar. Geomys bursarius, p. 155 152 University of Kansas Ptjbls., Mus. Nat. Hist. Thomomys talpoides Northern Pocket Gopher The northern pocket gopher occurs in Nebraska only in the ex- treme northwestern and southwestern parts of the Panhandle. In the northwest it seemingly replaces Geomys bursarins in the Pierre soils north of the Pine Ridge and White Paver. In the southwest the species occurs along with G. bursarius in the Rosebud soils on the Cheyenne Table but Thomomys has always been taken there on higher ground, never in the valleys. K- MuMvm of Natural History Uniyeniry of Karnes Ha SL. WL 9T Fig. 31. Distribution of Thomomys talpoides in Nebraska. 1. T. t. cheyen- nensis. 2. T. t. pierreicolus. For explanation of symbols see Fig. 5. Evidently Thomomys talpoides is not so common now as formerly in the southwestern Panhandle. Swenk (1940a:7), whose com- ments were based largely on field work conducted in 1919, noted that G. bursarius was entirely absent on the uplands of the Cheyenne Table "where it is replaced by Thomomys." In the summer of 1945 a field party from the University of Kansas Museum of Natural History spent several days trapping in the vicinity of Dalton in an attempt to secure specimens of T. t. cheyennensis. Members of the party trapped in all available upland soil types but took only G. bursarius. Probably the turning of the upland prairie for cultiva- tion, principally for wheat, has severely restricted T. talpoides on the Cheyenne Table in the past several decades and has facilitated invasion by G. bursarius of upland habitats. Mammals of Nebraska 153 Females probably breed only once annually; the litter is born in spring or early summer. According to Tryon (1947:19) an un- stated number of females from the Bridger Mountains, Montana, carried an average of 4.4 embryos per pregnancy. Thomomys talpoides cheyennensis Swenk Thomomys talpoides cheyennensis Swenk, Missouri Valley Fauna, 4:5, March 1, 1941 (type locality, 2 mi. S Dalton, Cheyenne Co., Nebraska); Hall, Univ. of Kansas Publ., Mus. Nat. Hist., 5:30, February 28, 1951; Miller and Kellogg, Bull. U. S. Nat. Mus., 205:311, March 3, 1955; Hall and Kelson, The mammals of North America, p. 437, March 31, 1959. Thomomys clusius clusius, Swenk, Nebraska Blue Book, p. 852, 1915. Thomomys talpoides clusius, Swenk, Nebraska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920. T[homomysJ. t[alpoides]. cheyennensis, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Known only from southwestern part of Pan- handle. See Fig. 31. External measurements, — Measurements of the holotype, a male, and two females from Kimball County are, respectively: 225, 225, 212; 66, 66, 63; 29, 26, 29; — , — , 5. For cranial measurements see Table 11. Remarks. — From Thomomys talpoides pierreicolus of northwest- ern Nebraska, T. t. cheyennensis differs in being paler, larger (both externally and cranially), and in having proportionately longer rostrum and nasals, more highly arched skull over the naso-frontal suture, less procumbent upper incisors, larger teeth, and larger auditory bullae but smaller external auditory meatuses. In all probability the geographic ranges of these two subspecies do not meet. T. t. cheyennensis occurs only in the southwestern part of the Nebraska Panhandle and at several places in the immediate vicinity of Pine Bluffs, Wyoming, just over the Nebraska border (Hall and Montague, 1951:30). V. Bailey (1915:100, footnote) suggested that the specimen on which the name Geomys boreaiis Bachman, 1839 (not Geomys borealis Richardson, 1837), was based was the one mentioned in Townsend's narrative as having been obtained near the prominent land mark of Scotts Bluff, in the present county of the same name. Bailey examined the specimen in question and identified it as Thomomys talpoides clusius. Because the species talpoides is not otherwise known from Scotts Bluff County, I suppose that the specimen mentioned by Townsend was instead Geomys bursarius, which is common in the vicinity of Scotts Bluff. Should T. talpoides be found to occur at Scotts Bluff, specimens would most likely be assignable to T. t. cheyennensis, known from the next county south- 154 University of Kansas Publs., Mus. Nat. Hist. ward in Nebraska, or to T. t. attenuatus, known from as near as 5 mi. SW Wheatland, Wyoming. Records of occurrence. — Specimens examined, 7, as follows: Cheyenne County: 2 mi. S Dalton, 2 (1 MVZ, 1 NSM); 4 mi. N Sidney, 1 (NSM). Kimball County: 10 mi. N Kimball, 2 (NSM); Smeed, 1; 9 mi. S Kimball, 1 (NSM). Additional records: Banner County: no specific locality (Fichter, 1941:28). Cheyenne County: 4 mi. S Sidney (Swenk, MS). Kimball County: 5 mi. S Kimball (Swenk, MS); 7 mi. S Kimball (Swenk, MS). Thomomys talpoides pierreicolus Swenk Thomomys talpoides pierreicolus Swenk, Missouri Valley Fauna, 4:2, March 1, 1941 (type locality, Wayside, Dawes Co., Nebraska); Miller and Kellogg, Bull U. S. Nat. Mus., 205:311, March 3, 1955; Hall and Kel- son, The mammals of North America, p. 443, March 31, 1959. Themomys [sic] talpoides, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880. Thomomys talpoides, Swenk, Proc. Nebraska Acad. Sci., 8:107, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:51, September, 1908. Thomomys talpoides nebulosus, Swenk, Nebraska Blue Book, p. 852, 1915. Thomomys talpoides hullatus, Swenk, Nebraska Blue Book, p. 409, De- cember, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:19, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920. T[homomys], t[alpoides]. pierreicolus, Jones, Tran. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Known only from extreme northwestern Ne- braska. See Fig. 31. External measurements. — Measurements of four adult topotypes, one male and three females, are, respectively: 205, 201, 198, 195; 52, 52, 56, 57; 28, 26, 26, 28; 6, 6, 7, 6. For cranial measurements see Table 11. Bespective weights in grams of the four topotypes were: 100.7, 94.0, 88.4, 87.8. Remarks. — For comparison with Thomomys talpoides cheyen- nensis, see account of that subspecies. T. t. pierreicolus is restricted in Nebraska to soils of the Pierre series north of the Pine Ridge in Sioux County and north of the White River in Dawes County. Cary (1902:69) recorded it from northern Sioux County "in both Upper Sonoran and Transition Zones" but, as Swenk (1941:1) pointed out, this statement was based on a single skull picked up along Indian Creek. The sub- species occurs in much of western South Dakota. Imler (1945:272, footnote) noted that one of the pocket gophers caught in snake traps at Crescent Lake National Wildlife Refuge, Garden County, in the summer of 1940, was a member of the genus Thomomys. Crescent Lake Refuge lies near the western edge of the Sand Hills and nearer the known geographic range of T. t. cheyen- nensis than that of T. t. pierreicolus. Because the specimen was not preserved I have not admitted Imler 's record here, but future investigations would be worthwhile to determine whether or not Mammals of Nebraska 155 Thomomys talpoides actually occurs directly north of the Platte River in the Panhandle. A third subspecies of the northern pocket gopher, Thomomys talpoides rufescens, may occur in Nebraska. It has been reported from old Ft. Randall, South Dakota (V. Bailey, 1915:99), only five miles north of the Nebraska border (Boyd County). Swenk (MS), however, made a fairly thorough search for pocket gophers in north- ern Boyd County in August, 1919, and found only Geomys bursarius. Records of occurrence. — Specimens examined, 31, as follows: Dawes County: Wayside, 27 (1 MVZ, 5 NSM); 5 mi. NW Chadron, 2 (NSM); Sand Creek Valley, NE of Horn, 1 (NSM). Sioux County: Indian Creek, N of Story, 1 (NSM). Geomys bursarius Plains Pocket Gopher The plains pocket gopher is state-wide in distribution and is com- mon, often abundant, throughout most of Nebraska. In the eastern, intensely cultivated part of the state the species now occurs mostly in pastures and other fallow lands, and in alfalfa fields. Five different subspecific names have been proposed for speci- mens of Geomys bursarius from Nebraska, based principally on sup- posed differences between specimens from different types of soil; only two of these names are recognized beyond. Myron H. Swenk (1939, 1940a) named four of the five kinds and the reader is re- ferred to his papers for analysis of the distribution of G. bursarius in relation to soils. 97 :& m* "' ■ -i < ' -« Museum of Natural History University of Kansas 1952 97 Fig. 32. Distribution of Geomys bursarius in Nebraska. 1. G. b. lutescens. 2. G. b. majusculus. For explanation of symbols see Fig. 5. 156 University of Kansas Publs., Mus. Nat. Hist. Thirteen females taken in the months of April through July carried an average of 3.6 (2-6) embryos. Lactating females have been collected in April and June. Inasmuch as pregnant females have been obtained as early as January (in Kansas, T. Scheffer, 1910:204), the current theory that females bear but a single litter annually may be in error. Of the 487 specimens of Geomys bursarius examined, three, all of the subspecies G. b. majusculus, were albinos. Geomys bursarius lutescens Merriam Geomys bursarius lutescens Merriam, N. Amer. Fauna, 4:51, October 8, 1890 (type locality, sandhills on Birdwood Creek, Lincoln Co., Ne- braska); Swenk, Nebraska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:19, March 1, 1919; Blossom, Occas. Papers Mus. Zool., Univ. Michigan, 368:1, April 6, 1938; Hooper, Occas. Papers Mus. Zool., Univ. Michigan, 420:3, June 28, 1940; Vilfa-R and Hall, Univ. Kansas Publ., Mus. Nat. Hist., 1:222 (measurements of topotypes on pp. 232-233), November 29, 1947; Miller and Kellogg, Bull. U. S. Nat. Mus., 205:335, March 3, 1955; Russell and Jones, Trans. Kansas Acad. Sci., 58:513, January 23, 1956; Hall and Kelson, The mammals of North America, p. 449, March 31, 1959. Geomys lutescens hylaeus Blossom, Occas. Papers Mus. Zool., Univ. Michi- gan, 368:1, April 6, 1938 (type locality, 10 mi. S Chadron, Dawes Co., Nebraska); Swenk, Missouri Valley Fauna, 2:9, February 1, 1940. Geomys lutescens levisagittalis Swenk, Missouri Valley Fauna, 2:4, Febru- ary 1, 1940 (type locality, Spencer, Boyd Co., Nebraska). Geomys lutescens vinaceus Swenk, Missouri Valley Fauna, 2:7, February 1, 1940 (type locality, Scottsbluff, Scotts Bluff Co., Nebraska). Geomys bursarius, Hayden, Exec. Doc, House of Representatives, 2nd Sess., 35th Cong., 2:708, 1859; Hayden, Trans. Amer. Philos. Soc, 12(n.s.): 146, 1863; Hayden, Catalogue of the collections in geology and natural history . . ., in Warren, Preliminary report of explorations in Ne- braska and Dakota . . ., p. 93, 1875; Coues, in Powell, Exploration of the Colorado River of the West and its tributaries . . ., p. 221, 1875; Coues, in Coues and Allen, Bull. U. S. Geol. Surv. Territories, 11:612, August, 1877; Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880 (part); Merriam, N. Amer. Fauna, 8:120, January 31, 1895 (part); Swenk, Proc. Nebraska Acad. Sci., 8:106, Sep- tember, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:50, September, 1908 (part); Jones, Nebraska Bird Rev., 20:10, January, 1952. Geomys lutescens, Merriam, N. Amer. Fauna, 8:127, January 31, 1895 (part); V. Bailey, Bull. Div. Ornith. Mamm., U. S. D. A., 5:39, 1895; Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902; Swenk, Proc. Nebraska Acad. Sci., 8:107, September, 1908 (part); Swenk Studies Zool. Lab., Univ. Nebraska, 89:51, September, 1908 (part); Lyon and Osgood, Bull. U. S. Nat. Mus., 62:71, January 28, 1909; Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Nebraska Blue Book, p. 481, December, 1920; Wade, Jour. Mamm., 8:310, November 11, 1927; Beed, Bull, Conserv. Surv. Div., Univ. Nebraska, 10:26, October, 1936; Poole and Schantz, Bull. U. S. Nat. Mus., 178:369, April 9, 1942; Imler, Jour. Wildlife Mgt., 9:272, October, 1945. Geomys bursarius hylaeus, Miller and Kellogg, Bull. U. S. Nat. Mus., 205:335, March 3, 1955; Hall and Kelson, The mammals of North America, p. 449, March 31, 1959. Mammals of Nebraska 157 Geomys bursarius levisagittalis, Miller and Kellogg, Bull. U. S. Nat. Mus., 205:335, March 3, 1955; Hall and Kelson, The mammals of North America, p. 449, March 31, 1959. Geomys bursarius vinaceus, Miller and Kellogg, Bull. U. S. Nat. Mus., 205:335, March 3, 1955. G[eomys]. bfursarius]. hylaeus, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. G[eomys]. b[ursarius]. levisagittalis, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. G[eomys]. b[ursarius]. lutescens, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Western two-thirds of state, east certainly to central Antelope, Boyd, Buffalo, Franklin, and northwestern Webster counties. See Fig. 32. External measurements. — Respective average and extreme measurements of five males and eight females from Lincoln County are: 271.8 (266-279), 241.9 (232-258); 84.4 (78-91), 73.2 (65-80); 33.8 (33-36), 31.6 (30-33); 6.03 (6), 5.6 (5-6). Measurements of two males, followed by average and extreme measurements of seven females, from the Pine Ridge in eastern Sioux County are: 278, 277, 252.1 (239-263); 83, 83, 73.6 (69-82); 34, 33, 31.7 (30-33); 6, 5, 5.1 (4-7). Measurements of two males and three females, respectively, from Scotts Bluff County are: 300, 269, 245, 244, 235; 86, 79, 73, 68, 68; 35, 35, 32, 32, 31; 6, 7, 6, 6, 6. Measurements of one male and three females, respec- tively, from the vicinity of Spencer, Boyd County, are: 280, 258, 255, 252; 77, 73, 69, 73; 37, 33, 30, 31; 6, 5, 5, 5. See Swenk ( 1940:9) for additional meas- urements and for cranial measurements see Table 11. Three males from Lincoln County weighed in grams 288.7, 275.6, 266.0; eight females from there averaged 165.6 (148.6-178.2). Two males from east- ern Sioux County weighed 285.0 and 305.0; seven females from there averaged 197.9 (170.8-225.0). Remarks. — From Geomys bursarius majusculus, geographically adjacent to the east in Nebraska, G. b. lutescens differs conspicu- ously in being smaller (both externally and cranially) and paler. Specimens from the eastern edge of the range of lutescens ( Adams, Antelope, Buffalo, Harlan, Holt, Kearney, and Webster counties, and from the tablelands to the north of the Niobrara River in Boyd and Keya Paha counties) are variously darker, and in some cases slightly larger, than typical lutescens and are judged to show inter- gradation with majusculus. Most of these specimens are grayer or more brownish than topotypes of lutescens but two from Ravenna are reddish brown. A series of nine specimens from 1 mi. SE Franklin are fairly typical of lutescens in both size and color. Speci- mens taken on the Sand Hills, including those from the type locality, average slightly paler than specimens from other parts of the range in Nebraska. Three named kinds of pocket gophers ( Geomys lutescens hylaeus Blossom, 1938, Geomys lutescens levisagittalis Swenk, 1940, Geomys lutescens vinaceus Swenk, 1940) are here regarded as synonyms of the earlier-named G. b. lutescens. One of these, vinaceus, was rel- 158 University of Kansas Publs., Mus. Nat. Hist. egated to synonymy under lutescens by Russell and Jones ( 1956 :512- 513) because a majority of the specimens of vinaceus examined by them did not differ significantly from topotypes of lutescens. Their argument was summarized (p. 513) as follows: "The differences that separate . . . vinaceus from . . . lutescens are slight and are reflected only in animals from the type locality. We in- terpret these slight differences as minor variations within a local population and as of no subspecific significance." The two remain- ing kinds, hylaeus and levisagittalis, have stood until now in the literature as valid subspecies. The specimens upon which the name levisagittalis was based are intergrades between G. b. lutescens and G. b. niajusculus of eastern Nebraska, although definitely assignable to the former. Swenk re- garded lutescens and majusculus as belonging to different species. Consequently, he was led to propose a new name for the population of pocket gophers on the tablelands to the north of the Niobrara River in Boyd, Keya Paha, and extreme northeastern Cherry coun- ties, individuals of which are slightly larger and somewhat darker than typical lutescens. Had Swenk been aware that lutescens and majusculus were conspecific he most certainly would have recog- nized these individuals as intergrades between the two. Specimens from the vicinity of the type locality of levisagittalis ( Spencer, Boyd County) are, on the average, the largest and darkest of the pocket gophers from the geographic range ascribed to that race by Swenk. In both size and color, however, specimens from the vicinity of Spencer are clearly nearer lutescens than majusculus. Westward from Spencer to Valentine on the tablelands north of the Niobrara pocket gophers become progressively smaller and paler and most specimens from the vicinity of the latter locality are typical of lutescens; only a few are darker. The name hylaeus was proposed for specimens from the Pine Ridge, 10 mi. S Chadron, that were alleged to differ from G. b. lutescens in being smaller and darker, especially middorsally. The five "adults" (holotype and four paratypes) that formed the basis of Blossom's (1938:1-2) description of hylaeus all are, instead, young adults. Actually, adult pocket gophers from localities on the Pine Ridge are approximately the same size as (if anything slightly larger than) topotypes of lutescens (see measurements herein and those of Swenk, 1940a: 9-10) and do not differ from them in cranial details. Some specimens from the Pine Ridge are darker dorsally, especially middorsally, than topotypes of lutescens but the color of many others is within the range of variation of the latter. For Mammals of Nebraska 159 example, of nine adults from the immediate vicinity of Crawford, in extreme eastern Sioux County, five fit fairly well into a series of topotypes of lutescens (at best only slightly darker than the aver- age), two are noticeably darker than the average of lutescens, but only two are darker than the darkest lutescens. The darkest of the two specimens mentioned last (NSM 12121, obtained on July 2, 1957, 6/2 mi. W Crawford ) resembles the holotype of hylaeus, which is the darkest of the specimens on which the name was based. NSM 12121 is molting; new, relatively pale pelage is present on the head and anterior part of the back. The remaining portion of the dorsal area is dark gray, quite in contrast to the sides, and seemingly caused by wear on the old pelage to the extent that most or all of the buffy subterminal band on each of the hairs has been worn away, leaving only the long, plumbeous base. Probably the hard, rough soils of the Pine Ridge cause greater wear on the pelage of gophers than do any of the other soil types within the range of lutescens in Nebraska; certainly they cause greater wear than does the pliable dunesand of the Sand Hills. Pocket gophers from other localities on the Pine Ridge in Ne- braska and adjacent South Dakota follow a similar pattern — that is, some, but not all, specimens are somewhat darker middorsally than lutescens but do not differ otherwise. Blossom (loc. cit.) thought a relationship existed "between the dark coloration of hylaeus and the dark, humus filled soil of its woodland habitat." Undoubtedly this is partly true, but the soils of the Pine Ridge are not especially darker in most places than those to the south of the Ridge. The Pine Ridge itself is relatively narrow, less than 10 miles wide in many places, and Geomys bursarius seemingly occurs only sparingly immediately to the north where Thomomys talpoides pierreicolus is found. The slightly darker color of pocket gophers on the Pine Ridge is continually diluted through complete intergradation with paler pocket gophers to the south, preventing the establishment of a stable genetic composition in the population. I am aware that a less conservative taxonomist might recognize hylaeus as a "weak" subspecies; I was tempted to do so myself at one stage. All things considered, however, I cannot, on the basis of the material now available, conscientiously admit its validity. Records of occurrence. — Specimens examined, 369, as follows: Antelope County: Neligh, 5 (2 NSM, 3 USNM); 1 mi. SW Neligh, 3. Banner County: 9 mi. N, 5 mi. E Harrisburg, 1; SE of Hubbard Gap, 1 (NSM); Bull Canyon, 1 (NSM). Boyd County: 1 mi. S Butte, 1; 5 mi. WNW Spencer, 1; 1 mi. WNW Spencer, 5; Spencer, 2 (NSM). Box Butte County: Hemingford, 2 (NSM). Buffalo County: Ravenna, 2 (UMMZ); Kearney, 1 (USNM). Cherry County: Valentine, 11 (1 NSM, 2 UMMZ, 2 UNDZ, 160 University of Kansas Publs., Mus. Nat. Hist. 6 USNM); Ft. Niobrara Nat'l Wildlife Refuge, 4 mi. E Valentine, 10 (5 NSM, 3 USNM); Snake River, 1 (USNM); 18 mi. NW Kennedy, 2 (USNM); 1 mi. W Headquarters, Valentine Nat'l Wildlife Refuge, 1 (UC); Hackberry Lake, Valentine Nat'l Wildlife Refuge, 7 (2 UMMZ); Kennedy, 13 (1 MVZ, 12 USNM); Brownlee, 1 (USNM); North Fork, Middle Loup River, NW of Mullen, 2 (NSM); no specific locality (7 from Clark's Canyon, near Valentine, according to Merriam, 1895:129), 8 (USNM). Cheyenne County: 2 mi. N Dalton, 4300 ft., 1; Dalton, 1 (NSM); 15 mi. S Dalton, 4300 ft., 11; J mi. S, 2 mi. E Bronson, 1; 3 mi. N Sidney, 4250-4300 ft., 2; 1.4 mi. NE Sidney, 4200 ft., 1; Sidney, 4 (3 NSM, 1 USNM); Lodgepole, 1 (NSM). Custer County: Victoria Springs, 3 (UMMZ); Callaway, 4 (USNM). Dawes County: Chadron, 3360 ft, 4 (2 CSTC, 1 NSM, 1 USNM); 6 mi. S Chadron, 1; 8 mi. S Chadron, 1 (NSM); 9 mi. S Chadron, 1; 10 mi. S Chadron, 14 (11 UMMZ); Crawford, 2 (1 NSM, 1 USNM); Ft. Robinson, 1 (USNM); no specific locality, 1 (AMNH). Dawson County: Lexington, 2 (NSM). Deuel County: Chappell, 1 (NSM). Dundy County: Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 8 (1 NGFPC); 2 mi. SW Benkelman, 1; Haigler, 2 (NSM). Franklin County: 1 mi. SE Franklin, 9. Frontier County: 4 mi. N Curtis, 1 (UC). Garden County: no specific locality, 6. Harlan County: 1 mi. S Alma, 1. Hitchcock County: Trenton, 2. Holt County: 6 mi. N Midway, 7; Ewing, 2 (USNM). Kearney County: 3% mi. 5 Kearney, 3. Keith County: 4 mi. NNW Keystone, 1; Ogallala, 1 (NSM); no specific locality, 1 (NSM). Keya Paha County: 10-12 mi. N Springview, 7. Kimball County: Kimball, 4 (NSM). Lincoln County: Myrtle, 2 (USNM); Birdwood Creek, 1 (USNM), the holotype; Birdwood Creek, 7-8 mi. N, 4 mi. W Hershey, 2950 ft., 32; 8 mi. N, 3 mi. W Hershey, 4; 2 mi. N North Platte, 1; forks of the Platte River, 1 (USNM); Conroy Canyon, sec. 9, T. 11 N, R. 27 W (5 mi. S, 2>k mi. W Brady), 4 (NSM); no specific locality, 6 (1 NSM, 5 USNM). Morrill County: 12-15 mi. N Bridgeport, 16 (NSM); Bridgeport, 6 (NSM); Redington Gap (2 mi. N Redington), 4 (NSM). Rock County: 1 mi. E Bassett, 1 (CNHM). Scotts Bluff County: 8 mi. NNW Scottsbluff, 1; 1 mi. W Scottsbluff, 3900 ft., 1; Scottsbluff, 3900 ft., 14 (2 AMNH, 3 HM, 7 NSM); 1 mi. E Scottsbluff, 3900 ft., 1; 2 mi. S, 1 mi. W Scottsbluff, 3900 ft., 8; 11-12 mi. S Scottsbluff, 4600 ft., 5. Sheridan County: Niobrara River, 1 (USNM); 18 mi. S Hay Springs, 2 (WSC); Mirage Twp., 3 (UMMZ); 16 mi. NE Alliance, 2 (UMMZ); 4 mi. N Antioch, 11 (UMMZ); NW side Snow Valley, N of Lakeside, 1 (NSM). Sioux County: Warbonnet Canyon, 1 (NSM); Plunkett's Ranch, 10 mi. NE Harrison, 3 (NSM); 8 mi. N Harrison, 1 (UMMZ); Harrison, 3 (2 NSM, 1 USNM); 6% mi. W Craw- ford, 8 (NSM); 1 mi. S, 4 mi. W Crawford, 5 (NSM); Glen, 1 (NSM); Agate, 3 (UMMZ); 3 mi. E Agate, 1; Running Water Creek, E of Agate, 1 (CM). Thomas County: Halsey, 9 (USNM); 1 mi. S, 3% mi. W Halsey, 1; Nebraska Nat'l Forest, 3 (NGFPC); Dismal River, 1 (USNM). Webster County: Bladen, 1 (HM). County unknown: Loup Fork, 3 (USNM); Platte River, 1 (USNM); South Platte River, 1 (USNM). Additional records: Cherry County: Center Lake and North Marsh Lake, Valentine Nat'l Wildlife Refuge (Jones, 1952:10). Garden County: Crescent Lake Nat'l Wildlife Refuge (Imler, 1945:272); Ash Hollow, 3 mi. SE Lewellen (Champe, 1946:44, archeological site). Hooker County: no specific locality (Fichter, 1941:28). Lincoln County: North Platte (Wade, 1927fc:310). Red Willow County: 9 mi. NE Bartley (Jones, 1949^:5). Sioux County: Orella (Jones, 1949&:5). Thomas County: Seneca (Swenk, MS). Wheeler County: Ericson (Merriam, 1895:120). See also Swenk (1940o:2-9). Geomys bursarius majusculus Swenk Geomys bursarius majusculus Swenk, Missouri Valley Fauna, 1:6, December 5, 1939 (type locality, Lincoln, Lancaster Co., Nebraska); Villa-R and Hall, Univ. Kansas Publ., Mus. Nat. Hist., 1:223 (topotypes mentioned on p. 225), November 29, 1947; Miller and Kellogg, Bull. U. S. Nat. Mus., 205:334, March 3, 1955; Hall and Kelson, The mammals of North America, p. 450, March 31, 1959. Mammals of Nebraska 161 Pseudostoma bursaria, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . .,1:369,1823. Geomys bursarius, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880 (part); Merriam, N. Amer. Fauna, 8:120, January 31, 1895 (part); V. Bailey, Bull. Div. Ornith. Mamm., U. S. D. A., 5:33, 1895; Swenk, Proc. Nebraska Acad. Sci., 8:106, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:50, September, 1908 (part); Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Ne- braska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Wade and Gilbert, Amer. Midland Nat., 16:960, 1935; Whelan, Trans. Kansas Acad. Sci., 39:365, 1937. Geomys lutescens, Merriam, N. Amer. Fauna, 8:127, January 31, 1895 (part); Swenk, Proc. Nebraska Acad. Sci., 8:107, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:51, September, 1908 (part). G[eomys]. b[ursarius] . majusculus, Jones, Trans. Kansas Acad. Sci., 60:276, October 22, 1957. Distribution in Nebraska. — Eastern third of state, west certainly to Adams, Antelope, and Knox counties. See Fig. 32. External measurements. — Average and extreme measurements of 48 male and 50 female topotypes (after Swenk, 1939:3) are, respectively: 319.6 (294- 352), 290.2 (278-316); 95.2 (75-107), 88.6 (77-102); 38.7 (36-43), 35.4 (33-39). The length of ear of three male topotypes measured 7, 8 and 9. For cranial measurements see Table 11. Weight in grams of three male topotypes was 415.5, 417.0 and 402.5; that of a male and female from 2 mi. S and M mi. E Bamston, respectively, 411.0 and 271.0; that of a female from 5 mi. W Tilden, 316.8. Remarks. — G. b. majusculus is so much larger, both externally and cranially, and so much darker than Geomys bursarius lutescens that it is easy to understand why Merriam (1895), Swenk (1939, 1940a, and elsewhere), and others, lacking certain evidence of inter- gradation, regarded the two as distinct species. The area of intergradation between lutescens and majusculus is relatively narrow in most areas to the north of the Platte River. In Antelope County, for example, nearly typical (slightly darker) specimens of lutescens have been taken in the vicinity of Neligh, whereas two specimens from Oakdale, only five miles to the south- east, are clearly assignable to majusculus ( although slightly smaller than topotypes), as is a specimen from 5 mi. W Tilden. G. b. majusculus occurs also in western Knox county but pocket gophers from the tableland in central Boyd County, less than 35 miles west- ward, are clearly G. b. lutescens, although somewhat darker and slightly larger than topotypes of the latter. To the south of the Platte River intergradation between the two subspecies is evident in five specimens from Hastings. All five are relatively dark, but slightly more reddish than typical majusculus, to which subspecies they are herein assigned, whereas in size the five are, if anything, nearer lutescens. 11—6532 162 University of Kansas Publs., Mus. Nat. Hist. Table 11. — Cranial Measurements of Thomomys and Geomys. r* c , Number of specimens 03 03 «3 H Eh T3 o § Is O is o 3 BO averaged or catalogue o number, and sex -r wo >>G a-* °8 m c3 a J2 ft o >> s-> o> V O SJ HH r^l cq h-3 Q Thomomys talpoides cheyennensis, Smeed, Kimball County 76922 KU, 9 1 39.5 | 23.8 | 6.5 | 19.9 | 8.0 | 7.8 Thomomys talpoides pierreicolus, topotypes 15136 KU, 15139 KU, 15142 KU, 15143 KU, 9 9 9 36.8 23.1 6.4 19.4 7.5 7.1 35.7 22.5 6.5 19.5 7.2 7.2 36.0 23.8 6.0 19.5 7.3 7.1 34.6 21.9 6.6 18.0 7.3 7.2 Geomys bursarius lutescens, vicinity Spencer, Boyd County 77960 KU, , 3 9). Minimum Maximum 39.2 23.8 13. 09 14.5 21.0 14.2 38.0 23.3 11.9 13.8 19.8 13.9 40.6 24.9 13.8 15.3 22.2 14.7 vicinity Crawford, in Sioux County Average 5 (2d1, 3 9). Minimum Maximum 39.2 24.0 13.3 14.4 21.6 14.0 37.7 23.0 12.9 13.7 21.0 13.8 39.8 24.6 13.8 14.9 22.0 14.2 5.4 5.0 5.6 5.2 4.8 5.7 Dipodomys ordii richardsoni, 5 mi. N, 2 mi. W Parks, Dundy County Average 5 (o") 40.1 24.4 12.9 14.7 21.7 14.0 5.3 Minimum 39.3 23.8 12.7 14.1 21.5 13.7 5.1 Maximum 41.1 24.9 13.5 15.8 22.2 14.2 5.6 3% mi. S Kearney, in Kearney County 69043 KU, c? 69044 KU, 9 69045 KU, k mi. E Ashland, 3 (NSM). Scotts Bluff County: 5 mi. W Mitchell, 1 (NSM); 2 mi. W Mitchell, 1 (NSM). Sioux County: 1 mi. W Montrose, 1 (NSM); 5& mi. W Crawford, 1 (NSM). Stanton County: Elkhorn Biver, 1 mi. S, 8 mi. E Norfolk, 1; Elkhorn River, 1 (NSM). Wehster County: Inavale, 1 (HM); Red Cloud, 1 (HM). County unknown: Platte River, 2 ( 1 UMMZ, 1 USNM). Additional records: Antelope County: Neligh (Cary, MS); Oak dale (Swenk, MS). Brown County: Niobrara River (Cary, MS). Cass County: Louisville (record on file, NGFPC). Cherry County: Niobrara River (Cary, MS); Ft. Niobrara Nat'l Wildlife Refuge (Beed, 1936:30). Cuming County: West Point (Swenk, MS). Dodge County: 1 mi. E North Bend (Velich, 1961:93); near Fremont (record on file, NGFPC). Fillmore County: 3J» mi. SW Grafton (record on file, NGFPC). SW of Geneva (record on file, NGFPC). Furnas County: no specific locality ( Swenk, MS ) . Gage County: 186 University of Kansas Publs., Mus. Nat. Hist. Barnston (record on file, NGFPC). Garden County: near Oshkosh (Swenk, MS). Hall County: Platte River, S of Grand Island (record on file, NGFPC). Hamilton County: N of Harvard (Swenk, MS). Knox County: Manuel's Creek, below [on Missouri River] mouth of Niobrara (not exactly located) (Hayden, 1863:146). Lancaster County: Salt Creek, within 12 mi. Lincoln (Swenk, 1908:89); Lincoln (Swenk, MS). Lincoln County: Junction of Platte rivers (Swenk, MS). Madison County: Elkhorn River, near Norfolk (Swenk, MS). Pierce County: Osmond (Velich, 1961:93). Scotts Bluff County: Scotts Bluff Nat'l Mon. (Mattes, 1958:57 ); Sioux County (Swenk, 1908:89): Jim Creek; Warbonnet Canyon; Biehle's Creek; Monroe Creek; Sowbelly Creek. Thomas County: Dismal River (Swenk, MS; no specific locality (Smith, 1958:61). Family Cricettdae — Native Rats and Mice Key to Nebraskan Cricettds 1. Cheek-teeth cusped, occlusal surface lacking lakes of dentine sur- rounded by enamel 2 1'. Cheek-teeth lacking cusps, occlusal surface composed of lakes of dentine surrounded by enamel 7 2(1). Pelage coarse, relatively hispid; hind foot more than 24; maxillary tooth-row more than 5.0 Sigmodon hispidus, p. 212 2'. Pelage relatively smooth; hind foot less than 24; maxillary tooth- row less than 5.0 3 3(2'). Length of head and body less than 80; upper incisors grooved on anterior surface 4 3'. Length of head and body usually more than 80; upper incisors smooth 5 4(3). Dark color on dorsum of tail a thin median line; breadth of brain- case 9.7 or less Reithrodontomys montanus, p. 191 4'. Dark color on dorsum of tail a relatively broad stripe; breadth of braincase 9.6 or more (usually 9.8 or more). Reithrodontomys megalotis, p. 187 5(3'). Tail less than 60 per cent of length of head and body; coronoid process long, extending higher than articular process. Onychomys leucogaster, p. 207 5'. Tail more than 60 per cent of length of head and body; coronoid process short, not extending higher than articular process 6 6(5')- Tail sharply bicolored; hind foot 21 or less (usually less than 20); braincase flattened and roughly parallel-sided. Peromyscus maniculatus, p. 199 6'. Tail not sharply bicolored (except occasionally in winter) ; hind foot 20 or more; braincase rounded, not flattened or parallel-sided. Peromyscus leucopus, p. 194 7(1'). Tail more than 100; greatest length of skull more than 35 8 7'. Tail less than 100; greatest length of skull less than 35 10 8(7). Tail laterally compressed; fringe of stiff hairs on toes of hind feet; maxillary tooth-row more than 12 Ondatra zibethicus, p. 234 8'. Tail rounded; toes of hind feet lacking stiff hairs; maxillary tooth- row less than 12 9 9(8'). Tail bushy; soles of hind feet furred from heel to plantar tubercle; nasal septum divided by prominent notch Neotoma cinerea, p. 214 9'. Tail fully haired but not bushy; soles of hind feet naked; nasal sep- tum complete Neotoma floridana, p. 215 10(7'). Tail approximately same length as hind foot; zygomatic breadth usually more than 17.5; upper incisors grooved on anterior surface. Synaptomys cooperi, p. 220 Mammals of Nebraska 187 10'. Tail longer than hind foot; zygomatic breadth usually less than 17.5; upper incisors smooth 11 11(10'). Dorsum blackish or brownish black, venter grayish or whitish; 8 mammae; fourth triangle of M2 having prominent heel that often- times appears as a distinct fifth triangle. Microtus pennsylvanicus, p. 227 11'. Dorsum brownish or reddish, venter usually washed with buff; 4 or 6 mammae; fourth triangle of M2 lacking heel 12 12(11'). Tail 29 or more; pelage relatively coarse, brownish or brownish gray dor sail y; 6 mammae Microtus ochrogaster, p. 222 12'. Tail less than 29 (usually less than 25); pelage soft and smooth, chestnut dorsally; 4 mammae Microtus pinetorum, p. 231 Reithrodontomys megalotis Western Harvest Mouse The western harvest mouse, a common inhabitant of grassy areas throughout Nebraska, is widely distributed in the eastern part of the state, but frequently is restricted to riparian communities in the western part. The species probably is more widespread now than formerly in some western areas owing to irrigation. Lush, lowland swales seem to provide the optimum habitat for this mouse but it Museum of Natural History University of Kansas 1952 I .103 . J0O_ 97 Fig. 39. Distribution of Reithrodontomys megalotis dychei in Nebraska. For explanation of symbols see Fig. 5. lives also in weedy fencerows, thickets, fallow fields, and on dry up- land areas where ground cover is abundant. Considering Nebraska as a whole, R. megalotis is second in abundance among native mam- mals only to the deer mouse, Peromysciis maniculatus. In color of pelage at least, the western harvest mouse varies less 188 University of Kansas Publs., Mus. Nat. Hist. in Nebraska than any other of the wide-ranging cricetid rodents; mice from the western part of the state average only slightly paler than those from the east. In external and cranial measurements, too, variation is slight, although individuals from southwestern counties have somewhat longer tails and longer rostra than speci- mens from elsewhere in the state. Geographic variation in the species on the central Great Plains and in adjacent regions was sum- marized by Jones and Mursaloglu (1961). Color abberations evi- dently are rare in R. megalotis; none was discovered in more than 1200 specimens examined from Nebraska and surrounding states. Judging from available data, the western harvest mouse breeds in all but the winter months in Nebraska. Seventy-five pregnant females, taken in the months of April through November, had an average of 4.3 (2-8) embryos; the mode was 4. Reithrodontomys megalotis dychei J. A. Allen Reithrodontomys dychei J. A. Allen, Bull. Amer. Mus. Nat. Hist.. 7:120, May 21, 1895 (type locality, Lawrence, Douglas Co., Kansas); J. A. Allen, Bull. Amer. Mus. Nat. Hist., 8:252, November, 1896; Swenk, Proc. Nebraska Acad. Sci., 8:97, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:41, September, 1908 (part). Reithrodontomys megalotis dychei, A. H. Howell, N. Amer. Fauna, 36:30, June 5, 1914; Swenk, Nebraska Blue Book, p. 852, 1915, Swenk, Ne- braska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Poole and Schantz, Bull. U. S. Nat. Mus., 178:342, April 9, 1942; Jones and Webb, Jour. Mamm., 30:313, August 17, 1949; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 9:388, May 12, 1958; Jones, Jour. Mamm., 41:132, February 20, 1960; Jones and Mursaloglu, Univ. Kansas Publ., Mus. Nat. Hist., 14:21, July 24, 1961. Ochetodon humilis [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880. Reithrodontomys dychei nehrascensis J. A. Allen, Bull. Amer. Mus. Nat. Hist., 7:122, May 21, 1895 (type locality, Kennedy, Cherry Co., Ne- braska); Swenk, Proc. Nebraska Acad. Sci., 8:98, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:42, September, 1908 (part); Lyon and Osgood, Bull. U. S. Nat. Mus., 62:116, January 28, 1909. [Reithrodontomys dychei] nehrascensis, Cary, Proc. Biol. Soc. Washington, 16:53, May 6, 1903. Rhithrodontomys [sic] dychii [sic], Elliot, Field Columb. Mus., Publ. 115 (Zool. Ser.), 8:256, 1907. R[eithrodontomys]. m[egalotis], dychei, Hanson, Field Mus. Nat. Hist., Zool. Ser., 29:206, October 26, 1944; Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — State-wide in suitable habitat. See Fig. 39. External measurements^ — Average and extreme measurements of 27 speci- mens (19 males, eight females) from Cherry County are: 134.7 (122-155); 62.8 (56-73); 17.4 (17-18); 12.8 (11-14). For cranial measurements see Table 14; for additional external and cranial measurements see Jones and Mursaloglu (1961). Mammals of Nebraska 189 Ten males from Cherry County weighed an average of 13.3 (11.7-14.7) grams and a female from there weighed 14.2; six males from southeastern Nebraska weighed an average of 11.8 (10.6-12.6) grams and two females weighed 13.5 and 14.1. Remarks.— When J. A. Allen (1895a: 122-123) named "Reithro- dontomys dychei nebrascensis" from Kennedy, Nebraska, he char- acterized it (p. 123) in comparison with the subspecies dychei as having "slightly larger size, slightly larger ears, and very much stronger suffusion of fulvous" dorsally. Allen further remarked: "In coloration it is parallel to the phase of Peromyscus found over the same region, and known as P. americanus nebrascensis [= P. maniculatus luteus], as compared with other conspecific forms of the latter group." The subspecies R. d. nebrascensis stood as valid in the literature until A. H. Howell (1914:30-31) placed it in synonymy under dychei (which was there regarded for the first time as a subspecies of R. megalotis) because he found (p. 31) specimens of nebrascensis "to be indistinguishable from specimens of typical dychei in comparable pelage." Examination of 839 specimens of the species JR. megalotis from Nebraska, along with direct comparisons of topotypes of nebras- censis with topotypes of dychei, convinces me that Howell was justified in denying recognition to nebrascensis (see also Jones and Mursaloglu, 1961:22). Specimens from Cherry County and from adjacent areas in western Nebraska do not average larger in any external or cranial dimensions, and average only slightly paler in comparable pelage, than specimens from eastern Nebraska and those from the type locality of dychei. Adults of R. megalotis, in Nebraska at least, have two distinct pelages annually, the paler of which is acquired in winter. Specimens in worn winter pelage are paler than those taken at any other time of year. The type of nebrascensis and other specimens available to Allen from the vicinity of Kennedy all were collected in late April and all are in worn winter pelage, which accounts for Allen's contention that they were more fulvous dorsally than mice from farther east. Also, Allen erred in thinking that variation in color in R. megalotis on the Great Plains paralleled that found in Peromyscus maniculatus; geographic variation in color of pelage is much more pronounced in the latter species than in R. megalotis. Specimens of R. m. dychei from southwestern Nebraska, espe- cially those from Dundy and Hitchcock counties, average larger than specimens from anywhere else in the state and approach R. m. 190 University of Kansas Publs., Mus. Nat. Hist. aztecus in some measurements, especially in length of rostrum (average 7.5 in 16 adults from the mentioned counties). Records of occurrence. — Specimens examined, 839, as follows: Adams County: Hastings, 1 (HM); no specific locality, 2 (HM). Antelope County: Neligh, 16 (6 NSM, 9 USNM). Boyd County: 5 mi. WNW Spencer, 1; 5 mi. S, 2 mi. E Spencer, 2; 6 mi. SSE Spencer, 1. Box Butte County: Alliance, 2 (USNM). Buffalo County: Kearney, 2 (USNM). Burt County: 1 mi. E Tekamah, 3. Butler County: 2 mi. N, 2 mi. W Bellwood, 2 (NSM); 4-5 mi. E Bising City, 11; 4 mi. E, 1 mi. S Rising City, 5. Chase County: 2 mi. SE Enders, 1. Cherry County: W of Crookston, 1 (NSM); Valentine, 2 (USNM); Ft. Niobrara Nat'l Wildlife Refuge, 4 mi. E Valentine, 6 (3 NSM, 1 UNDZ); 3 mi. SSE Valentine, 4; 3 mi. S Valentine, 12; Niobrara Biver, 10 mi. S Cody, 2 (1 USNM); 8 mi. S Nenzel, 2; 11 mi. 5, 2 mi. W Nenzel, 1; 18 mi. NW Kennedy, 8 (2 NSM, 6 USNM); Two Mile Lake (sec. 12, T. 31 N, B. 34 W), 6 (4 NSM, 2 USNM); Watt's Lake, Valen- tine Nat'l Wildlife Refuge, 4; Hackberry Lake, Valentine Nat'l Wildlife Befuge, 26 (12 UMMZ); & mi. W Headquarters, Valentine Nat'l Wildlife Refuge, 1 (UC); 2 mi. W to 4 mi. E Kennedy, 25 (4 UMMZ, 12 USNM); Pelican Lake, Valentine Nat'l Wildlife Refuge, 5 (2 NGFPC, 3 UC); 30 mi. S Woodlake, 4 (CNHM); no specific locality, 1 (USNM). Cheyenne County: 15 mi. S Dalton, 4300 ft., 1; 3 mi. N Sidney, 6; 4 mi. E Sidney, 42. Cuming County: Beemer, 1 (USNM). Custer County: 7 mi. NW Anselmo, 1 (UMMZ); within 1 mi. Victoria Springs, 9 (UMMZ); 2 mi. E Lillian, 1 (UMMZ); Corn- stock, 4 (3 AMNH, 1 NSM); Callaway, 3 (USNM); 6 mi. SE Mason City, 1 (UMMZ). Dawes County: Wayside, 1; 3 mi. E Chadron, 2; 6 mi. S Chadron, 1 (NSM); 8 mi. S Chadron, 1 (NSM); 10 mi. S Chadron, 1 (UMMZ); 1 mi. W Crawford, 2 (NSM); Crawford, 5 (3 AMNH, 2 UMMZ). Dawson County: 34 mi. S Gothenburg, 5; 3 mi. SSE Gothenburg, 4. Deuel County: 1 mi. N, 2 mi. W Chappell, 3. Dixon County: 3 mi. NE Ponca, 4. Dundy County: Bock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 46 (4 NGFPC); 2 mi. N, 2 mi. W Haigler, 1; Arikaree River, Parks, 2; 2 mi. SW Benkleman, 7; Haigler, 3 (1 NSM, 2 USNM). Franklin County: 1)4-2 mi. 5 Franklin, 10. Furnas County: 4 mi. W Holbrook, 1 (UI). Gage County: 1 mi. SE DeWitt, 3; 34 mi. W Homestead Nat'l Mon., 1; 1 mi. S, 1 mi. W Barnston, 1; Hz mi. S, 2 mi. E Barnston, 18. Garden County: Crescent Lake Nat'l Wildlife Befuge, 1; 35 mi. S Oshkosh, 1. Hall County: 6 mi. S Grand Island, 5. Harlan County: 1 mi. W Alma, 17. Hitchcock County: Be- publican Biver, Trenton, 3. Hooker County: Kelso, 3 (UMMZ). Holt County: 6 mi. N Midway, 4; 1 mi. S Atkinson, 4 (2 NSM); Ewing, 1 (USNM). Howard County: 1 mi. S St. Paul, 1 (NGFPC). Jefferson County: 7 mi. S, 2 mi. W Fairbury, 6; 3 mi. S, 1 mi. W Endicott, 1. Johnson County: 1 mi. S, 135 mi. E Burr, 1. Kearney County: l%-3% mi. S Kearney, 6. Keith County: 4 mi. WNW Keystone, 69. Keya Paha County: 12 mi. N Springview, 8; 12 mi. NNW Springview, 5. Kimrall County: 3 mi. E Kimball, 1; Smeed, 40. Knox County: 3 mi. W Niobrara, 2; 1-134 mi. SE Niobrara, 6 (1 NGFPC); 2 mi. S Niobrara, 2; Verdigre, 2 (USNM). Lan- caster County: 12 mi. N Lincoln, 2 (UC); within 5 mi. Lincoln, 48 (3 AMNH, 4 CNHM, 8 NSM, 1 BV, 13 UC, 6 UNDZ); 8 mi. S Lincoln, 1 (UC). Lincoln County: 2 mi. N North Platte, 1; Conroy Canyon, SW corner sec. 4, T. 11 N, B. 27 W (5 mi. S, 234 mi. W Brady), 2 (NSM). Logan County: 1-2 mi. NE Stapleton, 11. Madison County: Norfolk, 1 (USNM). Morrill County: 1 mi. N Bridgeport, 4. Nemaha County: 2 mi. SW Peru, 6; 3 mi. S, PA mi. E Peru, 2. Nuckolls County: 5 mi. N, 35 mi. E Nelson, 1 (UNM); 2 mi. WSW Superior, 5; 1 mi. SSW Hardy, 9. Otoe County: 1 mi. SE Ne- braska City, 3; 3 mi. S, 2 mi. E Nebraska City, 3. Pawnee County: Turkey Creek, 4 mi. NW Pawnee City, 2 ( NSM ) ; 4 mi. S, 8 mi. W Pawnee City, 7; 1 mi. S DuBois, 4. Platte County: Columbus, 4 (1 UNDZ, 3 USNM); 3'A mi. E Columbus, 1 (UNDZ). Polk County: 15 mi. W Osceola, 2. Bed Willow County: 5 mi. S, 234 mi. E McCook, 2; 8 mi. S, 3 mi. E McCook, 2. Bichardson County: 5 mi. N, 2 mi. W Humboldt, 2 (1 NSM); 4 mi. E Barada, 16; 334 mi. S, 1 mi. W Dawson, 6; 2 mi. N Falls City, 2; 4-6 mi. W Mammals of Nebraska 191 Falls City, 4; K mi. S, VA mi. W Rulo, 1. Rock County: Perch, 23 (21 AMNH, 2 CNHM). Saline County: 2 mi. NE Crete, 1; % mi. W DeWitt, 1. Sarpy County: 1 mi. SE Bellevue, 1 (UNDZ); Fort Crook, 1 (AMNH); 1 mi. W Meadow, 1. Saunders County: 2 mi. NW Ashland, 3. Scotts Bluff County: 8 mi. NNW Scottsbluff, 1; Mitchell, 1 (NSM); %-l mi. S Mitchell, 13; 5 mi. S Gering, 10; 7 mi. S Gering, 1; 11-12 mi. S Scottsbluff, 4600-4800 ft., 8; J 2 mi. SSW Scottsbluff, 4700 ft., 5. Seward County: Milford, 1 (CNHM). Sheridan County: 18 mi. S Hay Springs, 1 (WSC). Sioux County: 1 mi. S, 4 mi. W Orella, 1 (NSM); 8 mi. N Harrison, 2 (UMMZ); Monroe Canyon, 5% mi.- N, 2% mi. W Harrison, 4 ( NGFPC ) ; Monroe Canyon, 1 (AMNH); 6Y2-7 mi. W Crawford, 3 (1 NSM); S2A mi. N, 1 mi. E Glen, 1 (NSM); 3 mi. NE Glen, 1 (NSM); Glen, 3 (NSM); Agate, 4600 ft., 1. Stanton County: VA mi. S Pilger, 3; 8 mi. SE Norfolk, 1. Thomas County: 1 mi. W Halsey, 2; Halsey, 5 (4 AMNH, 1 NSM). Thurston County: 1 mi. S Winnebago, 8. Valley County: 2 mi. W Ord, 1; 2 mi. S, 4 mi. E Ord, 6; 10 mi. S Ord, 10 (NGFPC). Washington County: 1 mi. E Blair, 6; 3 mi. SE Blair, 2; 6 mi. SE Blair, 7; 3 mi. S, 2 mi. E Ft. Calhoun, 1 (NSM). Wayne County: % mi. W to 2lA mi. E Wayne, 3. Webster County: 3 mi. S Red Cloud, 2. Reithrodontomys montanus Plains Harvest Mouse This harvest mouse seemingly lives exclusively in upland habitats. The western harvest mouse, Reithrodontomys megalotis, sometimes taken in upland areas with montanus, generally inhabits more mesic associations. R. montanus is another species for which the Missouri River and its riparian association provide a barrier to eastward dispersal. The species is nowhere known from east of the Missouri, although it reaches the bluffs of that river in northern Nebraska and adjacent South Dakota and occurs within a few miles of the Missouri in southeastern Nebraska and northeastern Kansas. The 40- -48 i'ilil--^ Museum of Natural History University of Kansas 1952 I J0O Fig. 40. Distribution of Reithrodontomys montanus in Nebraska. 1. R. albescens. 2. R. m. griseus. For explanation of symbols see Fig. 5. m. 192 University of Kansas Publs., Mus. Nat. Hist. plains harvest mouse is known throughout western Nebraska, ex- cept that no specimens are presently available from the Pine Ridge or adjacent areas in the northwestern part of the state. The known distribution of the species suggests, however, its occurence there. Some specimens of Reithrodontomys montanus are difficult to distinguish from those of R. megalotis but (when compared directly with megalotis) the vast majority can be fairly easily identified as follows: upper parts usually paler, having a distinct, dark mid- dorsal stripe; dorsal stripe on tail much narrower; buffy postauricular patch usually present; smaller, both externally and cranially (see measurements); rostrum relatively shorter; braincase narrower; lateral margins of skull as a whole more nearly straight-sided when viewed from above, mostly owing to the narrower braincase. Females are polyestrous, probably breed throughout the warmer months of the year, and according to Hall and Kelson (1959:582) have 2-5 young per litter. A female from 3 mi. SE Brady gave birth to 5 young in a live-trap on the night of June 22-23, 1939. Three pregnant females from Anderson County, Kansas (two taken in March, one in July), carried 3, 4, and 5 embryos. Reithrodontomys montanus albescens Cary Reithrodontomys albescens Cary, Proc. Biol. Soc. Washington, 16:53, May 6, 1903 (type locality, 18 mi. NW Kennedy, Cherry Co., Nebraska); Swenk, Proc. Nebraska Acad. Sci., 8:99, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:45, September, 1908; Lyon and Osgood, Bull. U. S. Nat. Mus., 62:111, January 28, 1909. Reithrodontomys montanus albescens, Cary, N. Amer. Fauna, 33:110, August 17, 1911; Benson, Tour. Mamm., 16:141, May 15, 1935; Poole and Schantz, Bull. U. S. Nat. Mus., 178:341, April 9, 1942; Hall and Kelson, The mammals of North America, p. 582, March 31, 1959. Reithrodontomys albescens albescens, A. H. Howell, N. Amer. Fauna, 36:22, June 5, 1914; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Ne- braska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:21, October, 1936. Reithrodontomys albescens], albescens, Imler, Jour. Wildlife Mgt., 9:272, October, 1945. R[eithrodontomys]. m[ontanus], albescens, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Western two-thirds of state, east certainly to Antelope, Kearney, and Knox counties. See Fig. 40. External measurements. — Average and extreme measurements of eight speci- mens (seven males, one female) from Cherry County, including the holotype and three topotypes, are: 124.5 (113-133.5); 54.7 (48-60); 16.5 (16-17); 12.53 (12-13). Corresponding measurements of seven specimens (four males, three females) from Dundy and Kearney counties are: 118.7 (113-125); 53.0 (48-60); 15.9 (15-17); 12.6 (11-15). For cranial measurements see Table 14. Three males from Kearney County and two males from Boyd County Mammals of Nebraska 193 weighed, respectively, 10.2, 10.9, 10.0, 11.3, and 11.6 grams; a female from Dundy County weighed 10.5 grams. Remarks. — From Reithrodontomys montanus griseus, geographi- cally adjacent to the southeast in Nebraska, R. m. albescens differs principally in paler upper parts and dorsal stripe of tail (in al- bescens the upper parts are pale grayish to pale brownish whereas in griseus the upper parts, taken as a whole, average near buffy brown and the middorsal stripe is darker than in albescens) . Judg- ing from specimens currently available from the northern part of the range of R. m. griseus (Kansas and Nebraska), albescens may average slightly larger than griseus in external and cranial dimen- sions but there is complete overlap among specimens of the two sub- species that I have seen. Specimens of R. m. albescens from Cherry County and other lo- calities in the Sand Hills average slightly more grayish dorsally than mice from other Nebraskan localities; some specimens from Antelope, Boyd, Knox, and Kearney counties are somewhat darker dorsally than examples from farther west and evidence intergrada- tion with griseus. The type locality of albescens, 18 mi. NW Kennedy, is noted else- where by its describer ( Cary, MS ) as being on "the sand hills north of the Snake River," where several specimens were taken (Cary, 1903:54) "by overturning millet shocks in a sandy field." Records of occurrence. — Specimens examined, 70, as follows: Antelope County: Neligh, 12 (4 NSM, 8 USNM); I mi. SW Neligh, 1. Boyd County: 4 mi. N Bristow, 2. Cherry County: Valentine, 1 (UNDZ); Niobrara River, 10 mi. S Cody, 2 (1 NSM, 1 USNM); 18 mi. NW Kennedy, 7 (3 NSM, 4 USNM), including the holotype; Watt's Lake, Valentine Nat'l Wildlife Refuge, 1 (UC); Hackberry Lake, Valentine Nat'l Wildlife Refuge, 6 (5 UMMZ); E side Duck Lake, Valentine Nat'l Wildlife Refuge, 1 (UC); Kennedy, 1 (USNM); 4 mi. E Kennedy, 1. Cheyenne County: 15 mi. S Dalton, 4300 ft., 2. Custer County: 1-4 mi. NW Gavin, 5 (UMMZ); 7-8 mi. NW Anselmo, 2 (UMMZ). Deuel County: 1 mi. N, 2 mi. W Chappell, 1. Dundy County: 5 mi. N, 2 mi. W Parks, 3; 2 mi. SW Benkleman, 2. Grant County: 5 mi. W Ashby, 1 (MVZ). Hooker County: Kelso, 2 (UMMZ). Kearney County: 3% mi. S Kearney, 3. Keith County: 4 mi. WNW Key- stone, 3. Knox County: Niobrara, 1 (USNM); Verdigre, 4 (USNM). Lincoln County: 3 mi. SE Brady, 1 (NSM). Logan County: 1-2 mi. NE Stapleton, 3. Sheridan County: 6 mi. W Rushville, 1 (NGFPC); 16 mi. NE Alliance, 1 (UMMZ). Additional records: Cherry County: Cody (Cary, 1903:54); Ft. Niobrara Nat'l Wildlife Refuge (Beed, 1936:21). Garden County: Crescent Lake Nat'l Wildlife Refuge (Imler, 1945:272). Reithrodontomys montanus griseus V. Bailey Reithrodontomys griseus V. Bailey, N. Amer. Fauna, 25:106, October 24, 1905 (type locality, San Antonio, Bexar Co., Texas); Swenk, Proc. Ne- braska Acad. Sci., 8:99, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:43, September, 1908. 13—6532 194 University of Kansas Publs., Mus. Nat. Hist. Reithrodontomys montanus griseus, Benson, Jour. Mamm., 16:141, May 15, 1935; Hall and Kelson, The mammals of North America, p. 583, March 31, 1959. Reithrodontamys dychei, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 7:120, May 21, 1895. Reithrodontomys albescens griseus, A. H. Howell, N. Amer. Fauna, 36:23, June 5, 1914; Swenk, Nebraska Blue Book, p. 852, 1915; Svvenk, Ne- braska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Whelan, Trans. Kansas Acad. Sci., 39:366, 1937. R[eithrodontomys]. m[ontanus], griseus, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Southeastern part of state. See Fig. 40. External measurements. — Measurements of two males and two females from the vicinity of Lincoln are, respectively: 111, 105, 115, 119; 49, 41, 52, 48; 15, 14, 16, 14; 15, 11 (crown), — , 10 (crown). For cranial measurements see Table 14. The weight of five specimens (four males, one female) from Douglas County, Kansas, averaged 8.3 (6.9-9.5) grams. Remarks. — For comparison with Reithrodontomys montanus al- bescens, geographically adjacent to the west in Nebraska, see ac- count of that subspecies. R. m. griseus is seemingly uncommon in Nebraska, probably ow- ing to destruction in the eastern part of the state of most of the original upland prairie. According to Swenk (MS), however, Grace Kiernan Weber trapped this mouse with some frequency in upland situations at the southeastern edge of Lincoln in the autumn and winter of 1928-29. Swenk himself (1908:99) reported it as "not common" on the salt flats near [north and west of] Lincoln, indicat- ing that it inhabited "dry open fields and prairies." I personally have taken only one specimen in the state. R. m. griseus presently is known in Nebraska only from south of the Platte River. Records of occurrence. — Specimens examined, 8, as follows: Gage County: 1 mi. S, 1 mi. W Barnston, 1. Lancaster County: Lincoln, 3 (2 AMNH, 1 NGFPC); Capitol Reach (Lincoln), 1 (NSM); College View (Lincoln), 1 (CNHM). Nemaha County: London, 2 (USNM). Additional record: Lancaster County: 9 mi. NW Lincoln (Whelan, 1937:366). Peromyscus leucopus White-footed Mouse The white-footed mouse is characteristically an inhabitant of wooded areas and is commonest in Nebraska along the eastern border of the state where deciduous woodlands are fairly extensive. In other parts of eastern Nebraska the species occurs mainly in the wooded bottomland along streams, but is found also in the remain- ing patches of upland timber, woodlots, shelter belts, hedgerows, Mammals of Nebraska 195 97 *mmmm & -42 rt-y'V'K-'^-i.^— fei'7 J c v "-■•am-- sr -at ' •■*• 'i 1 • J-'l« Museum of Natural History University of Kansas 1952 I H 97 Fig. 41. Distribution of Peromyscus leucopus in Nebraska. 1. P. I. aridulus. 2. P. Z. noveboracensis. For explanation of symbols see Fig. 5. and sometimes on brushy hillsides and along over-grown fencerows in patches of sumac and wild plum. Suitable habitat for P. leucopus is restricted in most parts of cen- tral and western Nebraska to deciduous riparian communities along stream courses and consequently the distribution of the species as- sumes a dendritic pattern within the range of P. I. aridulus. The white-footed mouse is not especially common, or only locally so, in most areas where it occurs in the western part of the state and its distribution may be discontinuous in some places. So far as known, the species does not occur along the Republican River in extreme southwestern Nebraska nor along the western reaches of the Platte and its tributaries and I assume that deciduous timber along these rivers is not extensive enough ( or at least was not extensive enough prior to settlement by white men) to support populations of this mouse. On the Pine Ridge in extreme northwestern Nebraska in- dividuals occasionally are taken on conifer-covered hills and slopes, especially in or near outcropping rock, as well as along streams. Throughout its range in Nebraska P. leucopus is sympatric with the deer mouse (Peromyscus maniculatus) and the two species are frequently taken in the same trap line, although P. maniculatus typically lives in non-wooded habitats. P. leucopus can be dis- tinguished in Nebraska from P. maniculatus as follows: size larger, especially length of tail and length of hind foot; upper parts gen- 196 University of Kansas Publs., Mus. Nat. Hist. erally duller, tail less pilose and less sharply bicolored (except in some instances in winter pelage); skull larger, braincase decidedly more inflated (both dorsally and laterally), auditory bullae larger. In extreme northwestern Nebraska some individuals of P. m. ne- brascensis reach the linear external and cranial dimensions of P. I. aridulus but have more buffy upper parts, usually have smaller skulls, and have the narrower, flatter braincase and smaller bullae. The species breeds in Nebraska throughout the warmer months of the year. Forty-three pregnant females, taken in the months of April through October, carried an average of 4.4 (2-6) embryos; the mode was 5. Peromyscus leucopus aridulus Osgood Peromyscus leucopus aridulus Osgood, N. Amer. Fauna, 28:122, April 17, 1909 (type locality, Fort Custer, Big Horn Co., Montana); Swenk, Ne- braska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:21, October, 1936; Hall and Kelson, The mammals of North America, p. 629, March 31, 1959. Hesperomys leucopus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880 (part). Peromyscus texianus subarcticus, Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902. Peromyscus subarcticus, Swenk, Proc. Nebraska Acad. Sci., 8:96, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:40, September, 1908. Peromyscus leucopus, Swenk, Proc. Nebraska Acad. Sci., 8:96, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:40, Septem- ber, 1908 (part). [Peromyscus leucopus] aridulus, Dice, Contrib. Lab. Vert. Genetics, Univ. Michigan, 4:2, January, 1937. P[eromyscus], l[eucopus]. aridulus, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Central and northwestern parts of state, east certainly to Boyd, Holt, Valley, Buffalo, and Webster counties. See Fig. 41. External measurements. — Average and extreme measurements of 25 speci- mens (16 males, nine females) from the vicinity of Valentine are: 173.2 (161- 186); 74.8 (68-81); 22.2 (21-23); 15.8 (15-17). For cranial measurements see Table 14. Eight specimens (five males, three females) from northwestern Nebraska weighed an average of 30.5 (27.5-35.6) grams. Remarks. — From Peromyscus leucopus noveboracensis, geographi- cally adjacent to the east in Nebraska, P. I. aridulus differs princi- pally in color, having distinctly paler upper parts and dorsum of tail in both summer and winter pelages. Nebraskan specimens of the two subspecies do not differ in external or cranial measurements with the possible exception of zygomatic breadth, which averages more in specimens of aridulus that I have studied. Osgood (1909:123) Mammals of Nebraska 197 described ariduhis as being larger (as well as paler) than nove- boracensis but the difference is not borne out by the measurements he listed. He referred specimens from the eastern parts of Nebraska and Kansas to noveboracensis but remarked that they were "ap- parently intermediate between noveboracensis and aridulus, having the darker color of noveboracensis and the larger size of aridulus." As might be expected, specimens from the eastern part of the range of aridulus in Nebraska average darker dorsally than indi- viduals from farther west and are intergrades with noveboracensis. This is especially true of specimens from Boyd, Holt, and Valley counties. Because the distribution of P. I. aridulus assumes a dendritic pat- tern along the major river systems of the central Great Plains, most of which are eastward-flowing, it is conceivable that mice of the subspecies from along the western part of one river system are more closely related genetically to mice from along the same river farther eastward — mice that are nominally of the subspecies noveboracensis — than to individuals of aridulus from the same longitude but from along other river systems. If this is true, populations from through- out much of the range of aridulus reflect similar and independent adaptation to a similar environment rather than relationship in the strict sense, because gene-flow between them is restricted or entirely absent. On the other hand, the geographic distribution of aridulus may have been, as I suspect, much more extensive in a warmer, wetter post- Wisconsin period than it is today, and the dendritic segments thus could be relics of a once more or less continuous and interbreeding population. Records of occurrence. — Specimens examined, 242, as follows: Blaine County: Dismal River, 2 mi. S, 8 mi. W Dunning, 5. Boyd County: 5 mi. WNW Spencer, 1; 6 mi. SSE Spencer, 3. Buffalo County: 1 mi. E Ravenna, 3 (UMMZ). Cherry County: Valentine, 34 (3 NSM, 19 UMMZ, 3 UNDZ, 9 USNM); Ft. Niobrara Nat'l Wildlife Refuge, 4 mi. E Valentine, 8 (3 NSM); 3 mi. S Valentine, 12; 3 mi. SSE Valentine, 16; Niobrara River, 10 mi. S Cody, 7 (3 NSM, 4 USNM); Niobrara River, 18 mi. NW Kennedy, 1; Hackberry Lake, Valentine Nat'l Wildlife Refuge, 3 (1 UMMZ). Custer County: 2 mi. E Lillian, 1 (UMMZ); 6 mi. SE Mason City, 1 (UMMZ). Dawes County: 6-8 mi. S Chadron, 3 (NSM); Chadron State Park, 2 (NGFPC); 10 mi. S Chadron, 27 (UMMZ); 1 mi. W Crawford, 1 (NSM); Crawford, 2 (UMMZ). Dawson County: 4 mi. E Gothenburg, 1 (UC); M mi. S Gothenburg, 5. Franklin County: Vk mi. S Franklin, 5. Harlan County: 1 mi. S Alma, 6. Holt County: 6 mi. N Midway, 11. Kearney County: 1% mi. S Kearney, 4. Keya Paha County: 12 mi. N Springview, 2; 12 mi. NNW Springview, 11. Lincoln County: Platte River, sec. 14, T. 12 N, R. 27 W (IJ2 mi. S Brady), 1 (NSM). Red Willow County: McCook, 4 (2 NSM, 2 WFR). Sheridan County: Gordon, 2 (NSM); 11 mi. S Gordon, 5. Sioux County: Warbonnet Canyon, 4 (NSM); 5% mi. N, 28 mi. W Harrison, 7 (NGFPC); Monroe Canyon, 5 mi. N Harrison, 5 (UMMZ); Monroe Canyon, 4 mi. N, 2 mi. W Harrison, 5 (NSM); West Monroe Canyon, N of Harrison, 5 (NSM); 1 mi. S, 4 mi. W Crawford, 3 (NSM); Glen, 15 (3 AMNH, 12 NSM). 198 University of Kansas Publs., Mus. Nat. Hist. Thomas County: 4 mi. W Halsey, 1; l-VA mi. W Halsey, 2 (1 UC); Ne- braska Nat'l Forest, 2 (1 NGFPC, 1 UNDZ). Valley County: 2 mi. W Ord, 3; 10 mi. S Ord, 1 (NGFPC). Webster County: 3 mi. S Red Cloud, 1. Additional records: Adams County: Logan Twp. (Swenk, MS). Cherry County: Cody (Swenk, 1908:96). Peromyscus leucopus noveboracensis (Fischer) Mus sylvaticus S noveboracensis Fischer, Synopsis mammalium, p. 318, 1829 ( type locality, New York ) . Peromyscus leucopus noveboracensis, Miller, Proc. Boston Soc. Nat. Hist., 28:22, April 30, 1897; Osgood, N. Amer. Fauna, 28:117, April 17, 1909; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Whelan, Trans. Kansas Acad. Sci., 39:366, 1937; Jones and Webb, Jour. Mamm., 30:312, August 17, 1949; Hall and Kelson, The mammals of North America, p. 630, March 31, 1959; Jones, Jour. Mamm., 41:132, February 20, 1960. ?Mus agrarius, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823. Hesperomys (Vesperimus) leucopus, Coues, in Coues and Allen, Bull. U. S. Geol. Surv. Territories, 11:50, August, 1877. Hesperomys leucopus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880 (part). Peromyscus leucopus, Swenk, Proc. Nebraska Acad. Sci., 8:96, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:40, Septem- ber, 1908 (part). Pleromyscus] . l[eucopus], noveboracensis, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Eastern part of state, west certainly to Knox, Antelope, Hall, and Nuckolls counties, See Fig. 41. External measurements. — Average and extreme measurements of 25 speci- mens (14 males, 11 females) from 4 mi. E Barada are: 180.0 (169-188); 80.3 (75-87); 21.4 (20-23); 16.0 (15-17). For cranial measurements see Table 14. Twelve specimens (five males, seven females) from southeastern Nebraska weighed an average of 27.7 (21.4-33.5) grams. Remarks. — For comparison with Peromyscus leucopus aridulus, geographically adjacent to the west in Nebraska, see account of that subspecies. Except for specimens from the southeastern part of the state, all others herein assigned to P. I. noveboracensis from Nebraska average paler than specimens from Ohio, Pennsylvania, and New York, and are intergrades with P. I aridulus. Specimens from localities near the western edge of the range of noveboracensis in Nebraska, from Neligh and Saronville for example, resemble specimens from along the Missouri River in Burt and Washington counties slightly more than they resemble specimens of aridulus from Valentine, but are almost exactly intermediate between specimens of aridulus from western Nebraska and specimens of noveboracensis from the eastern Mammals of Nebraska 199 United States. Assignment of specimens from some localities within the zone of intergradation between the two subspecies is admittedly arbitrary. Records of occurrence.— Specimens examined, 476, as follows: Antelope County: Neligh, 5 (3 NSM, 2 USNM); 1 mi. SW Neligh, 5; Oakdale, 1 (NSM). Burt County: 1 mi. E Tekamah, 2. Butler County: 4 mi. N, n. mi. E Octavia, 2 (NSM); 2 mi. N, 2 mi. W Bellwood, 2 (NSM); 4-5 im. E Rising City, 14. Cass County: Louisville, 1 (NGFPC); Rock Blutt, 2 (UNDZ). Clay County: Saronville, 4 (UF). Cuming County: 1 mi. S Beemer, 10. Dlxon County: 3 mi. NE Ponca, 9. Douglas County: Ralston, 1 (RV). Gage County: 1 mi. SE DeWitt, 1; 1 mi. S, 1 mi. W Barnston, 4; m mi. S, 2 mi. E Barnston, 3; 2 mi, S, & mi. E Barnston, 4; 3 mi. SW Barnston, 1 (NGFPC). Hall County: 6 mi. S Grand Island, 8. Jefferson County: 7 mi. S, 2 mi. W Fairbury, 1; 3 mi. S, 1 mi. W Endicott, 1. Johnson County: 1 mi. S, 1% mi. E Burr, 6. Knox County: 3 mi. W Niobrara, 3; Niobrara State Park, 2 (NGFPC); 1 mi. W Niobrara, 1; 1 mi. SE Niobrara, 1; 2 mi. S Niobrara, 5; 8 mi. SW Niobrara, 1 (NGFPC); Verdigre, 2 (USNM). Lan- caster County: 12 mi. N Lincoln, 3 (UC); within 6 mi. Lincoln, 140 (1 CM, 1 NGFPC, 17 NSM, 105 UC, 21 UNDZ); 8 mi. S Lincoln, 8 (UC). Nemaha County: 3 mi. N Pent, 2; Peru, 2 (NSM); 2 mi. SW Peru, 3; 3 mi. S, 1% mi. E Peru, 3; London, 1 (USNM); South Auburn, 4 (USNM). Nuckolls County: 2 mi. E Nelson, 7 (UNM); 2 mi. WSW Superior, 6; 1 mi. SSW Hardy, 1. Otoe County: 1 mi. SE Nebraska City, 5; 1 mi. S Nebraska City, 1 (MSU); 1 mi. S Syracuse, 1 (WFR); 3 mi. S, 2 mi. E Ne- braska City, 2. Pawnee County: 4 mi. S, 8 mi. W Pawnee City, 19. Platte County: 3)2 mi. E Columbus, 1 (UNDZ). Polk County: 15 mi. W Osceola, 2. Richardson County: 4 mi. E Barada, 52; 35-2 mi. S, 1 mi. W Dawson, 7; 2 mi. N Falls City, 1; 4 mi. W Falls City, 1; 'A mi. S, Vk mi. W Rulo, 1; 3-5 mi. SE Rulo, 10 (7 NGFPC). Saline County: 2 mi. NE Crete, 3; Crete, 4 (WFR). Sarpy County: Fontanelle Forest, 1 (UNDZ); 2 mi. SE La Platte, 4; 1 mi. W Meadow, 2. Saunders County: 2 mi. NW Ash- land, 9. Stanton County: 1% mi. S Pilger, 3. Thurston County: %, mi. E Winnebago, 2; J mi. S Winnebago, 3. Washington County: Blair, 21 (2 RV, 19 UMMZ); 1 mi. E Blair, 8; 3 mi. SE Blair, 22; 6 mi. SE Blair, 2. Wayne County: Wayne, 7. County unknown: Platte River Junction, 1 (NSM). Additional records: Lancaster County: 9 mi. NW Lincoln (Whelan, 1937:366). Seward County: Milford (Swenk, MS). Washington County: Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun] ( James, 1823:369). Peromyscus maniculatus Deer Mouse The deer mouse is without question the most abundant mam- malian species in Nebraska and one of the most widely distributed. Individuals occur in every major terrestrial habitat with the excep- tion of dense woods and low, marshy places but the species usually is commonest in upland habitats having a moderate cover of grasses or weeds. In areas devoted mainly to cultivation of crops P. maniculatus finds homesites in fallow fields and along fencerows, especially those bordering roads, where it sometimes is the only species of small mammal trapped. 200 University of Kansas Publs., Mus. Nat. Hist. 97 rf^~. -« ^•r :•:••!>• ■r*\ ,J J.,,* T.,_ 1-- i~ -it**^ Museum of Natural History University of Konsai 1952 I 97 Fig. 42. Distribution of Peromyscus maniculatus in Nebraska. 1. P. m. bairdii. 2. P. m. luteus. 3. P. m. nebrascensis. For explanation of symbols see Fig. 5. Geographic variation in P. maniculatus in Nebraska is marked, both in size and in color of upper parts, the latter seemingly cor- related with the color of soil on which the mice live (see Fig. 4). Three distinct subspecies are found in the state, P. m. bairdii in the east, P. m. luteus on the Sand Hills and adjacent areas in the central part, and P. m. nebrascensis on the Pine Ridge and elsewhere in the Panhandle. P. m. bairdii is the smallest of the three and typically has blackish or dark brown upper parts; P. m. luteus averages slightly larger than bairdii and is the palest of the three, typically having upper parts of bright ochraceous-buff; P. m. nebrascensis is the largest and typically has buffy gray upper parts. Thus, bairdii differs from luteus more in color than in size, whereas luteus differs from nebrascensis more in size than in color. Dice (1941) previously studied variation in the deer mouse in Nebraska and my findings are more or less in accord with his. The deer mouse breeds at least throughout the warmer parts of the year in Nebraska. Sixty-two pregnant females collected in the months of March through November carried an average of 4.5 ( 2-9 ) embryos; the mode was 5. Peromyscus maniculatus bairdii (Hoy and Kennicott) Mus bairdii Hoy and Kennicott, Exec. Doc, House of Representatives, 3rd Sess., 34th Cong. (Rept. of Comm. Patents for 1856), 65:92, 1857 (type locality restricted to Bloomington, McLean Co., Illinois, by Osgood, N. Amer. Fauna, 28:79, April 17, 1909). Mammals of Nebraska 201 Peromyscus maniculatus bairdi, Osgood, N. Amer. Fauna, 28:79, April 17, 1909; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Ne- braska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, De- cember, 1920; Whelan, Trans. Kansas Acad. Sci., 39:366, 1937. H[esperomys]. Michiganensis, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880. Peromyscus michiganensis, Swenk, Proc. Nebraska Acad. Sci., 8:95, Sep- tember, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:39, Sep- tember, 1908. Peromyscus maniculatus bairdii, Dice, Contrib. Lab. Vert. Genetics, Univ. Michigan, 15:16, July, 1941; Bole and Moulthrop, Sci. Publ. Cleveland Mus. Nat. Hist, 5:144, September 11, 1942; Jones and Webb, Jour. Mamm., 30:313, August 17, 1949; Hall and Kelson, The mammals of North America, p. 618, March 31, 1959; Jones, Jour. Mamm., 41:132, February 20, 1960; Galbreath, Trans. Kansas Acad. Sci., 64:226, No- vember 1, 1961. P[eromyscus]. mfaniculatus], bairdii, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Eastern part of state, west certainly to Adams, Boyd, and Valley counties. See Fig. 42. External measurements. — Average and extreme measurements of 17 speci- mens (nine males, seven females, one of unknown sex) from Bichardson County are: 147.5 (125-164); 58.5 (43-66); 18.7 (16-20); 14.0 (13-15). For cranial measurements see Table 14. Eight specimens (three males, five females) from the above-mentioned series weighed an average of 21.4 (20.0-24.0) grams. Remarks. — For comparison with Peromyscus maniculatus luteus, geographically adjacent to the west in Nebraska, see account of that subspecies. Specimens of P. m. bairdii from southeastern Nebraska do not differ in color of upper parts or in size when compared with speci- mens from Iowa and Illinois and are regarded as typical of the subspecies. On the other hand, specimens from the western and, to a lesser extent, northern parts of the range of bairdii in Nebraska average variously paler in color of upper parts than do typical speci- mens and thereby are intergrades with P. m. luteus. For example: eight of 11 adults from Saronville approach bairdii in color whereas three are intermediate between bairdii and luteus; among 15 speci- mens from 10 mi. S Ord, none is so dark as typical bairdii but none is so pale as typical luteus and the average is nearer bairdii than luteus; and of five skins from 1 mi. SW Neligh, three approach bairdii from southeastern Nebraska, one is noticeably paler than bairdii but nearer it than luteus, and the fifth approaches luteus. Many specimens from northeastern Nebraska are slightly paler than typical bairdii, having upper parts that are dark brown but that lack a suffusion of blackish. The zone of intergradation between bairdii and luteus is broad. Most intergrades can be readily assigned on the basis of color of 202 University of Kansas Publs., Mus. Nat. Hist. upper parts to one subspecies or the other but in a few instances assignment of individuals is difficult and necessarily made on geo- graphic grounds. To the north of the Niobrara River intergrades from Boyd County are adjudged nearer bairdii than luteus; specimens from adjacent parts of South Dakota also have been described as resembling bairdii in color (Dice, 1941:8-9). Farther to the west on the table- lands north of the Niobrara intergrades from Keya Paha County and northeastern Cherry County are assignable to luteus. Records of occurrence. — Specimens examined, 438, as follows: Adams County: 4 mi. N, 2 mi. E Hastings, 5 (UNM); 1 mi. N, 334 mi. E Hastings, 3 (UNM); Hastings, 2 (NSM); 10 mi. S Hastings, 7 (UNM); no specific locality, 23 (HM). Antelope County: 1 mi. SW Nehgh, 10; Oakdale, 2 (NSM). Boyd County: 5 mi. WNW Spencer, 1; 4 mi. N Bristow, 5; Spencer, 1 (UNDZ); 5 mi. S, 2 mi. E Spencer, 4; 6 mi. SSE Spencer, 2. Burt County: 1 mi. E Tekamah, 1. Butler County: 4 mi. N, J4 mi. E Octavia, 3 (2 NSM); 2 mi. N, 2 mi. W Bellwood, 1 (NSM); 4-5 mi. E Rising City, 9; 4 mi. S, 4 mi. W David City, 1; 4 mi. E, 1 mi. S Rising City, 2; 5 mi. SW Garrison, 1 (UNDZ). Clay County: Saronville, 12 (UF). Cuming County: 1 mi. S Beemer, 1. Dixon County: 3 mi. NE Ponca, 3. Fillmore County: Geneva, 3 (NSM). Gage County: 34 mi. W Homestead Nat'l Mon., 1; Barnston, 1 (NSM); 1 mi. S, 1 mi. W Barnston, 1; 1% mi. S, 2 mi. E Barnston, 16; 2 mi. S, 1 mi. E Barnston, 1. Greeley County: 1 mi. W Scotia, 2 (NGFPC). Hall County: Grand Island, 1 (USNM); 6 mi. S Grand Island, 11. Holt County: 6 mi. N Midway, 6; Ewing, 1 (USNM). Jefferson County: 7 mi. S, 2 mi. W Fairbury, 5; 3 mi. S, 1 mi. W Endicott, 16. Johnson County: 1 mi. S, 134 mi. E Burr, 2. Knox County: 3 mi. W Niobrara, 4; W side Niobrara State Park, 2 (NGFPC); 1-134 mi. SE Niobrara, 11 (1 NGFPC); 2-234 mi, S Niobrara, 2 (1 NGFPC); 8 mi. SW Niobrara, 1 (NGFPC); Verdigre, 1 (USNM). Lancaster County: 12 mi. N Lincoln, 4 (UC); 9 mi. N Lincoln, 8 (UMMZ); 8 mi. N Lincoln, 1 (UC); 8-9 mi. N\V Lincoln, 4 (3 NGFPC); within 5 mi. Lincoln, 45 (6 CNHM, 1 NGFPC, 15 UC, 6 UNDZ, 12 NSM). Nemaha County: 3 mi. SW Peru, 1; 3 mi. S, l'A mi. E Peru, 2; London, 5 (NSM). Nuckolls County: 5 mi. N, 34 mi. E Nel- son, 3 (UNM); 2 mi. WSW Superior, 5; 1 mi. SSW Hardy, 2. Otoe County: 3 mi. S, 2 mi. E Nebraska City, 2. Pawnee County: NW of Pawnee City, 5 (NGFPC); 4 mi. S, 8 mi. W Pawnee City, 14. Platte County: 2 mi. N Columbus, 1 (UNDZ); 6 mi. S Monroe, 1 (UC); Columbus, 3 (USNM); 3% mi. E Columbus, 1 (UNDZ); 3 mi. S Columbus, 1 (CNHM). Polk County: 15 mi. W Osceola, 2. Richardson County: 5 mi. N, 2 mi. W Humboldt, 2 (1 NSM); 4 mi. E Barada, 9; 3J4 mi. S, 1 mi. W Dawson, 9; 2 mi. N Falls City, 9; 4-6 mi. W Falls City, 6; 8 mi. S, 1 mi. E Dawson, 4; 3 mi. 5 Rulo, 1. Saline County: 2 mi. NE Crete, 1; 34 mi. W DeWitt, 1. Sarpy County: Fort Crook, 3 (AMNH); 2 mi. ESE La Platte, 14; 1 mi. W Meadow, 1. Saunders County: 2 mi. NW Ashland, 2. Seward County: 1 mi. N Pleasant Dale, 2; Milford, 1 (UNDZ). Stanton County: 134 mi. S Pilger, 11; 8 mi. SE Norfolk, 1. Thayer County: 6 mi. E Hubbell, 2 (CNHM). Thurston County: % mi. E Winnebago, 1; 1 mi. S Winnebago, 7. Wash- ington County: Blair, 13 (UMMZ); 1 mi. E Blair, 2; 3 mi. SE Blair, 1; 6 mi. SE Blair, 2. Wayne County: 234 mi. E Wayne, 2; 4 mi. W Hoskins, 10. Valley County: 4 mi. E, 2 mi. S Ord, 5; 10 mi. S Ord, 15 (NGFPC). York County: Waco, 4 ( 1 NSM, 3 UMMZ). Additional records: Clay County: Inland (Swenk, MS). Cuming County: West Point (Swenk, MS). Mammals of Nebraska 203 Peromyscus maniculatus luteus Osgood Peromyscus luteus Osgood, Proc. Biol. Soc. Washington, 18: 77, February 21, 1905 (type locality, Kennedy, Cherry Co., Nebraska). Warren, Colorado Coll. Publ., Engin. Ser., 1:74, January, 1908; Swenk, Proc. Nebraska Acad. Sci., 8:95, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:39, September, 1908 (part); Lyon and Osgood, Bull. U. S. Nat. Mus., 62:133, January 28, 1909. Peromyscus maniculatus luteus, Osgood, N. Amer. Fauna, 28:77, April 17, 1909; Warren, The mammals of Colorado . . ., p. 132, 1910; Cary, N. Amer. Fauna, 33:103, August 17, 1911; Jones, Proc. Biol. Soc. Wash- ington, 71:110, July 16, 1958; Hall and Kelson, The mammals of North America, p. 1081, March 31, 1959 (part, see also p. 622); Jones and Mursaloglu, Proc. Biol. Soc. Washington, 74:102, May 19, 1961. Hesperomys sonoriensis, Baird, Mammals, in Reports of explorations and surveys . . . from the Mississippi River to the Pacific Ocean . . ., 8(1):474, July 14, 1858. Hesperomys leucopus sonoriensis, Coues, in Coues and Allen, Bull. U. S. Geol. Surv. Territories, 11:79, August, 1877. H[esperomys] '. sonariensis [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880. Peromyscus texanus nebrascensis, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 8:251, November, 1896. Peromyscus texensis nebrascensis, Elliot, Field Columb. Mus., Zool. Ser. (Publ. 115), 8:220, 1907. Peromyscus maniculatus nebrascensis, Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dent. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Clark, Jour. Mamm., 17:45, February 14, 1936; Beed, Bull. Conserv. Surv. Div., Univ. Ne- braska, 10:21, October, 1936; Dice, Contrib. Lab. Vert. Genetics, Univ. Michigan, 15:1, July, 1941; Poole and Schantz, Bull. U. S. Nat. Mus., 178:324, April 9, 1942; Warren, The mammals of Colorado . . ., p. 203, 1942; Lindeborg, Contrib. Lab. Vert. Biol., Univ. Michigan, 58:3, June, 1952; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 9:338, May 12, 1958; Hall and Kelson, The mammals of North America, p. 622, March 31, 1959 (part). Peromyscus m[aniculatus]. nebrascensis, Imler, Jour. Wildlife Mgt., 9:272, October, 1945. Peromyscus maniculatus, Jones, Nebraska Bird Rev., 20:10, January, 1952. P[eromyscusJ. m[aniculatusj. nebrascensis, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Sand Hills and adjacent areas of central part of state, east certainly to Holt and Webster counties, west certainly to Garden and Sheridan counties. See Fig. 42. External measurements. — Average and extreme measurements of 30 adults (15 males, 15 females) from eastern Cherry County are: 147.9 (130-164); 59.6 (50-72); 19.3 (18-20); 14.5 (13-15). For cranial measurements see Table 14. Two females from Cherry County weighed 19.1 and 18.2 grams. Twelve males from the vicinity of Franklin weighed an average of 21.1 (18.7-24.9) grams. Remarks. — From Peromyscus maniculatus bairdii, geographically adjacent to the east in Nebraska, P. m. luteus differs in being 204 University of Kansas Publs., Mus. Nat. Hist. slightly larger (see measurements), but especially in having de- cidedly paler upper parts (ochraceous buff rather than blackish brown). From Peromyscus maniculatus nebrascensis, geographi- cally adjacent to the west in Nebraska, P. m. luteus differs in be- ing somewhat paler (ochraceous buff rather than buffy gray), but especially in being smaller, both externally and cranially ( see meas- urements), although there is some overlap in all measurements I have analyzed. The most useful single measurement in separating luteus from nebrascensis seems to be length of ear from notch, which in the former is usually 15 or less and in the latter usually 16 or more. Peromyscus maniculatus luteus is the name currently applied to the small, pale-colored deer mice on the eastern part of the Great Plains from western North Dakota south to western Oklahoma. For many years the name P. m. nebrascensis was applied to these mice because its type locality was thought to be in Nebraska. Actually, the type locality of nebrascensis is in Wyoming ( see Jones, 1958& ) , well within the geographic range of the subspecies formerly des- ignated as P. m. osgoodi. Consequently, nebrascensis replaced os- goodi and luteus, formerly in synonymy under nebrascensis, became the valid name for the eastern population on the Great Plains. Specimens of luteus from localities on the Sand Hills of Nebraska are paler on the average than specimens from elsewhere in the range of the subspecies. Even so, specimens of luteus from other places (both in Nebraska and neighboring states) are decidedly paler than bairdii and are less grayish and markedly smaller than nebrascensis. Of note is the fact that, despite the paleness of most specimens, some individuals in every series from the Sand Hills are darker (more grayish or brownish or both) than typical specimens and approach in color either nebrascensis or intergrades between luteus and bairdii. Dice (1941:18) suggested that this variation was "probably due in considerable part to constant interbreeding with the darker-colored populations which surround the sand hills on every side." Specimens from all along the eastern part of the range of P. m. luteus in Nebraska are intergrades with P. m. bairdii; especially notable in this regard are specimens examined from Keya Paha, Rock, Holt, Custer, Buffalo, and Webster counties. A series of 25 specimens from Comstock illustrates the point. Eight of the 25 resemble typical luteus, three would, standing alone, be referred to bairdii, while the remaining specimens are intermediate in color Mammals of Nebraska 205 between the two subspecies but on the average resemble luteus to a greater degree than bairdii. Specimens from the western edge of the range of luteus, which more or less coincides with the western edge of the Sand Hills, are intergrades with nebrascensis. To the north, in northwestern Cherry County and adjacent Sheridan County, some specimens referable to luteus tend to resemble ne- brascensis in color of upper parts but are typical of luteus in size. Conversely, specimens from more southern localities, Garden and Dundy counties for example, resemble luteus in color but some ap- proach nebrascensis in size; this is illustrated especially among specimens in the series examined from 5 mi. N and 2 mi. W Parks. Records of occurrence. — Specimens examined, 637, as follows: Buffalo County: 1 mi. E Ravenna, 5 (UMMZ); Elm Creek, 1 (NSM). Cherry County: W of Crookston, 12 (NSM); Valentine, 5 (2 UMMZ, 2 UNDZ, 1 USNM); Ft. Niobrara Nat'l Wildlife Refuge, 4 mi. E Valentine, 21; Ft. Nio- brara Nat'l Wildlife Refuge, 8 (NSM); 3 mi. SSE Valentine, 4; 8 mi. S Nenzel, 4- 10 mi. E Gordon, 4 (CNHM); Niobrara River, 10 mi. S Cody, 6 (2 NSM, 4 USNM); 11 mi. S, 2 mi. W Nenzel, 1; 12 mi ESE Gordon, 5 (CNHM); 18 mi. NW Kennedy, 6 (2 NSM, 4 USNM): Two Mile Lake (sec. 12, T. 31 N, R. 34 W), 2 (1 NSM, 1 USNM); Snake River, 1 (USNM); Watt's Lake, Valentine Nat'l Wildlife Refuge, 3 (UC); % mi. W Headquarters, Valentine Nat'l Wildlife Refuge, 2 (UC); Hackberry Lake, Valentine Nat'l Wildlife Refuge, 18 (9 UMMZ, 1 UNDZ); Rice Lake, Valentine Nat'l Wildlife Refuge, 1 (NGFPC); Pelican Lake, Val. Nat'l Wildlife Refuge, 3 (UC); Valentine Nat'l Wildlife Refuge, 1 (NSM); Kennedy, 23 (3 UMMZ, 20 USNM); 2-4 mi. E Kennedtf, 26; 11 mi. E Kennedy, 4; Pony Lake, Valentine Nat'l Wildlife Refuge, 1 (NGFPC); 30 mi. S Wood Lake, 1 (CNHM); North Fork, Middle Loup River, NW of Mullen, 6 (NSM); no specific locality, 12 (USNM). Custer County: 1-4 mi. NW Gavin, 6 (UMMZ); within & mi. Victoria Springs, 5 (UMMZ); Comstock, 27 (2 AMNH, 25 NSM); Broken Bow, 1 (USNM); Callaway, 9 (USNM); 6 mi. SE Mason City, 1 (UMMZ). Dawson County: % mi. S Gothenburg, 1; 3 mi. ESE Gothenburg, 5; 5 mi. S Gothenburg, 6. Dundy County: Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 51 (5 NGFPC); Benkelman, 2 (WFR); 2 mi. N, 2 mi. W Haigler, 3; Arikaree River, Parks, 5; 2 mi. SW Benkelman, 5; Haigler, 10 (2 NSM, 8 USNM). Franklin County: 1 mi. SE Franklin, 3; 2 mi. S Franklin, 11. Frontier County: 3 mi. N Curtis, 1 (UC). Furnas County: 5 mi. W Holbrook, 5 (UI). Garden County: Crescent Lake, 1 (USNM); X mi. S Oshkosh, 5; Windlass Hill (2 mi. SE Lewellen), 2. Garfield County: 10 mi. N Burwell, 1 (UNM). Gosper County: 6 mi. N Elwood, 2 (NSM). Harlan County: 1 mi. W Alma, 4; 1 mi. S Alma, 1. Hitchcock County: 8 mi. S, 3 mi. W Trenton, 6. Holt County: 10 mi. NE Stuart, 2 (NSM); 1 mi. S Atkinson, 10 (5 NSM). Hooker County: Kelso, 10 (UMMZ). Kearney County: H-33i mi. S Kearney, 5. Keith County: 4 mi. WNW Keystone, 85. Keya Paha County: 10-12 mi. N Springview, 6; 12 mi. NNW Springview, 9; Springview, 2 (NSM). Lincoln County: Birdwood Creek, 8 mi. N, 4 mi. W Hershey, 2; 2 mi. N, 5 mi. W North Platte, 2; sees. 9 and 14, T. 11 N, R. 27 W (approximately 6 mi. S, 2 mi. W Brady), 4 (NSM); near Brady, 3 (NSM); 6 mi. NE Dickens, 1 (UMMZ). Logan County: 1-2 mi. NE Stapleton, 47. Red Wdllow County: 8 mi. S, 3 mi. E McCook, 2. Rock County: Perch, 13 ( 11 AMNH, 2 CNHM). Sheridan County: Gordon, 5 (NSM); 11 mi. S Gordon, 9; Mirage Twp., 2 (UMMZ); 16 mi. NE Alliance, 7 (UMMZ); 5 mi. N Antioch, 1 (UMMZ). Thomas County: 1-4 mi. W Halsey, 13; Halsey, 10 (6 AMNH, 1 NSM, 3 USNM); Nebraska Nat'l Forest, 3 (NGFPC); no specific locality, 1 (USNM). Webster County: Bladen, 14 (HM); % mi. E, 2 mi. N Inavale, 2 (NSM); Red Cloud, 1 (NSM); 3 mi. S Red Cloud, 1. 206 University of Kansas Publs., Mus. Nat. Hist. Additional records: Brown County: 22 mi. S Ainsworth (specimen cata- logued in CNHM, but not now to be found). Cherry County: 1& mi. W Sparks (Dice, 1941:6); Center Lake, Valentine Nat'l Wildlife Refuge (Jones, 1952:10). Furnas County: no specific locality (Rapp and Gates, 1957:53). Kearney County: Ft, Kearney (Coues, in Coues and Allen, 1877:82). Lin- coln County: North Platte (Swenk, MS). County unknown: Englemann Creek, Republican River (Baird, 1858:476); Republican River and Platte River (Coues, in Coues and Allen, 1877:82). Peromyscus maniculatus nebrascensis (Coues) Hesperomys sonoriensis var. nebrascensis Coues, in Coues and Allen, Bull. U. S. Geol. Surv. Territories, 11:79, August, 1877 (type locality restricted to Deer Creek, approximately five miles from its mouth, Converse Co., Wyoming, by Jones, Proc. Biol. Soc. Washington, 71:108, July 16, 1958, and others). Peromyscus maniculatus nebrascensis, Osgood, N. Amer. Fauna, 28:75, April 17, 1909; Sprague, Trans. Kansas Acad. Sci., 42:487, 1939; Quay, Jour. Mamm., 29:181, May 14, 1948; Jones, Proc. Biol. Soc. Washington, 71:109, July 16, 1958; Hall and Kelson, The mammals of North America, p. 1081, March 31, 1959 (part, see also p. 622); Jones and Mursaloglu, Proc. Biol. Soc. Washington, 74:102, May 19, 1961. Peromyscus texianus nebrascensis, Cary, Proc. Nebraska Omith. Union, 3:69, December, 1902. Peromyscus luteus, Swenk, Proc. Nebraska Acad. Sci., 8:95, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:39, Septem- ber, 1908 (part). Peremyscus [sic] nebrascensis, Swenk, Proc. Nebraska Acad. Sci., 8:96, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:40, September, 1908. Peromyscus maniculatus osgoodi, Swenk, Bull. Agric. Exp. Sta., Univ. Nebraska, 154:29, August 15, 1915; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 480, December, 1920; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 7:485, April 21, 1954; Hall and Kelson, The mammals of North America, p. 622, March 31, 1959 (part). P[eromyscus]. m[anicukitus]. osgoodi, Dice, Contrib. Lab. Vert. Genetics, Univ. Michigan, 15:1 (see especially p. 17), July, 1941; Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Panhandle, excluding Sand Hills, east at least to Dawes and Deuel counties. See Fig. 42. External measurements. — Average and extreme measurements of 30 speci- mens (17 males, 13 females) from northeastern Sioux County are: 160.7 (151- 177); 63.6 (52-77); 19.9 (18-21); 16.5 (15-19). For cranial measurements see Table 14. Weight in grams of 26 specimens from the above-mentioned series averaged 25.0 (19.8-27.9). Remarks. — For comparison with Peromyscus maniculatus luteus, geographically adjacent to the east in Nebraska, see account of that subspecies. The characters of P. m. nebrascensis are best developed in Ne- braska in specimens from the Pine Ridge and adjacent areas in Sioux and Dawes counties; mice from there are inseparable from specimens from the type locality. Specimens from most localities Mammals of Nebraska 207 to the south of the Pine Ridge, especially from the southwestern part of the Panhandle, approach P. m. luteus in color of upper parts but are typical of nebrascensis in size and are referred to the latter. Swenk (1908:95-96) was the first author to recognize the occur- rence of three distinct kinds of deer mice in Nebraska although his assignment of some specimens was incorrect. Osgood (1909) did not record P. m. nebrascensis from the state although he examined ( and properly identified to species on the specimen label ) a speci- men in the Carnegie Museum from the head of Warbonnet Creek, Sioux County. Probably this was the specimen that he (op. c#.:124) listed under Peromyscus leacopus aridulus. Records of occurrence. — Specimens examined, 347, as follows: Banner County: 9 mi. N, 5 mi. E Harrisburg, 3; 10 mi. W Harrisburg, 6 (NSM); 15 mi. SW Harrisburg, 1 (NSM); 8 mi. SW Redington, 1 (NSM). Box Butte County: near Hemingford, 3 (NSM). Cheyenne County: 15 mi. S Dalton, 4300 ft., 10; 3 mi. N Sidney, 4250 ft., 1; 4 mi. E Sidney, 14. Dawes County: Chadron, 12 (6 CSTC, 6 NSM); 3 mi. E Chadron, 2; Sand Creek, NE of Horn, 6 (NSM); 6-8 mi. S Chadron, 10 (NSM); Chadron State Park, 5 (4 NGFPC, 1 NSM); 10 mi. S Chadron, 24 (UMMZ); Ft. Robinson, 1; 1-3 mi. W Crawford, 8 (NSM); Crawford, 8 (5 NSM, 3 UMMZ); 1 mi. S Crawford, 2 (RV); 3 mi. SW Crawford, 1. Deuel County: 1 mi. N, 2 mi. W Chappell, 4. Kimball County: 3 mi. E Kimball, 14; Smeed, 10. Morrill County: Courthouse Rock, 1 (NSM). Scotts Bluff County: 8 mi. NNW Scottsbluff, 3; Mitchell, 1 (NSM); %-l mi. S Mitchell, 4; Scottsbluff, 13 (1 AMNH, 12 HM); 5 mi. S Gering, 5; 10-11 mi. S Scottsbluff, 4300-4600 ft., 3; 12 mi, SSW Scottsbluff, 4700 ft., 5. Sioux County: 20 mi. NW Harrison, 2 (WSC); 1 mi. S, 4 mi. W Orella, 29 (NSM); Squaw Canyon, 1 (CM); head Warbonnet Creek, 1 (CM); Warbonnet Canyon, 12 (NSM); 8-9 mi. N Harrison, 2 (UMMZ); 5S mi. N, 2% mi. W Harrison, 4 (NGFPC); Monroe Canyon, 4 mi. N, 2 mi. W Harrison, 4 (NSM); Monroe Canyon, 8 (3 NGFPC, 1 NSM, 4 UNDZ); 4 mi. N, 1% mi. W Harrison, 1 (NGFPC); West Monroe Canyon, 1 (NSM); 10 mi. W, IX mi. N Crawford, 10 (8 NSM); 5%-7 mi. W Crawford, 21 (16 NSM); 3% mi. N, 1 mi. E Glen, 34 (NSM); 3 mi. N Glen. 2 (NSM); Glen, 23, (NSM); Agate, 4600 ft., 6 (1 CNHM, 4 UMMZ); 3 mi. E Agate, 4; 8 mi. E Agate, 1 ( NSM ) . Onychomys leucogaster Northern Grasshopper Mouse The northern grasshopper mouse is a common inhabitant of western Nebraska where in my experience it is most frequently taken along the borders of little-used roads and upland grain fields and in relatively undisturbed upland prairie. The species occurs also in most of eastern Nebraska but is rare, probably because most of the original upland prairie there has been turned for agricultural purposes — although this cricetid may never have been common on the tall-grass prairie of the eastern part of the state. The Missouri River and its deciduous riparian association evidently present an effective barrier to eastward dispersal of this grasshopper mouse at 208 University of Kansas Publs., Mus. Nat. Hist. the latitude of Nebraska. Farther to the north in South Dakota, this barrier is breached and O. leucogaster occurs on the eastern side of the Missouri in southeastern South Dakota and even reaches northwestern Iowa (see Hall and Kelson, 1959:664, map 380). -42 Museum of Natural History University of Kansas 1952 1_ Kg JOO 97 Fig. 43. Distribution of Onychomys leucogaster in Nebraska. 1. O. I. arc- ticeps. 2. O. I. breviauritus. For explanation of symbols see Fig. 5. In summer O. leucogaster is largely carnivorous (mostly arthro- pods ) , possibly accounting for the fact that members of the species show a predilection for home-sites along road-sides and the borders of grain fields. Despite the preference for animal food, the northern grasshopper mouse is not difficult to trap in summer using con- ventional baits such as rolled oats. In winter food probably consists mostly of grain and seeds of native weeds and grasses. Hollister (1914) reviewed the systematics of grasshopper mice and Bailey and Sperry (1929) wrote on their life history. The northern grasshopper mouse, like other Nebraskan cricetids, is polyestrous. Nine pregnant females from the months of April, June (three), July (three), and August (two) carried an average of 4.7 (3-8) embryos. Onychomys leucogaster arcticeps Rhoads Onychomys arcticeps Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 50:194, May 3, 1898 (type locality, Clapham, Union Co., New Mexico). Onychomys leucogaster arcticeps, Hollister, Proc. U. S. Nat. Mus., 47:439, October 29, 1914; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Beed, Bull. Conserv. Surv. Mammals of Nebraska 209 Div., Univ. Nebraska, 10:21, October, 1936; Hall and Kelson, The mammals of North America, p. 662, March 31, 1959. Hesperomys (Onychomys) leucogaster, Coues, in Coues and Allen, Bull. U. S. Geol. Surv. Territories, 11:108, August, 1877. H[esperomys]. leucogaster, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880. Onychomys leucogaster, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 8:253, November, 1896; Cary, Proc. Nebraska Omith. Union, 3:65, December, 1902; Elliot, Field Columb. Mus., Zool. Ser. (Publ. 115), 8:200, 1907; Swenk, Proc. Nebraska Acad. Sci., 8:93, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:37, September, 1908 (part); Jones, Nebraska Bird Rev., 20:10, January, 1952. Onychomys leucogaster pallescens, Swenk, Proc. Nebraska Acad. Sci., 8:93, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:37, September, 1908 (part). Onychomys leucogaster articeps [sic], Swenk, Nebraska Blue Book, p. 480, December, 1920. Onychomys l[eucogaster]. arcticeps, Imler, Jour. Wildlife Mgt., 9:272, Octo- ber, 1945. Olnychomys], Ifeucogaster], arcticeps, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Western half of state, east certainly to Custer and Rock counties. See Fig. 43. External measurements. — Average and extreme measurements of 13 speci- mens (eight males, five females) from Kimball and Logan counties are: 140.5 (135-146); 39.8 (37-44); 20.8 (20-21); 15.3 (14-17). Corresponding meas- urements of five specimens (three males, two females) from Cherry County are: 151.6 (147-159); 39.8 (36-42); 21.0 (20-22); 16.0 (15-17, three speci- mens). For cranial measurements see Table 14. A male and female from 2 mi. E Kemiedy weighed 40.9 and 34.0 grams, respectively. Two males from Sioux County weighed 43.2 and 35.4 grams. Remarks. — From Onychomys leucogaster breviauritus, geographi- cally adjacent to the east in Nebraska, O. I. arcticeps differs prin- cipally in having paler upper parts (pale grayish rather than sooty in juveniles, pale brownish gray rather than grayish black in sum- mer-taken adults, buffy brown lightly washed with pinkish rather than dark brown in winter-taken adults ) . Additionally, O. I. arcti- ceps averages slightly smaller than O. I. breviauritus, usually has a whitish rather than a cinnamon-buff tuft at the base of the ear, and may have a large area of white terminally on the tail. Of the specimens herein assigned to arcticeps the four from Calla- way average darker than typical specimens and are regarded as intergrades with breviauritus. When specimens from Cherry County taken in the same season are compared with those from Callaway, the darkest can be matched by the palest from the latter locality. Records of occurrence. — Specimens examined, 257, as follows: Banner County: 10 mi. W Harrisburg, 1 (NSM). Box Butte County: near Hemingford, 1 (NSM). Cherry County: W of Crookston, 1 (NSM); Ft. Niobrara Nat'l Wildlife Refuge, 1 (NSM); Valentine, 24 (1 NSM, 23 USNM); Niobrara River, Clark's Canyon, near Valentine, 1 (USNM); 10 mi. S Cody, 2 (USNM); 18 mi. NW Kennedy, 5 (2 NSM, 3 USNM); Snake River, 1 14—6532 210 University of Kansas Publs., Mus. Nat. Hist. (USNM); Watt's Lake, Valentine Nat'l Wildlife Refuge, 3 (UC); Hackberry Lake, Valentine Nat'l Wildlife Refuge, 22 (18 UMMZ); 2 mi. W to 4 mi. E Kennedy, 7 (1 UMMZ, 2 USNM); Valentine Nat'l Wildlife Refuge, 1 (NSM); 30 mi. S Woodlake, 4 ( CNHM ) ; no specific locality, 14 ( USNM ) . Cheyenne County: 15 mi. S Dalton, 4300 ft., 8. Custer County: 1-4 mi. NW Gavin, 12 (1 MVZ, 11 UMMZ); 7 mi. NW Anselmo, 4 (UMMZ); Callaway, 4 (USNM). Dawes County: 3 mi. E Chadron, 3; Chadron State Park, 2 (NGFPC); 10 mi. S Chadron, 1 (UMMZ); 1 mi. W Crawford, 1 (NSM). Dundy County: 5 mi. N, 2 mi. W Parks, 5; 1 mi. S Parks, 1; Haigler, 5 (USNM). Furnas County: 5 mi. W Holbrook, 3 (UI). Garden County: 10 mi. S Antioch, 5 (UMMZ); Crescent Lake Nat'l Wildlife Refuge, 1 (USNM); 2 mi. S Oshkosh, 1. Grant County: Hyannis, 2 (UMMZ); 13 mi. S Hyannis, 2 (CNHM). Hitchcock County: 8 mi. S, 3 mi. W Trenton, 1. Hooker County: Kelso, 5 (UMMZ). Keith County: 4 mi. WNW Keystone, 4; 1-4 mi. N, 7 mi. E Ogallala, 5. Kimhall County: 3 mi. E Kimball, 7. Lincoln County: Myrtle, 2 (USNM); Birdwood Creek, 8 mi. N, 4 mi. W Hershey, 2950 ft., 3; Rirdwood Creek, 2 (USNM); NW corner sec. 2, T. 12 N, R. 27 W (IK mi. N Brady), 1 (NSM); sec. 9, T. 11 N, R. 27 W (5)4 mi. S, 2 mi. W Brady), 2 (NSM); 6 mi. NE Dickins, 1 (UMMZ); no specific localitij, 3 (USNM). Logan County: 2 mi. NE Stapleton, 7. Morrill County: 6 mi. S Bridgeport, 2 (MVZ). Rock County: Perch, 18 (17 AMNH, 1 CNHM). Scotts Bluff County: Mitchell, 8 (NSM); Scotts- bluff, 1 (HM). Sheridan County: 12 mi. S Gordon, 6 (MVZ); 16 mi. NE Alliance, 4 (UMMZ); 4-8 mi. N Antioch, 8 (UMMZ); Lakeside, 4 (USNM). Sioux County: Warbonnet Canyon, 4 (NSM); 5/2-7 mi. W Crawford, 3 (NSM). Thomas County: 10 mi. W Halsey, 1 (UMMZ); Halsey, 1 (USNM); 1 mi. S, S'A mi. W Halsey, 1; Nebraska Nat'l Forest, 1 (NGFPC); no specific locality, 4 (USNM). Additional record: Sioux County: Orella (Jones, 1949&:5). Onychomys leucogaster breviauritus Hollister Onychomys leucogaster breviauritus Hollister, Proc. Biol. Soc. Washington, 26:216, December 20, 1913 (type locality, Ft. Reno, Canadian Co., Oklahoma); Hollister, Proc. U. S. Nat. Mus., 47:453, October 29, 1914; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 480, December, 1920; Miller and Kellogg, Bull. U. S. Nat. Mus., 205:517, March 3, 1955; Hall and Kelson, The mammals of North America, p. 663, March 31, 1959. Onychomys leucogaster, Swenk, Proc. Nebraska Acad. Sci., 8:93, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:37, Sep- tember, 1908 (part). Ofnychomys], Ifeucogaster] '. breviauritus, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Eastern part of state except eastern edge, west certainly to Antelope and Franklin counties. See Fig. 43. External measurements. — Average and extreme measurements of eight speci- mens (five males, three females) from Antelope and Knox counties are: 148.0 (140-158); 42.0 (38-46); 21.8 (20.5-22.5); 17.03 (17). Measurements of a male from Saronville followed by a male from 2 mi. S Franklin are: 163, 163; 44, 50; 23, 23; — , 20. For cranial measurements see Table 14. Remarks. — For comparison with Onychomys leucogaster arcti- ceps, see account of that subspecies. Specimens from the northwestern part of the range of O. I. brevi- auritus in Nebraska (Antelope and Knox counties) average smaller Mammals of Nebraska 211 Table 14. — Cranial Measurements of Three Genera of Cricetines. ,xj e +3 r> Number of specimens averaged or catalogue C ■g .3 terorbital constricti* t4-H £ J3 ■£ isive amen 3 CG O i of xillary th-row number, and sex CD So P ngtl inc for ,£5 ft ■13 ca g t«>a.S o s-i >> j3 IB CD CD o SJ h- 1 *1 ^ Q J Reithrodontomys megalotis dychei, Cherry County Average 20 (14 cf, 6 9).. Minimum Maximum 21.0 10.9 3.1 7.3 4.4 7.9 20.4 10.0 2.9 6.8 4.3 7.5 22.1 11.3 3.3 7.8 4.7 8.4 116354 USNM, 116358 USNM, 116359 USNM, 69052 KU, cf 69053 KU, & 69054 KU, d1 Reithrodontomys montanus albescens, type locality o", & 9 (type) . 19.5 10.3 3.1 6.5 3.9 7.7 19.8 10.1 3.0 6.7 4.2 7.6 19.7 10.3 3.1 6.9 4.1 7.5 3% mi. S Kearney, in Kearney County 19.5 19.2 19.0 10.4 10.3 10.8 2.8 2.9 2.9 6.5 6.5 6.4 4.0 3.9 7.5 7.3 7.5 Reithrodontomys montanus griseus, Lancaster County 19.1 10.1 6.4 7.5 19.0 10.3 3.3 6.4 7.7 4313 NSM, & 34858 CNHM, 9 Peromyscus leucopus aridulus, vicinity Valentine, Cherry County Average 23 (16 o", 7 9). Minimum Maximum 27.3 14.5 4.2 10.3 5.4 9.8 26.2 13.7 3.8 9.5 5.1 9.3 28.3 15.2 4.4 10.9 5.7 10.3 3.2 3.7 3.5 3.3 3.5 3.4 3.5 3.4 3.2 3.5 4.0 3.8 4.3 Peromyscus leucopus noveboraccnsis, 4 mi. E Barada, Richardson County Average 25 (11 cf, 14 9), Minimum Maximum 27.1 13.9 4.2 10.3 5.4 9.7 25.4 13.0 3.9 9.3 4.8 9.1 28.3 14.7 4.4 11.0 5.8 10.1 Peromyscus maniculatus bairdii, Richardson County Average 15 (8d", 7 9) Minimum Maximum 24.4 23.1 24.8 13.1 3.8 9.4 5.2 8.9 12.5 3.7 8.9 4.9 8.5 13.7 4.0 9.6 5.5 9.3 Peromyscus maniculatus luteus, Cherry County Average 20 (11 cf, 9 9). Minimum Maximum 24.5 13.3 4.0 9.4 5.2 9.0 23.3 12.6 3.7 8.9 4.8 8.8 25.5 13.7 4.2 10.1 4.6 9.3 Peromyscus maniculatus nebrascensis, Sioux County Average 25 (15 cf, 10 9) Minimum Maximum 25.6 13.6 3.9 10.0 5.5 9.2 24.3 13.0 3.7 9.3 5.1 8.6 26.5 14.3 4.3 10.3 5.9 9.9 73381 KU, c? 73383 KU, 9 78374 KU, & Onychomys leucogaster arcticeps, Cherry County 27.9 15.6 4.4 9.7 4.9 10.2 28.4 15.5 4.7 10.5 5.5 10.3 27.3 15.6 4.7 9.6 5.2 10.3 5 mi. N, 2 mi. W Parks, Dundy County Average 5 (3cT, 2 9). Minimum Maximum 28.0 14.8 4.8 10.1 5.3 10.4 27.5 14.4 4.6 9.8 4.9 10.0 28.9 15.6 4.9 10.6 5.9 10.8 Onychomys leucogaster breviauritus, Franklin County 74990 KU, c? 1 29.1 | 14.9 | 4.7 | 10.5 | 5.9 | 10.4 3.9 3.5 4.1 3.7 3.4 3.8 3.8 3.6 4.3 4.0 3.6 4.3 4.7 4.7 4.5 4.5 4.2 4.7 I 4.8 212 University of Kansas Publs., Mus. Nat. Hist. than other Nebraskan specimens and approach O. I. arcticeps in this regard; they are, however, fairly typical of breviauritus in color. As mentioned previously, the riparian association along the Mis- souri River undoubtedly serves as a barrier to eastward dispersal of Onychomys leucogaster at the latitude of Nebraska. Findley (1956&:33) referred grasshopper mice from Clay County, South Dakota (on the north side of the Missouri opposite Cedar and Dixon counties), to the subspecies O. I. leucogaster. Probably that sub- species is limited in the southern part of its range to the region north and east of the Missouri. The grasshopper mouse from Dickinson County, Iowa, that was referred by Dice (1924:66) to O. I. brevi- auritus is, on physiographic grounds, most likely referable to O. I. leucogaster. Records of occurrence. — Specimens examined, 24, as follows: Adams County: no specific locality, 5 (HM). Antelope County: Neligh, 8 (3 NSM, 5 USNM). Clay County: Saronville, 2 (UF). Franklin County: 2 mi. S Franklin, 1. Knox County: 1-1M mi. SE Niobrara, 4 (3 NGFPC); 22 mi. S Niobrara, 1 (NGFPC). Lancaster County: S of Lincoln, 1 (NSM). Wayne County: 4 mi. SE Carroll, 1 (NSM). Webster County: Bladen, 1 (HM). Additional records: Adams County: Logan Twp. (Swenk, MS). Clay County: Trumbull (Swenk, MS). Sigmodon hispidus Cotton Rat The cotton rat is known from but a single locality, which is in Richardson County (Jones, 1960b: 132) in the southeastern corner of the state and is the northernmost record for the species in North America. There, on the night of November 15-16, 1958, R. R. Pat- terson and I trapped 12 specimens, one adult and 11 juveniles, in ditches along a little-used road in the valley of the South Fork of the Nemaha River, 3M mi. S and 1 mi. W Dawson. Most of the cotton rats were trapped in the bottoms of the ditches in fairly thick stands of slough grass and switch grass; most were trapped in runs that were used by, and perhaps partially made by, at least seven other species of small mammals, especially Microtus ochrogas- ter and Synaptomys cooperi. Patterson and Sydney Anderson vis- ited this same locality the following spring, found that catde had grazed and trampled the ditches, and found no cotton rats there or elsewhere in the immediate vicinity. Probably Sigmodon hispidus occurs at some other places along the southern border of Nebraska, especially in the southeastern part as far west as the Blue River, and in the valley of the Republican River. The species has been recorded from Brown, Marshall, Nor- Mammals of Nebraska 213 Muwum of Natural Hirtory Univertity of KofUOft 1952 Fig. 44. Distribution of Sigmodon hispidus texianus in Nebraska. For expla- nation of symbols see Fig. 5. ton, and Smith counties, Kansas (Cockrum, 1952:186; Anderson and Nelson, 1958:306), all of which adjoin Nebraska. Cockrum (1948) summarized the northward spread in this cen- tury of the cotton rat in Kansas, which in the 14 years from 1933 to 1947 averaged slightly more than seven miles per year. After 1947 dispersal of the species northward and westward continued; the specimens collected in Nebraska in 1958 were taken in an area where cotton rats had been sought in almost every year since 1945. Probably the general warming trend on the North American continent is mosdy responsible for the northward movement of Sigmodon hispidus. Severe winters, which have prolonged periods of low temperature or a heavy ground-cover of snow or ice, are known to cause drastic reductions in numbers of the cotton rat in northeastern Kansas and are thought to be the principal limiting factor to continued northward dispersal. The winters of 1948-49, 1951-52, 1959-60, and 1961-62 were severe enough in the vicinity of Lawrence, Kansas, to reduce significantly the population of cotton rats there. Sufficient suitable habitat for S. hispidus is available in southern Nebraska but the species probably will be found in numbers only after two or more consecutive mild winters. The cotton rat breeds from early spring to late autumn (in the warmer parts of its range) according to Asdell (1946:239). Cock- rum (1952:186) reported an average of 6.0 (3-12) embryos per pregnant female in Kansas. 214 University of Kansas Purls., Mus. Nat. Hist. Sigmodon hispidus texianus (Audubon and Bachman) Arvicola texiana Audubon and Bachman, The viviparous quadrupeds of North America, 3:229, 1853 (type locality, Brazos River, Texas). Sigmodon hispidus texianus, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 3:287, June 30, 1891; Jones, Jour. Mamm., 41:132, February 20, 1960. Distribution in Nebraska. — Known only from one locality in Richardson County; probably ocurs also in other areas in extreme southern Nebraska. See Fig. 44. External measurements. — Measurements of a male from Richardson County are: 285; 113; 31.5; 16. This specimen weighed 157.5 grams. Cockrum (1952:186) recorded the average of three males and 12 females, respectively, from Kansas as: 239.6, 251.5; 102.3, 102.5; 30.5, 31.6; 17.0, 17.5; weight, 71.7 and 94.6 grams. For cranial measurements of the male from Richardson County see Table 15. Records of occurrence. — Specimens examined, 12, as follows: Richardson County: 3& mi. S, 1 mi. W Dawson, 12. Neotoma cinerea Bushy-tailed Woodrat The bushy-tailed woodrat inhabits the cliffs and rocky out- croppings of the western part of the Panhandle and occurs also in the rough breaks and rocky areas along the North Platte River east at least to the vicinity of Oshkosh. In some places the species is common, for example in the outcroppings of the Arikaree group (Miocene) on the Pine Ridge in Sioux County and on the Wildcat Ridge in Banner County; it occurs also in out- croppings and breaks of the Ogallala group (Plio- cene) in the southern part of the Panhandle, and in the Badlands of the Brule formation (White River Oligocene) to the north of the Pine Ridge and elsewhere. While rocks seem to provide the preferred location for homesites, N. cinerea fre- quently inhabits abandoned buildings as well. No specimens of this woodrat have been taken to date in Dawes County, but the species almost certainly occurs there on at least the higher areas of the Pine Ridge. The easternmost report of oc- currence in Nebraska, from Oshkosh, is a manuscript record by Swenk, but specimens have been taken at a place 3 mi. NW Lisco, only 17 miles northwestward from Oshkosh, and seemingly suitable habitat for N. cinerea is present along the North Platte Valley at Oshkosh and on eastward into Keith County. A female obtained on July 4, 1957, in Sioux County had four suckling young. Finley (1958:395-398) recorded 1-6 embryos per pregnancy for the species in Colorado; he noted that females may breed in their first year and that adults may breed twice annually. Mammals of Nebraska 215 Neotoma cinerea rupicola J. A. Allen Neotoma rupicola J. A. Allen, Bull. Amer. Mus. Nat. Hist., 6:323, November 7, 1894 (type locality, Corral Draw, 3700 ft., Shannon Co., South Dakota); Cary, Proc. Nebraska Ornith. Union, 3:66, December, 1902; Swenk, Proc. Nebraska Acad. Sci., 8:100, September, 1908 (part); Swenk, Studies Zool. Lab., Univ. Nebraska, 89:44, September, 1908 (part). Neotoma cinerea rupicola, Goldman, N. Amer. Fauna, 31:107, October 19, 1910; Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Quay, Jour. Mamm., 29:181, May 14, 1948; Hall and Kelson, The mammals of North America, p. 704, March 31, 1959. N[eotoma]. cinera [sic], Aughey Sketches of the physical geography and geology of Nebraska, p. 121, 1880. Neotoma orolestes, Swenk, Proc. Nebraska Acad. Sci., 8:101, September, 1908 (part); Swenk, Studies Zool. Lab. Univ. Nebraska, 89:45, Sep- tember, 1908 (part). N[eotoma]. c[inerea], rupicola, Jones, Trans. Kansas Acad. Sci., 60:278, October 22, 1957. Distribution in Nebraska. — Western part of Panhandle, east certainly along breaks of North Platte River to Garden County. See Fig. 45. External measurements. — Average and extreme measurements of six speci- mens (three males, three females) from the Panhandle are 353.8 (325-387); 149.7 (137-159); 39.7 (37-44); 33.04 (32-34). For cranial measurements see Table 15. Two males and two females from the above-mentioned series weighed in grams, respectively, 284.9, 230.9, 235.0 and 174.7. Records of occurrence. — Specimens examined, 34, as follows: Banner County: 10 mi. W Harrisburg, 5 (NSM). Morrill County: 3 mi. NW Lisco, 3. Scotts Bluff County: Scottsbluff, 1 (HM); 11-12 mi. S. Scotts- bluff, 4600-4800 ft., 2. Sioux County: 11 mi. N Harrison, 1; Warbonnet Canyon, 2 (NSM); 8 mi. N Harrison, 1 (UMMZ); Five Points, sec. 5, T. 32 N, R. 54 W, 1 (NSM); Monroe Canyon, 5% mi. N, 2% mi. W Harrison, 3 (NGFPC); Monroe Canyon, 3 (1 AMNH, 2 NSM); 1% mi. N, 11 mi. W Crawford, 5 (3 NSM); Glen, 5 (NSM); 4 mi. E Agate, 1; no specific locality, 1 (NSM). Additional record: Garden County: Oshkosh (Swenk, MS). Neotoma floridana Eastern Woodrat The eastern woodrat occurs in Nebraska only in the southwest and in an isolated area along the Niobrara River in the north-central part of the state. In the vicinity of Valentine, according to V. Bailey (1905:109), individuals "inhabit the cliffs and caves along the [wooded] canyon walls, and forage in the brush and timber along the sides and bottoms of the canyons." I have found them there also in abandoned or little-used buildings. In the southwest, the species inhabits the few areas of rock outcroppings, such as those along the Frenchman River, 5 mi. S Imperial (where nests have been observed ) , but most often builds its characteristic stick houses in wooded valleys, in thickets in rough canyons and breaks, or in abandoned buildings. 216 University of Kansas Publs., Mus. Nat. Hist. -« MuHvm of Notural Hbtoiy University of Komos its I JOB 97 Fig. 45. Distribution of two species of woodrats in Nebraska. 1. Neotoma cinerea rupicola. 2. Neotoma floridana baileyi. 3. Neotoma floridana campes- tris. For explanation of symbols see Fig. 5. Inset map shows distribution of N. floridana in North America. Insofar as now known, the geographic range of Neotoma floridana does not overlap that of the bushy-tailed woodrat, Neotoma cinerea, in Nebraska or elsewhere. Presently, N. f. campestris is known from the Platte Valley at North Platte and N. c. rupicola is known from 85 miles westward along the Platte at Oshkosh. Seemingly suitable habitat for N. floridana prevails, however, in the Platte Valley west- ward into Keith County and the species possibly occurs there along both the north and south forks of the river; on the other hand, rock outcroppings along the North Platte as far southeast as Ogallala may provide suitable homesites for N. cinerea. The places in Keith County where overlap might be found have, to my knowledge, not been investigated intensively. JV. floridana is easily distin- guished from N. cinerea externally by its darker upper parts, smaller ears, and non-bushy tail, and cranially by its shorter incisive foramina, broader and more arched interorbital region, smaller bullae, forked anterior palatal spine, much broader mesopterygoid fossa, and lack of a foramen in the nasal septum. A female obtained on July 15 carried 4 embryos. Each of two females (one taken on June 16 and the other on June 26) were accompanied by 4 young. Rainey (1956:609-610) reported females with 1-5 embryos or young in eastern Kansas. Mammals of Nebraska 217 Neotoma floridana baileyi Merriam Neotoma baileyi Merriam, Proc. Biol. Soc. Washington, 9:123, July 2, 1894 (type locality, Valentine, Cherry Co., Nebraska). Neotoma floridana baileyi, V. Bailey, N. Amer. Fauna, 25:109, October 24, 1905; Swenk, Proc. Nebraska Acad. Sci., 8:100, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:44, September, 1908; Goldman, N. Amer. Fauna, 31:24, October 19, 1910 (part); Swenk, Nebraska Blue Book, p. 852, 1915; Swenk, Nebraska Blue Book, p. 409, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:18, March 1, 1919; Swenk, Nebraska Blue Book, p. 481, December, 1920; Poole and Schantz, Bull. U.S. Nat. Mus., 178:286, April 9, 1942; Hall and Kelson, The mammals of North America, p. 683, March 31, 1959. Neotoma Floridana, Aughey, Sketches of the physical geography and geology of Nebraska, p. 121, 1880. N[eotoma]. baileyi, J. A. Allen, Bull. Amer. Mus. Nat. Hist., 6:323, No- vember 7, 1894. N[eotoma]. f[loridana]. baileyi, Blair, Occas. Papers Mus. Zool., Univ. Michigan, 403:7, June 16, 1939; Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Known presently only from vicinity of Niobrara River in Brown and Cherry counties. See Fig. 45. External measurements. — Average and extreme measurements of 13 speci- mens (six males, seven females) from northern Cherry County are: 376.8 (350-398); 166.1 (136-180); 39.4 (38-41); 25.52 (25-26). For cranial meas- urements see Table 15. One of the females, pregnant with four large embryos ( 35 mm. crown-rump ) weighed 376.2 grams. Remarks. — For comparison with Neotoma floridana campestris of southwestern Nebraska, see account of that subspecies. N. f. baileyi represents an isolated population of woodrats in the Niobrara Valley of northern Nebraska. Post-Wisconsin climatic shifts probably are responsible for this relict population, as explained on pp. 26-27. Specimens are presently available only from along the Niobrara itself in northern Cherry County but a manuscript report (Swenk, MS) from Long Pine indicates that the subspecies occurs eastward along the Niobrara in northern Brown and southern Key a Paha counties. Probably it occurs also along at least some of the few tributaries of the Niobrara, like the Snake River and Gordon Creek to the south in central Cherry County, and along Minichaduza Creek to the north, whence it may reach South Dakota. The subspecies previously was reported from the latter state by Goldman (1910:25), based on a single specimen from Spring Creek, 18 mi. SE Rapid City, but my examination of this specimen in the U. S. National Museum indicates that it is without question Neotoma cinerea rupicola. In color and in some cranial features N. f. baileyi resembles Neo- toma- floridana osagensis Blair ( type locality, Okesa, Osage County, 218 University of Kansas Publs., Mus. Nat. Hist. Oklahoma) of eastern Kansas more than it does N. f. campestris. N. f. osagensis possibly occurs in extreme southeastern Nebraska, although I have sought it unsuccessfully in all southeastern counties bordering Kansas. Rainey (1956:634-637) reported the subspecies from localities in Marshall County, Kansas, only 15 miles south of the Nebraska border; he, too, failed to find osagensis in Nebraska, although he searched for it (p. 635) in Osage orange hedgerows in Pawnee and Richardson counties, and in rock outcroppings and abandoned buildings along the Rlue River in the vicinity of Barns- ton, Gage County. Rainey (pp. 636-637) concluded that both physiographical and biological factors limited dispersal of the eastern woodrat to south- eastern Nebraska. He pointed out that one of the major factors was "disruption of habitat," especially the absence of outcropping rock coupled with intervening areas of open country, and that "scarcity of overhead cover limits the spread of populations of woodrats when discontinous habitat is encountered." Climatic extremes also were mentioned as a possible limiting factor. Records of occurrence. — Specimens examined, 33, as follows: Cherry County: Valentine, 6 (USNM); 4 mi. E Valentine, 6; Clark's Canyon, near Valentine, 11 (USNM); 3 mi. SSE Valentine, 1; 10 mi. S Cody, 9 (4 NSM, 5 USNM). Additional record: Brown County: Long Pine (Swenk, MS). Neotoma floridana campestris J. A. Allen Neotoma campestris J. A. Allen, Bull. Amer. Mus. Nat. Hist., 6:322, No- vember 7, 1894 (type locality, Pendennis, Lane Co., Kansas). Neotoma floridana campestris, Kellogg, Kansas Univ. Mus. Nat. Hist., Zool. Ser., 1(1):5, January 30, 1914; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 7:485, April 21, 1954; Hall and Kelson, The mammals of North America, p. 683, March 31, 1959. Neotoma floridana baileyi, Goldman, N. Amer. Fauna, 31:24, October 19, 1910 (part). N[eotoma]. f[loridana]. campestris, Jones, Trans. Kansas Acad. Sci., 60:277, October 22, 1957. Distribution in Nebraska. — Southwestern part of state south of Platte River. See Fig. 45. External measurements. — Measurements of a male and two females from 5 mi. N and 2 mi. W Parks are, respectively: 395, 363, 378; 162, 160, 151; 44, 40, 39; 30, 25, 26. Four young adults from the same locality (a male and three females, respectively) measured: 360, 348, 324, 333; 155, 148, 147, 148; 42, 40, 43, 41; 31, 26, 30, 29. For cranial measurements see Table 15. Respective weights in grams of three of the last-mentioned specimens, the male and two females, were 234.0, 228.0, and 180.0. Remarks. — From Neotoma floridana baileyi of northern Ne- braska, N. f. campestris differs in: upper parts and dorsal aspect of tail distinctly paler; skull larger in most dimensions (see Table 15), especially in lengths of rostrum, nasals, incisive foramina, and tooth- Mammals of Nebraska. 219 rows, and in depth of skull; palate relatively and actually shorter; zygomatic notches deeper. The paleness, shortness of palate, and greater length of incisive foramina in comparison with haileyi were noted in the original description of campestris (J. A. Allen, 1894:323). The subspecies N. f. campestris was first reported from Nebraska (Jones, 1954:485) based on specimens from 5 mi. N and 2 mi. W Parks, although previously Goldman (1910:25) listed a specimen from Haigler as N. f. baileiji. He regarded campestris as a synonym of haileyi. Records of occurrence. — Specimens examined, 20, as follows: Dawson County: Quinn's Canyon, 10 mi. S Gothenburg, 1 (NSM). Dundy County: Rock Creek Fish Hatchery, 5 mi. N, 2 mi. W Parks, 9 (1 NGFPC); Haigler, 1 (USNM). Hays County: & mi. S Hamlet, 1 (NSM). Lincoln County: North Platte, 1 (NSM); Conroy Canyon, sec. 10, T. 11 N, R. 27 W (5 mi. S, Tk mi. W Brady), 6 (NSM). Red Willow County: McCook, 1 (NSM). Additional records: Chase County: 5 mi. S Imperial (see account of species above). Frontter County: vicinity Curtis (Swenk, MS). Table 15. — Cranial Measurements OF SlGMODON AND NEOTOMA. -C a DO Is t>0 _o 03 03 t— 1 3 ^^ Number of specimens °g *.2 a m 53 o _ £ § averaged or catalogue Ifl bC J2 "£ o o ^5 zi ' o.£| number, and sex 03 *t£ 2§ S3 o bfl c J *= a ngth max toot ngth incif fora o >> a o Q Sigmodon h-ispidus texianus, Richardson County 79157 KU, d1 | 36.0 | 19.9 | 5.4 | 13.3 | 13.7 | 6.8 Neotoma cinerea rupicola, 3 mi. NW Lisco, in Morrill County 80974 KU, 9 80976 KU, & 8.0 46.9 6.3 19.3 16.3 9.7 48.2 26.2 6.1 19.0 16.5 9.5 Sioux County 4248 NSM, 9 . . 4252 NSM, cf.. 335 NGFPC, > Interorbit constri 03 -u 03 Kh O -a ho 0 O a u S3 h3 >-H Q a; 79080 KU, 79178 KU, 80141 KU, 80142 KU, Synaptomys cooperi gossii, Richardson County o" 29.8 18.5 3.6 14.4 8.3 cf 29.6 17.7 3.2 14.0 8.5 l/£ mi. W Homestead Nat'l Mon., Gage County 9 29.7 30.6 18.0 18.3 3.7 3.3 13.9 13.8 8.0 7.9 11.9 12.3 11.7 11.8 78379 KU, o* 51617 KU, 72603 KU, (type) Microtus ochrogaster haydenii, Cherry County Average 23 (5d\ 18 9) Minimum Maximum Scotts Bluff County Average 14 (7d\ 7 9 ) ■ Minimum Maximum Microtus ochrogaster ochrogaster, Richardson County Average 15 (10c?, 5 9 ) . . . . Minimum Maximum Microtus pennsylvanicus ftnitus, type locality Average 15 (7d\ 8 9) Minimum Maximum 29.8 16.3 3.5 12.4 8.1 11.7 7.5 28.3 15.4 3.1 11.8 7.4 11.1 7.2 31.5 17.4 3.8 13.4 9.0 12.4 8.0 Microtus pennsylvanicus pennsylvanicus, northern Nebraska Average 10 (7c?1, 3 9) Minimum Maximum Microtus pinetorum nemoralis, London, Nemaha County 52783 USNM, 9 52784 USNM, ,£ 3 Number of specimens GO o£ ei O fl •y s 53 O averaged or catalogue O^ IS -£ O o £ t*- number, and sex ~ bC 2 § 8 o xi bfl ngth max toot a, O >> a i— i CD tn > e o 9 '0 JA ■5 °3 g .2* « MP"1 4a e3 mS3 o o >> aj Q O NJ >— < 2 G hJ 8 mi. S, 4 mi. W Pawnee City, Pawnee County 72205 KU, & 72206 KU, & 22.6 20.1 10.9 4.3 9.7 8.9 21.6 19.0 10.4 4.2 9.4 9.0 3.3 3.5 2 mi. S Schuyler, Colfax County 76880 KU, t 1 i o ! T " ~r — "^c i J Seel* MO JO t-r-l 1 •oMilci =1 Museum of Natural Hiitory University of Kansas 1952 97 Fig. 57. Distribution of Urocyon cinereoargenteus ocyihous in Nebraska. For explanation of symbols see Fig. 5. As in the case of the two species of Vulpes, populations of the gray fox probably were drastically reduced by the widespread, indis- criminate use of poison baits in the late 1800's and early 1900's to control the wolf and coyote. In any event, although a few uncon- firmed reports of the presence of the species were received in the first half of the 20th Century, no certain record of its occurrence in the state after 1894 was forthcoming until 1953 when three indi- viduals were taken, one in Omaha (Velich, 1958:148), another near Ulysses (A. V. Hascall, personal communication), and the third in the vicinity of Enola. Reports of occurrence, some verified by actual specimens, have become increasingly frequent since 1953 Mammals of Nebraska 259 and U. cinereoargenteus seems now to be well established, although not so common as the red fox, in the eastern part of Nebraska and evidently in the Platte River drainage nearly to the western border of the state. Similar increases in numbers of the gray fox in recent years have been reported for Iowa (Polder, 1958:560-562) and Kansas (Anderson and Nelson, 1958:308-309). According to Polder (loc. cit.) the species frequents "weedy flood plains and brushy timber bordering streams" in northwestern Iowa. I have no evidence to suggest whether the current population of this fox in Nebraska results from increase and dispersal of native stock, from invasion from areas to the eastward, or from both, but it is doubtful that the species ever was entirely extirpated in Ne- braska. Females bear young from late March to May at the latitude of Nebraska; litters comprise 2-7 offspring according to Asdell (1946: 162). Urocyon cinereoargenteus ocythous Bangs Urocyon cinereoargenteus ocythous Bangs, Proc. New England Zool. Club, 1:43, June 5, 1899 (type locality, Platteville, Grant Co., Wisconsin); Polder, Proc. Iowa Acad. Sci., 65:560, November 20, 1958; Hall and Kelson, The mammals of North America, p. 863, March 31, 1959. [Canis] cinereo-argenteus, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823. V[ulpes]. Virginianus, Aughey, Sketches of the physical geography and geol- ogy of Nebraska, p. 119, 1880. Urocyon cinereo-argenteus ocythous, Swenk, Proc. Nebraska Acad. Sci., 8:123, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:67, September, 1908; Swenk, Nebraska Blue Book, p. 853, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919. Urocyon cireneo argenteus [sic] ocythous, Swenk, Nebraska Blue Book, p. 482, December, 1920. U[rocyon]. c[inereoargenteus]. ocythous, Jones, Trans. Kansas Acad. Sci., 60:279, October 22, 1957; Velich, Jour. Mamm., 39:148, February 20, 1958. Urocyon cinereoargenteus, Velich, Jour. Mamm., 42:93, February 20, 1961. Distribution in Nebraska. — Eastern third of state and west in Platte River drainage to Panhandle; also reported from archeological site in Chase County See Fig. 57. External measurements. — No measurements of Nebraskan-taken individuals are available. Findley ( 1956a: 1) recorded the following measurements of a male from Jerauld County, South Dakota: 964; 343; 140; 75. Two females from Douglas County, Kansas, measured: 975, 980; 350, 330; 135, 143; 62, 82. The weight of the first-listed female was lOM lbs. For cranial measurements see Table 19. Remarks. — A single specimen from the Sioux Ordinance Depot, Cheyenne County (KU 83467), a skull only of unknown sex (prob- ably male, judging from its large size), is clearly referable to U. c. ocythous rather than to the smaller U. c. scottii, which was reported 260 University of Kansas Publs., Mus. Nat. Hist. from Loveland, Colorado, in the foothills of the Rocky Mountains approximately 125 miles southwestward, by Cary (1911:176). The skull from Cheyenne County was obtained in June of 1960 from a recently killed animal and signals the probable occurrence of ocy- thous in adjacent parts of Colorado and Wyoming. Recent records of U. c. ocythous from western South Dakota indicate that the species may be found in the Niobrara Valley and adjacent areas of northern Nebraska where it is not now known to occur. Table 19. — Cranial Measurements of Three Species of Foxes. a a CO 13 "3 o o 43 CO 03 >,£ Number of specimens CO c3 o^ 3 g bC CI a 3 P averaged or catalogue £2 JO O +3 On £> 15 QJ o ngth oi maxill tooth- number, and sex ndyl leng H a 2g _Q CO O O ■£ ° CO "«3 133 j3 ft a o >> a O o3 03 0) O S3 Ph Pl. i-5 hS FwZpes veZoz reZox, Ft. Kearney, Kearney County 1345 USNM, tf 1343 USNM, 9 1347 USNM, 9 113.1 62.4 23.3 23.3 59.5 42.5 109.5 63.4 23.9 21.7 56.6 40.2 108.6 60.4 23.4 23.9 56.2 39.1 53.6 52.9 51.9 Republican Fork, Dundy County 2613 USNM, ? | 105.8 | 62.2 | 24.8 | 24.0 | 54.5 | 38.8 | 49.9 Vulpes vulpes regalis, eastern Nebraska Average 8 (o71). Minimum Maximum Average 10 ( 9 ) Minimum Maximum 139.3 133.8 146.0 132.9 128.2 137.1 75.6 73.7 77.5 71.2 67.8 74.3 26.8 25.3 28.8 25.5 24.1 27.2 22.7 21.0 24.2 22. 59 20.4 24.4 71.9 68.0 76.4 68.0 64.2 70.9 Ft. Kearney, Kearney County 1325 USNM, 9 | 142.1 | 71.6 | 25.3 | 22.0 | 71.8 5 mi. E Lewellen, Garden County 84909 KU, & | 137.0 | 76.4 | 31.5 | 24.2 | 71.9 Urocyon cinereoargenteus ocythous, Knox County 287701 USNM, cf 287702 USNM, d1 55.8 50.7 59.1 53.0 49.5 56.8 54.2 58.0 120.5 123.3 69.3 70.5 24.9 26.3 28.4 29.3 59.5 43.4 44.1 63.8 61.5 66.9 60.5 57.6 63.3 65.0 64.1 52.4 52.0 Sioux Ordinance Depot, Cheyenne County 83467 KU, ? | 123.3 | 71.0 | 27.4 | 31.4 | 60.4 | 49.6 | 50.7 Records of occurrence. — Specimens examined, 4, as follows: Cheyenne County: NW corner Sioux Ordinance Depot, 1. Knox County: Center, 1 (USNM); S of Center, 1 (USNM). Madison County: IK mi. N, 135 mi. W Enola.l (NGFPC). Mammals of Nebraska 261 Additional records: Butler County: near Ulysses (see text). Chase County: 12 mi. N Wauneta (Hill and Metcalf, 1942:204, archeological site). Douglas County: Omaha (Velich, 1958:148); Otis Park, near Omaha (Swenk, MS). Hall County: no specific locality (Stolley, 1946:77). Loup County: Almeria (Velich, 1961:93). Pierce County: no specific locality (Aughey, 1880:119). Washington County: N of Fremont (R. Velich, per- sonal communication); Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun] (James, 1823:369); near Ft. Calhoun (Velich, 1961:93). Family Ursidae — Bears Key to Nerraskan Ursids 1. Usually pale brownish; front claws more than 50, longer than hind claws; ml having one cusplet or more medially in concavity between metaconid and entoconid; M2 broadest anteriorly Ursus horribilis, p. 263 1'. Usually blackish or cinnamon; front claws less than 50, about equal in length to hind claws; ml lacking cusplets in concavity between meta- conid and entoconid; M2 broadest approximately midway along its length Ursus americanus, p. 26 1 Ursus americanus Black Bear Historical accounts indicate that the black bear occurred in eastern Nebraska and westward along the Niobrara and Loup rivers at least to Cherry County. No records are available to indicate that it occurred also in the western part of the state but it is difficult to believe that the species did not range westward along all the larger rivers and into the Pine Ridge area as well. Probably U. americanus was more or less limited to wooded areas. KB i^O 1 '■ r-i- — \ — fQ"i ! f T i — \ L._._^L ! i i i I i L.— *•■ j J V^_A 4C- ^ri j_._.i-._. r-t-rt Museum of Natural History University of Kansas 1952 Fig. 58. Records of occurrence of two species of bears in Nebraska. Ursus americanus americanus ( circles ) . Ursus horribilis horribilis ( inverted triangles ) . Inset map shows distribution of U. americanus in North America. 262 University of Kansas Publs., Mus. Nat. Hist. Judging from the available information the species was uncom- mon in Nebraska except possibly along the Missouri River in the southeast. Most of the records in the literature are from along the Missouri. Lewis and Clark recorded (Thwaites, 1905:122): "The Black Bear is found in abundance [along the Missouri] as high as the little Sieoux [sic] river ... [it is] found much higher but scarce [sic]." J. J. Audubon, however, saw only one bear in his trip up the Missouri in 1843 and remarked as follows (Audubon and Coues, 1898:490): "In talking to our captain [of the river steamer Omega] he tells us that the Black Bear is rarely seen swimming this river, and that one or two of them are about all he observes on going up each trip." The most recent record of the black bear in Nebraska is Swenk's (1908:124) report of an individual killed near Valentine in the winter of 1907. There have been persistent reports that a few black bears have invaded the Pine Ridge in recent years but these remain to be verified. Given adequate protection I suspect that a small number of bears could exist on the Pine Ridge. Ursus americanus americanus Pallas Ursus americanus Pallas, . . . Spicilegia zoologica . . ., fasc. 14:5, 1780 (type locality, eastern North America); Swenk, Proc. Nebraska Acad. Sci., 8:124, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:68, September, 1908; Jones, Bull. Univ. Nebraska State Mus., 4:92, November 26, 1962. Ursus Americanus, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823; Aughey, Sketches of the physi- cal geography and geology of Nebraska, p. 118, 1880. Ursus americanus americanus, Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent, Univ. Nebraska, 23:20, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920. U[rsus]. a[mericanus]. americanus, Jones, Trans. Kansas Acad. Sci., 60:279, October 22, 1957. Distribution in Nebraska. — Formerly eastern part of state, west certainly to Cherry County; probably also in wooded areas of western part of state; now extirpated. See Fig. 58. Measurements. — No Nebraska-taken specimens are known. V. Bailey ( 1927:191 ) recorded the external measurements of an adult male from Montana as: 1680; 105; 275. According to Burt (1948:121) the length of skull varies from 257-291 and the zygomatic breadth from 150-176. Records of occurrence. — Specimens examined, none. Additional records (Jones, 1962:92-93, unless otherwise noted): Cherry County: Bear Creek (Swenk, 1908:124); near Valentine (Swenk, 1908:124); between North Loup River and Bush Lake ( 101° 28' W, 42° 23' N). Dakota County: northern part, along Missouri River. Greeley County: 40 mi. N Loup River on Cedar River (location not certainly placed in Greeley County). Nemaha County: Sun Island, Missouri River, between Peru and Brownville. Otoe County: "Missouri bottom" (Swenk, 1908:123). Washington County: Rockport (Swenk, 1908:124); Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun] (James, 1823:369). County unknown: Niobrara River (Swenk, 1908:123). Mammals of Nebraska 263 Ursus horribilis Grizzly Bear The former distribution of the grizzly bear in Nebraska is not well documented. Probably the species occurred uncommonly on the High Plains of the Panhandle and eastward some distance in the hills and breaks along the Platte and Niobrara rivers. Only one actual specimen, a skull picked up in the 1930's at Roubadeau Pass, Scotts Bluff County, is known. I have found only three citations to the grizzly bear in the his- torical literature of Nebraska (Jones, 1962:93) : Edwin James noted in a general discussion of the species that a hunter had seen a "bear," presumably a grizzly, on the "Qui Court [Niobrara] river," but gave no specific locality; J. H. Carlton saw tracks along Ash Creek, Garden County, in 1845; and R. B. Marcy encountered a female with two cubs on the "elevated table-lands lying between the two forks of the Platte River," probably in western Keith County, in 1858. Marcy (1863:172-173) gave an account of the killing of the adult. The paucity of records of the species in literature dealing with the early exploration of Nebraska and the complete absence of rec- ords from the archeological sites thus far reported upon corroborate the contention that the grizzly bear was comparatively rare in the state. G. M. Allen's (1942:144) statement that it was found in some numbers in Nebraska was based upon the specimens from "Ne- braska" listed by Baird (1858:225), all of which actually originated from some other western state. Ursus horribilis horribilis Ord Ursus horribilis Ord, in Guthrie, A new geographical, historical, and com- mercial grammer . . ., ed. 2, 2:291, 299, 1815 (type locality, north side of Missouri River, near mouth of Wolf Creek, Roosevelt Co., Montana); Jones, Bull. Univ. Nebraska State Mus., 4:93, November 26, 1962. Ursus horribilis horribilis, Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920. U[rsus]. h[orribilis]. horribilis, Jones, Trans. Kansas Acad. Sci., 60:279, October 22, 1957. Distribution in Nebraska. — Formerly rare on High Plains of western part of state; eastern limits of distribution not certainly known; probably east along Platte and Niobrara rivers to about the 100th meridian; now extirpated. See Fig. 58. Measurements. — No external measurements of a specimen from Nebraska are available. Some cranial measurements of an individual of unknown sex from Scotts Bluff County are as follows: greatest length of skull, 371; con- dylobasal length, 330; zygomatic breadth, 195. Remarks. — The type locality of U. h. horribilis has been located at different places in northeastern Montana by different authors. 264 University of Kansas Publs., Mus. Nat. Hist. The specimen on which Ord based the description of Ursus horri- bilis was obtained by members of the Lewis and Clark Expedition on May 5, 1805, on the north side of the Missouri River near the mouth of Wolf Creek in what is now Roosevelt County, Montana (see discussion in Coues, 1893:292-301). Some recent authors (Couturier, 1954:329; Erdbrink, 1953:339; Rausch, 1953:105, and others) have regarded the brown bears of the Palearctic and Nearctic regions as conspecific and therefore em- ployed the name Ursus arctos horribilis for the grizzly bear. Records of occurrence. — Specimen examined, 1, as follows: Scotts Bluff County: Roubadeau Pass, SW of Scotts Bluff Nat'l Mon., 1 (Scotts Bluff Nat'l Mon. Collection). Additional records : See text above. Family Procyonidae — Raccoons and Allies Procyon lotor Raccoon The raccoon is state-wide in distribution in suitable habitat — woodlands, usually where water is present, and around lakes and marshes. It is perhaps the most abundant of Nebraskan carnivores and one of the most important economically. The pelt has remained of sufficient value that many still are marketed each year; the meat is eaten by man and is said to be in greater demand than that of any other mammal normally classed as a fur-bearer; and the hunt- ing of raccoons is a popular sport, especially in the southeastern part of the state, where it provides recreational and economic bene- fit to many residents. Corn is one of the staple foods and high concentrations of individuals result, on occasion, in significant loss to farmers. Raccoons are inactive in the coldest parts of the winter; in fact, Sharp and Sharp (1956:170-177), who studied behavior of the species on the Valentine National Wildlife Refuge, reported that adults could forecast approaching storms. The paucity of accounts that mention the raccoon in the literature dealing with the early settlement of Nebraska suggests that it was less common then than now. Unquestionably the conversion to agriculture of the river valleys and adjacent areas in the western part of the state has provided food and shelter for substantial popu- lations of raccoons where few or no individuals occurred previously. Around the marshes of the Sand Hills, where few trees grow, in- dividuals find refuge primarily in burrows in the ground. I have no record of the introduction of raccoons into Nebraska from other states but it is possible that some introductions have Mammals of Nebraska 265 Fig. 59. Distribution of Procyon lotor hirtus in Nebraska. of symbols see Fig. 5. For explanation been made. Stains (1956:27) reported that approximately 2000 raccoons were brought from other places and liberated in Kansas between 1939 and 1956. Females bear young only once annually — usually in late spring. Stains (loc. cit. :30) reported an average of 4.6 (3-7) young for eight litters from Kansas. A female taken on July 17, 1957, in Sheridan County was lactating; no other data on reproduction are available from Nebraska. Procyon lotor hirtus Nelson and Goldman Procyon lotor hirtus Nelson and Goldman, Jour. Mamm., 11:455, November 11, 1930 (type locality, Elk River, Sherburne Co., Minnesota); Gold- man, N. Amer. Fauna, 60:37, November 7, 1950. Procyon lotor, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823; Baird, Mammals, in Reports of ex- plorations and surveys . . . from the Mississippi River to the Pacific Ocean . . ., 8(1):209, July 14, 1858; Hayden, Exec. Doc, House of Representatives, 2nd Sess., 35th Cong., 2:708, 1859; Hayden, Trans. Amer. Philos. Soc, 12(n. s.):143, 1863; Hayden, Catalogue of the collections in geology and natural history . . ., in Warren, Preliminary report of explorations in Nebraska and Dakota . . ., p. 92, 1875; J. A. Allen, Bull. U. S. Geol. Surv. Territories, 2(4):325, July 1, 1876; Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902; Swenk, Proc. Nebraska Acad. Sci., 8:124, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:68, September, 1908; Sharp and Sharp, Jour. Mamm., 37:170, June 9, 1956. Procyon loter [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880 (part). P[rocyon], Hernandezzii [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880 (part). 266 University of Kansas Publs., Mus. Nat. Hist. Procyon lotor lotor, Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, Marcb 1, 1919; Swenk, Nebraska Blue Book, p. 482, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:27, October, 1936. P[roycon]. l[otor]. hirtus, Jones, Trans. Kansas Acad. Sci., 60:279, October 22, 1957. Distribution in Nebraska. — State-wide in suitable habitat. See Fig. 59. Measurements. — External measurements of three males and three females from southeastern Nebraska are, respectively: 908, 908, 889, 825, 832, 871; 248, 324, 273, 254, 270, 251; 121, 122, 114, 117, 105, 112; 60 (one female). Corresponding respective measurements of four males and three females from northwestern Nebraska are: 881, 842, 914, 838, 808, 795, 838; 293, 258, 254, 254, 246, 254, 228; 125, 130, 140, 127, 110, 116, 127; 69, 67, 64, — , 59, 64, 63. The weights of two males and two females (all summer-taken) from the last-mentioned series were, respectively, 15/4, 14/2, 12, and 12M lbs.; a winter- taken male and female weighed 16% and 22/2 lbs., respectively. Cranial measurements of two males and a female from Butler County, fol- lowed by those of a male and female from Sioux County, are, respectively: condylobasal length, 119.1, , 110.5, 119.8, 113.6; zygomatic breadth, 84.0, 83.0, 75.5, 83.2, 72.9; interorbital constriction, 25.9, 24.9, 24.6, 27.4, 22.3; postorbital constriction, 24.6, 22.7, 24.7, 24.8, 20.9; mastoid breadth, 66.8, 68.7, 59.7, 64.1, 61.6; alveolar length of maxillary tooth-row, 45.5, 45.0, 42.3, 44.1, 42.2. Records of occurrence. — Specimens examined, 103, as follows: Brown County: Plum Creek, N of Johnstown, 10 (AMNH); Plum Creek, 19 (AMNH); [Long] Pine Creek, 1 (AMNH); Bone Creek, 10 (AMNH); Cedar Creek, 1 (AMNH); Johnstown, 1 (USNM); 6 mi. SW Johnstown, 3 (AMNH); Kirkpatrick Marsh (approximately 15 mi. S, 3 mi. W Johnstown), 4 (AMNH). Butler County: Platte River, 1; 11 mi. NE David City, 1; 9 mi. NE David City, 1; near David City, 8. Cass County: Louisville, 1 (NSM); 35 mi. E Lincoln, 1 (UC). Chase County: 1 mi. N, 6.4 mi. W Imperial, 3300 ft., 1. Cherry County: Ft. Niobrara Nat'l Wildlife Refuge, 4 (3 NSM, 1 USNM); Schlegel Creek, 1 (NSM); Valentine Nat'l Wildlife Refuge, 8 (3 NSM); near Kennedy, 2; Beaver Lake, 2 (NSM); Rat Lake, 1 (NSM); Goose Creek, 3 (AMNH). Cuming County: Beemer, 2 (USNM). Custer County: Victoria Springs, 1 (UMMZ). Dawes County: 4 mi. SW Crawford, 2 (NSM). Hall County: Doniphan, 1 (HM). Johnson County: 1 mi. S, & mi. E Burr, 1; 10 mi. E Sterling, 1 (NSM). Keya Paha County: Niobrara River, 6 (AMNH). Kimball County: Smeed, 1. Lancaster County: Lincoln, 2 (1NSM, 1UC). Merrick County: Silver Creek, 1 ( RV ) . Pawnee County: 4 mi. S, 8 mi. W Pawnee City, 1. Rock County: Short Pine Creek, 3 (AMNH); head of Elkhorn River, 1 (AMNH). Sarpy County: Papillion, 1 (RV). Saunders County: Ashland, 1 (NSM). Seward County: Staple- hurst, 3 (NSM). Sioux County: Squaw Canyon, 1 (WSC); "Toadstool Park" (SW of Orella), 1 (NSM); Sowbelly Canyon, 1 (NGFPC); 6%-7 mi. W Craw- ford, 4 (2 NSM); Agate, 3 (RV). Sheridan County: 11 mi. S Gordon, 1. Valley County: 7 mi. NW Ord, 1 (NGFPC). Webster County: Red Cloud, 2 (NSM). County unknown: "Nebraska," 1 (USNM); vicinity Republican River between Red Cloud and Superior, 1 (NSM). Additional records: Adams County: Logan Twp. (Swenk, MS). Ante- lope County: Neligh (Cary, MS). Burt County: Tekamah (Swenk, MS). Clay County (Swenk, MS): Trumbull; Harvard; Inland. Cuming County: West Point (Cary, MS). Dodge County: Fremont (specimen catalogued in NSM, not now to be found). Douglas County: Omaha (Cary, MS). Dundy County: Haigler (Goldman, 1950:38). Frontier County: Maywood (Swenk, MS). Hall County: Grand Island (specimen formerly in HM). Hamilton County: no specific locality (specimen formerly in HM). Kearney County: Ft. Kearney (Baird, 1858:212). Knox County: near mouth of Niobrara River (Hayden, 1859:708). Lincoln County: no specific locality (Swenk, MS). Madison County: Norfolk (Cary, MS). Otoe County: Mammals of Nebraska 267 Nebraska City (Cary, MS); 2 mi. N Talmage (specimen catalogued in NSM, not now to be found). Phelps County: Holdrege (Swenk, MS). Richard- son County: Falls City (Cary, MS); 4 mi. SE Rulo (Hill and Wedell, 1936:63, archeological site). Scotts Bluff County: 2 mi. W Mitchell (specimen catalogued in NSM, not now to be found); Scotts Bluff Nat'l Mon. (Mattes, 1958:57). Washington County: Engineer Cantonment [= approximately 2 mi. E Ft. Calhoun] (James, 1823:369). County unknown: "Ft. Riley to Ft. Kearney" (Baird, 1858:212). Family Mustelidae — Weasels, Skunks and Allies Key to Nebraskan Mustelids 1. Toes webbed; 36 teeth (premolars 4/3) Lulra canadensis, p. 296 1'. Toes not webbed or only slightly so; 34 or 38 teeth (premolars 3/3 or 4/4) 2 2(1'). Upper parts black and white; bony palate extending posteriorly be- yond Ml less than length of that tooth 3 2'. Upper parts brownish, yellowish, or grayish over-all; bony palate ex- tending posteriorly beyond Ml more than length of that tooth 4 3(2). Upper parts having two white stripes; zygomatic breadth more than 40; maxillary tooth-row more than 20 Mephitis mephitis, p. 291 3'. Upper parts having four or more broken white lines (or spots) ; zygo- matic breadth less than 40; maxillary tooth-row less than 20. Spilogale putorius, p. 288 4(2'). Weight more than 5 pounds; tail only slightly longer than hind foot; condylobasal length more than 80 5 4'. Weight less than 5 pounds; tail more than twice length of hind foot (except in Mustela nivalis) ; condylobasal length less than 80 6 5(4). Upper parts brownish; 38 teeth (premolars 4/4) Gulo luscus, p. 282 5'. Upper parts yellowish gray to silvery gray; 34 teeth (premolars 3/3) . Taxidea taxus, p. 284 6(4'). Total length more than 500; condylobasal length more than 55 7 6'. Total length less than 500; condylobasal length less than 55 8 7(6). Upper parts dark brownish; interorbital breadth less than 17 in males and less than 16 in females Mustela vison, p. 279 7'. Upper parts yellowish brown; prominent black mask on face; inter- orbital breadth more than 17 in males and more than 16 in females. Mustela nigripes, p. 273 8(6'). Total length less than 300; tail not tipped with black; maxillary tooth- row less than 12 Mustela nivalis, p. 276 8'. Total length more than 300; tail tipped prominently with black; maxillary tooth-row more than 12 Mustela frenata, p. 267 Mustela frenata Long-tailed Weasel This species is distributed generally over the state but is nowhere especially common. Among the mustelids still extant in Nebraska it appears to be less numerous than the mink, striped skunk, and badger, perhaps about equal in numbers to the least weasel and spotted skunk, and more abundant than the black-footed ferret. A rough measure of its relative abundance is provided by the fur- bearers reported as taken in Nebraska in the 1959-60 season (Wild- life Leaflet 436, U. S. Fish and Wildlife Service, June, 1961). A 268 University of Kansas Publs., Mus. Nat. Hist. total of 139 long-tailed weasels were obtained in that period in com- parison with the following numbers of other small carnivores: rac- coon, 12,906; mink, 8,458; skunk (both species), 2,999; badger, 513. M. frenata molts to a white pelage in winter in northern Ne- braska as evidenced by specimens examined from Cedar, Cuming, Museum of Noturo! History University of Konscs J952 Fig. 60. Distribution of Mustela frenata in Nebraska. 1. M. /. longicauda. 2. M. /. primulina. 3. M. /. spadix. For explanation of symbols see Fig. 5. and Washington counties. South of the Platte River, however, the winter pelage is brown, longer and paler than that of summer, as seen in individuals from Adams, Clay, Fillmore, and Otoe counties. According to Hall (1951:217) females bear a single litter an- nually (in spring) that contains up to 9 young. Mustela frenata longicauda Bonaparte Mustela longicauda Bonaparte, Charlesworth's Mag. Nat. Hist., 2:38, 1838 (type locality, "possibly Carlton House, Saskatchewan," according to Hall and Kelson, The mammals of North America, p. 912, March 31, 1959). Mustela frenata longicauda, Hall, Publ. Carnegie Inst. Washington, 473: 105, November 20, 1936; Hall, Univ. Kansas Publ., Mus. Nat. Hist., 4:262, December 27, 1951 (part); Hall and Kelson, The mammals of North America, p. 912, March 31, 1959 (part). Pfutorius]. longicauda, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880. Putorius longicaudus, Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902; Swenk, Proc. Nebraska Acad. Sci., 8:130, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:74, September, 1908. Mustela longicauda longicauda, Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Mammals of Nebraska 269 Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:21, October, 1936. Mustela l[ongicauda]. longicauda, Imler, Jour. Wildlife Mgt, 9:272, Octo- ber, 1945. Mustela frenata alleni, Hall, Univ. Kansas Publ., Mus. Nat. Hist., 4:274, December 27, 1951 (part); Miller and Kellogg, Bull. U.S. Nat. Mus., 205:739, March 3, 1955 (part); Hall and Kelson, The mammals of North America, p. 911, March 31, 1959 (part). M[ustelaJ. f[renata], alleni, Jones, Trans. Kansas Acad. Sci., 60:280, October 22, 1957 (part). M[ustela]. f[renata]. longicauda, Jones, Trans. Kansas Acad. Sci., 60:280, October 22, 1957 (part). Distribution in Nebraska. — Western three-fourths of state, east certainly to Adams, Antelope, and Clay counties. See Fig. 60. External measurements. — Average and extreme measurements of 10 males, followed by those of five adult and young adult females, from western Nebraska are: 427.1 (400-459), 362.2 (343-375); 155.0 (138-175), 127.2 (115-142); 47.5 (42-54), 42.6 (39-47); 23.65 (19-26), 17.6 and 18 (two only). Two of the males weighed 275.0 and 315.5 grams. For cranial measurements see Table 20. Remarks. — From Mustela frenata spadix and Mustela frenata primulina, both geographically adjacent to the east in Nebraska, M. /. longicauda differs in being distinctly paler dorsally (clay color rather than dark brown ) in summer pelage. It differs additionally from primulina in being larger, in having the color of the venter extending onto the hind feet, and in having the least width of color of the underparts more than 40 per cent of the greatest width of color of the upper parts. It differs additionally from spadix ( Hall, 1951:263) by having in males a deeper occiput in which the depth of the skull, exclusive of the sagittal crest, amounts to more than 59 per cent of the mastoid breadth. Specimens assigned herein to longicauda from the eastern edge of its range in Nebraska are intergrades with one or the other (or both) of the two subspecies, M. /. primulina and M. /. spadix, that occur in the eastern part of the state. A female from Neligh, for example, is assigned to longicauda owing to its relative paleness but resembles primulina most in size. Hall (op. cit. : 266-267) dis- cussed reasons for assignment to longicauda of intergrades from Adams and Clay counties. Examination of the specimens men- tioned by him as well as additional specimens from these two counties, in which I find a rather wide range of individual variation in both size and color, underscores the difficulty of identifying them to subspecies. To my way of thinking weasels from Adams and Clay counties could be assigned with about equal propriety either to primulina or to longicauda; I follow Hall in listing them under the latter name. 270 University of Kansas Publs., Mus. Nat. Hist. Mustela frenata alleni (type locality, Custer, Custer County, South Dakota) was recorded from Nebraska by Hall (op. cit. :276) on the basis of four specimens from Mitchell, which he regarded as intergrades between alleni and longicauda. M. f. alleni (other- wise known only from the Black Hills of South Dakota and Wyoming) combines the pale coloration of longicauda with the small size of M. /. nevadensis, a subspecies occupying a large geographic range in the intermountain region to the west of Nebraska. The four individuals from Mitchell are indeed smaller than typical longicauda but resemble it in color and their original assignment to alleni is understandable. However, specimens ac- cumulated from northwestern Nebraska since the publication of Hall's revision are not so small as the four from Mitchell and are referable to longicauda. For example, a male from 2/2 mi. W Gering, but a few miles southeast of Mitchell, is larger (434; 155; 45; 24) than the average of specimens I have examined and a young male from 3 mi. W Crawford, on the Pine Ridge roughly equi-distant between Mitchell and the Black Hills, clearly is assign- able to longicauda, although smaller (417; 146; 46; 24) than average for the subspecies. Other specimens from northwestern counties (Sioux, Morrill, Dawes, and Sheridan) also approach longicauda to a greater degree than alleni and Hall himself (p. 269) assigned two individuals from Ft. Laramie, Wyoming, in the Platte Valley to the west of Mitchell, to the former. It thus appears that the specimens from Mitchell, surrounded as they are by localities from which have originated weasels assign- able to longicauda, are best placed with that subspecies. Their relative smallness, and that of certain other specimens examined from the northwestern part of the state, undoubtedly indicates intergradation with alleni or nevadensis or both. Records of occurrence. — Specimens examined, 68, as follows: Adams County: Hastings, 5 (2 AMNH, 3 HM); 6 mi. S Hastings, 1 (HM); no specific locality, 2 (HM). Antelope County: Neligh, 1 (NSM). Blaine County: 3 mi. SE Dunning, 1 (NGFPC). Brown County: Long Pine, 1 (Stanford Univ.); Long Lake, 1 (AMNH). Cherry County: W of Crookston, 1 (NSM); 5 mi. E Valentine, 1( NGFPC): near Simeon, 1 (NSM); Valentine Nat'l Wildlife Refuge, 4 (NSM); Hackberry Lake, Valentine Nat'l Wildlife Refuge, 1 (UMMZ); Kennedy, 1 (USNM); 11 mi. E Kennedy, 1; Goose Creek, 1 (AMNH); Sand Hill region, 1 (NSM); S part of county, 1 (NSM); no specific locality, 1 (USNM). Clay County: Inland, 9 (4 HM, 5 NSM). Custer County: Victoria Springs, 1 (UMMZ). Dawes County: Chadron, 2 (NSM); 3 mi. W Crawford, 1 (NSM). Garden County: no specific locality, 1. Holt County: Eagle Creek, 1. Keya Paha County: Springview, 2 (CSTC). Morrill County: 11 mi. N Bridgeport, 2 (NSM); 3 mi. S junction of hgys. 19 [=385] and 26, 1 (NSM); Bridgeport, 3 (NSM); Greenwood Canyon, 9 mi. S Bridgeport, 2 (NSM). Scotts Bluff County: Mitchell, 4 (NSM); 2% mi. W Gering, 1 (NSM). Sheridan County: 4 mi. N Antioch, 1 Mammals of Nebraska 271 (UMMZ); 19 mi. E, 2 mi. S Alliance, 1; no specific locality, 1 (NGFPC). Sherman County: 1 mi. NW Sweetwater, 1 (NGFPC). Sioux County: 21 mi. NW Crawford, 1 (NSM); badlands, 18 mi. NW Crawford, 1 (NSM); near Harrison, 1 (NSM); 3& mi. N Glen, 1 (NSM); Bald Butte (not exactly located), 2 (AMNH). Thomas County: near Halsey, 1. Webster County: Bladen, 1 (HM). Additional records (Swenk, MS, unless otherwise noted): Adams County: Logan Twp. Cherry County: Ft. Niobrara Nat'l Wildlife Refuge (Beed, 1936:21). Clay County: Trumbull. Garden County: Crescent Lake Nat'l Wildlife Refuge (Imler, 1945:272). Lincoln County: no specific locality. Sioux County: Warbonnet Canyon (Cary, MS). Webster County: Red Cloud. Mustela frenata primulina Jackson Mustela primulina Jackson, Proc. Biol. Soc. Washington, 26:123, May 21, 1913 (type locality, 5 mi. NE Avilla, Jasper Co., Missouri). Mustela frenata primulina, Hall, Publ. Carnegie Inst. Washington, 473:104, November 20, 1936. Distribution in Nebraska. — Southeastern part of state south of Platte River. See Fig. 60. External measurements. — Measurements of two males from Fillmore County, a male from Lancaster County, a male from Butler County, and an individual of unknown sex (probably a male) from Lancaster County are, respectively: 413, 376, 382, 400, 362; 131, 121, 131, 132, 132; 48, 45, 43, 42, 43; 22, 24, 19, , The smallest of the two males from Fillmore County weighed 293.7 grams. For cranial measurements see Table 20. No females are presently available from Nebraska. Hall (1951:233) re- corded the average and extreme measurements of six adult and subadult fe- males from Douglas County, Kansas, as follows: 339 (317-355); 107 (95- 115); 35 (34-37). Remarks. — From Mustela frenata spadix, geographically adjacent to the north in Nebraska, M. /. primulina typically differs as follows ( Hall, loc. cit. ) : "least width of color of under parts amounting to less than 40 per cent of greatest width of color of upper parts, by absence of color of underparts on hind leg below knee, and by smaller size." Another possible difference between these two sub- species, perhaps fortuitous, is that the line marking the place where white winter pelage (as opposed to brown winter pelage) is acquired parallels roughly the presently understood boundary be- tween them. For comparison with Mustela frenata longicauda, geographically adjacent to the west in the state, see account of that subspecies. The presence of M. /. primulina in southeastern Nebraska has been expected (Jones, 1957:280) but the specimens herein reported are the first from the state to be assigned definitely to that sub- species. Specimens examined from Adams and Clay counties are inter- grades between primulina and M. f. longicauda. The reasons for assigning them to longicauda are given in the account of that sub- species. 272 University of Kansas Ptjbls., Mus. Nat. Hist. Records of occurrence. — Specimens examined, 6, as follows: Butler County: Garrison, 1 (UNDZ). Fillmore County: 1 mi. S Fairmont, 1; 2 mi. N Geneva, 1. Lancaster County: Lincoln, 1 (NGFPC); 3 mi. N, 2 mi. W Bennet, 1. Otoe County: Nebraska City, 1 (RV). Mustela frenata spadix (Bangs) Putorius longicauda spadix Bangs, Proc. Biol. Soc. Washington, 10:8, Feb- ruary 25, 1896 (type locality, Fort Snelling, Hennepin Co., Minnesota). Mustela frenata spadix, Hall, Publ. Carnegie Inst. Washington, 473:105, November 20, 1936; Hall, Univ. Kansas Publ., Mus. Nat. Hist., 4:252, December 27, 1951; Hall and Kelson, The mammals of North America, p. 914, March 31, 1959. ?Putorius noveboracensis, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880 (part). ?P[utorius] . cigognanii [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880 (part). Mfustela]. f[renata]. spadix, Jones, Trans. Kansas Acad. Sci., 60:280, Octo- ber 22, 1957. Distribution in Nebraska. — Presently known from north of Platte River in northeastern part of state. See Fig. 60. External measurements. — Measurements of males from Cedar, Cuming, and Madison counties and a subadult female from Cuming County are, respectively: 370, 425, 372, 375; 130, 160, 120, 113; 44, 50, 50, 44; 21, _, 17, For cranial measurements see Table 20. Remarks. — For comparison with Mustela frenata longicauda and Mustela frenata primulina, both geographically adjacent to M. /. spadix in Nebraska, see accounts of those subspecies. I follow Hall (1951:261) in assigning weasels from northeastern Nebraska to M. f. spadix. Specimens presently available from there actually are intergrades between spadix and M. /. primulina, and possibly also with M. /. longicauda. Hall ( loc. cit. ) discussed his reasons for as- signing five specimens from Beemer to spadix. In addition to these five, males examined from Norfolk, Ft. Calhoun, and near Belden are assigned herein to that subspecies. The male from Norfolk, a skin only, has small external measure- ments, which are typical of M. /. primulina except that the hind foot (50 mm.) is large and intermediate between those of primulina and spadix. The color pattern resembles typical spadix in that the dorsum is dark brown, the least width of color of the underparts amounts to more than 41 per cent of greatest width of color of the upper parts, and the color of the underparts extends onto the hind feet. The specimen from near Belden, taken on November 17, 1958, is in white winter pelage. Its external measurements are typical of primulina but Belden is north of the other localities from which spadix is here recorded and this specimen is assigned to that subspecies on geographic grounds. Findley (1956&:24) identified two specimens from Clay County, South Dakota, just north across Mammals of Nebraska 273 the Missouri River from Cedar County, with M. /. spadix, but indi- cated the possibility of their being "three way intergrades" between spadix, longicauda, and primulina. The specimen from Ft. Cal- houn, a mounted animal in white winter pelage that lacks external measurements, also is assigned to spadix on geographic grounds, as are the additional records listed beyond. More specimens from eastern Nebraska are needed before the subspecific identity of weasels occurring there can be determined accurately. In a general way, individuals presently available from the northeastern part of the state combine the coloration of spadix with the external size of primulina and have crania that are nearer spadix than primulina in dimensions. A female from Neligh, herein assigned to M. /. longicauda because of its paleness, is slightly darker dorsally than typical specimens of longicauda (thus ap- proaching spadix and primulina) and resembles primulina in size. Records of occurrence. — Specimens examined, 8, as follows: Cedar County: near Belden, 1 (NSM). Cui^ing County: Beemer, 5 (USNM). Madison County: Norfolk, 1 (NSM). Washington County: Ft. Calhoun, 1 (RV). Additional records: Burt County: Oakland (Swenk, MS). Cuming County: West Point (Swenk, MS). Douglas County: Omaha (Cary, MS). Mustela nigripes Black-footed Ferret The black-footed ferret is among the rarest of North American mammals. In Nebraska the range of the species, both present and former, corresponds closely to that of the black-tailed prairie dog (Cynomys ludovicianus); in fact, the distribution of M. nigripes in general coincides with that of prairie dogs, which apparently serve as its principle source of food and whose burrows it inhabits. De- struction by man of many thousands of prairie dog towns on the Great Plains has undoubtedly affected adversely population levels of the ferret and yet the species seems to be holding its own fairly well. As Cahalane (1954:423) pointed out, M. nigripes obviously can and does prey upon small mammals other than prairie dogs. One correspondent reported to him (loc. cit.) that numbers of ferrets seemed not to have decreased markedly in South Dakota in periods when prairie dogs were nearly annihilated over broad areas of that state. The prairie dog still is widely distributed in western and central Nebraska and conditions therefore presently favor the survival of M. nigripes. Recorded occurrences in the state over the last four 18—6532 274 University of Kansas Publs., Mus. Nat. Hist. _..!..-> Museum of Natural History University of Kansas 1952 Fig. 61. Distribution of Mustela nigripes in Nebraska. For explanation of symbols see Fig. 5. Dashed line indicates approximate eastern limit of present distribution. decades do not indicate a reduction in the population of ferrets. Four occurrences were recorded in the 1920's, four in the 1930's, two in the 1940's, and ten in the 1950's. The most recent report that I know of is from E. W. Eustace (personal communication) of Lebanon, Kansas, who saw three or four black-footed ferrets north- east of Bridgeport in the autumn of 1959. The animals, possibly a family group, had opened several pocket gopher burrows. Cahalane (loc. cit.:422) reported the species most "numerous" in the region "from central and western Nebraska to the southwestern corner of North Dakota." Fichter and Jones (1953:387) commented on the relative abun- dance of M. nigripes on the Loess Plains of south-central Nebraska as opposed to other major land types in the western part of the state and on the absence of records from the Sand Hills. Subsequent information shows the species to be widely distributed on the High Plains but has revealed little concerning the Sand Hills, although Cary's (MS) report of the species from the "Snake River region" of Cherry County does provide evidence of occurrence there. A speci- men from "near Anselmo" (Velich, 1961:93) is from the border between the Sand Hills and the Loess Plains. As suggested by Fichter and Jones, the greater activity of man on the cultivated Loess Plains in comparison to the grazing lands of the Sand Hills and High Plains probably has made for "more frequent contact Mammals of Nebraska 275 between ferrets and humans and thereby a greater take of speci- mens." Nevertheless, the paucity of records from the Sand Hills seems to indicate that the species is rarer there than in areas to the north, west, and south of the Sand Hills. Little is known concerning reproduction in this species. Cahalane (1954:420) recorded 4 young found in a nest in South Dakota. Birth of young evidently is in spring; Aldous (1940:23) captured a young female in New Mexico on July 10, 1929, and two young ferrets were killed by a cat in South Dakota in June, 1952 ( Cahalane, loc. cit.). A subadult female (measurements: 428; 115; 47) was taken on May 6, 1946, 9 mi. S Gering, Nebraska. Must el a ni gripes (Audubon and Bachman) Putorius nigripes Audubon and Bachman, The viviparous quadrupeds of North America, 2:297, 1851 (type locality, Ft. Laramie, Goshen Co., Wyoming, according to Hayden, Trans. Amer. Philos. Soc, 12(n. s.):138, 1863); Swenk, Proc. Nebraska Acad. Sci., 8:130, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:74, September, 1908. Mustek, nigripes, Miller, Bull. U. S. Nat. Mus., 79:102, December 31, 1912; Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Fichter and Jones, Jour. Mamm., 34:385, August 14, 1953; Cahalane, Jour. Mamm., 35:418, August 20, 1954; Jones, Trans. Kansas Acad. Sci., 60:280, October 22, 1957; Hall and Kelson, The mammals of North America, p. 914, March 31, 1959; Velich, Jour. Mamm., 42:93, February 20, 1961. Putorius (Cynomyanax) nigripes, Coues, Misc. Publ. U. S. Geol. Surv. Ter- ritories, 8:149, 1877. P[utorius]. nigripas [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880. Distribution in Nebraska. — Formerly western three-fourths of state, east cer- tainly to Dodge and Lancaster counties; presently confined to western two- thirds of state. See Fig. 61. External measurements. — Measurements of a male from Rosemont, followed by those of a male from S of Overton, are: 522, 572; 130, 140; 68, 63; _, 32. A male from Hermosa, South Dakota, measured: 533; 127; 63; — For cranial measurements see Table 20. Records of occurrence. — Specimens examined, 12, as follows: Banner County: 9 mi. S Gering, 1 (NSM). Box Butte County: 5 mi. SE Marsland, 1 (NSM). Buffalo County: [near] Gibbon, 2 (HM). Clay County: Glenvil, 1 (HM). Frontier County: [near] Maywood, 1 (HM). Furnas County: [near] Cambridge, 1 (HM). Phelps County: S of [Platte] River bridge, Overton, 1 (NGFPC). Sheridan County: Spotted Tail Indian Agency (approximately 11 mi. N, 2 mi. W Hay Springs), 1 (USNM). Sioux County: Agate, 1 (AMNH). Webster County: [2 mi. S] Rosemont, 1 (AMNH). County unknown: "N. Platte, Neb.," 1 ( USNM )— probably taken along North Platte River in present-day Nebraska or Wyoming. Additional records (Fichter and Jones, 1953:385-387, unless otherwise noted): Banner County: SW of Harrisburg (Cahalane, 1954:419). Buffalo County: Kearney. Cherry County: "Snake River region" (Cary, MS). Custer County: near Anselmo (Velich, 1961:93); Arnold; 10 mi. S Ansley (Cahalane, 1954:419); 20 mi. S Broken Bow (Cahalane, 1954:419). Dawes 276 University of Kansas Publs., Mus. Nat. Hist. County: Marsland; no specific locality (Cahalane, 1954:419). Dodge County: Fremont. Frontier County: Curtis. Garden County: Oshkosh. Hamilton County: N of Harvard. Lancaster County: Lincoln. Lincoln County: North Platte. Morrdll County: N of Bridgeport (see text). Sherman County: Loup City (record on file, NSM). Sioux County: no specific locality (Cahalane, 1954:419). The ferret reported to have been taken near Grand Island, Hall County, by Fichter and Jones (1953:387), based on information available at that time, actually was obtained near Anselmo, Custer County, according to Ralph Velich (correspondence, November 7, 1959, and 1961:93). Mustela nivalis Least Weasel The least weasel, a circumboreal species, reaches the southern limit of its North American distribution in Nebraska save for a nar- row zone extending southward in the Appalachian Mountains to North Carolina. Excepting from Clay County (where a "colony" was reported by Swenk, 1926) and the adjoining part of Adams County, from 4/2 mi. NW Springview (where two individuals were collected on February 8, 1959), and from the vicinity of Schuyler (see text below), M. nivalis is known only by a single specimen from each locality of record. This situation has led to the impres- sion among some naturalists that the species is rare in most of its range in the state. Possibly it is rare, but I suspect this dimunitive weasel oftentimes escapes detection owing to its small size and secretive habits; it is likely also that some are mistaken for young of Mustela frenata or otherwise misidentified. Several specimens have been found in recent years in the pellets of raptorial birds. As might be expected, detection of one individual from an area may lead to the subsequent discovery of others. This was the case in connection with the concentration reported from Clay County (from which area incidently a number of individuals have been taken subsequently) and it was also the case in the vicinity of Schuyler in the winter of 1950-51. Edward Hashberger trapped an immature female at Schuyler on November 25, 1950, and sent it in the flesh to the Nebraska Game, Forestation and Parks Commission for identification. I replied, providing identification and requesting additional information on the species in that area. Alerted, Hash- berger obtained evidence of at least three more individuals as set forth in his interesting letter dated February 9, 1951: "In reply to your inquiry concerning [the] least weasel, this is the first year I have encountered them and I have trapped about 57 years. The first one was taken in a number 1 Victor trap; it was evidently caught upright as it was instantly killed. The second one was met Mammals of Nebraska 277 1 • « 40- Museum of Natural History University of Kansas 1952 _10O Fig. 62. Distribution of Mustela nivalis campestris in Nebraska. For explana- tion of symbols see Fig. 5. while crossing a small piece of farm land lying between Shell and Lost Creeks, about 4/2 miles east of Schuyler. When it saw me coming it stood erect and squeaked, and was ready for a fight. I was wearing rubber boots and placed my foot on it. The reason I didn't think it a weasel was that it made no attempt to run but wanted to fight. Near where the first one was taken another was seen, and after the last snow I saw tracks near where I got the second one." Mustela nivalis evidently molts to a white pelage in winter throughout its range in North America excepting in the southern part of the range of the subspecies M. m. allegheniensis (Hall, 1951:170). Winter-taken sldns from Nebraska (Adams County, January 2, 1957; Holt County, February 1, 1918; Phelps County, December 20, 1958 ) all are entirely white. March-taken specimens from Clay and Merrick counties are molting from winter to summer pelage. A litter of 4 young was found at Trumbull on July 1, 1917 (Swenk, 1926:321). According to Hall (op cit.: 178) young may be born in any month of the year; seven litters recorded by him contained an average of 5.0 (3-10) offspring. Mustela nivalis campestris Jackson Mustela campestris Jackson, Proc. Biol. Soc. Washington, 26:124, May 21, 1913 (type locality, Beemer, Cuming Co., Nebraska); Beed, Bull. Con- serv. Surv. Div., Univ. Nebraska, 10:24, October, 1936. 278 University of Kansas Publs., Mus. Nat. Hist. Mustela nivalis campestris, Hall and Kelson, The mammals of North America, p. 1082 (addenda), March 31, 1959. P[utoriu.i]. pusillus, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880. Putorius rixosus, Swenk, Proc. Nebraska Acad. Sci., 8:131, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:75, September, 1908. Mustela rixosa campestris, Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 411, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919; Swenk, Nebraska Blue Book, p. 483, December, 1920; Swenk, Jour. Mamm., 7:329, No- vember 23, 1926; Hall, Univ. Kansas Publ., Mus. Nat. Hist., 4:190, December 27, 1951; Jones, Univ. Kansas Publ., Mus. Nat. Hist., 7:486, April 21, 1954; Velich, Jour. Mamm., 37:272, June 9, 1956; Velich, Jour. Mamm., 39:147, February 20, 1958; Hall and Kelson, The mammals of North America, p. 908 (text), March 31, 1959. M[ustela]. r[ixosa], campestris, Jones, Trans. Kansas Acad. Sci., 60:279, Oc- tober 22, 1957. Distribution in Nebraska. — Eastern part of state, excepting possibly extreme southeast, west certainly to Sheridan County in northern part and to Garden County in Platte Valley. See Fig. 62. External measurements. — Average and extreme measurements of three males, followed by those of 10 females, all from south-central Nebraska are: 224.3 (211-237), 200.6 (184-225); 36.7 (32-39), 31.5 (25-40); 26.7 (24-28), 21.3 (16-26); 14, 12, 11.5, 11 (two specimens each sex). A female from M mi. W Grand Island weighed 39.5 grams. For cranial measurements see Table 20. Remarks. — Reichstein (1958) studied cranial variation in the least weasel (M. rixosa) and the mouse weasel (M. nivalis) in Europe, concluded that the two were conspecific, and thus arranged rixosa as a synonym of the earlier-named nivalis. I follow Reich- stein (p. 169) in applying the specific name nivalis to the North American least weasel. Additional evidence of the close relation- ship of New World and Old World representatives is provided by the baculum. Comparison of the baculum of a specimen of M. n. mosanensis ( USNM 299205 ) from Korea with that of an individual of M. n. campestris (KU 83726) from Clay County shows the two to be strikingly similar and to differ only in slight detail. On March 14, 1959, a small weasel, of which the skull alone was saved, was captured 4/2 mi. N and 5 mi. W Rushville, between the then known ranges of M. n. campestris and the equally small Mustela erminea muricus, known from as near Nebraska as the Black Hills. The collector did not record whether or not the tip of the tail was black, but direct comparison of the skull with specimens of M. n. campestris and with specimens of M. e. muricus from Wyoming re- veals without doubt that it is assignable to the former. This record is the westernmost for the subspecies and reduces the distance be- tween the known ranges of M. n. campestris and M. e. muricus (/a mi. E Sylvan Lake, South Dakota — Hall, 1951:165) to approxi- mately 94 miles. Mammals of Nebraska 279 M. nivalis never has been reported from Kansas but the proximity to that state of Nebraskan records suggests that the species occurs at least along the northern border, especially in the area between the Republican and Blue rivers. Records of occurrence. — Specimens examined, 35, as follows: Adams County: Hastings, 3 (HM); no specific locality, 1 (HM). Cherry County: Wood Lake, 1 (CNHM). Clay County: Inland to 1 mi. E thereof, 14 (7 HM, 7 NSM); sec. 29, T. 6 N, R. 5 W (approximately 4 mi. N, 4 mi. E Ong), 1. Colfax County: Schuyler, 1 (NGFPC). Cuming County: Beemer, 1 (USNM). Gage County: Clatonia, 1 (RV). Hall County: M mi. W Grand Island, 1 (NGFPC). Holt County: Page, 1 (NSM). Keya Paha County: 452 mi. NW Springview, 2 (CSTC). Lancaster County: Lincoln, 1 (NGFPC). Madison County: Norfolk, 1 (NSM). Merrick County: Chapman, 1 (NSM). Phelps County: 1%, mi. N, 3 mi. W Holdrege, 1 (NSM). Platte County: Columbus, 1 (RV). Seward County: Goener, 1 (NSM). Sheridan County: 4K mi. N, 5 mi. W Rushville, 1 (NGFPC). Valley County: 10 mi. S Ord, 1 (NGFPC). Additional records: Buffalo County: Kearney (Swenk, MS). Cherry County: Ft. Niobrara Nat'l Wildlife Refuge (Beed, 1936:24). Clay County: (Swenk, 1926:321): Trumbull; Glenvil. Colfax County: 4% mi. E Schuyler (see text). Douglas County: Florence (Swenk, MS); near Ralston (Velich, 1958:147). Garden County: Oshkosh (Swenk, 1926:321). Rock County: Newport (Karl Menzel, personal communication). Stanton County: no specific locality (William J. Bailey, personal communication). Mustela vison Mink The mink is evidently the most abundant of the four species of the genus Mustela that occur in Nebraska. It is common along water courses throughout the state but probably is commonest in the lake regions of the Sand Hills where several thousand are Museum of Natural History University of Kansas 1952 J©_ KX> 97 Fig. 63. Distribution of Mustela vison letifera in Nebraska. For explanation of symbols see Fig. 5. 280 University of Kansas Publs., Mus. Nat. Hist. trapped annually. The pelt is presently more valuable than that of any other Nebraskan fur-bearer and M. vison now (1962) may account for more gross income than any other species. Females bear a single litter annually in late spring that according to Burt (1948:141) contains 3-10 young. Mustek vison letifera Hollister Mustela vison letifera Hollister, Proc. U. S. Nat. Mus., 44:475, April 18, 1913 (type locality, Elk River, Sherburne Co., Minnesota); Swenk, Nebraska Blue Book, p. 854, 1915; Swenk, Nebraska Blue Book, p. 410, December, 1918 (part); Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919 (part); Swenk, Nebraska Blue Book, p. 483, December, 1920 (part). Mustela minx [sic], James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:369, 1823 (part). [Mustela] vison, James, Account of an expedition from Pittsburgh to the Rocky Mountains .... 1:369, 1823 (part). P[utorius]. vison, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880 (part). P[utorius]. nigrescens, Aughey, Sketches of the physical geography and geology of Nebraska, p. 119, 1880 (part). Putorius vison lutreocephalus, Swenk, Proc. Nebraska Acad. Sci., 8:130, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:74, September, 1908. Mustela vison energumenos, Swenk, Nebraska Blue Book, p. 410, Decem- ber, 1918 (part); Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:20, March 1, 1919 (part); Swenk, Nebraska Blue Book, p. 483, December, 1920 (part); Beed, Bull. Conserv. Surv. Div., Univ. Nebraska, 10:27, October, 1936. M[ustela]. v[ison], letifera, Jones, Trans. Kansas Acad. Sci., 60:280, Octo- ber 22, 1957. Distribution in Nebraska. — State-wide in suitable habitat. See Fig. 63. External measurements. — Average and extreme measurements of seven males from Nebraska are: 630.7 (594-686); 200.3 (185-217); 71.05 (68-76); 26.33 (25-27); weights recorded for three of the seven males were 3 lbs., 2% lbs., and 1145 grams. Two females from Cherry County measured: 559, 560; 203, 185; 64, 62. For cranial measurements see Table 20. Remarks. — Swenk (1918:410 and in later checklists) recorded both M. v. letifera ("Common along water courses over most of the state") and M. v. energumenos ("Common northwestwardly") from Nebraska; subsequently Beed (1936:27) employed the name energumenos for mink from Ft. Niobrara National Wildlife Refuge in an ecological study of that area. I suspect that the use of energumenos by these two authors was predicated entirely on geographic considerations for examination of specimens of M . vison presently available from Nebraska indicates no basis for their as- signment to more than the one subspecies, M. v. letifera. Mammals of Nebraska 281 Table 20. — Cranial Measurements of Four Species of Mustela. 43 Number of specimens "os co o-B a 03.2 a .2 +3 T3 03 OP averaged or catalogue S2J3 '■§■2 13 -£ .-s.5 T3 oqii number, and sex O o 2§ •S § o o ■4-3 o CO O CO ngth ma> tool o >j (3 O a> U SI 1— I p4 s h3 Mustela frenala longicauda, Cherry County 73467 KU, <*«.... 12614 NSM, O^^J number, and sex -? Bo T3 oj a — ' 2 w S £ ■S S o o '3 c3 03 03 ngth mas toot o >, O fc-l 03 a> D N C^ s Ph hJ Spilogale putorius interrupta, eastern Nebraska Average 9 (cf). Minimum Maximum 58.7 35.9 15.1 32.0 22.3 57.2 35.1 14.5 29.7 21.2 61.4 37.0 15.6 33.2 23.6 147751 USNM, 9 12622 NSM, > & Number of specimens c3 «£ c3 u bO a a 3 O averaged or catalogue "■ST2 JH o 0:3.2 number, and sex •r 5 T3 CD 1=1— ' 2 ^ s a 71 +3 e3 *> bO a ngth max toot O >> oj a> CD O N i— i Pi h3 ►3 Dawes and Sioux counties Average 6 Minimum . Maximum (*). 30 NSM, 9 . . 4426 NSM, 9 118.7 115.9 120.6 107.0 109.7 91.2 87.7 93.4 80.4 85.7 25.8 24.2 27.9 24.0 21.6 51.3 50.1 53.6 44.9 46.5 32. 76 31.6 34.5 29.6 28.7 Brown and Cherry counties 164720 AMNH, 9T Fig. 75. Actual numbers of mule deer (M) and white-tailed deer (W) taken in representative Nebraskan counties in the 1960 hunting season. Figures for Sheridan and Sioux counties include deer from small parts of adjoining Box Butte and Dawes counties. All figures courtesy Nebraska Game, Forestation and Parks Commission. Mammals of Nebraska 317 were recorded in areas of western Nebraska that have been open to hunting for several years. In the Pine Ridge Management Unit, for example, the 1960 ratio was 6.5:100 as compared with 3.3:100 in 1958 and in the Upper Platte Management Unit the ratio was 5.3:100 as compared with 0.8:100 (same years). The actual numbers of the two species taken in the 1960 hunting season is shown for selected counties in Figure 75. I know of no introductions of white-tailed deer into Nebraska from other areas within the range of the species and assume that repopulation of the state has resulted mostly from increase and spread of native stock from Nebraska and adjoining states. I do know that the Nebraska Game, Forestation and Parks Com- mission has transplanted deer from the northeastern part of the state to the southeastern part in the past several years. Structural differences between O. virginianus and O. hemionus in Nebraska and adjoining regions are great. Externally, aside from the marked differences in length, shape, and color of tail, and be- tween the antlers of males, virginianus usually is more reddish brown, has smaller ears ( less than 180 mm. from notch in adults as opposed to more than 190), a much smaller preorbital gland, a smaller metatarsal gland ( usually less than 30 mm. long as opposed to 50 or more ) , and a larger, more conspicuous pad and tuft of hairs adjacent to (inside) the heel. Cranially, virginianus has markedly smaller lacrimal pits, larger bullae, smaller incisors, a narrower skull throughout relative to length ( see measurements ) , and the palatines extend much farther posteriorly beyond the last molars and are V-shaped at the posterior margin (rather than U-shaped, or broadly emarginate on either side of the midline). The generic name Dama has been applied to the large American deer by several authorities since Hershkovitz (1948) showed it to have 52 years priority over the long-used Odocoileus. However, Opinion 581 of the International Commission on Zoological Nomen- clature (Bull. Zool. Nomenclature, 17:267-275, September 16, 1960) validated Odocoileus Rafinesque, 1832, with type species O. speleus Rafinesque, 1832 [= Dama virginiana Zimmermann, 1780] as the generic name for these deer. Like the mule deer the white-tail breeds in early winter. Females bear 1-4 (usually 2, rarely 4) young from late May to early July after a gestation period of about six and a half months. Of seven pregnant females from eastern Nebraska of which I have record, three carried a single embryo, three carried twins, and the seventh carried triplets. 318 University of Kansas Publs., Mus. Nat. Hist. Odocoileus virginianus macrourus (Rafinesque) Corvus [sic] macrourus Rafinesque, Amer. Monthly Mag., 1:436, October, 1817 (type locality, "Plains of the Kangar [= Kansas] River;" restricted to plains near Wakarusa Creek, Douglas Co., Kansas, by Miller and Kel- logg, Bull. U. S. Nat. Mus., 205:804, March 3, 1955). Odocoileus virginianus macrourus, Cary, Proc. Nebraska Ornith. Union, 3:69, December, 1902; Swenk, Proc. Nebraska Acad. Sci., 8:73, September, 1908; Swenk, Studies Zool. Lab., Univ. Nebraska, 89:17, September, 1908; Swenk, Nebraska Bird Rev., 5:53, July 31, 1937. Cervus Virginianus, James, Account of an expedition from Pittsburgh to the Rocky Mountains . . ., 1:103, 370, 1823; Aughey, Sketches of the physical geography and geology of Nebraska, p. 118, 1880 (part). Cervus leucurus, Baird, Mammals, in Reports of explorations and surveys . . . from the Mississippi River to the Pacific Ocean . . ., 8(1):649, July 14, 1858. C[erviis]. leucrus [sic], Aughey, Sketches of the physical geography and geology of Nebraska, p. 118, 1880 (part). Odocoileus americanus macrourus, Swenk, Nebraska Blue Book, p. 851, 1915; Swenk, Nebraska Blue Book, p. 408, December, 1918; Swenk, Contrib. Dept. Ent., Univ. Nebraska, 23:17, March 1, 1919; Swenk, Ne- braska Blue Book, p. 480, December, 1920. 0[docoileus]. v[irginianus] . macrourus, Jones, Trans. Kansas Acad. Sci., 60:281, October 22, 1957 (O. v. dacotensis and O. v. texanus also mentioned as possibly occurring in Nebraska). Distribution in Nebraska. — State-wide in suitable habitat. See Fig. 74. External measurements. — No measurements are available of recently taken Nebraskan specimens. James (1823:103) recorded in inches (here converted to mm. ) the measurements of an animal of unknown sex taken in February, 1820 at Long's winter quarters in Washington County, as follows: 1645; 241 ("from lateral base"); 464; weight, 115 lbs. Baird (1858:653) recorded (in inches) a female taken on October 9, 1856, on the "Republican Fork" as measuring l778 in total length and 280 in length of tail, but these measurements may have been taken from the skin of the animal rather than in the flesh. Kellogg (1956:44) listed the measurements of the largest male of the subspecies examined by him as: 1820; 240; 450. For cranial measurements see Table 24. Mohler et al. (1951:147) recorded the hog-dressed weight of a female from Thomas County that was two and a half years old at 109 lbs. and that of a female three and a half years old from the same place as 134% lbs. Schwartz and Schwartz (1959:321) recorded the weight of the largest male known from Missouri as 369 lbs. Remarks. — No revisionary study of the species O. virginianus has ever been made and, excepting Kellogg's (1956) general remarks concerning characters, usable diagnoses for most of the earlier- named of the 30 currently recognized subspecies are lacking in the literature. By consequence, the biologist who attempts to identify specimens of the white-tailed deer from certain parts of North America to subspecies experiences considerable difficulty. Such is the case when specimens from Nebraska are considered. I tentatively refer all white-tailed deer from Nebraska to the subspecies O. v. macrourus because I find no cranial features that distinguish the available specimens from specimens of macrourus from the vicinity of the type locality in northeastern Kansas. Earlier (1957:281) I suggested that three different subspecies might be Mammals of Nebraska. 319 found to occur in Nebraska (see also Kellogg, 1956:35). The two in addition to macrourus were O. v. dacotensis Goldman and Kel- logg, 1940, with type locality on the White Earth River, Mountrail County, North Dakota, and O. v. texanus ( Mearns, 1898 ) , with type locality at Fort Clark, Kinney County, Texas. If O. v. texanus occurs at all in Nebraska it will be found in the southwestern part of the state. No specimens have been examined from this area but the few individuals that I have observed along the Republican River in the southwest were not suggestive of the small size and grayish color (as compared with macrourus) of texanus. Furthermore, the physiography of the region suggests that white-tails occurring there would likely show relationship to the population inhabiting the Republican drainage and other areas to the east rather than to the population occurring to the southwest. The subspecific name dacotensis currently is applied to the white- tailed deer that inhabit the northern part of the Great Plains. The subspecies was characterized by its describers (1940:82) as: "Size very large, equaling or exceeding Odocoileus virginianus macrourus of eastern Kansas . . .; antlers heavy, moderately spreading, with tines relatively short; color . . . paler than usual in macrourus or borealis; dentition heavier than in any other member of the virginianus group." Later, Kellogg (1956:44) contrasted macrourus with dacotensis as follows: "Similar to dacotensis of North Dakota, but averaging somewhat smaller; cheek tooth series averaging shorter; and color somewhat darker." All in all, the alleged differ- ences between the two subspecies do not appear to be great. Unfortunately, none of the available specimens from Nebraska nor those from the vicinity of the type locality in northeastern Kansas is represented by a skin or even by complete external measurements and comparisons in external features, therefore, are impossible. Inasmuch as no cranial distinctions are apparent when Nebraskan specimens are compared with those from Kansas, the name macrou- rus is here applied to white-tails throughout Nebraska. I recognize, however, that deer from the northern and western parts of the state (especially in the Niobrara drainage and in the Pine Ridge, and possibly along the western reaches of the Platte ) may be found best referable to dacotensis when more abundant materials are available for study. Records of occurrence. — Specimens examined, 13, as follows: Boyd County: 3 mi. E Bristow, 1 (NSM). Cedar County: 1 mi. S, 33a mi. W St. Helena, 1 (NSM). Cherry County: Valentine Nat'l Wildlife Refuge, 1. Dakota County: Hubbard, 1 (NSM). Dixon County: 9 mi. NW Ponca, 1. Hamilton County: no specific locality, 1 (HM). Holt County: 6 mi. S, 1 mi. E Atkinson, 1 (NSM); 9 mi. S Emmet, 1 (NSM). Nance County: Loup 320 University of Kansas Publs., Mus. Nat. Hist. River at Fullerton, 1 (NSM). Sarpy County: Linoma Beach, 1 (RV). Saunders County: 5 mi. NE Ashland, 1 (NSM). Sioux County: & mi. W Ft. Robinson, 1; 8 mi. W Crawford, 1. Thomas County: near Halsey, 1. Selected additional records ( Swenk, MS, unless otherwise noted ) : Ante- lope County: 5 mi. W Neligh (Cary, MS). Blaine County: between Brewster and Dunning (Cary, MS). Brown County: Ainsworth (Cary, MS). Chase County: 12 mi. N Wauneta (Hill and Metcalf, 1942:204, archeological site). Cuming County: Wisner; 2 mi. E Beemer (Cary, MS); West Point. Douglas County: Omaha (record on file, NGFPC). Holt County: south- western part. Madison County: N of Battle Creek (Cary, MS); Norfolk (Swenk, 1908:73). Nemaha County: no specific locality (record on file, NGFPC). Otoe County: "Missouri River, below Nebraska City." Richard- son County: 4 mi. SE Rulo (Hill and Wedel, 1936:63, archeological site). Sarpy County: Child's Point. Sheridan County: Gordon. Sioux County: Warbonnet and Jim Creek canyons (Swenk, 1908:73). Stanton County: no specific locality. Valley County: % mi. N, 6 mi. W North Loup (Hill and Kivett, 1941:183, archeological site). Washington County: De Soto Bend Wildlife Refuge (Velich, 1961:94); Ft. Calhoun; Rockport; Engineer Canton- ment [= approximately 2 mi. E Ft. Calhoun] (James, 1823:370). Wayne County: no specific locality. County unknown (Baird, 1858:653): Platte River; Republican Fork. Table 24. — Cranial Measurements of Two Species of Odocoileus. CO ■Ji £ Catalogue number and sex "o3 CO ~-i 5 ."tt " e3 CO a *-* o of man premol • row r+ ^ S-. +i rj JS^^ -3 b S JC' b£ a <3 P 2 -*J +S X 4J +3 c3,5 T3 C o p t-i c faC M c3 O hD-3 O s^ — i •i.^-yj i \ •! ,/ : 'r— ? I I L /' I l._.J >J^~ \ i V \ \ \ \ \ i._.J L^Li i i ! [_ _|_ i i i i ! i j i.._L._-L — J---L- Museum of Noturol Hislofy University of Konsos 1952 | J°3_ 97 Fig. 80. Records of occurrence of Rattus norvegicus in Nebraska. planation of symbols see Fig. 5. For ex- Insofar as known R. norvegicus is the only species of the genus found in Nebraska although at least three subspecies of another species, Rattus rattus, also have been introduced into the United States. If it occurs at all in Nebraska, R. rattus, the black rat, prob- ably will be found only in large urban areas such as Omaha and Lincoln. R. rattus differs from R. norvegicus as follows: tail longer, rather than shorter, than head and body; ears larger, meas- uring approximately 21 mm. instead of approximately 18 mm.; fe- males normally having 10 mammae instead of 12; temporal ridges of skull strongly bowed outward posteriorly rather than approxi- mately parallel. The number of young per litter of R. norvegicus usually ranges between 2 and 14; litters of more than 14 are occasionally reported. The species breeds the year around. Only one subspecies of the Norway rat, R. n. norvegicus, is known to have been introduced into the United States. Records of occurrence. — Specimens examined, 36, as follows: Adams County: no specific locality, 1 (HM). Box Butte County: Hemingford, 1 (NSM). Buffalo County: Elm Creek, 1 (HM). Cherry County: W of Crookston, 2 (NSM). Custer County: Comstock, 1 (AMNH). Dawes Mammals of Nebraska 335 County: 9 mi. S Chadron, 1 (UMMZ); Crawford, 8 (NSM). Douglas County: 2 mi. N junction highways 133 and 64 (on 133), W of Omaha, 1. Franklin County: 1M mi. S Franklin, 1. Kimball County: 3 mi. E Kimball, 1. Lancaster County: within 6 mi. Lincoln, 18 (2 NGFPC, 3 NSM, 9 UC, 4 UNDZ). Additional records: Adams County: Hastings (Gates, 1945:13). Banner County: no specific locality (Fichter, 1941:28). Deuel County: no spe- cific locality (Rapp and Gates, 1957:53). Douglas County: near Irvington (Haecker, 1941:10). Dundy County: 5 mi. N, 2 mi. W Parks (Jones, 1954: 485). Sioux County: no specific locality (Fichter, 1941:28). Table 26. — Cranial Measurements of Rattus norvegicus and Mus musculus. Catalogue number and sex be a -^ — T* — »__ : • I I i / / L-r.-.u .«...«1*fez^ri ^^v^r .-■ ' — *•— -^ / h — *• — t — *-*-•' § L.-.-i J J^^f~^l. Descriptions of new American mammals. Bull. Amer. Mus. Nat. Hist., 7:327-340, November 8. 1896. List of mammals collected by Mr. Walter W. Granger, in New Mexico, Utah, Wyoming and Nebraska, 1895-96, with field notes by the collector. Bull. Amer. Mus. Nat. Hist., 8:241-258, Novem- ber 25. Anderson, S. 1956. Subspeciation in the meadow mouse, Microtus pennsylvanicus, in Wyoming, Colorado, and adjacent areas. Univ. Kansas Publ., Mus. Nat. Hist., 9:85-104, 2 figs., May 10. Anderson, S., and B. C. Nelson 1958. Additional records of mammals of Kansas. Trans. Kansas Acad. Sci., 61:302-312, November 21. ASDELL, S. A. 1946. Patterns of mammalian reproduction. Comstock Publ. Co., Ithaca, x + 437 pp., 12 pis., 1 fig. Audubon, J. J., and J. Bachman 1856. The quadrupeds of North America. New York, privately published, 2:1-334, pis. 51-100. Audubon, M. R., and E. Coues 1898. Audubon and his journals. John C. Nimmo, London, l:xiv + 1-532, illustrated. Aughey, S. 1880. Sketches of the physical geography and geology of Nebraska. Daily Republican Book and Job Office, Omaha, 346 pp. Bailey, V. 1893. The prairie ground squirrels or spermophiles of the Mississippi Valley. Bull. Div. Ornith. Mamm., U. S. D. A., 4:1-69, 3 pis., 4 maps. 1895. The pocket gophers of the United States. Bull. Div. Omith. Mamm., U. S. D. A., 5.T-47, frontispiece, 6 figs., 1 map. •342 University of Kansas Publs., Mus. Nat. Hist. 1900. Revision of American voles of the genus Microtus. N. Amer. Fauna, 17:1-88, 5 pis., 17 figs., June 6. 1905. Biological survey of Texas. N. Amer. Fauna, 25:1-222, 16 pis., 24 figs., October 24. 1907. Wolves in relation to stock, game, and the National Forest reserves. Bull. U. S. Forest Service, 72:1-31, 3 pis., 5 figs., January 19. 1915. Revision of the pocket gophers of the genus Thomomys. N. Amer. Fauna, 39:1-136, 8 pis., 10 figs., November 15. 1927. A biological survey of North Dakota. N. Amer. Fauna, 49:vi -f- 1- 226, 21 pis., 8 figs., 1 map, January 8. 1932. The mammals of New Mexico. N. Amer. Fauna, 53:1-412, 22 pis., 58 figs., March 1. Bailey, V., and C. C. Sperry 1929. Life history and habits of grasshopper mice, genus Onychomys. Tech. Bull. U. S.D.A., 145:1-19, 4 pis., 1 fig., November. Bailey, W., Jr., G. Schildman and P. Agee 1957. Nebraska deer. Nebraska Game, Forestation and Parks Comm., Lincoln, 37 pp., illustrated. Baird, S. F. 1858. Mammals, in Reports of explorations and surveys . . . from the Mississippi River to the Pacific Ocean . . ., 8(l):xxi-xlviii + 1-757, 43 pis. (XVII-XXVIII and XXX-LX), July 14. Baker, R. H. 1954. A hoary bat from northwestern Kansas. Trans. Kansas Acad. Sci., 57:196, August 2. Banfteld, A. W. F. 1962. A revision of the reindeer and caribou, genus Rangifer. Bull. Nat. Mus. Canada, 177:vi + 1-137, 12 pis., 15 figs., February 7. Bangs, O. 1898. Descriptions of two new skunks of the genus Mephitis. Proc. Biol. Soc. Washington, 12:31-33, March 24. Beed, W. E. 1936. A preliminary study of the animal ecology of the Niobrara Game Preserve. Bull. Conserv. Surv. Div., Univ. Nebraska, 10:1-33, 3 figs., October. Beidleman, R. G. 1956. An early record of the wolverine in western Nebraska. Jour. Mamm., 37:445-446, September 11. Blair, T. A. 1941. Climate of the states — Nebraska, pp. 967-978, in Yearbook of Agri- culture for 1941. U. S. Gov't Printing Office, Washington, D. C, xii -f 1248 pp., illustrated. Blair, W. F. 1953. Factors affecting gene exchange between populations in the Pero- myscus maniculatus group. Texas Jour. Sci., 5:17-33, 1 fig., March. 1959. Distributional patterns of vertebrates in the southern United States in relation to past and present environments, pp. 433-468, 11 figs., in Zoogeography. Publ. Amer. Assoc. Adv. Sci., 51:x + 1-509, illustrated, January 16. Blossom, P. M. 1938. Description of a new race of pocket gopher (Geomys hursarius hylaeus) from northwestern Nebraska. Occas. Papers Mus. Zool., Univ. Michigan, 368:1-2, April 6. Mammals of Nebraska 343 Bole, B. P., Jr., and P. N. Moulthrop 1942. The Ohio Becent mammal collection in the Cleveland Museum of Natural History. Sci. Publ. Cleveland Mus. Nat. Hist., 5:83-181, September 11. Braun, E. L. 1950. Deciduous forests of eastern North America. The Blakiston Co., Philadelphia and Toronto, xiv -f- 596 pp., illustrated. Bronson, F. H. 1958. Notes on body size of black-tailed jackrabbits. Trans. Kansas Acad. Sci., 61:109, April 23. Bronson, F. H., and O. W. Tiemeier 1958. Beproduction and age distribution of black-tailed jackrabbits in Kansas. Jour. Wildlife Mgt., 22:409-414, October. Brown, H. L. 1947. Why has the white-tailed jackrabbit (Lepus townsendii campanius Hollister) become scarce in Kansas? Trans. Kansas Acad. Sci., 49:455-456, April 5. BUECHNER, H. K. 1960. The bighorn sheep in the United States, its past, present, and future. Wildlife Monog., 4:1-174, frontispiece, 11 figs., May. Burnett, W. L. 1920. A contribution to the life history of the Wyoming ground squirrel (Citellus elegans) in Colorado. Circ. State Ent., Colorado Agric. Coll., 30:1-12, 2 pis., September. 1931. Life-history studies of the Wyoming ground squirrel [Citellus elegans elegans] in Colorado. Bull Exp. Sta., Colorado Agric. Coll., 373:1-23, 6 figs., April. Burt, W. H. 1948. The mammals of Michigan. Univ. Michigan Press, Arm Arbor, xv + 288 pp., 13 pis., 107 figs., 67 maps. Cahalane, V. H. 1954. Status of the black-footed ferret. Jour. Mamm., 35:418-424, 1 fig., August 20. Cary, M. 1902. Some general remarks upon the distribution of life in northwest Nebraska. Proc. Nebraska Ornith. Union, 3:63-75, pis., 6-9, December. 1903. A new Beithrodontomys from western Nebraska. Proc. Biol. Soc. Washington, 16:53-54, May 6. 1906. Identity of Eutamias pallidas (Allen), with description of a related form from the South Dakota bad lands. Proc. Biol. Soc. Wash- ington, 19:87-90, June 4. 1911. A biological survey of Colorado. N. Amer. Fauna, 33:1-256, 12 pis., 39 figs., August 17. MS. The mammals of Nebraska. On file, U. S. Fish and Wildlife Serv- ice, Washington, D. C, 143 handwritten pp., about 1905. Champe, J. L. 1946. Ash Hollow Cave. Univ. Nebraska Studies, l(n. s.):ix + 1-104, 22 pis., 17 figs., October. Churcher, C. S. 1959. The specific status of the New World red fox. Jour. Mamm., 40:513-520, 1 fig., November 20. Clements, F. E. and B. W. Chaney 1937. Environment and life in the Great Plains. Suppl. Publ. Carnegie Inst. Washington, 24 (revised): 1-54, 10 pis., 2 figs., February 15. 344 University of Kansas Publs.. Mus. Nat. Hist. Cockrum, E. L. 1948. The distribution of the hispid cotton rat in Kansas. Trans. Kansas Acad. Sci., 51:306-312, 3 figs., October 11. 1951. A new pocket mouse (genus Perognathus) from Kansas. Univ. Kansas Publ., Mus. Nat. Hist., 5:203-206, December 15. 1952. Mammals of Kansas. Univ. Kansas Publ., Mus. Nat. Hist., 7:1-303, 73 figs., August 25. 1953. Aberrations in the color of the prairie vole, Microtus ochrogaster. Trans. Kansas Acad. Sci., 56:86-88, 1 fig., March 21. 1956. Reproduction in North American bats. Trans. Kansas Acad. Sci., 58:487-511, January 23. CONDRA, G E. 1934. Geological phases of soil erosion investigation and control in Nebraska. Paper Nebraska Geol. Surv., 6:1-22, 13 figs. Condra, G. E., and E. C. Reed 1943. The geological section of Nebraska. Bull. Nebraska Geol. Surv., 14:vii -f- 1-82, 25 figs., January. Cook, H. J. 1931. A mountain sheep record for Nebraska. Jour. Mamm., 12:170-171, May 14. Coues, E. 1875. A critical review of the North American Saccomyidae. Proc. Acad. Nat. Sci. Philadelphia, pp. 272-327, August 31. 1893. History of the expedition under the command of Lewis and Clark . . . . Francis P. Harper, New York, l:cxxxii -f- 1-352 and 3:vi + 821-1298. Coues, E. and J. A. Allen 1877. Monographs of North American Rodentia. Bull. U. S. Geol. Surv. Territories, ll:xii + x + 1-1091, 7 pis., August. Couturier, M. A. J. 1954. L'Ours brun. . . . Grenoble, France, privately published, xi + 904 pp., frontispiece, 82 pis., 49 figs. Cowan, I. M. 1940. Distribution and variation in the native sheep of North America. Amer. Midland Nat., 24:505-580, 4 pis., 1 map, November. 1956. What and where are the mule and black-tailed deer, pp. 334-359, figs. 13-17, in Taylor, W. P. (ed.), The deer of North America .... The Stackpole Co., Harrisburg, and The Wildlife Mgt. Inst., Washington, D. C, 668 pp., illustrated. Cowan, I. M., and C. J. Guiguet 1960. The mammals of British Columbia. Handbook British Columbian Prov. Mus., 11 (2nd ed.): 1-413, 103 pis., 53 maps, June 8. Davis, W. B. 1960. The mammals of Texas. Bull. Texas Game and Fish Comm., 41: 1-252, 73 figs., 64 maps. Deevey, E. S. 1949. Biogeography of the Pleistocene (Part 1: Europe and North America). Bull. Geol. Soc. Amer., 60:1315-1416, 27 figs., Sep- tember. 1961. Recent advances in Pleistocene stratigraphy and biogeography, pp. 594-623, 3 figs., in Vertebrate speciation. Univ. Texas Press, Austin, xvi + 642 pp., illustrated. Deevey, E. S., and R. F. Flint 1957. Postglacial Hypsithermal Interval. Science, 125:182-184, Febru- ary 1. Mammals of Nebraska 345 DEGERB0L, M. 1935. Systematic notes. Pt. 1, pp. 1-67, figs. 1-12, in Mammals, Rept. 5th Thule Exped. 1921-24, 2(4-5) : 1-278, illustrated. de Vos, A., R. H. Manville and R. G. Van Gelder 1956. Introduced mammals and their influence of the native biota. Zoologica, 41:163-194, 1 fig., December 31. Dice, L. R. 1924. The grasshopper mouse in Iowa. Jour. Mamm., 5:66, February 9. 1941. Variation of the deer mouse (Peromyscus maniculatus) on the Sand Hills of Nebraska and adjacent areas. Contrib. Lab. Vert. Genetics, Univ. Michigan, 15:1-19, 1 map, July. Dillon, L. S. 1956. Wisconsin climate and fife zones in North America. Science, 123: 167-176, 12 figs., February 3. Dorf, E. 1959. Climatic changes of the past and present. Contrib. Mus. Paleo., Univ. Michigan, 13:181-210, 1 pi., 3 figs., 7 maps, April 17. Ellerman, J. R. 1941. The families and genera of living rodents. Rritish Museum, Lon- don, 2:xii+ 1-690, 50 figs., March 21. Engels, W. L. 1936. Distribution of the races of the brown bat (Eptesicus) in western North America. Amer. Midland Nat., 17:653-660, 1 fig., May. Erdbrink, D. P. 1953. A review of fossil and Recent bears of the Old World. . . . Deventer, Jan de Lange, xii + 597 pp., 12-page index, 22 pis., 61 figs., foldout map. Fenneman, N. M. 1931. Physiography of the western United States. McGraw-Hill Book Co., Inc., New York and London, xiii + 534 pp., 173 figs. Fichter, E. 1941. The role of owl pellet analyses in faunistics. Nebraska Bird Rev., 9:26-29, December 31. 1944. Nebraska trapping take — 1942. Outdoor Nebraska, 21:18, January. 1950. Watching coyotes. Jour. Mamm., 31:66-73, February 21. Fichter, E., and M. F. Hansen 1947. The Goss lemming mouse, Synaptomys cooperi gossii (Coues), in Nebraska. Bull. Univ. Nebraska State Mus., 3(2): 1-8, 2 figs., September. Fichter, E., and J. K. Jones, Jr. 1953. The occurrence of the black-footed ferret in Nebraska. Jour. Mamm., 34:385-388, 1 fig., August 14. Fichter, E., G. Scidxdman and J. H. Sather 1955. Some feeding patterns of coyotes in Nebraska. Ecol. Monog., 25: 1-37, 33 figs., January. FlGGINS, J. D. 1933. The bison of the western area of the Mississippi Basin. Proc. Colo- rado Mus. Nat. Hist., 12:16-33, 9 pis., December 5. FlNDLEY, J. S. 1953. Pleistocene Soricidae from San Josecito Cave, Nuevo Leon, Mexico. Univ. Kansas Publ., Mus. Nat. Hist., 5:633-639, December 1. 1956a. Distribution of some South Dakotan mammals. Nat. Hist. Misc., Chicago Acad. Sci., 155:1-2, April 30. 346 University of Kansas Publs., Mus. Nat. Hist. 1956k. Mammals of Clay County, South Dakota. Univ. South Dakota Publ. Biol., 1:1-45, 3 6gs., May 15. Finley, R. B. 1958. The wood rats of Colorado: distribution and ecology. Univ. Kan- sas Publ., Mus. Nat. Hist., 10:213-552, 34 pis., 8 figs., November 7. Flint, R. F. 1957. Glacial and Pleistocene geology. John Wiley and Sons, Inc., New York, xiii + 553 pp., 5 pis., numerous illustrations in text. FRYE, J. C, AND W. H. SCHOEWE 1953. The basis for physiographic subdivision of Kansas. Trans. Kansas Acad. Sci., 56:246-252, 2 figs. Garretson, M. S. 1938. The American bison. . . . New York Zool. Soc, xii -f- 254 pp., illustrated. GASHWTEER, J. S., W. L. ROBINETTE AND O. W. MORRIS 1961. Breeding habits of bobcats in Utah. Jour. Mamm., 42:76-84, February 20. Gates, D. B. 1945. Notes on fleas ( Siphonaptera ) in Nebraska. Ent. News, 56:10-13, January. Gates, D. B., and J. Wolcott 1946. Four red bats in one fitter. Jour. Mamm., 27:84-85, March 14. Gier, H. T. 1957. Coyotes in Kansas. Kansas Agric. Exp. Sta., Manhattan, 97 pp., 32 figs., August. Glass, B. P. 1947. Geographic variation in Perognathus hispidus. Jour. Mamm., 28: 174-179, 1 fig., June 1. Goldman, E. A. 1910. Revision of the wood rats of the genus Neotoma. N. Amer. Fauna, 31:1-124, 8 pis., 14 figs., October 19. 1944. Classification of wolves, pp. 387-507, pis. 88-131, figs. 14-15, in Young and Goldman, The wolves of North America. Amer. Wild- life Inst., Washington, D. C, xx -f 636 pp., 131 pis., 15 figs., May 29. 1946. Classification of the races of the puma, pp. 175-302, pis. 46-93, fig. 6, in Young and Goldman, The puma, mysterious American cat. Amer. Wildlife Inst., Washington, D. C, xiv + 358 pp., 93 pis., 6 figs., November 16. 1950. Raccoons of North and Middle America. N. Amer. Fauna, 60: vi + 1-153, 21 pis., 2 figs., November 7. Goldman, E. A., and R. Kellogg 1940. Ten new white-tailed deer from North and Middle America. Proc. Biol. Soc. Washington, 53:81-90, June 28. Grinnell, G. B. 1904. American big game and its haunts. Forest and Stream Publ. Co., New York, 497 pp., frontispiece and other illustrations. 1929. Pronghorn antelope. Jour. Mamm., 10:135-141, May 9. Grinnell, J., and J. Dixon 1924. Revision of the genus Lynx in California. Univ. California Publ. Zool., 21:339-354, pi. 11, 1 fig., January 24. Grizzell, R. A., Jr. 1955. A study of the southern woodchuck, Marmota monax monax. Amer. Midland Nat., 53:257-293, 9 figs., April. Mammals of Nebraska 347 guilday, j. e., and j. k. doutt 1961. The collared lemming (Dicrostonyx) from the Pennsylvania Pleis- tocene. Proc. Biol. Soc. Washington, 74:249-250, December 8. Haecker, F. W. 1941. Nesting of the great horned owl in Douglas County. Nebraska Bird Rev., 9:8-11, January-June. Hall, E. R. 1936. Mustelid mammals from the Pleistocene of North America. . . . Publ. Carnegie Inst. Washington, 473:41-119, 5 pis., 6 figs., November 20. 1946. Mammals of Nevada. Univ. California Press, Berkeley, xi + 710 pp. frontispiece, 11 pis., 485 figs., July 1. 1951. American weasels. Univ. Kansas Publ., Mus. Nat. Hist., 4:1-466, 41 pis., 31 figs., December 27. 1955. Handbook of mammals of Kansas. Misc. Publ. Mus. Nat. Hist., Univ. Kansas, 7:1-303, illustrated, December 13. Hall, E. R. and E. L. Cockrum 1953. A synopsis of the North American microtine rodents. Univ. Kansas Publ., Mus. Nat. Hist, 5:373-498, 149 figs., January 15. Hall, E. R., and K. R. Kelson 1951. Comments on the taxonmoy and geographic distribution of some North American rabbits. Univ. Kansas Publ., Mus. Nat. Hist., 5:49-58, October 1. 1959. The mammals of North America. Ronald Press, New York, 2 vols. ( 1 :xxx + 1-546 + 79, 2: viii 4- 547-1083 +79), 553 numbered figs., 500 maps, March 31. Hall, E. R., and H. G. Montague 1951. Two new pocket gophers from Wyoming and Colorado. Univ. Kansas Publ., Mus. Nat. Hist., 5:25-32, February 28. Hamilton, W. J., Jr. 1943. The mammals of eastern United States. Comstock Publ. Co., Inc., Ithaca, ( 10) + 432 pp., frontispiece, 184 figs. 1944. The biology of the little short-tailed shrew, Crtjptotis parva. Jour. Mamm., 25:1-7, 1 pi., February 15. 1958. Life history and economic relations of the opossum (Didelphis marsupialis virginiana) in New York State. Mem. New York State Agric. Coll., 354:1-48, 12 figs., March. Haugen, A. O. 1961. Wolverine in Iowa. Jour. Mamm., 42:546-547, November 20. Hayden, F. V. 1859. Mammals. Exec. Doc, House of Representatives, 2nd Sess., 35th Congress, 2:706-711. 1863. On the geology and natural history of the Upper Missouri. Trans. Amer. Philos. Soc, 12 (n. s.) : 1-218, 10 figs., 1 map. Hershkovttz, P. 1948. The technical name of the Virginia deer with a fist of South American forms. Proc. Biol. Soc. Washington, 61:41-45, April 30. Hibrard, C. W. 1949. Pleistocene stratigraphy and paleontology of Meade County, Kansas. Contrib. Mus. Paleo., Univ. Michigan, 7:63-90, 1 pi., 2 figs., 3 maps, March 2. 1958. Summary of North American Pleistocene mammalian local faunas. Papers Michigan Acad. Sci., Arts, and Letters, 43:3-32. HlBBARD, E. A. 1957. Range and spread of the gray and fox squirrels in North Dakota. Jour. Mamm., 37:525-531, 1 fig., January 9. 348 University of Kansas Publs., Mus. Nat. Hist. Hill, A. T., and P. Cooper 1937. The Schrader site .... Nebraska Hist., 17:222-252, 7 pis., 5 figs., June. Hill, A. T., and M. Kivett 1941. Woodland-like manifestations in Nebraska. Nebraska Hist., 21: 146-243, 34 pis., 4 maps, May. Hill, A. T., and G. Metcalf 1942. A site of the Dismal River Aspect in Chase County, Nebraska. Ne- braska Hist., 22:158-226, 11 pis., 1 fig., 2 maps, February. Hill, A. T., and W. R. Wedel 1936. Excavations at Leary Indian village and burial site, Richardson County, Nebraska. Nebraska Hist., 17:3-73, 10 pis., 4 figs., October. Hinton, M. A. C. 1926. Monograph of the voles and lemmings (Microtinae), living and extinct. British Museum, London, l:xvi + 1-488, 15 pis., 110 figs., June 26. HOLLISTER, N. 1911. A systematic synopsis of the muskrats. N. Amer. Fauna, 32:1-47, 6 pis., April 29. 1914. A systematic account of the grasshopper mice. Proc. U. S. Nat. Mus., 47:427-489, pi. 15, 3 figs., October 29. 1916. A systematic account of the prairie-dogs. N. Amer. Fauna, 40:1-37, 7 pis., 2 figs., June 20. Hooper, E. T. 1952. A systematic review of the harvest mice (genus Reithrodontomys) of Latin America. Misc. Publ. Mus. Zool., Univ. Michigan, 77:1- 255, 9 pis., 24 figs., 12 maps, January 16. Hoover, R. L., C. E. Till and S. Ogilvie 1959. The antelope of Colorado. . . . Colorado Dept. Game and Fish, 110 pp., illustrated, June. Hoover, R. L., and L. E. Yeager 1953. Status of the fox squirrel in northeastern Colorado. Jour. Mamm., 34:359-365, 1 fig., August 14. HORNADAY, W. T. 1889. The extermination of the American bison. . . . Ann. Rept. U. S. Nat. Mus., for 1887, pp. 367-548, 22 pis. Howell, A. B. 1927. Revision of the American lemming mice (genus Synaptomys). N. Amer. Fauna, 50:1-37, 2 pis., 11 figs., June 30. Howell, A. H. 1901. Revision of the skunks of the genus Chincha. N. Amer. Fauna, 20:1-62, 8 pis., August 31. 1914. Revision of the American harvest mice (genus Reithrodontomys). N. Amer. Fauna, 36:1-97, 7 pis., 6 figs., June 5. 1918. Revision of the American flying squirrels. N. Amer. Fauna, 44:1-64, 7 pis., 3 figs., June 13. 1929. Revision of the American chipmunks (genera Tamias and Eu- tamias). N. Amer. Fauna, 52:1-157, 10 pis., 9 figs., November 30. 1938. Revision of the North American ground squirrels. . . . N. Amer. Fauna, 56:1-256, 32 pis., 20 figs., May 18. Hudson, G. E. 1932. On the food habits of Marmosa. Jour. Mamm., 13:159, May 11. Mammals of Nebraska 349 Imler, R. H. 1945. Bullsnakes and their control on a Nebraska wildlife refuge. Jour. Wildlife Mgt., 9:265-273, 9 figs., October. Jackson, H. H. T. 1915. A review of the American moles. N. Amer. Fauna, 38:1-100, 6 pis., 27 figs., September 30. 1951. Classification of the races of the coyote, pp. 227-341, pis. 58-81, figs. 20-28, in Young and Jackson, The clever coyote. The Stockpole Co., Harrisburg, and The Wildlife Mgt. Inst., Washington, D. C, xv + 411 pp., 81 pis., 28 figs., November 29. 1955. The Wisconsin puma. Proc. Biol. Soc. Washington, 68:149-150, October 31. Jakway, G. E. 1958. Pleistocene Lagomorpha and Rodentia from the San Josecito Cave, Nuevo Leon, Mexico. Trans. Kansas Acad. Sci., 61:313-327, 1 fig., November 21. James, E. 1823. Account of an expedition from Pittsburgh to the Rocky Mountains. . . . H. C. Carey and I. Lea, Philadelphia, 1: (4) + 1-503. Jones, J. K., Jr. 1949a. The occurrence of the mountain lion in Nebraska. Jour. Mamm., 30:313, August 17. 1949&. Notes on small mammal content of pellets of the barn owl (Tyto alba pratincola) in Nebraska. Nebraska Bird Rev., 17:4-5. 1952. Notes on the food habits of the great horned owl in Cherry County, Nebraska. Nebraska Bird Rev., 20:10-11, January. 1953. Geographic distribution of the pocket mouse, Perognathus fasciatus. Univ. Kansas Publ., Mus. Nat. Hist., 5:515-526, 7 figs., August 1. 1954. Distribution of some Nebraskan mammals. Univ. Kansas Publ., Mus. Nat. Hist., 7:479-487, April 21. 1957. Checklist of mammals of Nebraska. Trans. Kansas Acad. Sci., 60:273-282, October 22. 1958a. A new bog lemming (genus Synaptomys) from Nebraska. Univ. Kansas Publ., Mus. Nat. Hist., 9:385-388, May 12. 1958&. The type locality and nomenclatorial status of Peromyscus mani- culatus nebrascensis (Coues). Proc. Biol. Soc. Washington, 71:107- 111, July 16. 1960a. The pronghom, Antilocapra americana, in western Iowa. Amer. Midland Nat., 63:249, January. 1960b. The hispid cotton rat in Nebraska. Jour. Mamm., 41:132, February 20. 1962 Early records of some mammals from Nebraska. Bull. Univ. Ne- braska State Mus., 4:89-100, November 26. Jones, J. K., Jr., and G. L. Cortner 1961. The subspecific identity of the gray squirrel (Sciurus carolinensis ) in Kansas and Nebraska. Trans. Kansas Acad. Sci., 63:285-288, January 11. Jones, J. K., Jr., and J. S. Findley „,'.... 1954. Geographic distribution of the short-tailed shrew, Blanna brevi- cauda, in the Great Plains. Trans. Kansas Acad. Sci. 57:208-211, 1 fig., August 2. Jones, J. K., Jr., and B. P. Glass 1960 The short-tailed shrew, Blarina brevicauda, in Oklahoma. South- western Nat., 5:136-142, 2 figs., November 1. 350 University of Kansas Publs., Mus. Nat. Hist. Jones, J. K., Jr., and B. Mursaloglu 1961. Geographic variation in the harvest mouse, Reithrodontomys megalotis, on the central Great Plains and in adjacent regions. Univ. Kansas Publ., Mus. Nat. Hist., 14:9-27, 1 fig., July 24. Jones, J. K., Jr., and R. L. Packard 1958. Myotis keenii septentrionalis in South Dakota. Jour. Mamm., 39:150, February 20. Jones, J. K., Jr., and O. L. Webb 1949. Notes on mammals from Richardson County, Nebraska. Jour. Mamm., 30:312-313, August 17. Kellogg, R. 1956. What and where are the whitetails, pp. 31-55, figs. 2-3, in Taylor, W. P. ( ed. ) , The deer of North America. . . . The Stackpole Co., Harrisburg, and The Wildlife Mgt. Inst., Washington, D. C, 668 pp., illustrated. Kellogg, R. S. 1905. Forest belts of western Kansas and Nebraska. U. S. D. A., Forest Serv. Bull., 66:1-44, 6 pis., 1 map, after September 7. Kendeigh, S. C. 1954. History and evaluation of various concepts of plant and animal communities in North America. Ecology, 35:152-171, 8 figs., April. 1961. Animal ecology. Prentice-Hall, Inc., Englewood Cliffs, New Jersey, x -j- 468 pp., illustrated. Kiener, W. 1951. P. A. Rydberg's "Report of a botanical exploration, made in western Nebraska in the summer of 1891, as a special agent of the Depart- ment of Agriculture." Nebraska Hist., 32:217-239, September. KLrNE, P. D. 1959. Additional mule deer records for Iowa. Jour. Mamm., 40:148-149, February 20. Koford, C. B. 1958. Prairie dogs, whitef aces, and blue grama. Wildlife Monog., 3:1-78, frontispiece, 16 figs., December. Krutzsch, P. H. 1954. North American jumping mice (genus Zapus). Univ. Kansas Publ., Mus. Nat. Hist, 7:349-472, 47 figs., April 21. Lee, O. B. 1962. Patchwork. South Dakota Conserv. Digest, 29(2). -21, illustrated. Lugn, A. L. 1935. The Pleistocene geology of Nebraska. Bull. Nebraska Geol. Surv., 10:1-223, 2 pis., 38 figs. Lyon, M. W., Jr., and W. H. Osgood 1909. Catalogue of the type-specimens of mammals in the United States National Museum, including the Biological Survey collection. Bull. U. S. Nat. Mus., 62:x -f 1-325, January 28. Marcy, R. B. 1863. The prairie traveler. . . . Triibner and Co., London, xvi + 251 pp., illustrated. Martin, P. S. 1959. Pleistocene ecology and biogeography of North America, pp. 375- 420, 6 figs., in Zoogeography. Publ. Amer. Assoc. Adv. Sci., 51: x -f- 1-509, illustrated, January 16. Martin, P. S., J. Schoenwetter and B. C. Arms 1961. The last 10,000 years. Geochronology Lab., Univ. Arizona, vi -f- 119 pp., 14 pis., 31 figs., July. Mammals of Nebraska 351 Mattes, M. J. 1958. Scotts Bluff National Monument, Nebraska. Hist. Handbook, Nat'l Park Serv., 28:1-64, illustrated. McDowell, S. B., Jr. 1958. The Greater Antillean insectivores. Bull. Amer. Mus. Nat. Hist., 115:113-214, 46 figs., May 5. Mearns, E. A. 1891. Observations on the North American badgers, with especial refer- ence to the forms found in Arizona, with description of a new subspecies from northern California. Bull. Amer. Mus. Nat. Hist., 3:239-251, June 5. Merriam, C. H. 1889. Revision of the North American pocket mice. N. Amer. Fauna, lrviii + 1-36, 4 pis., October 25. 1895. Monographic revision of the pocket gophers. . . . N. Amer. Fauna, 8:1-258, frontispiece, 19 pis., 71 figs., 4 maps, January 31. 1897. Revision of the coyotes or prairie wolves, with descriptions of new forms. Proc. Biol. Soc. Washington, 11:19-33, March 15. 1901. The prairie dog of the Great Plains. Yearbook of Agriculture for 1901, pp. 257-270, pis. 22-24, figs. 24-25. Miller, G. S., Jr. 1896. Genera and subgenera of voles and lemmings. N. Amer. Fauna, 12:1-84, 3 pis., 40 figs., July 23. 1897. Revision of the North American bats of the family Vespertilionidae. N. Amer. Fauna, 13:1-140, 3 pis., 40 figs., October 16. Mohler, L., J. H. Wampole and E. Fichter 1951. Mule deer in Nebraska National Forest. Jour. Wildlife Mgt., 15: 129-157, pis. 5-8, 1 fig., April. MURIE, O. J. 1951. The elk of North America. The Stackpole Co., Harrisburg, and Wildlife Mgt. Inst., Washington, D. C, 376 pp., colored frontis- piece, 29 pis., 32 figs. Nelson, E. W. 1909. The rabbits of North America. N. Amer. Fauna, 29:1-314, 13 pis., 19 figs., August 31. 1925. Status of the pronghorned antelope, 1922-1924. Bull. U. S. D. A., 1346:1-64, 6 pis., 21 figs., August. Osgood, W. H. 1900. Revision of the pocket mice of the genus Perognathus. N. Amer. Fauna, 18:1-72, 4 pis., 15 figs., September 20. 1904. Two new pocket mice of the genus Perognathus. Proc. Biol. Soc. Washington, 17:127-128, June 9. 1909. Revision of the mice of the American genus Peromyscus. N. Amer. Fauna, 28:1-285, 8 pis., 12 figs., April 17. Packard, R. L. 1955. Release, dispersal and reproduction of the fallow deer in Nebraska. Jour. Mamm., 36:471-473, 1 fig., August 30. 1956. The tree squirrels of Kansas. Misc. Publ. Mus. Nat. Hist., Univ. Kansas, 11:1-67, 2 pis., 10 figs., August 20. Parmalee, P. W., and D. F. Hoffmeister 1957. Archaeozoological evidence of the spotted skunk in Illinois. Jour. Mamm., 38:261, May 27. 352 University of Kansas Publs., Mus. Nat. Hist. Peterson, R. L., and S. C. Downing 1952. Notes on the bobcats (Lynx rufus) of eastern North America with description of a new race. Contrib. Royal Ontario Mus., 33:1-23, 7 figs., April 8. Polder, E. 1958. Recent locality records for some Iowa mammals. Proc. Iowa Acad. Sci., 65:559-564, November 20. Pool, R. J. 1914. A study of the vegetation of the Sand Hills of Nebraska. Minne- sota Bot. Studies, 4:189-312, pis. 26-40, 16 figs. 1957. Handbook of Nebraska trees. Nebraska Conserv. Bull., 32:1-179, illustrated, April. Pound, R., and F. E. Clements 1900. The phytogeography of Nebraska. Jacob North and Co., Lincoln, Nebraska, 2nd ed., 422 pp., 4 maps, after February 1. Presnall, C. C. 1958. The present status of exotic mammals in the United States. Jour. Wildlife Mgt, 22:45-50, January. Quaife, M. M. 1916. The journals of Captain Meriwether Lewis and Sargent John Ord- way. . . . Publ. State Hist. Soc. Wisconsin, 22:1-444, illu- strated. Quay, W. B. 1948. Notes on some bats from Nebraska and Wyoming. Jour. Mamm., 29:181-182, May 14. Rainey, D. G. 1956. Eastern woodrat, Neotoma floridana: fife history and ecology. Univ. Kansas Publ., Mus. Nat. Hist, 8:535-646, 12 pis., 13 figs., August 15. Rapp, W. F., Jr., and D. B. Gates 1957. A distributional check-fist of the fleas of Nebraska. Jour. Kansas Ent. Soc, 30:50-53, April. Rausch, R. 1953. On the status of some arctic mammals. Arctic, 6:91-148, 17 figs., July. Reichstein, H. 1958. Schadelvariabilitat europaischer Mauswiesel (Mustela nivalis L.) und Hermeline ( Mustela erminea L. ) in Beziehung zu Verbreitung und Geschlecht. Zeitschrift fur Saugetierkunde, 22:151-182, 7 figs. Reynolds, H. C. 1952. Studies on reproduction in the opossum (Didelphis virginiana vir- giniana). Univ. California Publ. Zool., 52:223-284, pis. 3-7, 7 figs., November 13. Rode, P., and R. Didier 1946. Atlas des mammiferes de France. N. Boubee and Co., Paris, 219 pp., illustrated. Rodeck, H. G. 1952. Guide to the mammals of Colorado. Leaflet Univ. Colorado Mus., 10:1-72, illustrated, September. Russell, R. J., and J. K. Jones, Jr. 1956. The taxonomic status of Geomys bursarius vinaceus Swenk. Trans. Kansas Acad. Sci., 58:512-513, January 23. Rydrfrp P A 1895. Flora of the Sand Hills of Nebraska. Contrib. U. S. Nat. Herb., 3:v + 133-203, 2 pis., 1 fig., September 14. Mammals of Nebraska 353 Sather, J. H. 1954. The dentition method of aging muskrats. Nat. Hist. Misc., Chicago Acad. Sci., 130:1-3, 2 figs., March 8. 1957. Skull dimensions of the Great Plains muskrat, Ondatra zibethicus cinnamominus. Jour. Mamm., 37:501-505, January 9. 1958. Biology of the Great Plains muskrat in Nebraska. Wildlife Monog., 2:1-35, 13 figs., May. SCHANTZ, V. S. 1953. Additional information on distribution and variation of eastern badgers. Jour. Mamm., 34:388-389, August 14. 1910.' The pocket gopher. Bull. Exp. Sta., Kansas State Agric. Coll., 172: 197-223, illustrated, September 3. SCHULTZ, C. B., G. C. LUENTNGHOENER AND W. D. FRANKFORTER 1951. A graphic resume of the Pleistocene of Nebraska (with notes on fossil mammalian remains). Bull. Univ. Nebraska State Mus., 3(6): 1-41, 11 figs., July. Schultz, C. B., AND W. D. Frankforter 1948. Preliminary report on the Lime Creek sites: new evidence of early man in southwestern Nebraska. Bull. Univ. Nebraska State Mus., 3(4):43-62, 13 figs., November. Schwartz, C. W., and E. R. Schwartz 1959. The wild mammals of Missouri. Univ. Missouri Press and Missouri Conserv. Comm., viii + 341 pp., colored frontispiece and other illustrations. Schwarz, E., and H. K. Schwarz 1943. The wild and commensal stocks of the house mouse, Mus musculus Linnaeus. Jour. Mamm., 24:59-72, February 20. 1937. Mammals of Iowa. Iowa State Coll. Jour. Sci., 12:43-97, 1 fig., October. Sears, P. B. 1961. A pollen profile from the grassland province. Science, 134:2038- 2039, 2 figs., December 22. Seton, E. T. 1929. Lives of game animals. . . . Doubleday, Doran and Co., Inc., Garden City, New York, 2(pt. 2):370-746, 3(pts. 1 and 2):xix + 1-780, and 4(pt. 2):441-949, illustrated. Setzer, H. W. 1949. Subspeciation in the kangaroo rat, Dipodomys ordii. Univ. Kansas Publ., Mus. Nat. Hist., 1:473-573, 27 figs., December 27. Sharp, W. M., and L. H. Sharp 1956. Nocturnal movements and behavior of wild raccoons at a winter feeding station. Jour. Mamm., 37:170-177, 1 pi., 1 fig., June 9. SrLVER, J. 1941. The house rat. U. S. Fish and Wildlife Serv. Circ2 6:iv+ 1-17, 15 figs. Skinner, M. F., and O. C. Kaisen 1947. The fossil Bison of Alaska and preliminary revision of the genus. Bull. Amer. Mus. Nat. Hist, 89:123-256, pis. 8-26, 5 figs., 3 maps, October 31. 23—6532 354 University of Kansas Publs., Mus. Nat. Hist. Smith, C. E. 1958. Natural history of Thomas County, Nebraska. Privately published, Broken Bow, Nebraska, 99 pp. Smith, P. W. 1957. An analysis of post-Wisconsin biogeography of the prairie peninsula region based on distributional phenomena among terrestrial verte- brate populations. Ecology, 88:205-218, 46 figs., April. Smith, R. E. 1958. Natural history of the prairie dog in Kansas. Misc. Publ. Mus. Nat. Hist., Univ. Kansas, 16:1-36, 4 pis., 9 figs., June 17. Sowls, L. K. 1948. The Franklin ground squirrel, Citellus franklinii (Sabine), and its relationship to nesting ducks. Jour. Mamm., 29:113-137, 3 pis., 2 figs., May 14. Stains, H. J. 1956. The raccoon in Kansas. Misc. Publ. Mus. Nat. Hist., Univ. Kansas, 10:1-76, 4 pis., 14 figs., July 6. Stephens, T. C. 1945. Say's bat in Nebraska. Jour. Mamm., 26:92, February 23. Stevens, W. R. 1959. Climates of the states — Nebraska. Climatogeography of the United States, U. S. Gov't Printing Office, Washington, D. C, 60-25:1-16, illustrated, December. Stolley, W. 1946. History of the first settlement of Hall County, Nebraska. Spec. Issue Nebraska Hist., xi -f- 90 pp., illustrated, April. Stormont, C, W. J. Miller and Y. Suzuki 1961. Blood groups and the taxonomic status of American buffalo and domestic cattle. Evol, 15:196-208, June 1. Swenk, M. H. 1908. A preliminary review of the mammals of Nebraska, with synopses. Proc. Nebraska Acad. Sci., 8(3):61-144, September (issued con- currently as Studies Zool. Lab., Univ. Nebraska, 89:1-88). 1915a. The prairie dog and its control. Bull. Agric. Exp. Sta., Univ. Ne- braska, 28(2):l-38, 3 figs., August 15. 1915&. On a new subspecies of flying squirrel from Nebraska. Univ. Ne- braska Studies, 15:151-154, 1 pi., September 25. 1915c. The birds and mammals of Nebraska. Nebraska Blue Book . . ., pp. 835-855. 1916. On a new subspecies of porcupine from Nebraska. Univ. Nebraska Studies, 16:115-125, 3 pis., November 21. 1918. The birds and mammals of Nebraska. Nebraska Blue Book . . ., pp. 392-411, December. 1919. The birds and mammals of Nebraska. Contrib. Dept. Ent., Univ. Nebraska, 23:1-21, March 1. 1920c. On a new subspecies of otter from Nebraska. Univ. Nebraska Studies, 18:1-6, 1 pi., May 15. 1920&. The birds and mammals of Nebraska. Nebraska Blue Book . . ., pp. 464-483, December. 1926. Notes on Mustek campestris Jackson, and on the American forms of least weasels. Jour. Mamm., 7:313-330, 1 fig., November 23. 1938. Distribution of Marmota monax in the Missouri Valley region. Jour. Mamm., 19:348-353, 1 fig., August 18. Mammals of Nebraska 355 1939. A study of local size variations in the prairie pocket-gopher (Geomys bursarius), with description of a new subspecies from Nebraska. Missouri Valley Fauna, 1:1-8, December 5. 1940a. A study of subspecific variation in the yellow pocket-gopher ( Geo- mys lutescens) in Nebraska, and the geographical and ecological distribution of the varients. Missouri Valley Fauna, 2:1-12, Feb- ruary 1. 1940&. A study of the geographical and ecological distribution of the buffy plains pocket-mouse (Perognathus flavescens flavescens), with de- scription of a new subspecies from Nebraska. Missouri Valley Fauna, 3:1-8, June 5. 1941. A study of subspecific variation in the Richardson pocket-gopher (Thomomys talpoides) in Nebraska, with descriptions of two new subspecies. Missouri Valley Fauna, 4:1-8, March 1. MS. An untitled collection of notes concerning Nebraskan mammals. Currently on file in Museum of Natural History, The University of Kansas. Taylor, W. E. 1888. Local variations in the colors of a few Nebraska flying squirrels. Amer. Nat., 22:744-745, August. Thwaites, R. G. 1905. Original journals of the Lewis and Clark expedition, 1804-1806. Dodd, Meade and Co., New York, 6:ix + 1-280. TOLSTEAD, W. L. 1942. Vegetation of the northern part of Cherry County, Nebraska. Ecol. Monog., 12:255-292, 35 figs., July. Tryon, C. A., Jr. 1947. The biology of the pocket gopher (Thomomys talpoides) in Mon- tana. Tech. Bull. Agric. Exp. Sta., Montana State Coll., 448:1-30, 13 figs., December. Vance, L. P., and others 1958. Annual report, Game Division, Nebraska Game, Forestation and Parks Comm., Lincoln, 52 pp., processed. Van den Brink, F. H. 1953. La musaraigne masquee, espece circum-boreale. Mammalia, 17: 96-125, 3 figs., 1 map, June. Van Gelder, R. G. 1959. A taxonomic revision of the spotted skunks (genus Spilogale). Bull. Amer. Mus. Nat. Hist., 117:229-392, 47 figs., June 15. Velich, R. 1947. Gray eastern chipmunk in Nebraska. Jour. Mamm., 28:185-186, May 19. 1954. Notes on mammals from eastern Nebraska. Jour. Mamm., 35:429- 430, August 20. 1956. Mammals from eastern Nebraska. Jour. Mamm., 37:271-272, June 9. 1958. Notes on mammals from eastern Nebraska. Jour. Mamm., 39:147- 148, February 20. 1961. Notes on mammals from Nebraska and southwestern Iowa. Jour. Mamm., 42:92-94, February 20. Wade, O. 1927a. Breeding habits and early fife of the thirteen-striped ground squir- rel, Citellus tridecemlineatus (Mitchell). Jour. Mamm., 8:269-276, pi. 23, November 11. 1927&. Food habits of a pocket gopher. Jour. Mamm., 8:310-311, No- vember 11. 1(& 356 University of Kansas Publs., Mus. Nat. Hist. 1948. Rapid fat production by ground squirrels preceding hibernation. Nat. Hist. Misc., Chicago Acad. Sci., 28:1-3, October 12. Wade, O., and P. T. Gilbert 1940. The baculum of some Sciuridae and its significance in determining relationships. Jour. Mamm., 21:52-63, 3 figs., February 14. Warren, E. R. 1942. The mammals of Colorado, their habits and distribution. Univ. Oklahoma Press, Norman, xviii + 330 pp., frontispiece, 50 pis., after June 15. Weaver, J. E. 1954. North American prairie. Johnson Publ. Co., Lincoln, Nebraska, xi + 348 pp., 87 figs. Weaver, J. E., and F. W. Albertson 1956. Grasslands of the Great Plains. . . . Johnson Publ. Co., Lin- coln, Nebraska, ix + 895 pp., 93 figs. Weaver, J. E., and W. E. Bruner 1954. Nature and place of transition from true prairie to mixed prairie. Ecology, 35:117-126, 2 figs., April. Weaver, J. E., and F. E. Clements 1938. Plant ecology. McGraw-Hill Book Co., Inc., New York and Lon- don, xxii + 601 pp., colored frontispiece, 271 figs. Webb, O. L., and J. K. Jones, Jr. 1952. An annotated checklist of Nebraskan bats. Univ. Kansas Publ., Mus. Nat. Hist., 5:269-279, May 31. Wetzel, R. M. 1955. Speciation and dispersal of the southern bog lemming, Synaptomys cooperi (Baird). Jour. Mamm., 36:1-20, 5 figs., February 28. Whelan, D. B. 1937. Some mammals of an eastern Nebraska prairie. Trans. Kansas Acad. Sci., 39(for 1936) : 365-366. White, J. A. 1953. Geographic distribution and taxonomy of the chipmunks of Wyo- ming. Univ. Kansas Publ., Mus. Nat. Hist., 5:583-610, 3 figs., December 1. Winter, J. M. 1936. An analysis of the flowering plants of Nebraska. . . . Bull. Conserv. Surv. Div., Univ. Nebraska, 13 :iii + 1-203, April. Wolcott, R. H. 1906. Biological conditions in Nebraska. Proc. Nebraska Acad. Sci., 8(2) : 23-34, December 5. 1909. An analysis of Nebraska's bird fauna. Proc. Nebraska Ornith. Union, 4(2) : 25-55, 6 pis., August 25. Young, S. P. 1946. History, life habits, economic status, and control, pp. 1-173, pis. 2-45, figs. 1-5, in Young and Goldman, The puma, mysterious American cat. Amer. Wildlife Inst., Washington, D. C, xiv + 358 pp., 93 pis., 6 figs., November 16. 1951. Its history, life habits, economic status and control, pp. 1-226, pis. 2-57, figs. 1-19, in Young and Jackson, The clever coyote. The Stackpole Co., Harrisburg, and The Wildlife Mgt. Inst., Washing- ton, D. C, xv + 411 pp., 81 pis., 28 figs., November 29. 1958. The bobcat of North America. . . . The Stackpole Co., Harris- burg, and The Wildlife Mgt. Inst., Washington, D. C, 193 pp., 29 pis., numerous illustrations in text. Transmitted January 2, 1963. □ 29-6532 University of Kansas Publications Museum of Natural History Volume 16, No. 2, pp. 357-407 February 12, 1965 Synopsis of the Lagomorphs and Rodents of Korea BY J. KNOX JONES, JR., AND DAVID H. JOHNSON University of Kansas Lawrence 1965 £- fs/A - JL l^^ctj University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 16, No. 2, pp. 357-407 Published February 12, 1965 MUS. CON*. . - OOL LIBRARY DEC o 1 HARVARD UNIVERSITY University of Kansas Lawrence, Kansas PRINTED BY HARRY (BUD) TIMBERLAKE. STATE PRINTER TOPEKA. KANSAS 1965 30-3967 Synopsis of the Lagomorphs and Rodents of Korea BY J. KNOX JONES, JR., AND DAVID H. JOHNSON CONTENTS PAGE Introduction 359 Order Lagomorpha 361 Family Ochotonidae 361 Family Leporidae 362 Order Rodentia 364 Family Sciuridae 364 Family Cricetidae 370 Family Muridae 379 Some Zoogeographic CoNsroERATioNS 398 Gazetteer 401 Literature Cited 404 INTRODUCTION The lagomorphs and rodents of Korea have never before been reviewed systematically. Aside from descriptions of new taxa, most of the accounts in the literature concerning Korea deal with small collections from widely scattered localities (see, for example, Allen and Andrews, 1913, Kuroda, 1917 and 1934, Mori, 1938 and 1939, Thomas, 1907a and 1907b, and Won and Woo, 1956 and 1959) or are compilations of a general nature, such as those of Kuroda ( 1938 and 1940), Tokuda (1941), Won and Woo (1958b), and Won ( 1961 ) , some annotated, of the known elements of the fauna. The present paper is an outgrowth of studies relating to hemor- rhagic fever that were initiated by the U. S. Army in the early 1950's. In this connection, we undertook a systematic appraisal of Korean mammals, some results of which have been published previously (Johnson and Jones, 1955a and 1955b, Jones and John- son, 1955, 1956, and 1960, Jones, 1956 and 1959). Herein is set forth a systematic review of the three species of lagomorphs and 16 species of rodents presently known to occur in Korea, based prin- cipally on specimens acquired through the auspices of the Field Unit of the Commission on Hemorrhagic Fever, Armed Forces Epidemiological Board, with which one of us (Jones) was associ- ated in 1954 and 1955. The majority of the specimens available to us for study (a total (359) 360 University of Kansas Publs., Mus. Nat. Hist. of 1471) originated from the central and southern parts of the Korean Peninsula. We have been able to examine only limited materials from northern Korea and the adjacent parts of Manchuria and Siberia, and the present treatment must be regarded, therefore, as provisional. Most of the specimens examined are housed in the United States National Museum (USNM). Some are in the Museum of Natural History of The University of Kansas ( KU ) and still others are scattered among institutions in North America and the Old World as follows: American Museum of Natural History (AMNH); British Museum (Natural History) (BM); Carnegie Museum ( CM ) ; Museum of Comparative Zoology, Harvard ( MCZ ) ; Museum of Vertebrate Zoology, University of California (MVZ); Museum of Zoology, University of Michigan (UMMZ), including the collections formerly in the Cleveland Museum of Natural His- tory (CMNH); National Science Museum of Japan (NSMJ); Sung Kung Kwang University, Seoul, Korea (SKKU); and Yama- shina Institute for Ornithology and Zoology, Tokyo (YI). We are indebted to the persons in charge of these several collections for allowing us to study at the institution concerned or for the loan of specimens. In addition to specimens examined, reference is made in many accounts under "additional records" to any locality mentioned in the literature from which we did not examine speci- mens. It is a pleasure to note here the surge of activity among Korean biologists, especially in natural history, since the end of the Korean War. In this regard, the contributions of P. O. Won and H. C. Woo (Won, 1961, Won and Woo, 1956, 1961, and elsewhere), some of which are in English and others of which have English summaries, are especially noteworthy. The training of these two investigators, however, apparently has been in forestry and ecology rather than in taxonomy as evidenced not only in their publications but also in our personal conversations with Won. Inasmuch as the contri- butions of Won and Woo and their colleagues necessarily have been made in the absence of adequate comparative materials and litera- ture, we have relied upon their identifications only to the level of species. Actually, correct identification of faunal elements to the species level is all that is needed with reference to the studies in forestry now underway in Korea and it would seem appropriate for investigators there who are not familiar with procedures in sys- tematic zoology to avoid the use of subspecific names. Although this paper is a contribution from the Museum of Natural History of The University of Kansas and from the United States Lagomorphs and Rodents of Korea 361 National Museum, much of the work was sponsored by the Walter Reed Army Institute of Research. We are especially indebted to Henry S. Fuller of the mentioned Institute for his continued interest in our studies. We are grateful also to Nagamichi Kuroda, the late Tamezo Mori, and P. O. Won for their helpfulness in locating cer- tain place-names in Korea and to Yoshinori Imaizumi for transla- tions of papers in Japanese, and other courtesies. All measurements in the accounts that follow are in millimeters. When known, the altitude at which specimens were obtained is recorded, either in feet (ft.) or meters (m.), depending on which was used on the specimen labels. ORDER LAGOMORPHA Three species of lagomorphs, two hares and a pika, are indige- nous to Korea. Additionally, a feral population of the European rabbit, Oryctolagus cuniculus, may now exist (or may have existed for a time following cessation of hostilities) in the vicinity of Seoul. An adult male of this species (USNM 299505), in wild-type pelage, was captured on a military compound six miles east of Seoul in February, 1953, and was kept there until October 4, 1954. While a captive it mated successfully at least twice with domesticated fe- males of O. cuniculus in a laboratory colony. Family Ochotonidae — Pikas Ochotona hyperborea coreana Allen and Andrews Northern Pika Ochotona (Pika) coreanus Allen and Andrews, Bull. Amer. Mus. Nat. Hist., 32:429, September 2, 1913. Type locality: Pochong, 3000 ft., Korea. Ochotona hyperborea coreana, Kuroda, A list of the Japanese mammals, p. 42, June 20, 1938. Distribution in Korea. — Mountainous areas in extreme northeastern part, south at least to Ch'ail-bong. Measurements. — External measurements of the holotype, an adult female, and an adult male topotype are, respectively: Length of head and body, 204, 195; length of hind foot, 30, 33; length of ear from notch (dry), 14.4, 16.7. Cranial measurements of the holotype (followed in parentheses by those avail- able for the male) are: Occipitonasal length, 42.9; basal length, 36.6; zygo- matic breadth, 22.1 (22.0); breadth across auditory bullae, 21.0 (20.7); in- terorbital breadth, 5.1; depth of braincase, 11.2; length of nasals, 13.6; length of incisive foramina, 6.7; length of molariform tooth-row, 8.4. Remarks. — In the original description Allen and Andrews wrote of this animal as follows: "This species lives at a low altitude (about 3000 feet) for a pika, and not in rock piles as is so frequently the case. It was seen only at Pochong, where the three specimens were 362 University of Kansas Publs., Mus. Nat. Hist. taken." Mori (1939:4) recorded seeing a pika at Ch'ail-bong in (translated from Japanese) "a rocky region of the alpine zone." Rumors of the occurrence of pikas in mountainous areas in cen- tral Korea remain to be verified. Records of occurrence. — Specimens examined, 3, all from the type locality (AMNH 34049-51, including the holotype). Additional records: Ch'ail-bong (Mori, 1939:4); Yonam-dong (Kishida and Mori, 1930:49); Paektu-san (Won, 1961:43). Family Leporidae — Hares and Rabbits Lepus coreanus Thomas Korean Hare Lepus sinensis coreanus Thomas, Ann. Mag. Nat. Hist., ser. 6, 9:146, Feb- ruary, 1892. Type locality: Seoul, Korea. Lepus coreanus, Thomas, Proc. Zool. Soc. London, 1906:865, April 11, 1907. Distribution in Korea. — Probably entire peninsula in suitable habitats. Measurements. — External measurements of an adult male and adult female from the vicinity of Seoul are, respectively: Total length, 475, 490; length of tail-vertebrae, 60, 75; length of hind foot, 122, 118; length of ear from notch, 79, 73. External measurements of an adult male and adult female from Mokp'o are, respectively: Length of head and body, 425, 448; length of tail, 50, 51; length of hind foot, 108, 115; length of ear from notch, 76, 79. For cranial measurements see Table 1. Remarks. — Lepus coreanus was originally described by Thomas as a subspecies of Lepus sinensis, although at the time he remarked that it might be necessary, upon the acquisition of additional ma- terial, to elevate it to full specific rank. This he did in his next mention of Korean specimens (1907a: 865). Subsequently, Eller- man and Morrison-Scott (1951:442) again relegated coreanus to subspecific status under L. sinensis. We prefer for the present to retain L. coreanus as a distinct species, although we recognize its close relationship to sinensis. L. coreanus differs from L. sinensis (subspecies sinensis and for- mosus) as follows: Larger; pelage considerably heavier and more blackish dorsally; tail markedly longer; nasals broader in relation to length, much less attenuated anteriorly, rarely exceeding pre- maxillae anteriorly; auditory bullae slightly smaller; external auditory meatuses conspicuously larger, meatal tubes directed more upward and outward; anterior extension of basisphenoid much broader; mandible larger and heavier; teeth, especially incisors, larger. The two species resemble each other in the general size and configura- tion of the skull. Lepus coreanus and L. sinensis, as now known, are allopatric, sinesis having been recorded in China only as far north as the prov- inces of Anhwei and Kiangsu (G. M. Allen, 1938:560). Lagomorphs and Rodents of Korea 363 Table 1. — Cranial Measurements of Three Species of Lepus a en CQ o3 »»* Catalogue 00 c3 «5 eadth aci auditory meatuse 0) C b o number ££ ,d -tj-a "8.3 *s.^*a OSJ and sex cipitc leng bJO CO ^ 2 =3 a £ ^a oo CO ngth inch fora ngth max toot . « ej >> u > .2 .13 C 5 o o-2 -5 v. mi a ►3 ,-h c3 03 CD — <- O tf « a 03 h5 . — eg CO Oc3 a," o Q "5 « 2 03 Central Korea Average 6 (3d", 39) Minimum Maximum USNM 299227, USNM 305964, 39.6 20.9 5.8 14.1 8.1 7.9 14.4 38.3 20.0 5.5 13.4 7.7 7.2 13.9 41.9 22.5 5.9 14.8 8.5 8.7 14.8 Vicinity Mosulp'o, Cb eju Do Korea 9* 40.3 37.2 19.5 18.9 5.4 5.3 15.4 13.1 7.5 7.6 7.0 6.9 14.5 13.3 5.7 5.5 6.0 5.9 5.9 150 mi. up Yalu River, Korea USNM USNM 199624, 199625, 9 9* 40.8 36.7 22.3 19.4 5.3 5.4 14.5 13.0 8.0 7.6 7 6 1 6 14 13 5 4 5 5 5 5 • Young adult. We follow Kuroda (1934:231-232 and elsewhere) in regarding Asiocricetus bampensis and A. yamashinai, both named by Kishida (1929) from Manp'o, Korea, as synonyms of C. t. nestor. Speci- mens from northern Korea (Manp'o, Nongsa-dong, Yalu River) average smaller in some measurements than specimens of nestor from central Korea and approach C. t. triton in this regard. Future taxonomic consideration of long-tailed hamsters from northern Korea and adjacent regions must take into account the first of Kishida's names (bampensis) as well as Tschershia albipes Ognev, 1914 (type locality, bank of River Tumen-Lau, southern Primorsk, Siberia), which, like bampensis, is currently regarded as a synonym of C. t. nestor (see Ellerman and Morrison-Scott, 1951:626). Dry hillsides covered with grass or scrub seemingly provide the preferred habitat of this hamster in central Korea. Specimens were obtained also in agricultural areas and occasionally in grassy low- lands; Won (1961:46) recorded the species as occurring also in forested areas. Loukashkin (1944:173) reported that C. triton breeds in spring in Manchuria and that females have 4 to 6 young per litter. We obtained pregnant or lactating females in central Korea in late June and in August, and juveniles in October. Records of occurrence. — Specimens examined, 82, as follows: Chip'o-ri, 1 (USNM 294633); 3 mi. NW Chip'o-ri, 145 m., 1 (KU 60434); 48 mi. W Chip'o-ri, 155 m., 1 (USNM 299088); Ch'ongyang-ni, 1 (USNM 298060); Ch'onsong-ni, 2 (USNM 294634, 298061); 5 mi. S Ch'orwon, 1 (USNM 372 University of Kansas Publs., Mus. Nat. Hist. 299089); Hant'anch'on Valley, approximately 7 mi. ESE Yonch'on, 2 (UMMZ 102517-18); Kumhwa, 20 (BM 7.6.3.50-52, including the hole-type; CM— 1 specimen; USNM 294635-43, 298050-54; YI 117-118); Manp'o, 10-50 ft, 10 (YI 60, 63, 69, 70, 73, 75, 78, 79, 82, 83); Mosulp'o, Cheju Do, 1 (USNM 305964); 1 mi. N Mosulp'o, 10 m., Cheju Do, 1 (USNM 299277); 7 mi. SSE Munsan-ni, 1 (USNM 302912); Nongsa-dong, 6 (AMNH 34044-46, 34073- 75); Ori-dong, 5 (USNM 298055-57, 299601; UMMZ 99588); 6 mi. E Seoul, 45 m., 11 (KU 60436, 63836-38; USNM 298948, 299092-94, 299508, 299602, 300648}; 2 mi. E Songdong-ni, 95 m., 2 (USNM 299090-91; Songu-ri, 1 (USNM 298062); Taehoesan-ni, 180 m.. 1 (KU 60435); Yangwon-ni, 1 (USNM 301244); 150 mi. up Yalu River, 7 (USNM 199624-30); Yongp'yong, 1 (USNM 301245); Yonch'on, 3 (USNM 298058-59, 301246); central Korea, 2 (USNM 301919-20). Additional records: Anju (Kuroda, 1940:115); Seoul, (Tokuda, 1941:37); Toktun-ni (Lawrence and Harriss, MS). Clethrionomys rufocanus Eurasian Red-backed Vole This red-backed vole is fairly common in central Korea, where individuals are trapped most frequently on scrub-covered hillsides, on talus slopes, and in forested areas. Near Oho-ri, however, it was obtained along paddy dikes within several hundred feet of the Sea of Japan, and individuals occasionally were taken in abandoned paddy fields and other lowland habitats elsewhere in central Korea. The species usually was associated with Apodemus peninsulae peninsulae. The breeding season extends from late March to October. Fe- males may give birth to several litters per year and have 3 to 6 young per litter. In northern Korea, C. rufocanus is sympatric with another species of red-backed vole, C. rutilus. The two kinds resemble each other externally, but in winter pelage rutilus is brighter rufous on the head and back, thus having a sharper contrast between back and the grayish ochraceous sides, is less grayish ventrally, and has a more pilose and more strikingly bicolored tail. They are readily dis- tinguished by cranial characters in that C. rutilus has a narrower skull than C. rufocanus, smaller auditory bullae, smaller teeth, and distinctly shorter molariform tooth-rows ( less than 5.5 mm. in rutilus, more than 6.0 in rufocanus). Also, adults of rutilus have rooted cheek-teeth, whereas those of rufocanus do not (see Jameson, 1961). Clethrionomys rufocanus arsenjevi (Dukelski) Evotomys (Craseomys) arsenjevi Dukelski, Zool. Anzeiger, 77:40, May 15, 1928. Type locality: Stekljannaja Padj, 75 versts [= approximately 50 mi.] NE Vladivostok, Siberia. Clethrionomys rufocanus arsenjevi, Goodwin, Amer. Mus. Novit., 681:12, December 30, 1933. Lagomorphs and Rodents of Korea 373 Distribution in Korea. — Known only from extreme northeastern part. Measurements. — Average and extreme external measurements of four adults, one male and three females, from extreme northeastern Korea, are: Total length, 153.2 (151-155); length of tail-vertebrae, 36.0 (34-39); length of hind foot, 19.7 ( 19-20). For cranial measurements see Table 3. Remarks. — For comparison with Clethrionomys rufocanus regulus, geographically adjacent to the south, see account of that subspecies. We tentatively refer specimens from northeastern Korea to C. r. arsenjevi. We have seen no topotypes of arsenjevi but our material seems to fit the description of that subspecies and the type locality is not far distant from the localities whence our specimens from northeastern Korea originated. Ognev (1950:105) regarded arsen- jevi as a synonym of C. r. irkutensis, Kuznetzov (in Bobrinsky et al., 1944:346) regarded it as a synonym of C. r. bedfordiae of the island of Hokkaido, Japan, and Ellerman and Morrison-Scott (1951:666) erroneously listed both arsenjevi and bedfordiae as synonyms of "Clethrionomys rufocanus smithii" (Jameson, 1961). Korean speci- mens examined differ from C. r. bedfordiae from Hokkaido in hav- Tajble 3. — Cranial Measurements of Two Species of Clethrionomys ^ o 03 u 05 s A 03 Fi +3 o Catalogue t-. o o number « ri S- i>s , , «<-! >1 and sex cipitonat length ndyloba length latal length a £ o S eadth ac auditor 03rC o £ CB-0 ngth of nasals ngth of incisive OB ■B S c w o o3 >> ■~ a 03 a a O O CS3 pq 1-J hJ ►J Clethrionomys rufocanus arsenjevi, Potai-dong, Korea USNM 197977, a" AMNH 34009, o* USNM 197976, 9 26.8 26.2 13.8 15.2 12.8 3.9 7.6 5.4 25.6 25.3 13.3 14.3 12.6 3.8 7.6 5.1 25.6 25.5 13.2 14.4 12.2 3.7 7.6 5.1 Clethrionomys rufocanus regulus, central Korea USNM 294649, & USNM 298064, d" USNM 298065, d" USNM 298068, 9 USNM 300646, 9 USNM 199639, 9 USNM 199642, 9 USNM 199665, 9 27.3 27.2 14.2 15.5 12.8 4.6 8.1 5.6 26.4 25.9 13.2 15.0 12.5 4.3 7.7 5.2 27.2 27.0 13.9 15.8 13.2 4.5 8.2 5.6 25.6 25.3 13.3 14.8 12.3 4.2 7.4 5.4 26.3 26.2 13.6 14.9 12.8 4.5 7.8 5.2 120-150 mi. up Yalu River, Korea 25.6 25.4 13.4 14.9 12.6 4.2 7.6 5.2 25.9 25.6 13.6 15.3 12.9 4.2 8.0 5.1 25.8 25.4 13.5 14.7 12.6 4.1 8.0 5.5 6.6 6.5 6.7 6.5 6.4 6.2 6.1 6.3 6.3 6.2 6.3 Clethriom AMNH 34027, & AMNH 34034, 9 rmys ru 26.2 24.6 tilus hh 25.2 24.4 itoni, v 13.0 12.8 cinity '. 14.1 13.8 \'ongsa- 12.4 12.0 dong, 4.0 4.1 Korea 8.0 7.3 5.6 5.3 5.4 5.2 2-^3967 374 University of Kansas Publs., Mus. Nat. Hist. ing slightly more reddish upper parts, a much shorter tail, a smaller and less massive skull, relatively broader and more bowed zygo- matic arches, and longer incisive foramina. The type locality of C. r. arsenjevi is listed in the original descrip- tion as "Stekljannaja Pad], 75 Werst nordostl. von Wladiwostok, Ussuri-Gebiet." On another page of the same paper, Stekljannaja Padj is listed as the type locality of "Mus (Alsomys) major rufulus" but is there located as "75 Werst sudostlich von Wladiwostok." We have been unable to locate Stekljannaja Padj on any maps available to us. Records of occurrence. — Specimens examined, 24, as follows: Nongsa-dong, 1 (AMNH 34029); 13K mi. SW Nongsa-dong, 7 (AMNH 34023, 34030, 34035, 34038-40; BM 13.5.27.55); 18 mi. SW Nongsa-dong, 1 (AMNH 34036); 43 mi. SW Nongsa-dong, 1 (AMNH 34037); Pochong, 4 (AMNH 34016-18; BM 13.5.27.56); Potai-dong, 9 (AMNH 34007, 34009, 34011, 34015; BM 13.5.27.53-54; MCZ 15792; USNM 197976-77); Tumen River, Korean-Man- churian border, 2500 ft, 1 (BM 1938.8.8.16). Additional record: Kwanmo-bong, 2000 m. (Tokuda, 1941:134). Clethrionomys rufocanus regulus (Thomas) Craseomys regulus Thomas, Proc. Zool. Soc. London, 1906:863, April 11, 1907. Type locality: Min-gyong [= Mun'gyong], 110 mi. SE Seoul, 1000 ft., Korea. Clethrionomys rufocanus regulus, Howell, Proc. U. S. Nat. Mus., 75:51, June 7, 1929. Distribution in Korea. — Entire peninsula except extreme northeastern part. Measurements. — Average and extreme external measurements of 10 adults (four males, six females) from central Korea are: Total length, 154.5 (150- 161); length of tail-vertebrae, 46.6 (42-51); length of hind foot, 19.3 (18- 20.5); length of ear from notch, 14.3 (13-15). For cranial measurements see Table 3. Four adult males and three non-pregnant females from west-central Korea weighed 36.4, 29.0, 26.6, 22.8, 38.5, 30.7, and 23.0 grams, respectively. Remarks. — From specimens provisionally referred to Clethriono- mys rufocanus arsenjevi from northeastern Korea, C. r. regulus dif- fers as follows: Upper parts, in comparable pelages, conspicuously brighter; underparts more buffy (less grayish); tail noticeably longer; skull averaging larger; rostrum and interorbital region much broader; molariform tooth-rows shorter; auditory bullae larger. The geographic range of C r. regulus evidently extends into south- western Manchuria and Jehol (Kuroda, 1939:21). Records of occurrence. — Specimens examined, 83, as follows: Central Na- tional Forest, near Pup'yong-ni, 3 (UMMZ 99593; USNM 298068, 300646); Changjon, 300 ft, 2 (YI); Chip'o-ri, 4 (USNM 294644-47); near Ch'ongju, 800 ft, 8 (BM 7.6.3.53-60); Ch'onsong-ni, 2 (USNM 298065-66); 3 mi. SE Ch'orwon, 1 (KU 67231); Hant'an-chon Valley, approximately 7 mi. ESE Yonch'on, 2 (UMMZ 102519-20); Kaloguai, 55 mi. NE Seoul, 500 ft, 1 (BM 7.6.3.62); Kumhwa, 6 (BM 7.6.3.61; USNM 294648-50, 298063-64); Mun'gyong, 110 mi. SE Seoul, 1000-1300 ft, 19 (BM 6.12.6.89-106, including the holotype; MVZ 30373); Oho-ri, 50 ft, 1 (UMMZ 102433); 1 mi. N Oho-ri, Lagomorphs and Rodents of Korea 375 1-2 m., 2 (USNM 298952, 298956); 1 mi. NW Oho-ri, 6 m., 3 (KU 60438-39; USNM 298953); Ori-dong, 1 (USNM 298067); near Pammol, 1 (USNM 301251); near Pusan, 1 (USNM 301535); 30 mi. N Pusan, 1 (USNM 298069); 5 mi. E Seoul, 1 (USNM 302914); 3 mi. SSE Sumil-li, 1468 m., 3 (USNM 299095, 301249-50); 10 mi. N Taegu, 1200 ft, 4 (BM 6.12.6.107-110); Taegwang-ni, 300 ft., 1 (USNM 298949); 1 mi. W Tangjonggok, 425 m., 2 (USNM 298954-55); Tongp'yonch'on, 1 (USNM 301248); 120 mi. up the Yalu River, 1 (USNM 199665); 150 mi. up the Yalu River, 5 (USNM 199638- 42); 3 mi. SW Yanggu, 450 m., 2 (USNM 298950-51); 4 mi. NE Yanggu, 1 (NSMJ); Yonch'on, 1 (NSMJ); Yonggwang, 800 ft., 2 (YI); central Korea, 1 (USNM 301247). Additional records (Jones, MS, unless otherwise noted): Anju (Kuroda, 1938:58); Ch'angch'on (Won, 1961:45); 3 mi. SW Chigyong-dong; vicinity Chinmokchong; Chiri-san (Won, 1961:45): Ch'orwon; Ch'unch'on; Kumgang- san (Tokuda, 1941:134); Nap'a-dong, 175 m.; Seoul (Tokuda, 1941:134); Soch'on-ni; Sorak-san (Won, 1961:45); Taehoesan-ni; 2 mi. S Tongduch'on-ni; Tongp'yongch'on; Wach'o-ri; 15 mi. NW Wonju (Jameson and Toshioka, 1954: 12); Yami-ri; Yongp'yong, 110 m. See also the map published by Won and Woo (1958c:5) that purports to show localities whence C. rufocanus has been reported from Korea. On that map the species is indicated as occurring at several localities that are not substantiated in any other published source, in- cluding Won's (1961:45) own subsequent list. Clethrionomys rutilus hintoni Vinogradov Northern Red-backed Vole Clethrionomys rutilus hintoni Vinogradov, in Zolotarev, Mammals of the Iman River Basin, p. 81, 1936. Type locality: Iman River, Ussuri Region, southeastern Siberia. Distribution in Korea. — Mountainous areas of northeastern part, south at least to Ch'ail-bong. Measurements. — Average and extreme external measurements of four adults (two males, two females) from the vicinity of Nongsa-dong are: Total length, 148.2 (142-162); length of tail-vertebrae, 32.5 (31-34); length of hind foot, 19.2 ( 18-20). For cranial measurements see Table 3. Remarks. — The Korean specimens of C. rutilus examined are only provisionally referred to the subspecies hintoni (type from the Iman River, southeastern Siberia), because we have been unable to study typical material. The Korean specimens at hand seem to fit the diagnosis of hintoni (as given by Kuznetzov, in Bobrinsky et al., 1944:345), and the type locality is near northeastern Korea. Ognev (1950:141) regarded hintoni as a synonym of C. r. amurensis (type from mouth of the Amur River, near Nikolaevsk, eastern Siberia). C. r. hintoni apparently is confined in Korea to the high moun- tainous areas of the northeastern part of the peninsula. The speci- men reported by Mori (1939:3) from Mt. Shazitsuho [= Ch'ail- bong] has a slightly longer tail (40 mm.) than do the specimens from farther to the north. As previously pointed out (Jones and Johnson, 1956), Allen and Andrews (1913:430) listed specimens of C. rutilus and C. rufocanus from northeastern Korea together under the name "Craseomys 376 University of Kansas Publs., Mus. Nat. Hist. regulus." We have examined 35 of the 37 specimens originally re- ported by them and among these find 23 that are referable to C. rufocanus arsenjevi and 12 that are referable to C. rutilus kintoni. Allen and Andrews (op. cit.ASl) wrote of red -backed voles in the vicinity of Nongsa-dong as follows: "A large series was . . . trapped some little distance within the edge of the forest. . . . They were caught about old logs and tree stumps and often near the banks of small streams." These statements may apply equally well to either rutilus or rufocanus, as both species were obtained from all save one of the localities visited by Andrews in the vicinity of Nongsa-dong. Records of occurrence. — Specimens examined, 12, as follows: 13/2 mi. SW Nongsa-dong, 7 (AMNH 34024, 34031-32, 34034, 34041, 34043; MCZ 15293); 18 mi. SW Nongsa-dong, 3 (AMNH 34025, 34027, 34042); 43 mi. SW Nongsa- dong, 2 (AMNH 34022, 34026). Additional records: Ch'ail-bong (Mori, 1939:3); Kwanmo-bong, 2000 m. (Tokuda, 1941:131). Microtus fortis Reed Vole The reed vole was obtained in the central part of the Korean Peninsula for the first time in 1952. Individuals were trapped in lowland habitats, principally along the banks of streams and in abandoned paddies, in areas deserted by civilians at the onset of combat activities in 1950. Evidently the species does not long sur- vive in areas where it is in direct competition with man because, insofar as we are aware, it does not occur in lowland habitats ma- terially altered for agricultural purposes. Under conditions of in- tensive cultivation the species may exist, in central Korea at least, only in small, more or less isolated colonies, which possibly accounts for the fact that prior to 1952 it was known only from the extreme northeastern part of the country. The breeding season extends from late March to mid-November. Many females give birth to several litters annually and have 3 to 7 young per litter. Microtus fortis pelliceus Thomas Microtus pelliceus Thomas, Ann. Mag. Nat. Hist., ser. 8, 7:383, April, 1911. Type locality: Ussuri River, southeastern Siberia. M[icrotus]. f[ortis], pelliceus, G. M. Allen, The mammals of China and Mongolia, 2:860, September 3, 1940. Distribution in Korea. — Known only from two localities in extreme north- eastern part. Measurements. — External measurements of an adult male from Manp'o are: Length of head and body, 140; length of tail, 60; length of hind foot (without claw), 24; length of ear from notch, 14.5. External and cranial measurements Lagomorphs and Rodents of Korea 377 of an adult male and an adult female from the Sungari River, 60 mi. SW Kirin, Manchuria, are, respectively: Length of head and body, 147, 132; length of tail, 60, 53; length of hind foot (without claw), 23, 23; length of ear from notch, 15, 14; condylobasal length, 32.2, 31.9; occipitonasal length, 30.9, 31.3; palatal length, 19.1, 18.9; zygomatic breadth, 17.9, 17.6; breadth across audi- tory bullae, 14.8, 14.5; interorbital breadth, 4.2, 4.1; length of nasals, 8.7, 8.7; length of incisive foramina, 6.0, 6.4; length of maxillary tooth-row, 7.8, 8.3. Remarks. — From Microtus fortis uliginosus of central Korea, M . f. pelliceus differs in: Upper parts, in general, less suffused with ochraceous and having a slightly darker and less olivaceous ap- pearance; winter pelage longer and denser; underparts slightly darker and lacking faint buffy tinge; upper surfaces of hind feet wholly dark rather than paler on inner margins; tail averaging darker vertrally; skull smaller (especially in condylobasal, occipito- nasal, and palatal lengths, and in zygomatic and interorbital breadths) and less massive; nasals less expanded anteriorly; infra- orbital canals broader when viewed from the front; auditory bullae and cheek-teeth smaller. Records of occurrence. — Specimens examined, 9, as follows: Manp'o, 9 (YI). Additional record: Ranto (island), off Unggi (Kuroda, 1934:231). Microtus fortis uliginosus Jones and Johnson Microtus fortis uliginosus Jones and Johnson, Proc. Biol. Soc. Washington, 68:193, December 31, 1955. Type locality: Chip'o-ri (38°08' N, 127° 19' E), Korea. Distribution in Korea. — Known presently only from a restricted area in central Korea bounded by Kumhwa and Ch'orwon on the north and the 38th parallel of latitude on the south. Measurements. — Average and extreme external and cranial measurements of five adult males, followed by those of five adult females (including the holotype), are, respectively: Total length, 207.8 (193-223), 207.0 (197-215); length of tail-vertebrae, 64.2 (57-70), 58.6 (55-62); length of hind foot, 24.4 (23-26), 24.2 (21-27); length of ear from notch, 16.4 (15-18), 15.4 (14-17); condylobasal length, 34.4 (33.9-35.0), 33.3 (32.8-34.0); occipitonasal length, 33.1 (32.2-33.6), 32.6 (32.4-33.2); palatal length, 19.9 (19.5-20.2), 19.6 (19.2- 20.2); zygomatic breadth, 18.7 (18.4-19.2), 18.7 (18.3-19.7); breadth across auditory bullae, 15.1 (14.6-15.4), 14.9 (14.5-15.6); interorbital breadth, 4.5 (4.3-4.7), 4.4 (4.4-4.5); length of nasals, 9.1 (8.5-9.6), 9.1 (8.7-9.5); length of incisive foramina, 6.3 (5.9-6.5), 6.0 (5.7-6.3); length of maxillary tooth-row, 8.4 (8.1-8.7), 8.3 (7.9-9.0). An adult male from Taegwang-ni weighed 81.7 grams and a pregnant fe- male from Yongp'yong 67.6 grams. Remarks. — For comparison with Microtus fortis pelliceus of ex- treme northeastern Korea see the account of that subspecies. The known geographic range of M. /. uliginosus is nearly 400 miles south of the most southerly record of occurrence of M. f. pelliceus. Records of occurrence. — Specimens examined, 95, as follows: Chip'o-ri 150 m., 52 (KU 60442, 63839-41, 67233; UMMZ 99529; USNM 294651-59, 294661-63, 298070-89, 298958, 299509-15, 300647, 301252-53, 301256, 301912, 378 University of Kansas Publs., Mus. Nat. Hist. 301915, including the holotype); 1% mi. NW Chip'o-ri, 140 m., 1 (KU 60437); 2 mi. N Chip'o-ri, 150 m., 1 (USNM 298959); 3 mi. NW Chip'o-ri, 145 m., 6 (KU 60443; USNM 298961-63, 299096-97); Ch'ongyang-ni, 9 (CM— 1 speci- men; USNM 294660, 294664, 298090-93, 298099-100); Ch'onsong-ni, 6 (US- NM 298094, 5 uncatalogued embryos); Ch'orwon, 1 (USNM 301916); vicinity Ch'orwon, 1 (KU 67232); Kumhwa, 6 (NSMJ— 1 specimen; USNM 294665-66, 298096-98); Taegwang-ni, 300 ft, 2 (KU 60440; USNM 301255); & mi. S Taegwang-ni, 2 (USNM 301913-14); Ugu-dong, 3 (USNM 298957, 298960, 301254); White Horse Mt, NW of Ch'orwon, 1 (MCZ 47136); Yonch'on, 1 (USNM 301257); Yongp'yong, 110m., 1 (KU 60441); central Korea, 2 (USNM 301917-18). Additional records (Jones, MS): Oji-ri; Unson-ni, 100m.; Yami-ri. Microtus mandarinus kishidai Mori Mandarin Vole Microtus kishidai Mori, Jour. Chosen Nat. Hist. Soc, 10:53, July 31, 1930. Type locality: Seiryo-ri [= Ch'ongyang-ri], near Seoul, Korea. Microtus mandarinus kishidai, Ellerman and Morrison-Scott, Checklist of Palaearctic and Indian mammals, p. 710, November 19, 1951. Distribution in Korea. — Known only from lowland areas in west-central and southwestern parts. Measurements. — External measurements of an adult male, a young adult male, and an adult female from Suwon, 5 mi. W Kwangju, and the Hant'anch'on Valley, respectively, are: Total length, 137, 131, 131; length of tail-vertebrae, 23, 22, 20; length of hind foot, 18, 17, 18; length of ear from notch, 8, 10, 9. Cranial measurements of the two males are, respectively: Occipitonasal length, 24.8, 25.0; condylobasal length, 26.9, 26.6; palatal length, 16.0, 15.6; zygo- matic breadth, 17.7, 16.3; breadth across auditory bullae, 12.5, 12.3; interorbital breadth, 4.3. 4.2; length of nasals, 7.0, 7.1; length of incisive foramina, 4.1, 3.5; length of maxillary tooth-row, 6.7, 6.6. Remarks. — Microtus mandarinus kishidai is the darkest known subspecies of the species. The race of M. mandarinus nearest to kishidai geographically is M. m. faeceus, known from a place in Jehol nearly 500 miles to the north of the northernmost record of kishidai. Presumably the Mandarin vole will be found to occur in at least the western parts of North Korea. This vole occupies lowland habitats along the Korean west coast at least as far north as the 38th parallel. Evidently it is rare, be- cause the records enumerated herein bring the total number of known specimens only to 13. The individual from five miles west of Kwangju was trapped adjacent to a marshy area in a place over- grown with rank grasses. Records of occurrence. — Specimens examined, 5, as follows: Hant'anch'on Valley (approximately 7 mi. ESE Yonch'on), 1 (USNM 297423); 5 mi. W Kwangju, 13 m., 1 (USNM 299098); 30 mi. NE Seoul, 1 (USNM 283678); Suwon, 1 (MCZ 43397); central Korea, 1 (37th Preventive Medicine Com- pany, U. S. Army). Additional records: Ch'ongyang-ri, near Seoul (type locality); Iksan-gun (Tokuda, 1941:140). Lagomorphs and Rodents of Korea 379 Family Muridae — Murids Micromys minutus Old World Harvest Mouse This harvest mouse is common in central Korea, abundant in some places. Grassy areas in lowlands and on the lower slopes of hill- sides seemingly constitute the preferred habitat. In summer and autumn, harvest mice make their homes in round nests of grass and leaves that are constructed in tall grasses, shrubs, or occasionally in small trees. In winter and spring, however, these mice ap- parently live in burrows, perhaps those abandoned by other small mammals. Individuals are most easily trapped in spring when food is scarce and vegetation has not yet reached heights suitable for nesting. Breeding evidently takes place in all the warm months but, judg- ing from our data, is concentrated in September and October. Litters of from 5 to 9 young have been recorded. Micromys minutus hertigi Johnson and Jones Micromys minutus hertigi Johnson and Jones, Proc. Biol. Soc. Washington, 68:167, December 31, 1955. Type locality: 2 mi. SE Mosulp'o, 3 m., Cheju Do (Quelpart Island), Korea. Distribution in Korea. — Known only from Cheju Do. Measurements. — External and cranial measurements of a young adult male and adult female (the holotype) are, respectively: Total length, 147, 160; length of tail-vertebrae, 81, 84; length of hind foot, 17, 18; length of ear from notch, 10, 10; occipitonasal length, — , 21.5; zygomatic breadth, — , 10.0; in- terorbital breadth, — , 3.8; length of nasals, — , 7.1; breadth of braincase, 9.7, 9.8; depth of braincase, 6.1, 6.3; length of maxillary tooth-row, — , 3.3. Remarks. — From Micromys minutus ussuricus of the adjacent Korean mainland (specimens from various localities in central and southern Korea), M. m. hertigi differs as follows: Upper parts, in summer pelage, brighter ochraceous, especially middorsally; skull, in general, larger and more massive; zygomatic notches deeper; zygomatic processes of maxillae and squamosals broader and more massive in lateral view; nasals narrower and more attenuate pos- teriorly; mesopterygoid fossa relatively narrower, pterygoids less di- vergent posteriorly. From Micromys minutus pygmaeus of central and southern China (specimens from Yochow, Hunan), M. m. hertigi differs in: Upper parts (summer pelage) brighter ochra- ceous; occipitonasal length, nasal length, and zygomatic breadth greater; braincase much broader but not so deep; zygomatic notches deeper; nasals narrower; pterygoids less divergent posteriorly. M. m. hertigi seemingly differs from all other described Oriental 380 University of Kansas Publs., Mus. Nat. Hist. subspecies of Micromys minutus in generally larger cranial size, deeper zygomatic notches, broader braincase, and brighter orchra- ceous upper parts. Specimens examined from the Korean mainland are uniformly darker dorsally than hertigi save for a specimen from Songu-ri, which approaches it in color. An adult male from five miles west of Kwangju, southwestern Korea, approaches hertigi in some cranial measurements. Records of occurrence. — Specimens examined, 2, from the type locality (USNM 299103-04, including the holotype). Micromys minutus ussuricus (Barrett-Hamilton) Mus minutus ussuricus Barrett-Hamilton, Ann. Mag. Nat. Hist, ser. 7, 3:344, April, 1899. Type locality: Ussuri, Coast Province, southeastern Siberia. Micromys minutus ussuricus, Thomas, Proc. Zool. Soc. London, 1906:863, April 11, 1907. Distribution in Korea. — Entire peninsula in suitable habitats. Measurements. — Average and extreme external and cranial measurements of seven adults (three males, four females) from west-central Korea are: Total length, 149.1 (140-163); length of tail-vertebrae, 76.1 (72-85); length of hind foot, 16.7 (15.5-18.0); length of ear from notch, 10.8 (10-13); occipitonasal length, 19.6 (19.2-20.4); zygomatic breadth, 9.5 (9.3-9.6); interorbital breadth, 3.4 (3.2-3.6); length of nasals, 6.2 (6.0-6.7); breadth of braincase, 9.2 (9.0-9.4); depth of braincase, 6.0 (5.6-6.3); length of maxillary tooth-row, 3.1 (3.0-3.4). Weights in grams of four adults, one male and three non-pregnant females, from the vicinity of Seoul are, respectively: 10.4, 9.9, 11.6, 10.0. Remarks. — For comparisons with Micromys minutus hertigi of Cheju Do see account of that subspecies. Two specimens examined from five miles west of Kwangju differ slightly in certain cranial features when compared with specimens from farther to the north; one approaches hertigi in several cranial measurements. Many of our spring-taken specimens were born the previous autumn and are seemingly in a winter-like postjuvenal ( as opposed to juvenal or adult) pelage. The dorsal areas of this pelage are dark brownish except for a paler, more reddish, rump patch. The underparts are darker than those in adult mice, having a grayish wash, and the lateral line is absent or indistinct. Records of occurrence. — Specimens examined, 81, as follows: Chip'o-ri, 4 (USNM 294713, 298101, 298105, 301262); 2 mi. N Chip'o-ri, 150 m., 2 (KU 60428; USNM 298970); Ch'ongyang-ni, 1 (USNM 301376); Hant'anch'on Valley (approximately 7 mi. ESE Yonch'on), 5 (UMMZ 102508-12); 5 mi. W Kwangju, 13 m., 2 (USNM 299100-01); Manp'o, 11 (YI); Mun'gyong, 110 mi. SE Seoul, 1000 ft, 1 (BM 6.12.6.86); Munsan-ni, 2 (USNM 300453, 301261); Nongsa-dong, 6 (AMNH 34076-78, 34080-81; BM 13.5.27.57); 1 mi. N Oho-ri, 1-2 m., 2 (USNM 298968, 298971); Ori-dong, 1 (USNM 298103); 5 mi. ENE Pusan, 2 m., 1 (USNM 299102); 5 mi. E Seoul, 45 m., 2 (USNM 299525, 301931); 6 mi. E Seoul, 45 m., 16 (KU 64407-12, USNM 299099, 299517-22, 299524, 299577, 300649); Songu-ri, 1 (USNM 298104); Suwon, 5 (MCZ 43401-05); 10 mi. N Taegu, 1200 ft, 2 (BM 6.12.6.87-88); Taeg- wang-ni, 300 ft., 1 (KU 60431); 1 mi. W Tangjonggok, 425 m., 1 (USNM Lagomorphs and Rodents of Korea 381 298969); Tokkum-ni, 110 m., 1 (KU 60432); Tumen River, Korean-Man- churian border, 2500 ft., 4 (BM 1938.8.8.12-15); Unson-ni, 100 m., 2 (USNM 299516, 299523); 3 mi. SW Yanggu, 450 m., 3 (USNM 298965-67); Yonch'on, 1 (USNM 294714); Yongp'yong, 110 m., 2 (USNM 298964, 301260); central Korea, 2 ( USNM 301258-59 ) . Additional records (Jones, MS, unless otherwise noted): Ch'onsong-ni (Lawrence and Harriss, MS); 4 mi. W Ch'ungju; Kyangyang-ni; 3 mi. S Osan, 17 m.; Seoid (Won, 1961:47); Taeam-dong (Kuroda, 1934:234); Taehoe- san-ni; Tongp'yonch'on; Ugu-dong. Apodemus agrarius Striped Field Mouse Four subspecies of Apodemus agrarius are herein recognized as occurring in Korea: A. a. mantchuricus in the extreme northern part; A. a. coreae throughout the major portion of the peninsula; A. a. pallescens in the coastal lowlands of southern and southwest- ern Korea; and A. a. chejuensis on Cheju Do (Quelpart Island). A. a. chejuensis is a well-marked insular race, larger than any known subspecies of Apodemus agrarius and conspicuously darker than adjacent Korean (A. a. pallescens) or Chinese (A. a. pallidior) mainland specimens. Subspeciation on the Korean mainland is less clearly defined. Thomas (1899:774, footnote) named A. a. mant- churicus, a dark, long-furred subspecies having a distinct dorsal stripe, from Manchuria near the Korean-Manchurian border. Later (1908:8), after commenting on the considerable individual varia- tion of the mice before him, Thomas described A. a. coreae from Min-gyong [= Mun'gyong] in south-central Korea, distinguishing it from mantchuricus as follows : "General colour above approximat- ing to 'cinnamon' of Ridgway, not so ruddy as in mantchuricus. . . . Belly hairs grey basally, white terminally, not washed with tawny or buffy. Dorsal streak variable, but never of the clear well-defined unspeckled black throughout. . . ." We named A. a. pallescens (Johnson and Jones, 1955fl : 169), a drab-colored subspecies having an indistinct dorsal stripe, from eight miles southwest of Kunsan, Korea, as the terminus of a cline in color that extends from the forested, mountainous areas of Manchuria (dark), southward to the coastal lowlands of southern and southwestern Korea (pale). We also noted, to a lesser extent, a correlated increase in size from north to south. The increase in size seemingly occurs primarily in the northern part of the cline. Specimens of mantchuricus available to us from several localities in southern Manchuria and from extreme northern Korea are smaller, both externally and cranially, than specimens of coreae from central Korea. Conversely, there is only a slight dif- ference in size between coreae and pallescens. As concerns the 382 University of Kansas Publs., Mus. Nat. Hist. cline in color, if summer-taken specimens of mantchuricus from the Sungari River, Manchuria, are assigned a dorsal color rating of 10 and summer-taken specimens of pallescens from the type locality are assigned a dorsal color rating of 1, then summer-taken specimens from the Kumhwa-Ch'orwon area, here considered as representative of coreae, have an average dorsal color rating of between 6 and 7. A. a. coreae, then, differs from mantchuricus more in size than in color whereas the reverse is true when it is compared with pal- lescens. We emphasize that the differences discussed are average; most of the available series of coreae vary considerably. We have seen no specimens from the vast area of northern Korea lying between the Yalu River on the north and the Kumhwa- Ch'orwon area on the south, a distance of more than 250 miles. When specimens are available from this area we would expect to find mantchuricus in the high mountains of extreme northern Korea and coreae in the north-central parts, and we would expect future specimens to illustrate a rather gradual change from north to south within the cline discussed above. Curiously, a parallel cline, at least in color, extends westward from Manchuria and thence south along the North China coast to culminate in the pale race, pallidior, described from the Shantung Peninsula by Thomas (1908:8). Kuroda (1939:38) named an in- termediate subspecies in this cline, A. a. gloveri, which was con- sidered a synonym of mantchuricus by G. M. Allen (1940:957). In central Korea striped field mice inhabit most available ecologi- cal niches but are especially abundant in open grassland, both in valleys and on hillsides. The species is common around the en- virons of man, especially along paddy dikes and in cultivated fields, and resides in forested areas wherever low cover and some open ground are present. The breeding season extends from late March or early April to mid-October with a slack period in mid-summer. Many females give birth to several litters each year. The number of young per litter ranges from 2 to 9, averaging between 5 and 6. Apodemus agrarius chejuensis Johnson and Jones Apodemus agrarius chejuensis Johnson and Jones, Proc. Biol. Soc. Washing- ton, 68:171, December 31, 1955. Type locality: 10 mi. NE Mosulp'o, 420 m., Cheju Do (Quelpart Island), Korea. Distribution in Korea. — Known only from Cheju Do. Meaurements. — Average and extreme external measurements of nine adults (eight males, one female), including the holotype, are: Total length, 222.8 (216-232); length of tail-vertebrae, 103.1 (96-107); length of hind foot, 23.8 (23-25); length of ear from notch, 15.7 (15-17). For cranial measurements see Table 4. Lagomorphs and Rodents of Korea 383 Remarks. — From Apodemus agrarius pallescens of the adjacent coastal areas of the Korean mainland, A. a. chejuensis differs in being larger, both externally and cranially, and in having darker upper parts, feet, tail, and ears, a more distinct dorsal stripe, and under- parts that are tinged with buff. A. a. chejuensis differs in most of the same features from A. a. pallidior of northeastern China, A. a. coreae of central Korea, and A. a. mantchuricus of northern Korea and Manchuria. The dorsal coloration of chejuensis approaches that of mantchuricus but is richer and has a more cinereous appear- ance. A. a. chejuensis is larger, both externally and cranially, than any other described subspecies of Apodemus agrarius and is easily dis- tinguished from the other known races. The rich, dark coloration of chejuensis seems to reflect the color of the dark, reddish volcanic soils found on Cheju Do. Records of occurrence. — Specimens examined, 34, all from Cheju Do as fol- lows: Halla-san, 4000 ft., 2 (YI 98-99); 2 mi. SE Mosulp'o, 3 m., 3 (USNM 299220-22), 4 mi. E Mosulp'o, 100 m., 5 (USNM 299215-19); 6 mi. NE Mosulp'o, 200 m., 9 (USNM 299207-14, 299627); 10 mi. NE Mosulp'o, 420 m., 5 (USNM 299203-06, 299626, including the holotype); Sogwi-ri, 2500 ft., 1 (YI 100); 6 mi. NNE Sogwi-ri, 460 m., 2 (USNM 299223-24); no exact locality, 3000-4500 ft., 7 (BM 6.12.6.5-11). Additional record: near Sogwi-ri, 1200 m. (Won and Woo, 1958a:9). Apodemus agrarius coreae Thomas Apodemus agrarius coreae Thomas, Proc. Zool. Soc. London, 1908:8, July 3, 1908. Type locality: Min-gyong [= Mun'gyong], 110 mi. SE Seoul, 1000 ft., Korea. Distribution in Korea. — Entire peninsula excepting extreme northern part and coastal lowlands in south and southwest. Measurements. — Average and extreme external measurements of ten adults (eight males, two females) from the vicinity of Ch'orwon are: Total length, 201.2 (188-212); length of tail-vertebrae, 91.2 (80-102); length of hind foot, 21.7 (19-23); length of ear from notch, 14.4 (13-15.5). For cranial measure- ments see Table 4. Three adults, two males and a non-pregnant female, from 5-6 mi. E Seoul weighed 35.0, 33.5, and 38.8 grams, respectively. Two adult males from Taegwang-ni weighed 35.1 and 37.3. Remarks. — From Apodemus agrarius mantchuricus, geographi- cally adjacent to the north, A. a. coreae differs as follows: Larger, both externally and cranially; skull more robust; underparts averag- ing paler in comparable pelages; dorsal stripe averaging narrower and less distinct. From Apodemus agrarius pallescens, geographi- cally adjacent to the southward, A. a. coreae differs in averaging slightly smaller in both external and cranial dimensions, and in hav- ing darker upper parts and a darker, more distinct dorsal stripe. For comparisons with Apodemus agrarius chejuensis of Cheju Do, see account of that subspecies. 384 University of Kansas Publs., Mus. Nat. Hist. Table 4. — Cranial Measurements of Four Subspecies of Apodemus agrarius Number JH T of s ^3 O specimens oj o averaged "o3 O O >J or CO -. ri ^3 03 Xi 03 «*H & 0> a3 catalogue O H-* 3 £ c3 3 "2 eadth o brainc %-- *oJ2 •— — number, and sex •2 bti 2 °s a a 7- °3 hStS a03 — in ^.2 c o § r— ( *H Q 0) 3 Apodemus agrarius manlchuricus, Sungari River, Manchuria 26.1 12.6 10.7 4.4 11.3 9.6 9.9 5.2 25.1 26.6 12.3 12.9 10.2 10.9 4.1 4.6 10.7 11.6 9.2 9.9 9.3 10.4 5.0 5.6 Average 8 .(4^,49) Minimum Maximum Apodemus agrarius coreac, vicinity Ch'orwon, Korea Average 8 .(4c?, 49) Minimum Maximum Apodemus agrarius pallescens, 8 mi. SW Kunsan, Korea USNM 299161, 9 (type) Average 8 (5o*, 39) Minimum Maximum Apodemus agrarius chejuensis, vicinity Mosulp'o, Cheju Do, Korea 27.4 13.1 11.5 4.5 11.7 10.0 10.7 5.3 26.3 27.8 12.7 13.5 11.3 11.8 4.2 4.7 11.5 12.0 9.7 10.2 10.4 10.9 4.9 5.7 28.8 13.7 11.9 4.5 12.3 10.0 10.8 5.6 27.9 13.0 11.4 4.5 11.7 10.0 10.5 5.6 27.1 29.0 12.5 13.5 11.0 12.0 4.3 4.8 11.3 12.1 9.7 10.3 10.1 10.9 5.3 6.0 4.3 4.1 4.4 4.3 4.0 4.5 4.1 4.3 4.1 4.4 USNM 299204, > number a -w S E o J3 ° 2 o.rs and sex ndyl leng S3 u ngth incis fora ngth max toot ngth audi bull o >> H 0J O tS3 hH j ^ J t-l Foochow, Fukien, China USNM 282757, -5 ■z z X X X X Affinities c o o3 P"-i PER PER PER P P P P P P R R R R R R E E E E E E PExR PER PER PExR PER PER PExR OExR PExR .So Q..2 X X X X X X X X X X X 03 CD ti X X X X X X X O -3 -0.0 a,T3 Ph X X X X X X X 0J 03 Oh O S'-S ■ — ! +^ ^.S Q,T3 1-9 x x X X X X X X X _2 X 1. Terminology after Hershkovitz (1958:588-591); abbreviations: PER (Palearctic endemic regionalite ) , PExR (Palearctic excurrent regionalite), O Ex R (Oriental excur- rent regionalite). 2. R. rattus appears to have tropical affinities. em islands (Honshu, Shikoku, and Kyushu) of Japan. Aside from Mus musculus and the two species of Rattus, the only species con- sidered here that occurs also in southern Japan is Micromys minutus. Perhaps it is significant that M. minutus probably has the broadest natural distribution of any of the rodents of Korea, occurring from England and continental western Europe eastward to southeastern Siberia, China, Japan, and Formosa, and southward to Assam and the northern parts of Burma and Indo-China. This mouse evi- dently reached southern Japan at some time in the Pleistocene when the islands were connected with the Asiatic mainland via Hokkaido 400 University of Kansas Publs., Mus. Nat. Hist. and Sakhalin (although the species does not now occur on Hok- kaido where biotic conditions are not unlike those in parts of southeastern Siberia where this species does occur). Jameson (1961:603) suggested a connection in the Pleistocene between Kyushu and the Korean Peninsula, via some of the islands in the Korean Strait, but we see little evidence of such a connection. For one thing, the relatively deep Korean Strait, about 60 fathoms at the shallowest place, argues against this view, as does the marked difference between the mammalian faunas of Korea and southern Japan. Mammalian Distributional Areas With regard principally to lagomorphs and rodents, but taking into account the entire mammalian fauna, Korea can be divided into two main distributional areas, one of which can be divided further into two districts. Northern Highlands Distributional Area This distributional area comprises the far northeastern part of Korea, the Kaima Plateau and surrounding mountains in the north- central part, and possibly extends southward along the relatively high mountains adjacent to the east coast to the northern part of the Taebaek Range. Most of the area lies above 3000 feet (up to more than 9000 feet on Paektu-san, on the Korean-Manchurian border) and most is (or was) covered with boreal forest. Many of the higher mountainous areas supported isolated glaciers in the Pleistocene. Species herein discussed that are restricted in Korea to the Northern Highlands are Ochotona hyperborea and Clethrionomys rutilus. Lepus mandshuricus, although possibly not limited to this area, is a typical inhabitant. Subspecies of wide-ranging species that are more or less limited to this distributional area are Eutamias sibiricus orientalis, Pteromys volans arsenjevi, Clethrionomys rufo- canus arsenjevi, Microtus fortis pelliceus, and Apodemus agrarius mantchuricus. Peninsular-Insular Distributional Area This area includes all of Korea not encompassed by the Northern Highlands, namely the lowlands of the northwest, the central and southern parts, and the adjacent islands, including Cheju Do. The area is characterized by the absence of the boreal elements that are restricted to the Northern Highlands, by Microtus mandarinus, and Lagomorphs and Rodents of Korea 401 by a number of southern and insular subspecies of wide-ranging species. Deciduous and mixed forests formerly prevailed in this distri- butional area; most of the lowlands now are devoted to agricul- tural pursuits. Some mountains in southern Korea reach respectable heights (Chiri-san, 6283 feet, in the Sobaek Range, and Halla-san, 6398 feet, on Cheju Do, for example) but are isolated from the mountains of the north and do not support mammals typical of more northerly regions. Two districts of the Peninsular-Insular Distributional Area are here recognized: 1) the Mainland and Adjacent Islands District (including Ullung Do), and 2) the Cheju Do District. The former differs from the latter in having a lagomorph (Lepm coreanus) and a number of species of rodents (three sciurids and three microtines, for example) that are not found on Cheju Do, and dif- ferent subspecies of at least three species (Apodemus agrarius, Micromijs minntus, and Mus muscvlus) that occur in both districts. The mammalian fauna of Cheju Do is typically Korean and the island obviously was connected with the mainland at some time in the Pleistocene. Cheju Do is of volcanic origin. Won (1961:59-60) regarded Ullung Do [=Dagelet Island], an island in the Sea of Japan some 85 miles off the eastern coast of Korea, as belonging to the same faunal unit as the adjacent main- land, a point of view with which we agree. Ullung Do, a volcanic island, is separated from the mainland by depths of between 500 and 1000 fathoms (3000 to 6000 feet) and thus could not possibly have been connected with the peninsula in the Pleistocene. The known mammalian fauna of the island consists of six species (two bats, one shrew, and the three murine rodents that are commensals of man), all of which occur on the Korean mainland. The four non-volant kinds no doubt were introduced on Ullung Do. The two endemic subspecies, a shrew (Crocidura suaveolens utsuryoen- sis) and Mus musculus utsuryonis, are doubtfully distinct from sub- species occurring on the adjacent peninsula. GAZETTEER Excepting the few localities identified in text, the following list includes all geographic place-names in Korea used in the foregoing accounts. The names for which the precise latitude (north) and longitude (east) are given can be found in "Gazetteer to maps of Korea," 3 vols., AMS 2, U. S. Army Map Service, September, 1950, and can be located on the maps of AMS series L751 (1:50,000). 402 University of Kansas Publs., Mus. Nat. Hist. Most localities can be found also on the maps of AMS series L552 (Korea) and L542 (Manchuria), both 1:250,000. The McCune- Reischauer system of romanization of place-names is used. The compilation of this gazetteer has spanned several years, and we have been able, through the help of colleagues in Japan and Korea, to locate nearly all place-names that have appeared in the literature with reference to lagomorphs or rodents in Korea. For those few names not precisely placed, we have ascertained at least approximate locations. Japanese (italized) and other names, in- cluding variant spellings, are listed parenthetically after some en- tries. Anju (Atisiu). 39°37', 125°40' Central National Forest. A small mixed forest 15-18 mi. NE Seoul (see Kwangnung and Pup'ycmg-ni) Ch'ail-bong (Shanichiho, Shazitsuho) . 40°42', 127°42' Ch'angch'on. 37°46', 128°24' Chang-ni. 37°31', 126°49/ Changjon (Chian Zen, Chosen). 38° 44', 128° 11' Cheju. 33°31', 126°31' Cheju Do (Quelpart Island, Saishu-to). A large island in the East China Sea off the southern tip of Korea (see Cheju, Mosulp'o, and Sog- wi-ri ) Chi Do (Chi-to). 35°04, 126° 13' Chigyong-dong. 38° 14', 127°21' Chinbu-ri. 38° 17', 128°22' Chinmokchong. 38°02', 127°58' Chip'o-ri. 38°08', 127° 19^ Chiri-san (Chili-san). 35°20', 127°44' Ch'onan (Tenan). 36°48', 127°09' Ch'ongju (Seishu). 36°38', 127°29' Chon'gong-ni. 38°01', 127°04' Ch'ongyang-ni. 38° 15', 127°23' Ch'ongyang-ri (Seiryo-ri). Not ex- actly located, but in or near Seoul Ch'onma-san. 37°41', 127° 16' Ch'onsong-ni. 38°02', 127°09' Ch'orwon (Cholwon, Tetsugen). 38° 15', 127° 13' Ch'unch'on. 37° 53', 127°43' Chunggangjin ( Chunkang-chin ) . 41° 47', 126°52' Ch'ungju. 36°58', 127°57' Chuuronjang (Juul, Syuotsu, Syuotu). 41°35', 129°36' Daichi-bei. Not exactly located, but approximately 42° 25', 129°45'; Won ( 1961 ) referred to this locality un- der the name Daichonmi Hadong. 35°04', 127°45' Halla-san. 33°22', 126°32' Hamhung (Kanko). 39°55', 127°32' Hongch'on. 37°41', 127°53' Inch'on. 37°28', 126°38' Iksan-gun (Ekisangun). 36°00', 127° 03' Kaloguai. Not exactly located; listed as 55 mi. NE Seoul by Thomas (1907fc:462) Kangnung. 37°45', 128°54' Koyang-gun (Koyo-gun). Approxi- mately 37°37', 127°02' Kuksa-bong. Not exactly located; probably the mountain by that name at 38°05', 126°37' Kumgang-san. Mountain range ap- proximately 38°40', 128°08' Kumhwa (Kim-hoa, Kim kua, Kinka). 38°17', 127°28' Kunsan. 35°59', 126°43' Kwamno-bong (Kamboho). 41°28', 129°01' Kwangnung (Korio, Koryo). 37°45', 127°11' Kwangju (Kosiu). 35°09', 126°55' Kyangyang-ni. 37°51', 126°49' Kyonggi Province. The province in west-central Korea in which Seoul is located Lagomorphs and Rodents of Korea 403 Manp'o (Bampo). 42°20', 130°32' Mokp'o (Moppo). 34°47', 126°23' Mosulp'o. 33° 13', 126° 15' Mun'gyong (Min-gyong). 36°44', 128°07' Munsan-ni. 37°51', 126°47' Musan (Mosan). 42° 13', 129° 13' Nap'a-dong. 37°53', 126°52' Nongsa-dong (Nojido). 42°02', 128° 49' Oho-ri. 38°20', 128°32' Oji-ri. 38° 10', 127° 14' Ori-dong. 38°03', 126°58' Osan. 37°09', 127°04' Paektu-san (Hakuto). 42°00', 128° 03' Paju-ri. 37°50', 126°49' Pammol. 38°01', 127°09' Penchan. Not exactly located; listed as 50 mi. NE Seoul by Thomas (1907fc:462) Pochong. Not exacdy located; ap- proximately 41°31', 128° 18' Potai-dong. Not exactly located; ap- proximately 41°43', 128°22' P'ungsan-dong (Hozando). 42°09', 129°22' Pup'yong-ni. 37°44', 127° 12' Pusan (Fusan). 35°08', 129°04' Ranto. 42° 14', 130°32' (we are un- certain as to the Korean name for this island, but it may be Al-som) Sa-dong. 37°29', 130°54' Sangbonch'on-ni. 37°27', 127° 16' Seoul (Keijo). 37°30', 127°00' Sinsul-li. 38° 10', 127°25' Sinuiju (Shingisiu) . 40°05', 124°23' Soch'on-ni. 37°59', 127°04' Sogwi-ri (Seikiho). 33° 15', 126°34' Sohung-ni. 38° 11', 128° 13' Songdong-ni. 38°01', 127° 16' Songu-ri. 37°50', 127°09' Sorak-san (Solak-san). 38°07', 128° 28' Sosa. 37°29', 126°47' Sumil-li. 38°02', 127° 30' Suwon. 37°17', 127°01' Taeam-dong ( Daigan-do ) . 42° 19', 132°30' Taegu (Taiku, Taihju). 35°52', 128° 35' Taegwang-ni. 38° 11', 127°06' Taehoesan-ni. 38°04', 127° 14' Tangjonggok. 38° 11', 128° 19' To-dong (Dodo). 37°29', 130°54' Tokkum-ni. 38° 09', 127° 06' Toktun-ni. 37°58', 127°07' Tongbok (Tongpok). 35°04', 127° 08' Tongduch'on-ni. 37°56', 127°03' T'ongjin. 37°42', 126°33' Tongp'yongch'on. 37°59', 127°02' Tumen River. River that forms the northeastern border of Korea (with Manchuria and Soviet Siberia) Ugu-dong. 38° 18', 127°23' Ullung Do (Dagelet Island, Utsuryo- to). Small island in Sea of Japan off Korean east coast (see Sa-dong and To-dong) Ulsan (Urusan). 35°33', 129°19' Unggi (Yuki). 42°21', 130°24' Unson-ni. 38°03', 127° 12' Wach'o-ri. 38°08', 127°05' Wasu-ri. 38° 14', 127°27' Wonju. 37°21', 127°57' Yalu River. River that forms the nordiwestern border of Korea ( with Manchuria ) Yami-ri. 38°03', 127°16' Yanggu. 38°06', 128°00' Yangmun-ni. 38° 00', 127° 15' Yangwon-ni. 37°58', 127°02' Yonam-dong (Engando, Yengan). 41° 34', 128°49' Yonch'on. 38°06', 127°04' Yongamp'o (Ryuganpo). 39°57', 124° 21' Yongdungp'o. 37°31', 126°55' Yonggwang (Reiko). 35° 16', 126° 31' Yongp'yong. 38°01', 127°13' 404 University of Kansas Publs., Mus. Nat. Hist. LITERATURE CITED Allen, G. M. 1938. The mammals of China and Mongolia. Amer. Mus. Nat. Hist., New York, l:xxv-|- 1-620, pis. 1-9, figs. 1-23, September 2. 1940. The mammals of China and Mongolia. Amer. Mus. Nat. Hist., New York, 2:xxviii -f- 621-1350, pis. 10-20, figs. 24-75, September 3. Allen, J. A., and Andrews, R. C. 1913. Mammals collected in Korea. Bull. Amer. Mus. Nat. Hist., 32:427- 436, September 2. Bobrinsky, N., Kuznetzov, B., and Kuzyaktn, A. 1944. Mammals of USSR. Gov't Printing Office, Moscow, 440 pp., 256 figs., 62 maps (in Russian). Ellerman, J. R. 1941. The families and genera of living rodents. . . . British Mus. (Nat. Hist), London, 3(l):v+ 1-210, March. Ellerman, J. R., and Morrison-Scott, T. C. S. 1951. Checklist of Palaearctic and Indian mammals, 1758-1946. British Mus. (Nat. Hist.), London, (6) + 810 pp., foldout map, Novem- ber 19. Hershkovitz, P. 1958. A geographic classification of Neotropical mammals. Fieldiana: Zool., 36:579-620, figs. 7-8, July 11. Howell, A. B. 1928. New Chinese mammals. Proc. Biol. Soc. Washington, 41:41-43, March 16. 1929. Mammals from China in the collections of the United States Na- tional Museum. Proc. U. S. Nat. Mus., 75:1-82, 10 pis., June 7. Imatzumi, Y. 1939. On Rattus norvegicus caraco captured in Korea. Bot. and Zool., 7:106, May (in Japanese). Jameson, E. W., Jr. 1961. Relationships of the red-backed voles of Japan. Pacific Sci., 15:594- 604, 2 figs., October. Jameson, E. W., Jr., and Toshioka, S. 1954. Notes on some chiggers (Acarina:Trombiculidae) from southern Korea. Pacific Sci., 8:11-22, 6 figs., January. Johnson, D. H., and Jones, J. K., Jr. 1955a. Three new rodents of the genera Micromys and Apodemus from Korea. Proc Biol. Soc. Washington, 68:167-172, December 31. 1955&. A new chipmunk from Korea. Proc. Biol. Soc. Washington, 68:175-176, December 31. Jones, J. K., Jr. 1956. Comments on the taxonomic status of Apodemus peninsulae, with description of a new subspecies from North China. Univ. Kansas Publ., Mus. Nat. Hist., 9:337-346, 1 fig., August 15. 1959. Comments on the biology of the Quelpart Island shrew, Crocidura dsinezumi quelpartis Kuroda. Jour. Mamm. Soc. Japan, 1:105-114, 3 figs., November 17. 1960. Absence of third upper premolar in Eutamias. Jour. Mamm., 41:268-269, 1 pi., May 20. MS. Field notes. Currently on file at Museum of Natural History, The University of Kansas, Lawrence. Jones, J. K., Jr., and Johnson, D. H. 1955. A new reed vole, genus Microtus, from central Korea. Proc. Biol. Soc. Washington, 68:193-195, December 31. Lagomorphs and Rodents of Korea 405 1956. Comments on two species of red-backed voles, genus Clethrionomys, from Korea and Manuchuria. Nat. Hist. Misc., Chicago Acad. Sci., 157:1-3, October 30. 1960. Review of the insectivores of Korea. Univ. Kansas Publ., Mus. Nat. Hist., 9:549-578, February 23. KlSHTDA, K. 1924. A monograph of mammals of Japan. Omith. Soc. Japan, Tokyo, 447 pp., illustrated (in Japanese). 1929. A synopsis of Corean hamsters. Lansania, 1:147-160, December 21. 1936. Notes on the Acarina — mite and tick, from the peninsula of Corea and the island of Quelpart collected in August, 1936. Lansania, 8:131-144, 9 figs., October 10. Kishida, K., and Mori, T. 1930. Summer pelage of the Corean piping hare, Ochotona coreana. Lansania, 2:49-53, 1 fig., May 25 (in Japanese). 1931. On the distribution of land mammals of Korea. Dobutsugaku Zasshi, 43:372-391, April (in Japanese). Kuroda, N. 1917. A small collection of mammals from Korea and Manchuria. Do- butsugaku Zasshi, 29:355-364, November 15 (in Japanese). 1934. Korean mammals preserved in the collection of Marquis Yamashina. Jour. Mamm., 15:229-239, August 10. 1938. A list of the Japanese mammals. Privately published, Tokyo, (4) + iii + 122 pp., June 20. 1939. Mammal fauna of Manchoukou preserved in the collection of Mar- quis Yamashina. Bull. Biogeogr. Soc. Japan, 9(l):l-50, Janu- ary 31. 1940. A monograph of the Japanese mammals. . . . The Sansiedo Co., Ltd., Tokyo and Osaka, 2+1 + 11 + 2 + 311 pp., 48 colored pis., July 15 (in Japanese). 1952. Descriptions of three new forms of Rattus from Hokkaido and South China. Jour. Mamm. Soc. Japan, 1:1-4, April. Kukoda, N., and Mori, T. 1923. Two new and rare mammals from Korea. Jour. Mamm., 4:27-28, February 9. Lawrence, W. H., and Harriss, T. T. MS. An account of the small mammals collected during a survey of endemic areas of hemorrhagic fever in Korea, May-October, 1952. Manuscript on file at U. S. National Museum, Washington, D. C. LOUKASHKIN, A. S. 1943. On the hares of northern Manchuria. Jour. Mamm., 24:73-81, 1 pi., 2 figs., February 20. 1944. The giant rat-headed hamster, Cricetulus triton nestor Thomas, of Manchuria. Jour. Mamm., 25:170-177, 1 pi., 2 figs., May 25. Mori, T. 1927. On three new mammals from Manchuria. Annot. Zool. Japonenses, 11:107-109, July 25. 1937. On some small mammals from the Island Utsuryo, Chosen. Jour. Chosen Nat. Hist. Soc, 22:40-42, September 1 (in Japanese and English). 1938. On some small mammals from the Isl. Utsuryo, Chosen (II). Jour. Chosen Nat. Hist. Soc, 23:16-18, September 1 (in Japanese and English). 1939. On the birds and mammals collected from Mt. Shazitsuho. Jour. Chosen Nat. Hist. Soc, 27:1-4, December 20 (in Japanese). 406 University of Kansas Publs., Mus. Nat. Hist. Ognev, S. I. 1940. The mammals of USSR and adjacent countries. Moscow and Leningrad, 4:1-615, illustrated (in Russian). 1950. The mammals of USSR and adjacent countries. Moscow and Leningrad, 7:1-706, illustrated (in Russian). Schwarz, E., and Schwarz, H. K. 1943. The wild and commensal stocks of the house mouse, Mus musculus Linnaeus. Jour. Mamm., 24:59-72, February 20. Sowerbv, A. de C. 1921. Notes on east Asiatic members of the species Sciurus vulgaris, Linn., with description of two new subspecies. Ann. Mag. Nat. Hist., ser. 9, 7:249-254, March. 1923. The naturalist in Manchuria. Tientsin Press Ltd., 2:xxvii-f- 1-191. Temminck, C. J. 1845. Mammiferes (in von Seibold, Fauna Japonica), pp. 1-59, 20 pis. Thomas, O. 1899. On mammals collected by Mr. J. D. La Touche at Kuatun, N. W. Fokien, China. Proc. Zool. Soc. London, pp. 769-775 (for 1898), April. 1907a. The Duke of Bedford's zoological exploration in eastern Asia. — II. List of small mammals from Korea and Quelpart. Proc. Zool. Soc. London, pp. 858-865 (for 1906), April 11. 1907&. The Duke of Bedford's zoological exploration in eastern Asia. — V. Second list of mammals from Korea. Proc. Zool. Soc. London, pp. 462-466, October 9. 1908. The Duke of Bedford's zoological exploration in eastern Asia. — VI. List of mammals from the Shantung Peninsula, N. China. Proc. Zool. Soc. London, pp. 5-10, July 3. Tokuda, M. 1941. A revised monograph of the Japanese and Manchou-Korean Muridae. Trans. Biogeogr. Soc. Japan, 4( 1): (4) + 1-155, 9 pis., 88 figs., December. Whang, C. H. 1959. Studies on the murine rodents of Korea. Jour. Applied Zool., 2:46-71, April (in Korean with English summary). Won, P. H., Won, P. O., and Woo, H. C. 1959. Notes on the birds and mammals from Mt. Solak in summer. Jour. Applied Zool., 2:12-21, April (in Korean with English summary). Won, P. O. 1961. Land mammals of Korea, pp. 36-64, 1 fig., in Avi-mammalian fauna of Korea. Inst. Agric, Suwon, Korea, (4) -f- 139 pp., illu- strated, December. Won, P. O., and Woo, H. C. 1956. On the mammals from Dagelet Island (I). Nat. Forest Exp. Sta., Korea, (6) + 18 pp. (in Korean with English summary). 1958a. Mammals of Cheju Island. Jour. Applied Zool., 1:5-13, illustrated (in Korean with English summary). 19586. A distributional list of the Korean birds and mammals. Forest Exp. Sta., Inst. Agric, Seoul, (6) + 10 + 96+ 12 pp., September. 1958c. Forest damage by the red-backed mouse in Korea. . . . Res. and Invest. Inst. Agric, Korea, 1:1-9, illustrated, October (in Korean with English summary). 1959. Notes on the avi-mammal fauna of Chili Mt., Korea. Bull. Forest Exp. Sta., 8:126-136, December (in Korean with English sum- mary). Lagomorphs and Rodents of Korea 407 1960. On the roof rat of Dagelet Island. Jour. Applied Zool., 3:49-52, September ( in Korean with English summary ) . 1961. Taxonomic notes on the rodents of Korea. Chosen Gakuho, 21/22: 106-131, October (in Korean). ZlMMERMANN, K. 1962. Die Untergattungen der Gattung Apodemus Kaup. Bonn. Zool. Beitrage, 13:198-208, 1 fig. Transmitted July 7, 1964. D 30-3967 ^ - \tf\- JL |oaa^^U^ University of Kansas Publications Museum of Natural History Volume 16, No. 3, pp. 409-419, 1 fig. MUS. CCA.. . OC April 13, 1965 ' iRRAR DEC 31 1t ) HARVARD UNIVERSITY Mammals from Isla Cozumel, Mexico, With Description of a New Species of Harvest Mouse BY J. KNOX JONES, JR., AND TIMOTHY E. LAWLOR University of Kansas Lawrence 1965 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 16, No. 3, pp. 409-419, 1 6g. Published April 13, 1965 University of Kansas Lawrence, Kansas PRINTED BY HARRY (BUD) TIMBERLAKE, STATE PRINTER TOPEKA. KANSAS 1 965 30-3968 ] — h4A - K)£^u~ km. N San Miguel, where opossums were seen nightly at a garbage dump. The female that carried the six young was obtained on August 8; the young weighed an average of 18.4 (17.6-19.5) grams. We tentatively retain the subspecific name cozumelae for the insular opos- sums. Comparison of our material with specimens of D. m. ijucatanensis from the adjacent mainland fails to support Merriam 's (1901:102) contention that the two differ in certain cranial features or that cozumelae is the larger in size of body. The tail does, however, average shorter in relation to length of (411) 412 University of Kansas Publs., Mus. Nat. Hist. body than in specimens from the mainland, and the white tip on the tail is noticeably shorter (one-half to two-thirds as long). Selected measurements of an adult male and the largest available female (the one with young) are, respectively: total length, 770, 633; length of tail, 319, 300; length of hind foot, 60, 53; length of ear, 54, 52; greatest length of skull, 115.1, 90.7; zygomatic breadth, 63.5, 45.2; palatal length, 65.7, 54.8; length of M1-M4, 19.5, 17.9. Micronycteris megalotis mexicana Miller, 1898. — Our only specimen (91539), a female in juvenal pelage and with unfused phalangeal epiphyses, was taken in a mist net stretched between two palm trees adjacent to the cottage in which we stayed. Goldman (1951:443) earlier listed this species from Cozumel under the name Macrotus pygmaeus. Artibeus jamaicensis yucatanicus J. A. Allen, 1904. — Judging from our experience, this species is the commonest of the bats occurring on Cozumel. Eighteen individuals were collected as follows: 4 km. N San Miguel, 6 (91724-29); 3!< km. N San Miguel, 12 (91730-40, 91781). All specimens taken were netted, either along small roads through the scrubby forest or among coconut palms adjacent to residences near the beach. Five of 11 females ob- tained were lactating; the testes of one male measured 10 mm. Several authors previously have reported this bat from the island. Artibeus lituratus palmarum Allen and Chapman, 1897. — One specimen (91780), a male having testes measuring 6 mm., was netted along with several individuals of A. jamaicensis among coconut palms 3/2 km. N San Miguel. This species has not been reported previously from Cozumel. Artibeus phaeotis phaeotis (Miller, 1902). — A male and two females of this small fruit-eating bat were trapped in mist nets stretched across a narrow road in the forest 4 km. N (91790) and 3¥i km. N (91791-92) San Miguel. Each of the females carried a single embryo ( 23 and 25 mm. crown-rump ) . Although this species long has been known from the Yucatan Peninsula, it was not formerly known from Cozumel. Previous authors ( Hershkovitz, 1949:449, Dalquest, 1953:64, and Davis, 1958:164, among others) have regarded A. p. phaeotis (type locality, Chichen- Itza, Yucatan) as a subspecies of Artibeus cinereus. Apparently none of the authors who thus treated phaeotis examined the holotype, which actually is identical with the species later described by Andersen (1906:422) as Artibeus turpis (type locality, Teapa, Tabasco). Therefore, A. p. phaeotis replaces A. t. turjns as the correct name for the bat of the Caribbean lowlands of southern Mexico and adjacent areas that is characterized by its small size, relatively broad and naked uropatagium, and short, up-turned rostrum. The slightly smaller subspecies of Pacific coastal areas (see Davis, 1958:163) henceforth should bear the name Artibeus phaeotis nanus. We are grateful to Dr. C. O. Handley, Jr., of the U. S. National Museum, who currently is revising the genus Artibeus, for allowing one of us ( Jones ) to examine the holotype of phaeotis. Our attention first was drawn to this mat- ter when we discovered that all individuals of small Artibeus in our collection from the Yucatan Peninsula resembled "turpis," which was not reported from there, rather than "cinereus," which was said to occur there. Measurements of the male and two females are, respectively: total length, 57, 54, 58; length of hind foot, 12, 10, 11; length of ear, 14, 16, 17; length of Mammals from Isla Cozumel, Mexico 413 forearm, 38.2, 38.3, 40.8; greatest length of skull, 19.6, 19.1, 19.3; zygomatic breadth, 11.5, 11.7, 11.7; length of maxillary tooth-row, 6.0, 5.8, 5.9. Natalus stramineus saturatus Dalquest and Hall, 1949. — This species, previ- ously unreported from the island, is represented in the U. S. National Museum by 32 specimens in alcohol from San Miguel. Oryzomys palustris cozumelae Merriam, 1901. — Rice rats were abundant in tangled, second-growth brush and vines. Thirty-six specimens were col- lected from 3 km. N (92185-86) and 38 km. N (92168-84, 92187-203) San Miguel. A female obtained on August 8 carried three embryos that measured 15mm. (crown-rump) and our sample contains many two-thirds to three- fourths grown young. Up to now, O. p. cozumelae has been regarded as a distinct species, al- though its close relationship with O. palustris of the adjacent mainland has been recognized (see Goldman, 1918:43). None of the specimens among our material are as large as the holotype of cozumelae, but a number fall within the range of variation cited for adults by Goldman ( loc. cit. ) . When our specimens were compared with individuals of O. p. couesi from the Yucatan Peninsula, we found that cozumelae differed noticeably only in being larger externally; cranially, couesi and cozumelae differ only in minor details (for example, the skull of cozumelae averages slightly larger, is less arched over the orbits, and has heavier teeth and larger nasals), and the latter averages only slightly darker than mainland specimens. Furthermore, adults of co- zumelae do not exceed in external size individuals from several of the named populations of O. palustris. For all these reasons, and because cozumelae long has been recognized as only an insular relative of palustris, we employ the name Oryzomys palustris cozumelae for it. We feel the relationships of the insular population are best reflected by such usage. Reithrodontomys spectabilis new species Holotype. — Adult male, skin and skull, no. 92294 Museum of Natural His- tory, The University of Kansas, from 2M km. N San Miguel, Isla Cozumel, Quintana Roo; obtained by Ticul Alvarez on August 8, 1962 (original no. 848). Distribution. — Known only from Cozumel Island. Diagnosis. — Size large both externally and cranially ( see measurements ) ; tail long in relation to head and body (134-148 per cent in adults), scantily haired; pelage short and relatively sparse; upper parts brownish ochraceous over-all, brighter ochraceous on sides; underparts grayish white, the individual hairs white terminally and plumbeous basally; pinkish buff pectoral spot some- times present; tail dark brown above, only slightly paler below; braincase relatively flattened and uninflated; zygomatic arches broad and strong; rostrum relatively short and broad; mesopterygoid fossa broad; auditory bullae large but only moderately inflated; incisive foramina rarely reaching level of Ml; teeth large; first and second molars typical of the subgenus Aporodon in having well developed mesolophs ( ids ) and mesostyles(ids); third lower molar essentially a smaller replica of first two; baculum long (9.5 and 10.9 mm. in two adult males), slender, curved dorsally at the distal end, broadly arrow- shaped basally (width of base 1.1 and 1.2 mm. in the two adult bacula studied), possibly largest among members of genus. The skull and teeth are illustrated in Figure 1. 414 University of Kansas Publs., Mus. Nat. Hist. Fig. 1. Skull and teeth of Reithrodontomys spectabilis. Right upper (A) and left lower (B) molars of KU 92293 (x 15), and dorsal (C) and ventral (D) views of skull of holotype, KU 92294 (x3). T. H. Swearingen made the drawings from photographs by J. F. Downhower. Measurements. — External and cranial measurements of the holotype followed by average and (in parentheses) extreme measurements of eight specimens (four males and four females, including the type) are: total length, 216, 213.8 (205-221); length of tail, 124, 125.7 (121-132); length of hind foot, 22, 21.3 (20-22); weight (in grams), 20.6, 20.2 (18.1-21.4); greatest length of skull. 24.7, 25.2 (24.6-26.2); zvgomatic breadth, 12.2, 12.3 (11.8-12.7); interorbital breadth, 3.7, 3.7 (3.5-3.9); breadth of braincase, 11.2, 11.2 (11.0-11.5); depth of skull, 8.5, 9.0 (8.5-9.4); length of rostrum, 8.8, 9.0 (8.7-9.8); breadth of rostrum, 4.1, 4.2 (3.9-4.5); length of incisive foramen, 4.4, 4.5 (4.4-4.8); breadth of mesopterygoid fossa, 1.7, 1.7 ( 1.5-1.8); length of palatal bridge, 3.9, 4.0 (3.8-4,3); alveolar length of maxillary tooth-row, 3.8, 3.8 (3.7-3.9); alveolar length of mandibular tooth-row, 3.4, 3.5 (3.4-3.7). Mammals from Isla Cozumel, Mexico 415 Comparisons. — The new species is a member of the subgenus Aporodon and is allied to Reithrodontomys mexicanus and R. gracilis of the R. mexicanus species group. It is the largest member of the mexicanus group as defined by Hooper ( 1952 ) and among the largest species of the genus Reithrodontomys. Of the two kinds to which it appears most closely related, the new species resembles R. gracilis of the adjacent mainland of the Yucatan Peninsula to a somewhat greater degree than R. mexicanus, known nearest Cozumel Island from the highlands of Guatemala and Honduras. In comparison with gracilis, R. spectabilis is immediately recognized by its much larger size (total length averaging 213.8 in adult spectabilis but only 175.7 in six adult R. g. gracilis from the Yucatan Peninsula, length of hind foot 21.3 and 17.8, greatest length of skull 24.7 and 21.9, zygomatic breadth 12.2 and 10.8), generally darker coloration, and in having a massive skull with broader, heavier zygomatic arches. R. spectabilis resembles R. gracilis (in contrast to R. mexicanus) in that the dark tarsal stripe does not extend onto the hind foot and in having a flattened and relatively uninflated braincase, incisive foramina that rarely reach the level of Ml, and in other general features of the cranium. The breadth and depth of the braincase are even less, relative to length of the skull, than in gracilis — the breadth averages 44.6 per cent of the greatest length of skull (47.5 in gracilis studied), and the depth of skull averages 35.9 in rela- tion to length (36.9 in gracilis). R. spectabilis resembles R. mexicanus more than R. gracilis in size (measure- ments of mexicanus studied — subspecies hotvelli and orinus — are intermediate between those of spectabilis and gracilis) and to some extent in general colora- tion. Cranially, aside from averaging smaller, mexicanus can be distinguished most easily from spectabilis by its proportionately broader and deeper braincase. Because of its resemblance in many features to the smaller R. gracilis, we assume that the precursors of R. spectabilis reached Cozumel from the adjacent mainland of the Yucatan Peninsula. The magnitude of the differences be- tween the two species suggests, to us at least, that they have been separated for a relatively long time, since at least late Pleistocene. Remarks. — Some of the harvest mice from Cozumel Island were trapped in tangled, second-growth vines and brush adjacent to (beachward from) scrub forest; Oryzomys palustris cozumelae was abundant in this same habitat. Other individuals were taken in forest in traps set at the bases of trees and along a stone wall. One specimen was caught by hand at night as it climbed in the branches of a small tree, indicating that the Cozumel harvest mouse is at least partly arboreal in habits. Our sample contains several juvenal and subadult specimens. One female, trapped on August 9, had been recently lactating, but no other females evidenced gross reproductive activity. The testes of two adult males measured 13 and 14 mm. Specimens examined, 16, as follows: 2/2 km. N San Miguel, 3 (92294-96); 3)2 km. N San Miguel, 13 (92281-93). Peromyscus leucopus cozumelae Merriam, 1901. — Six white-footed mice were trapped along trails in scrub forest or in places marginal between forest 416 University of Kansas Publs., Mus. Nat. Hist. and second-growth brush. Our specimens are from 3/2 km. N (92417-21) and 2?2 km. N (92422) San Miguel. A female obtained on August 11 was lactating. P. I. cozumelae differs from the subspecies of the mainland of the Yucatan Peninsula (P. I. castaneus) in being larger, both externally and cranially, and in having heavier teeth. The two kinds closely resemble each other in color. Dasyprocta punctata yucatanica Goldman, 1913. — According to Merriam (1901:100), D. punctata was introduced on Cozumel "shortly before" the visit of Nelson and Goldman to the island in 1901. Goldman actually observed an individual in the forest near San Miguel. Natives reported to us that agoutis still occur on the island. Agouti paca subsp. — On the morning of August 11, William E. Duellman observed a paca along a trail through the forest approximately 4 km. N San Miguel. We queried local residents concerning the status of this large rodent on the island and, while aware of its presence, they had no knowledge of whether or not it had been introduced. Urocyon cincreoargenteus subsp. — We did not obtain specimens of the gray fox, but local residents reported its occurrence to us. Earlier, Merriam (1901:99) wrote of this species on Cozumel as follows: "The only mammal heard of [by Nelson and Goldman] which was not secured is a small Gray Fox (Urocyon) reported by natives as rather rare, but more common on the eastern and southern parts of the island. From the accounts it agrees with the Rac- coon, Nasua, and Peccary in being much smaller than the mainland species." Procyon pygmaeus Merriam, 1901. — A subadult male raccoon (92565) was shot on August 8 from a coconut palm situated along the beach 3/2 km. N San Miguel. Two other individuals were seen in the same tree and the three may have been from the same family group. Our specimen differs in cranial features from raccoons of the Yucatan Peninsula (P. lotor shufeldti) in ways described by Goldman (1950:76-77), and we follow Goldman in preserving specific recognition for pygmaeus. It is perhaps worthy of note that our speci- men has a distinct "interparietal" bone approximately 13 mm. long by 8 mm. wide, at the juncture of the parietal and frontal bones. Nasua nelsoni Merriam, 1901. — According to local residents, coatis are com- mon in the vicinity of San Miguel. Several were seen at night and in early morning by our party. One (92570), an adult female with well-developed teats (probably recently lactating), was obtained 3% km. N San Miguel. We retain N. nelsoni as a full species because it differs so strikingly in size from the coati (Nasua narica yucatanica) of the adjacent mainland. Measure- ments of our specimen, followed in parentheses by measurements of an adult female of yucatanica from 7 km. N and 51 km. E Escarcega, Campeche, are as follows: total length, 741 (990); length of tail, 332 (485); length of hind foot, 76 (99); length of ear, 35 (40); greatest length of skull, 103.4 (118.6); zygomatic breadth, 50.3 (58.3); interorbital constriction, 20.4 (24.5); palatal length, 62.7 (72.9); breadth of braincase, 38.3 (42.0); alveolar length MI- MS, 16.6 (19.9). Aside from its over-all smaller size, the skull of nehoni is notable for its more delicate construction and distinctly smaller bullae when compared with N. n. yucatanica. Trichechus manatus manatus Linnaeus, 1758. — Local residents reported that manatees were observed occasionally along the west coast of the island and that they were common in the bays and lagoons on the adjacent coast of Quintana Roo. Mammals from Isla Cozumel, Mexico 417 Tayassu tajacu nanus Merriam, 1901. — The collared peccary of Cozumel was described as a subspecies distinct from that on the adjacent mainland of Yucatan ( T. t. angulatus) on the basis of smaller size and blacker nose and chin. Subsequently, Hershkovitz (1951:567) noted that the species had been introduced on the island from the adjacent mainland (see also de Vos et al., 1956:176) and suggested that the small size claimed for nanus resulted from heavy hunting pressure, which did not allow animals to attain adult size. Ad- ditional specimens are needed before Hershkovitz's interesting hypothesis can be tested. Natives on Cozumel reported the collared peccary as common and intensively hunted. Mammals Reportedly Collected on Cozumel by G. F. Gaumer George F. Gaumer, well-known naturalist who lived for many years on the Yucatan Peninsula, reported himself, or sent to others, a number of mammals alleged to have come from the island of Cozumel. Some of these probably originated from the island but others seemingly did not, as discussed below. Oldfield Thomas (1888), in the first technical paper dealing with mam- mals from Cozumel, reported five species that were collected by Gaumer and communicated to Thomas by Salvin and Godman. These five were Didelphis marsupialis, Ptcronotus parnellii, Artibeus jamaicensis, Tadarida laticaudata, and "Nasua nasica." The opossum, Jamaican fruit-eating bat, and coati (in the form of the small Nasua nelsoni) subsequently have been found to be common on the island. No other records of the two remaining bats, Pteronotus and Tadarida, have been forthcoming, but each is widespread on the adjacent Yucatan Peninsula and we do not doubt that each occurs on Cozumel. In his "Monografia de los mamiferos de Yucatan," Gaumer (1917:117) re- ported the presence of the Yucatan deer mouse, Peromyscus yucatanicus, on the island. He did not, however, record Peromyscus leucopus from Cozumel and Koopman (1959:237) concluded that Gaumer confused the two species. We are inclined to agree with Koopman, because insofar as we know P. yucatanicus does not occur on the island. Gaumer (op. cit. :63) also recorded the white-lipped peccary (as "Dicotyles labiatus") from Cozumel but this, too, seems to be in error. By far the most perplexing collection of mammals relating to Cozumel is a lot of specimens acquired from Gaumer by the Museum of Natural History in the early 1900's. Many of these specimens were cited by Hall and Kelson (1959) and all species represented were listed by Koopman (1959). The holotype and paratypes of Mimon cozumelae Goldman (1914) were among the specimens in this collection. Aside from M. cozumelae, species represented (and their catalogue numbers) are: Micromjcteris megalotis mexicana (1659- 60); Glossophaga soricina leachii (1655-58); Artibeus jamaicensis yucatanicus (1641-42); Centurio senex (1669-70); Lasiurus borealis teliotis (1655); Pleco- tus (possibly mexicanus) (1658); Molossus ater nigricans (1663-64); Ateles geoffroyi yucatanensis (885); Tamandua tetradactyla mexicana (869-872, 880); Heterogeomys hispidus yucatanensis (1370); Nasua narica yucatanica (876-77, 1599-1600); Galictis allamandi canaster (873); and Tayassu sp. (875 — said to be T. t. nanus, probably solely on supposed geographic grounds, but speci- men not now to be found ) . Most of the labels that now accompany the above-listed specimens are not the original labels of Gaumer, and, in any event, bear no additional informa- tion that could support or refute the contention that the specimens actually 418 University of Kansas Publs., Mus. Nat. Hist. came from Cozumel. Many other specimens received at the same time are labeled simply as from "Yucatan." Some of the specimens said to be from Cozumel obviously did not come from there as shown below and there is a strong possibility that others did not. Perhaps few or none of the specimens actually originated on the island. Of the eight bats, only two (A. jamaiccnsis and M. megalotis) have been obtained on Cozumel by other collectors. One, Plecotus, seems likely not to occur there (see also Koopman, 1959:237). The remaining five (Mimon, Glossopluiga, Centurio, Lasiurus, and Molossus) are widespread in Middle America and each is known from the adjacent mainland. We took G. soricino on the much smaller Isla Mujeres that lies to the north of Cozumel. There is a strong possibility that all five species actually occur on Cozumel and that additional collecting will establish their presence on the island. We are especially hopeful of this development with reference to Mimon cozumelae. With reference to the six strictly terrestrial kinds, we doubt that any save Taijassu occurs on the island. The major habitat, scrub forest, doubtfully would support tamanduas or monkeys ( although the latter might have been intro- duced) and neither was reported to us by local residents (nor was the grison mentioned). We especially questioned natives about the occurrence of pocket gophers but they assured us that "tuzas" were not present. All four coatis, formerly labeled "Nasua nelsoni," are unquestionably the much larger N. narica yucatanica that occurs only on the adjacent mainland. Zoogeography As Koopman (1959) pointed out, the zoogeographic relationships of Cozumel, at least with respect to mammals, are undoubtedly with the adjacent mainland, not with the Antilles. Even though the strait that separates Cozumel from the mainland of Quintana Roo is deep, and the current in it strong, we suppose that most of the mammals that occur on the island reached it by "rafting" across the strait or possibly from the mainland to the south of Cozumel. At a time of maximal glaciation, because of a lowering of the sea level, the strait would have been reduced to approximately half its present width, theoretically making "rafting" much easier than now, es- pecially if favorable winds prevailed. At least three of the mammals that currently inhabit the island are known or suspected to have been introduced by man. Mammals from Isla Cozumel, Mexico 419 LITERATURE CITED Andersen, K. 1906. Brief diagnoses of a new genus and ten new forms of stenodermatous bats. Ann. Mag. Nat. Hist., 18:419-423, December. Dalquest, W. W. 1953. Mexican bats of the genus Artibeus. Proc. Biol. Soc. Washington, 66:61-66, August 10. Davis, W. B. 1958. Review of Mexican bats of the Artibeus "cinereus" complex. Proc. Biol. Soc. Washington, 71:163-166, 1 fig., December 31. de Vos, A., Manvelle, R. H., and Van Geldeb, R. G. 1956. Introduced mammals and their influence on native biota. Zoologica, 41:163-194, 1 fig., December 31. Gaumer, G. F. 1917. Monografia de los mamiferos de Yucatan. Dept. de Talleres Graficos de la Secretaria de Fomento, Mexico, xii + 331 pp., 57 pis., 2 photographs, 1 map. Goldman, E. A. 1914. A new bat of the genus Mimon from Mexico. Proc. Biol. Soc. Washington, 27:75-76, May 11. 1918. The rice rats of North America (genus Oryzomys). N. Amer. Fauna, 43:1-100, 6 pis., 11 figs., September 23. 1950. Raccoons of North and Middle America. N. Amer. Fauna, 60: vi + 1-153, 22 pis., 2 figs., November 7. 1951. Biological investigations in Mexico. Smiths. Misc. Coll., 115: xiii + 1-476, frontispiece, 71 pis., 1 map, July 31. Hall, E. R., and Kelson, K. R. 1959. The mammals of North America. 2 vols. (xxx+ 1-546+ 79 and viii + 547-1083 + 79), illustrated, March 31. Hershkovitz, P. 1949. Mammals of northern Columbia. Preliminary report no. 5: bats (Chiroptera). Proc. U. S. Nat. Mus., 99:429-454, May 10. 1951. Mammals from British Honduras, Mexico, Jamaica and Haiti. Fieldiana-Zool., Chicago Mus. Nat. Hist., 31:547-569, July 10. Hooper, E. T. 1952. A systematic review of the harvest mice (genus Reithrodontomys) of Latin America. Misc. Publ. Mus. Zool., Univ. Michigan, 77: 1-255, 24 figs., 12 maps, January 16. Koopman, K. F. 1959. The zoogeographical limits of the West Indies. Jour. Mamm., 40: 236-240, May 21. Merriam, C. H. 1901. Six new mammals from Cozumel Island, Yucatan. Proc. Biol. Soc. Washington, 14:99-104, July 19. Paynter, R. A., Jr. 1955. The ornithogeography of the Yucatan Peninsula. Bull. Peabody Mus. Nat. Hist., 9:1-347, 4 pis., 2 maps. Thomas, O. 1888. List of mammals obtained by Mr. G. F. Gaumer on Cozumel and Ruatan Islands, Gulf of Honduras. Proc. Zool. Soc. London, p. 129, June. Transmitted Jidtj 7, 1964. □ 30-3968 ^- pjf\- J^f^^^urj University of Kansas Publications Museum of Natural History MUS. CON- . - O' Volume 16, No. 4, pp. 421-438, 2 figs. LIBRARY July 20, 1965 The Yucatan Deer Mouse, Peromyscus yucatanicus DEC b 1 j HARVARD UNIVERSITY. BY TIMOTHY E. LAWLOR University of Kansas Lawrence 1965 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Frank B. Cross Volume 16, No. 4, pp. 421-438, 2 figs. Published July 20, 1965 University of Kansas Lawrence, Kansas PRINTED BY ROBERT R. (BOBl SANDERS. STATE PRINTER TOPEKA. KANSAS I 965 30-7118 MUS. CO iv.. . . 00 The Yucatan Deer Mouse, Peromyscus yucatanicus DEC 3 1 BY HARVARD TIMOTHY E. LAWLOR UNIVERSITY CONTENTS PAGE Introduction 423 Materials, Methods, and Acknowledgments 423 Taxonomic Relationships 424 Non-Geographic Variation 426 Geographic Variation 427 Size 430 Color 430 Discussion and Taxonomic Assessment of Variation 431 Natural History 434 Evolution and Speciation 435 Literature Cited 437 INTRODUCTION Peromyscus yucatanicus was named and described by Allen and Chapman (1897:8) on the basis of six specimens from Chichen-Itza, Yucatan. Few specimens were available for study until 1962 and 1963 in which years more than 100 were obtained. Specimens from certain parts of the supposed geographic range of the species still are wanting but enough are at hand to permit a meaningful analysis of geographic variation in the species. The objectives of my study were to: 1) ascertain the characteristics of Peromyscus yucatanicus as compared with closely related species; 2) analyze geographic variation within the species and assess its taxonomic significance; 3) summarize available information concerning natural history; and 4) provide evidence relating to origin and evolution of the species. MATERIALS, METHODS, AND ACKNOWLEDGMENTS Unless otherwise indicated, specimens studied are in the Museum of Natural History of The University of Kansas. Others were borrowed from the American Museum of Natural History (AMNH), the Biological Surveys Collection in the United States National Museum (USNM), and the Museum of Zoology of the University of Michigan (UMMZ). Also some specimens of Peromyscus mexi- canus for comparison with P. yucatanicus were borrowed from the Chicago Natural History Museum. (423) 424 Univ. of Kansas Publs., Mus. Nat. Hist. In all, 213 specimens of P. yucatanicus were studied. They were grouped by sex, age, and geographic origin, so that individual variation could be as- sessed prior to study of geographic variation. In the following account males and females are grouped together for purposes of analysis because secondary sexual variation proved to be insignificant. External measurements employed are those recorded on specimen labels. The mastoid breadth as measured by me is the greatest distance across the mastoid bones perpendicular to the long axis of the skull. The manner in which other cranial measurements were taken is explained by Hoffmeister (1951:28) and Hooper (1952:9-11). The baculum of P. yucatanicus has a characteristic configuration (see Fig. 1C). Length of the baculum was measured from the posteriormost border of the base of the bone to the anteriormost point on the tip of the bone, and its (greatest) breadth was measured across the base perpendicular to the long axis of the baculum. Variation in color was recorded by a Photovolt Photoelectric Reflection Meter, Model 610, on which measurements are recorded as a percentage value of pure white. Readings were made for each of three color reflections — red, green, and blue — and were taken from specimens at the middorsal region of the back. Measurements of reflected wave lengths of red and green proved to be geographically variable, but reflections of blue did not vary significantly. For the loan of specimens I am indebted to Drs. S. Anderson of The American Museum of Natural History, E. T. Hooper of the Museum of Zoology of the University of Michigan, R. H. Manville of the Riological Surveys Col- lection of the U. S. Fish and Wildlife Service, and J. C. Moore of the Chicago Natural History Museum. Cost of collecting the specimens of P. yucatanicus in the Museum of Natural History was met by a contract (DA-49-193-MD-2215) from the Medical Research and Development Command of the U. S. Army and by the Kansas University Endowment Association. I am especially grateful to Dr. J. Knox Jones, Jr., for providing me with guidance during the study and for critical assistance with my manuscript. Dr. William E. Duellman also criticized parts of the manuscript. TAXONOMIC RELATIONSHIPS Peromyscus yucatanicus resembles Peromyscus boylii in color and size, but the species are allopatric. Furthermore, P. boylii has a well-haired tail, a rounded and inflated braincase, and a non-beaded supraorbital border as compared with the rather naked, blotchy tail, uninflated braincase, and beaded supraorbital ridge of P. yucatani- cus. Similarly, P. banderanus approaches yucatanicus in certain cranial characteristics and in coloration, but the two species are disjunct geographically and yucatanicus differs from banderanus in having a less beaded skull, a longer, more slender, distinctive bacu- lum (see Hooper, 1958:13 and 18), and in being smaller externally and cranially. The range of P. yucatanicus overlaps that of the white-footed mouse, Peromyscus leucopus, but the latter mouse can Yucatan Deer Mouse 425 be distinguished easily by its smaller size, shorter, non-beaded skull, and well-haired, bicolored tail. Of all known species, Peromyscus mexicanus most closely re- sembles P. yucatanicus. Osgood (1909:212) stated that "although quite distinct, this species [P. yucatanicus] is little more than a miniature of P. mexicanus." The smaller size of P. yucatanicus is the only readily apparent difference between the two kinds. The two species are allopatric, but the distance between the known locality of occurrence of P. mexicanus teapensis ( six miles southeast of Palenque, Chiapas) nearest that of yucatanicus (seven and one- half kilometers west of Escarcega, Campeche) is only 175 kilome- ters. It was recognized that the gap could be due to inadequate collecting in the intervening area, and that P. yucatanicus possibly was simply a small peninsular representative of P. mexicanus. Kuns and Tashian (1954:102) reported that the eleven specimens of mexicanus from six miles southeast of Palenque, in northern Chiapas, which they tentatively referred to P. m. teapensis, were smaller than typical representatives of the subspecies. Examination of these specimens in connection with the present report, however, revealed no significant differences in size from specimens of P. m. teapensis in the collection of the Museum of Natural History, and, therefore, no hint of intergradation with yucatanicus. That intergradation does not occur between the two species is evidenced, in part, by the fact that the smallest representatives of yucatanicus occur in that part of the range nearest the geographic range of the larger mexi- canus. Moreover, results of a detailed study of the morphology of P. yucatanicus and P. mexicanus indicate that they are distinct species. Skull. — P. yucatanicus is smaller than P. mexicanus, and has on the average a somewhat less beaded supraorbital ridge. The skulls of the two species closely resemble each other in being elongate and narrow, and in having small auditory bullae. Teeth. — Both species have small, stocky premolars and molars, but the molars of P. yucatanicus are more complex. The accessory ridges (mesolophs of Hooper, 1957:9) are well developed and fused with the labial styles ( mesostyles of Hooper, loc. cit. ) whereas in P. mexicanus the accessory ridges are reduced and are incom- pletely or not at all fused with the styles (Hooper, 1957:36). The same condition obtains in the lower molars. The patterns proved to be constant in P. yucatanicus and P. m. teapensis, in all specimens 426 Univ. of Kansas Publs., Mus. Nat. Hist. with unworn teeth that were examined. The dental topography of the two species is illustrated in Figure 1. Baculum. — The baculum in most specimens of mexicanus is no- ticeably curved ventrally whereas it is straight or only slightly curved ventrally in P. yucatanicus. The degree of curvature may be an artifact of preparation. The baculum of yucatanicus, al- though smaller than that of mexicanus, is larger in relation to the length of the body, and the base is wider in relation to the length of the bone. The bacula of yucatanicus and mexicanus are illus- trated in Figure 2. Hyoid apparatus. — Although smaller, the hyoid apparatus of P. yucatanicus is essentially like that of P. mexicanus in configuration. The entoglossal process of the basihyal bone seems to project slightly farther anteriorly in yucatanicus. Auditory ossicles. — The ear ossicles of the two species are similar although the malleus, incus, and stapes of yucatanicus are smaller. Hairiness of tail. — The tails of both species are sparsely haired and have concentric scales (or rings) overlapping distally and re- sembling paper cups placed one within another. Hairs extend posteriorly in groups of three from the surface of each scale at the point of farthest overlap of the preceding scale. Each group com- prises one long center hair and two short outer hairs; the center hair is approximately three scale widths in length, and the shorter hairs are about two scale widths in length. In yucatanicus the individual hairs on the tail are wider and the groups of hairs are situated closer together. NON-GEOGRAPHIC VARIATION The results of my detailed study of variation owing to age, secondary sexual features, and individualism (measurements available in a dissertation filed in the University of Kansas Library) were essential in recognizing geographic variation but are not recorded here because they do not differ significantly from the published results of previous studies of other species of Peromyscus by other workers. Hoffmeister (1951), for example, has recorded such data for Peromyscus truei. Post- juvenal molt (from juvenal to subadult pelage) and post-subadult molt (to adult pelage) of Peromyscus yucatanicus are similar to those of P. truei (Hoffmeister, 1951:4-5), P. boylii (Brown, 1963:467-468), and P. maniculatus gambeli (Collins, 1918:76-78 and 1923:58-63), and therefore a detailed description of the several molts in Peromyscus yucatanicus is not included in this report. Juvenal pelage is a drab gray, and resembles the same pelage in other species of Peromyscus. A pale gray pelage in several young specimens ap- peared to be intermediate between typical juvenal and subadult pelages. It Yucatan Deer Mouse 427 may well be that another rather ill-defined molt and pelage occurs between the juvenal and subadult pelages in this species, as was suggested by Hoff- meister ( 1951:5-6) for P. truei. Adult and subadult pelages were not always easily separable. In general, the adult pelage is a brighter ochraceous on the sides and dorsum, the ochra- ceous subterminal bands of the guard hairs being long. The underparts are yellowish white, and the hairs are often pure white or yellow, lacking a dark band. Subadult pelage is more dusky dorsally, the dark terminal band being long and the subterminal band short. The underparts are pale grayish with litde or no admixture of yellow. In adults seasonal molts are not so easily defined as are post-juvenal and post-subadult molts, and appear to be irregular in pattern and somewhat atypical of molt described for other species of the genus. Adults molt twice each year, once in spring and once in autumn. In theory two molts per year would seem to be unnecessary in mice inhabiting tropical climates. The distinct wet and dry seasons of the Yucatan Penisula may provide the environ- mental stimulus for two seasonal molts in P. yucatanicus, or, more probably, the evolutionary conservativeness of molt sequence has led to retention of an autumnal and a spring molt. Readings of reflection of red and green wave lengths were taken for indi- vidual specimens according to season. In general, winter pelage of adults is paler than summer pelage. Mean readings of color reflection from both seasonal pelages from three areas within the range of P. yucatanicus are given in Table 1. Table 1. — Average Colok Reflection Readings of Red and Green Wave Lengths for Summer and Winter Pelage of P. yucatanicus From Three Areas on the Yucatan Peninsula. Summer Winter Locality N Red Green N Red Green Northeastern Quintana Roo Central Yucat&n . 2 11 5 10.7 11.6 7.9 6.7 6.3 4.4 12 11 27 14.6 12.0 10.6 7.0 6.3 Southwestern Campeche. . . . 5.5 GEOGRAPHIC VARIATION The Yucatan Peninsula is a relatively flat limestone plain, devoid of major topographic features, and for the most part lacks perma- nent surface drainage. Paynter ( 1955:10) characterized the climate as "tropical, with a relatively constant average temperature through- out the year, and with moderately pronounced dry and rainy seasons." The vegetation varies from xerophilous scrub on the northern coast to quasi-rain forest in the central and southern parts. 428 Univ. of Kansas Publs., Mus. Nat. Hist. 30 CO O W H S w < ►J o w o (T1 cj -3 s.s 8 M «*i «*h - cu -G CO s-. o3 w ,0 G O -5 a> co t-3 ° •+3J-I o3 -u 1*3 C QJ be £ S3 co j- ^3 o~ ° ^ g bC<*-. ^5 h-1 fcH CD CM coco • 1 e C3i o -e so S 10 "3 1— 1 10 S" ft CM 1— 1 CM 1— 1 1 >— 1 CM CD' 'OS CO -H I— I co 00 -* 00 CM I CO CM (M CM O cm1^; fs CM 00 10 «o ■ I 10 CO CO CM CO 01 t^CO • I >o^ co ^2 00 10 10 • 1 »OCM CM >CM ^CO CI "3 CM id Tt* 2^ CO c o o 00 ~ d 10 0 C3 T3 00 CO CM "A CM° CM 07 »o OS CO CM •CM CO 1 00 CM ■ CM O CM ' CO "^ ~CM o ^2 Of^ _ Sco ^co C3 2- ^^ CM CO CM i. CO ^-^ CM "•— ' 1— t »— 1 va T— I CO »-H e C3> ^"■^ *"^ 01 ^^ ^3 V i~ co S3 0 00 S t^ O ^ 10 °s ^CM 0 ^ CO O co0^ C?CM «) s ^ k^ CM°t W C3 a. feet 00 *l &™ t^- ^ co t^ CO £ CM CM P, CM tf CM ^ 1 ' s"^' s~^ *^ Ifl CM CM' O CM OO CO 1 OSO co OS 0 0 i>o •CM CO 1 OSO OS CO Yucatan Deer Mouse 429 "* co IO CM od OO 1 CM CO I OCO . 1 COCO coco CD 00 lOCO iO »o >o IO v / ^ _^ ^^ f ^ 1-H o o t^ CDS ,*« »s ^^ ^9 2^ £co_ ^d CM »-H tN i-H I— 1 i-H I-H i-H w ^^ ^^ ^ ^_^ ^_^ r-H CO IO o «S *s OS -*d dob 00 '-'9 So i-H rH<=) <■— N d *^> d i-H r^* i-H N- i— < *»»} i-H i-H s • i-H N*^^ y^/ CO ".^^ /»— N v^_^ v ^ *^~* a ft. o i-H CO © CM i-H CO © ^^ o ,_^ ,_v CD ^-^ ' CO -^— t^ s t^ © "* © •K> e e c T3 o3 29 CM Hi CD s co «£, 1 H © i-H^ CO CD 00^ ^T^ i-H "^ co CD ftn © s i— t i-H CD v-i 1-H v e v-' ••-a 3 3 CD ^^ © cf o "■©• ,— ^ "a co •— ■ N © .•— n e • — s ^ ©> t^ CO 2 "* S i-H a. cd £ -*8 i CD .© © 1 CD ftn _ i s T^d .co ■ i •^ "S CO CM CM CO © gob CD 3 05 en © oo (M e co 1 u CD 00 CD CD d im oo CM CD CD Hi CD e CD c/2 e CD CD e cd , — v a, ^— ^ y. ^ K. ,■ — ^ ^> O CO O o r^>- O CD MCM T3 S O M •*^t 00 cm o"* .CN ^ cod 9i ,_,t^ .CM lOO 00 I-H .o • i-H "* 1 oo ■ r— 1 O 1 o o 2o cot1 2o o CO ^2 T^^ »—l cc2 H J, -9 co CO ~ noO rjj C CM TO I CO o CM X co CM Oi' o CM CM CM ° I CM O co rJH CM ■CM r-H I oo o 00 CD 430 Univ. of Kansas Publs., Mus. Nat. Hist. A transition zone of deciduous forest lies between scrub and rain forest. Quasi-rain forest extends along the east coast of the penin- sula to extreme northern Quintana Roo (see Paynter, 1955:15 and map 2). Size All external and cranial measurements of P. yucatanicus vary geo- graphically; in cranial characters variation is most pronounced in greatest length of skull, zygomatic breadth, rostral length and length of incisive foramen. The dimensions vary from small in the west to large in the east, irrespective of latitude. The pattern of variation, therefore, is generally clinal in nature, although two exceptions to the clinal distribution were noted. Individuals from La Vega, from 5 km. WS W Puerto Juarez, and from Puerto Morelos, all in northeastern Quintana Roo, are noticeably smaller cranially than individuals taken at Pueblo Nuevo X-Can, situated approxi- mately 75 kilometers to the west. The five specimens from seven and one-half kilometers east of Escarcega (in southwestern Cam- peche) are significantly larger in external and cranial dimensions than individuals in the sample from Apazote (approximately 60 kilometers to the northeast). Possibly this difference is the result of small sample size. A comparison of the external and cranial measurements of P. yucatanicus from selected localities is presented in Table 2. I have been unable to correlate changes in external and cranial size with environmental conditions on the peninsula. The facilita- tion of the genetic change (and therefore speciation), and the adaptive significance of the geographic variation in size are un- known. Color Only specimens in winter pelage were used in analyzing geo- graphic variation in color. Mean color reflections of red and green varied from a darker reflectance for individuals from the south (seven kilometers north, 51 kilometers east of Escarcega, red, 10.1, green, 5.5) to a lighter reflectance for specimens from the north (66 kilometers northeast of Merida, red, 16.6, green, 8.7). Color reflections of specimens from Esmeralda and Santa Rosa (west- central Quintana Roo), approximately equidistant between the above two localities, are intermediate (red, 12.1, green, 6.1). This kind of variation is in keeping with Gloger's Rule (that is to say, darker individuals are present in the more humid parts of the range of a species). Yucatan Deer Mouse 431 Variation in color coincides closely with vegetative conditions on the peninsula. Although the gradation is generally north-south, I noted at least one exception. Specimens labeled with reference to Pueblo Nuevo X-Can (in northwestern Quintana Roo) are no- ticeably darker than specimens from localities to the east, north, and west, exhibiting a low reflectance of red and green, presumably due to the effect of the extension of quasi-rain forest northward along the eastern coast of the peninsula. Discussion and Taxonomic Assessment of Variation Two subspecies of Peromyscus yucat aniens heretofore have been recognized: P. y. yucatanicus (type locality, Chichen-Itza, Yucatan) and P. y. badius, described by Osgood (1904:70-71) on the basis of 19 specimens from Apazote, Campeche. P. y. badius was defined by Osgood as: "Similar to P. yucatanicus but darker colored." A comparison of the geographic variation of external and cranial measurements with that of color in P. yucatanicus reveals a dis- cordance, because color varies from north (paler) to south (darker), whereas size varies from west (smaller) to east (larger). Three alternatives for expressing nomenclatorially this observed variation occur to me. One alternative would be to recognize four sub- species that would be characterized and distributed as follows: 1) small, dark mice in the southwestern part of the peninsula ( central Campeche, localities 1-3 on Fig. 2 ) ; 2 ) relatively small, pale mice from the northwest ( localities 4-6 ) ; 3 ) large, usually pale mice from the northeast (localities 7-11); and 4) large, dark mice from southern Quintana Roo (localities 12-14). The second alternative would be to retain the two previously named subspecies, one (P. y. yucatanicus) in the north, composed of populations that are gen- erally paler and that are on the average larger than those to the south (P. y. badius). The third alternative would be to recognize P. yucatanicus as a monotypic species. The geographic area occupied by the Yucatan deer mouse is relatively small. Infraspecific variation is clinal in nature and not particularly marked. Recognition of any of the variants at the sub- species level would, I think, obscure rather than clarify the varia- tion noted. Four subspecies (alternative one) necessarily would be weakly defined. For example, the mice of the northwestern part of the peninsula (represented in my material by specimens from localities 4-6) differ slightly in color, but not in size, from mice to the south of them (localities 1-3), and differ in the reverse from mice to the east (localities 7-11). Complete intergradation 432 Univ. of Kansas Publs., Mus. Nat. Hist. between mice of the four areas and certain local reversals in the mentioned clines would serve to make such a scheme confusing. Recognition of two subspecies, one in the south and one in the north, also would produce weak subspecies for several reasons: 1) the area of intergradation would be larger than the area occu- pied by any one subspecies; 2) there is clinal discordance of size and color; 3) there is local reversal of clinal variation; and 4) no other significant variation is apparant. Therefore, I choose to regard Peromyscus yucatanicus as a monotypic species, albeit varia- ble. P. y. badius is placed in synonomy under P. yucatanicus, which is defined as follows: Peromyscus yucatanicus J. A. Allen and Chapman Yucatan Deer Mouse 1897. Peromyscus yucatanicus J. A. Allen and Chapman, Bull. Amer. Mus. Nat. Hist., 9:8, February 23 (type locality, Chichen-Itza, Yucatan). 1904. Peromyscus yucatanicus badius Osgood, Proc. Biol. Soc. Washington, 17:70, March 21 (type locality, Apazote, Campeche). Geographic distribution. — Yucatan Peninsula of Mexico (Yucatan, and all but extreme southern parts of Campeche and Quintana Roo). See Figure 2. Diagnostic characters. — External: Size medium among species of Pero- myscus (see Table 2); upper parts brownish (in the south) to ochraceous buff (in the north) with an admixture of dusky; underparts yellowish white; orbital ring narrow, dark; tail dusky above, yellowish below except where blotched with darker pigment. Skull: Size medium; braincase narrow, elon- gate; supraorbital border slightly beaded; auditory bullae and teeth small; cusps of upper molars with well-developed labial styles and accessory ridges; lower molars having corresponding stylids and ridges. Baculum: Size me- dium; rod slender, elongate; tip small; base dorsoventrally flattened. Specimens examined, 213 (localities arranged from north to south in each state).— Campeche: (3) Apazote, 18 (USNM); (1) 7 km. N, 51 km. E Escarcega, 14; (2) 7/2 km. W Escarcega, 8. Quintana Roo: (11) 5 km. WSW Puerto Juarez, 5 m., 2; (11) La Vega, 28 (USNM); (JJ) Puerto Morelos, 1 (USNM); (10) Pueblo Nuevo X-Can, 10 m., 12; PA km. S, 1 km. E Pueblo Nuevo X-Can, 1; 2 km. S Pueblo Nuevo X-Can, 5; (7) Santa Rosa, 17 (UMMZ)- 1 km. S Santa Rosa, 2; (7) Esmeralda, 8 (UMMZ); Esmeralda, Laguna Chichancanab, 1; (12) 4 km. NNE Felipe Carrillo Puerto, 20; 2 km. N Felipe Carrillo Puerto, 5; (13) 60 km. N, 16 km. E Chetumal, 3; (14) 27 km. NW Chetumal, 1. Yucatan: (6) 66 km. NE Merida, 9; (9) 6 km. N Tizimin, 4; (5) Merida Airport, 6 km. S Merida, 4; (8) 3 km. N Piste, 10 m., 7; 2 km. N Piste, 12 m., 13; Piste, 3; Cenote Seco, 3 km. E Piste, 3; (8) Chichen-Itza, 21 (17 AMNH, 2 USNM, 1 UMMZ); (4) Calcehtok, 5 (UMMZ); Calcehtok, 500 m. N Casa Principal, 10 m., 1; 500 m. S Hda. Calcehtok, 1. Localities not plotted on the accompanying map, Figure 3 (because undue crowding of symbols would have resulted), are in italic type. Additional records (listed from north to south). — Yucatan (Gaumer, 1917: 117): Silam; Buctzotz; Temax; Tizimin; Izamal; Yaxcach; Xbac. In addi- tion, Hatt (1953:67 and elsewhere) reported remains of P. yucatanicus from five cave deposits in southwestern Yucatan. Yucatan Deer Mouse 433 anterior •—STYLE exterioM- extenor D Fig. 1. A and C. Peromyscus yucatanicus. A. Occlusal view of Ml-2 and ml-2 (KU 92460), X 12. Note the well-developed labial style and accessory ridge. C. Dorsal view of baculum (KU 92442), X 6. Note especially broader base relative to length of bone than in P. mexicanus. BandD. Peromyscus mexicanus. B. (KU 66888), X 12. D. (KU 66899), x 6. Remarks. — Gaumer ( loc. cit. ) reported P. yucatanicus from Cozu- mel Island, but Koopman (1959:237) suspected that the specimens involved were instead P. leucopus. That Koopman probably was correct is evidenced by the fact that a field party from The Uni- versity of Kansas took no P. yucatanicus on Cozumel Island in the summer of 1962, although several specimens of P. leucopus were taken. It is noteworthy that Percy L. Clifton obtained no specimens of P. yucatanicus when he collected mammals at several places in rain forest along the southern borders of Campeche and Quintana Roo in 1963. Therefore, the southernmost records of the species herein reported probably approximate the margin of the range. 434 Univ. of Kansas Publs., Mus. Nat. Hist. 90 87 1 1 21 /l., 4 YUCATAN / 1 ) /• /I0 7 V II J 21 • CAMPECHE i QUINTANA R00 1 13* 3* 1 14 •/^V/ P 2# • 1 # // 1 « // i ,__ . ■ Tl \— KILOMETERS ' M / ? 50 100 7 25 50 18 ""'""1 L-K // MILES _ 1 18 90 87 Fig. 2. Map showing the geographic distribution of Peromyscus yucatanicus. The numbers identify localities listed on page 432, in the paragraph of "Speci- mens examined." Solid circles represent localities from which specimens were examined; open circles are records from the literature. There are two instances in the literature in which misnomers have been applied to P. yucatanicus. Hooper (1957:36) employed the name of P. yucatanensis, and Koopman (1959:237) used P. yuca- tanica. NATURAL HISTORY Habitat. — The preferred habitat of P. yucatanicus seems to be thick brushy or forested areas, but the species has been trapped also in overgrown milpas (grain fields), and in dense grassy situations. Goldman (1951:337) recorded yucatanicus as occurring within the Arid Subzone of the Lower Tropical Life-zone. Recent records of capture indicate that the species occurs also in the Humid Subzone. P. yucatanicus is restricted to the Yucatan Peninsula Biotic Province as defined by Goldman and Moore (1946:360). Associated species. — Species of rodents caught in the same trapline with P. yucatanicus include Heteromys gaumeri, Ototylomys phijllo- Yucatan Deer Mouse 435 tis, Oryzomys alfaroi, O. melanotis, Sigmodon hispidus, Mus muscu- lus, and Peromyscus leucopus. The ecological separation of P. yucatanicus from the above-mentioned species is most likely deter- mined by the local environmental conditions and the number of species present. Of the two most common associates, Ototylomys phyllotis is primarily arboreal in habits, whereas Heteromys gaumeri generally inhabits denser vegetation than P. yucatanicus where the two species occur together (collected field notes, Museum of Nat- ural History, The University of Kansas ) . Where P. yucatanicus and P. leucopus occur in the same areas, yucatanicus is commonly pres- ent in dense forested situations, whereas leucopus is found along roads, in coconut fields, and around borders of milpas. Reproduction. — Available evidence suggests that the Yucatan deer mouse breeds the year around. Information recorded on speci- men labels concerning pregnant or lactating females is as follows (measurements of embryos, in millimeters, indicate crown-rump length ) : Female Data Date KU 93732 3 embs x 16 22 April KU 92437 3 embs x 15 15 July KU 92456 lactating, with 21 July placental scars KU 92492 3 embs x 10 31 July KU 92496 lactating 15 August KU 92499 3 embs x 22 15 August KU 93720 3 embs x 9 26 December Juvenal mice have been taken in March, July, August, November, and December. Parasites. — External parasites were collected from several speci- mens of P. yucatanicus by a University of Kansas field party on the Yucatan Peninsula in the summer of 1962. The following parasites have thus far been identified: louse, Hoplopleura hesperomydis (from KU 92471, female); ticks, Ixodes sp. (from KU 92461, female) and Amblyamma cajennense (from KU 92454, male). EVOLUTION AND SPECIATION The genus Peromyscus is generally considered to have originated no earlier than early Pliocene (Simpson, 1945:84; Wilson, 1937:50). If it can be assumed that the original area of development of a genus is indicated by the presence today of many more or less specialized species, then radiation of the genus Peromyscus may have taken place in central Mexico. Peromyscus yucatanicus is closely related to P. mexicanus as indi- cated by several characters. P. yucatanicus probably evolved from 436 Univ. of Kansas Publs., Mus. Nat. Hist. a Peromyscus mexicanus-like stock, the progenitors of which are unknown. No evolutionary or paleontological evidence is available for eluci- dating the formation of P. yucatanicus. Divergence of yucatanicus and mexicanus from each other may have resulted from peninsular and ecological isolation, but major physiographic or climatic barriers are not known to have separated the Yucatan Peninsula from the main axis of Mexico subsequent to the formation of the genus. Present distributional patterns of P. yucatanicus and P. mexicanus suggest divergence of the two species by ecological separation associated with vegetational changes. P. mexicanus is primarily a forest dweller of highland areas; the species is generally uncom- mon on the coastal plain (Hall and Dalquest, 1963:309). The habitat of P. yucatanicus is arid deciduous and quasi-rain forest, and scrub. Both species seem intolerant of tropical rain forest. During one of the glacial periods in the Pleistocene the progenitor of the two species may have inhabited a continuous area encompassing the eastern mountainous and coastal regions of central Mexico. As deglaciation occurred, tropical rain forest may have proliferated along the eastern coast of Mexico, separating two large segments of the range and forming a barrier to gene flow. Subsequently, P. yucatanicus and P. mexicanus could have diverged. The fact that the smallest representatives of P. yucatanicus are found at the margin of the range that is nearest geographically to the range of P. mexicanus suggests that character displacement probably occurred. In this regard, sympatry could have resulted later in the Pleistocene when deglaciation caused a partial sub- mergence of the Yucatan Peninsula (Paynter, 1955:10). At that time a limited amount of habitat would have been available, and the range of yucatanicus may have shifted southward, where it came in contact with that of the parental stock. This hypothesis would appear to discount the tropical rain forest as being a totally effective barrier to dispersal of yucatanicus and mexicanus. Per- haps the restriction of habitat during deglaciation necessitated an invasion by yucatanicus of less tolerable situations than those nor- mally occupied. Character displacement possibly occurred only recently, and the gap between the ranges of P. yucatanicus and P. mexicanus may be simply an artifact, namely lack of knowledge of the fauna of the area. Speciation probably occurred before the Wisconsin glacia- tion, since it seems that insufficient time has elapsed after the last Yucatan Deer Mouse 437 glacial period for the differentiation of yucatanicus, subsequent meeting of its range with that of mexicanus, and the development of character displacement. LITERATURE CITED Allen, J. A. and Chapman, F. M. 1897. On mammals from Yucatan, with descriptions of new species. Bull. Amer. Mus. Nat. Hist., 9:1-12, February 23. Brown, L. N. 1963. Maturational molts and seasonal molts in Peromyscus boylii. Amer. Midland Nat., 70:466-469, October 18. Collins, H. H. 1918. Studies in normal moult and of artificial induced regeneration of pelage in Peromyscus. Jour. Exp. Zool., 27:73-99, 15 figs., October. 1923. Studies of the pelage phases and of the nature and color variation in mice of the genus Peromyscus. Jour. Exp. Zool., 38:45-107, 57 figs. Gaumer, G. F. 1917. Monografia de los mamiferos de Yucatan. Dept. de Talleres Grafa- cos de la Secretaria de Fomento, Mexico, xli + 331 pp., 57 pis., 2 photographs, 1 map. Goldman, E. A. 1951. Biological investigations in Mexico. Smiths. Misc. Coll., 115:xiii + 1-476, frontispiece, 71 pis., 1 map, July 31. Goldman, E. A. and Moore, R. T. 1946. The biotic provinces of Mexico. Jour. Mamm., 26:347-360, Feb- ruary 12. Hall, E. R. and Dalquest, W. W. 1963. The mammals of Veracruz. Univ. Kansas Publ., Mus. Nat. Hist., 14:165-362, 2 figs., May 20. Hatt, R. T. 1953. The mammals, pp. 45-77, 2 pis., in Hatt et al, Faunal and archeo- logical researches in Yucatan caves. Bull. Cranbrook Inst. Sci., 33:1-119, illustrated, March. Hoffmeister, D. F. 1951. A taxonomic and evolutionary study of the pifion mouse, Pero- myscus truei. Illinois Biol. Monog., 21:x+ 1-104, 5 pis., 24 figs., November 12. Hooper, E. T. 1952. A systematic review of the harvest mice (genus Reithrodontomys) of Latin America. Misc. Publ. Mus. Zool., Univ. Michigan, 77:1- 255, 9 pis., 24 figs., 12 maps, January 16. 1957. Dental patterns in mice of the genus Peromyscus. Misc. Publ. Mus. Zool., Univ. Michigan, 99:1-59, 24 figs., March 28. 1958. The male phallus in mice of the genus Peromyscus. Misc. Publ. Mus. Zool., Univ. Michigan, 105:1-24, 14 pis., 1 fig., December 29. Koopman, K. F. 1959. The geographical limits of the West Indies. Jour. Mamm., 40:236- 240, May 20. Kuns, M. L. and Tashian, R. E. 1954. Notes on mammals from northern Chiapas, Mexico. Jour. Mamm., 35:100-103, February 10. 438 Univ. of Kansas Publs., Mus. Nat. Hist. Osgood, W. H. 1904. Thirty new mice of the genus Peromtjscus from Mexico and Guate- mala. Proc. Biol. Soc. Washington, 17:55-77, March 21. 1909. Revision of the mice of the American genus Peromyscus. N. Amer. Fauna, 28:1-285, 8 pis., 12 figs., April 17. Paynteb, R. A., Jr. 1955. The omithogeography of the Yucatan Peninsula. Bull. Peabody Mus. Nat. Hist., Yale Univ., 9:1-347, 4 pis., 2 maps. Simpson, G. G. 1945. The principles of classification and a classification of mammals. Bull. Amer. Mus. Nat. Hist., 85:xvi + 1-350, October 5. Wilson, R. W. 1937. Pliocene rodents of western North America. Publ. Carnegie Inst. Washington, 487:21-73, 2 figs., July 23. Transmitted March 18, 1965. □ 30-7118 ■Ir* 3 2044 093 361 483 Date Due