Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. Unirep Srates DeparTMENT OF AGRICULTURE, Bureau or Brotoercan SuRVEY, Washington, D. C., September 4, 1920. _ Sir: I have the honor to transmit herewith a report of the work of 0. Respectfully, E. W. NeEtson, Chief of Bureau. 2 “Hon, E. T. Merepirn, Secretary of Agriculture. WORK OF THE BUREAU OF BIOLOGICAL SURVEY. The activities of the Bureau of Biological Survey are conducted inder four divisions: (1) Investigations of the food habits of North nerican birds and mammals in relation to agriculture, in charge of . A. K. Fisher; (2) biological investigations, with special reference the habits and geographic distribution of native animals and plants, n charge of E. A. Goldman; (3) supervision of national mammal and bird reservations, in charge of Dr. G. W. Field until December 6, (919; in charge of H. F. Stone since July 1, 1920; (4) administration f the migratory-bird treaty act and enforcement of the Lacey Act ulating the importation of birds and wild mammals and the inter- tate shipment of game, in charge of George A. Lawyer. From the time of the or ganization of the Biological Survey its main urpose has been to study the habits and distribution of our wild urds and mammals, to assist in the conservation of the beneficial and larmless species, and to devise practical methods for the control of those classed as injurious. The files of the bureau contain an un- alleled volume of information drawn from 35 years of field work its experts in all parts of North America and from thousands of sollaborators as well as from published sources. During recent years a appreciation of the value of our wild life has orown rapidly, and constantly increasing demands are voiced for the sonservation of the useful and harmless forms. In this same time hanging conditions due to increased occupation of the country have : ed certain species both of birds and of mammals to become so eriously injurious to crops, forestry, and stock growing that it has ecome necessary to develop effective methods for controlling or de- troying them on a large scale. 11622201 2 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. As a result, the demands from many directions for increased activi- ties on the part of the bureau far exceed the possibilities of meeting them with the funds available. As in other branches of the Govern- ment, the bureau suffers from the loss of skilled employees due to. larger salaries paid outside the service and from the necessity of pay- ing higher prices for services and material. ECONOMIC INVESTIGATIONS. With the rising values of all food products and the urgency of increased production, the suppression of crop and stock destroying pests becomes increasingly important. At the time this work was launched on a large scale in 1917 it was estimated that injurious native rodents, as “eround squirrels, prairie dogs, pocket gophers, jack rabbits, and field mice, each year destroyed crops and forage in a United States valued at seorosimavely 300,000,000; house rats annually destroyed about $200,000,000 worth of food products and other property; while predatory animals were killing live stock having a value between $20,000,000 and $30,000,000. Recent inves- tigations of some of the smaller ge as kangaroo rats, show that the myriads of these animals also, which are largely seed and root eaters, have a far greater destructive effect on both cultivated crops. and native forage grasses than has been realized. The Biological Sur vey has demonstrated the possibility of elimi- nating the larger part of these losses. The destruction of mammat pests ‘has been so successful that farmers and stock growers of the West, where such losses are greatest, are increasing ‘their demands upon the bureau for more extended work to a degree which becomes embarrassing, in view of the limited Federal funds available. The fact that the unoccupied lands of the public domain are the main harboring and breeding places of these pests makes the need for added funds more pressing, since private landowners undertake to destroy the pests on their holdings and ask that the Government de- stroy them on public lands adjoining. The reduction of available funds by the discontinuance of the war emergency fund on June 30, 1919, together with a steady increase in the wages of men and in the cost of materials, has handicapped the bureau in its work. The amount of money being appropriated for cooperative undertakings by States, counties, associations, and individuals has rapidly increased until during the present year it has reached the sum of $1,114,000. This tangible evidence of appreci- ation of the practical value of the work is due to actual demonstra- tion of increased forage and stock production on the ranges and of additional crop yie Jds on farms through the elimination of mammal pests at a re sasonable cost. A conservative estimate of the saving effected during the year from the campaign against rodents amounts to about $10,000,000, and from operations ag inst predatory animals to about $6,000,000. The predatory-animal and rodent-pest suppression work is defi- nitely organized in 14 districts covering 18 States, the districts being in charge of inspectors with trained assistants cooperating with the States Relations Ser\ vice, State and county officials, and community BUREAU OF BIOLOGICAL SURVEY. 3 ganizations, as farm bureaus and stockmen’s associations. The dis- ricts are as follows: 1. Washington. 8. Utah. 2. Oregon. 9. Nevada. 3. Idaho. 10. California. 4. Montana. 11. Arizona. 5. North and South Dakota. 12. New Mexico. 6. Wyoming-Nebraska. 13. Oklahoma-Arkansas. 7. Colorado-Kansas. 14. Texas. As soon as funds are available it is planned to assist in the organ- ization of cooperative campaigns against mammal pests in Iowa and ‘Minnesota. Assistance in eliminating losses from rodents is being ‘requested in many other States from the Mississippi Valley to the Atlantic coast. PREDATORY ANIMALS. _ A force of skilled hunters and trappers, varying from 300 to 400 in number, were employed under bureau supervision during the year to destroy predatory animals. A part of these men were paid by the Federal Government and a part by cooperating States, counties. live- stock associations, and individuals. For this purpose $272,000 was ex- _ pended by cooperators in Arizona, Colorado, Montana, North Dakota, ‘Nevada, California, New Mexico, Oregon, Washington, Texas, Utah, and Wyoming. As heretofore, the skins taken by each hunter become the property of the organization or individual paying his salary. The numbers and kinds of skins taken by these hunters during the year were as follows: COU NIRS a ES Se TEES SS es ee re Se ms 523 CaO eS = = eee ek Se Sey ee ee eee ee ee 21, 558 GUT ATO: Hy TAS) a a as CS ae a Se a ern 189 {BSG OCCURS Spee a a Ee a na ER aR er SE ES See Ls oh 2, 987 “COEMMEIO I, IAMS bs at i Raa Se a ee 10 leSipe Veae Caen fT eee Sd ee LSS See bee oe eee 94 BARC tet cs seca ae a ee a A aN ae eS he 25, 361 $42,048.80, making a total to date of $240,791.65 turned into the United States Treasury in connection with this work. In addition, extended poisoning operations were conducted over ‘great areas, especially in Wyoming, Utah, Nevada, Arizona, and ew Mexico. Judging from the dead bodies found, the number of coyotes killed in this way was approximately the same as the total of all animals trapped. It has become evident that systematic poison- ng operations on a large scale, employing modern methods under areful supervision, are a most economical and practical means of reducing the number of coyotes. Extended experiments have been | mee ucted both at the Albuquerque, N. Mex., laboratory and on the ranges and forests. Good progress has been made in developing more effective poisons as well as improved methods of establishing stations and distributing poison for coyotes. These have been suc- cessfully applied in organized cooperative campaigns. _ In many large grazing ranges, mainly through poisoning followed Wy systematic trapping, coyotes have been so thoroughly eliminated that sheep owners, with practically no losses, now permit their sheep graze freely without close herding. Important lambing grounds 4 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. | have been similarly protected so that ewes and lambs are allowed to range freely without being driven to bedding grounds at night. This has made it possible to carry at least one- third more ewes on a | lambing ground, to save a higher percentage of lambs dropped, and | at the same time to reduce the expense of handling. The practical elimination of coyotes from the range country will result also in a | great increase in both the wool and the meat output. In addition to the sheep they kill, coyotes destroy many goats, calves, pigs, and domestic fowls, and are among the most destructive enemies of large and small game, including both birds and mammals. The bobcat ranks next to the coyote in destructiveness to sheep and goats, while wolves, mountain lions, and some bears cause heavy losses of cattle and horses. Not all predatory animals are equally destructive of live stock. Some individuals become strongly marked among their fellows be- cause of their depredations. This is particularly the case with moun- tain lions, wolves, and coyotes. As illustrative of losses caused by these animals, the following instances, which have occurred during | the year, may be cited: One mountain lion killed by a bureau hunter near Reosevele Ariza had a record of destroying 50 calves and 3 colts on one ranch besides many killings on other ranches. A trapper in New Mexico found 23 calves killed by a notorious wolf which he succeeded in taking; another wolf had killed 30 head of cattle in Wyoming before being captured; a pair of wolves killed | near Split Rock, W. yo., were each reported to have killed from — $1,500 to $2,000 worth of stock a year; another pair of wolves which — were taken were known to have killed 100 sheep and 7 colts for one rancher and 50 sheep for another during the month before they were captured. Coyotes in New Mexico were reported taking from 3 to 6 lambs > each night from one ranch, notwithstanding the fact that Mexican herders were sleeping in close proximity and that the usual devices. were employed to keep the animals away. After a bureau hunter had killed 7 large, old coyotes and 2 wildcats in the vicinity the losses entirely ceased. In Custer County, S.'Dak., during a period of six or seven years, one wolf still at large is credited with having killed more than $25, 000 worth of cattle. Other notorious individual stock- killing animals occur in all parts of the range country. Whenever a report of the activities of such predatory animals is _ made to a district inspector of the bureau, expert hunters are detailed to effect their capture. In this way the careers of many of the most | notorious stock killers of the western ranges have been ended. RABIES. Predatory animals are carriers of rabies, which still persists in California, Nevada, Utah, Idaho, Oregon, and Washington. The destruction of these animals through the campaign led by this bureau has greatly reduced the occurrence of the disease and the losses caused ‘by it. Now, whenever an outbreak of rabies is reported, trappers are concentrated about the locality, the affected animals’ are soon destroyed, and the disease promptly disappears. But for the BUREAU OF BIOLOGICAL SURVEY. 5 continuance of this preventive work rabies would quickly become as disastrous an epizootic as when its control was first undertaken. CONTROL OF RODENT PESTS. The work of rodent eradication has made a steady, consistent growth both in territory covered and in thoroughness of organiza- tion. In this the bureau has continued to cooperate through the States Relations Service with the State extension or ganizations, in- eluding county agents and farm bureaus. Wherever other State or local organizations were available, as State departments of agricul- ture and agricultural commissions, they also have been enlisted in the movement. The Forest Service has cooperated heartily in units of ‘operation involving national forests, while the Office of Indian Affairs of the Department of the Interior has joined similarly in work on Indian reservations. _ This cooperation, which has united all Federal, State, and local agencies in a carefully planned, concerted drive against rodent pests, has greatly increased the extent and effectiveness of the work. Under the leadership of bureau specialists detailed to organize and conduct these campaigns, rodent eradication has become one of the major ‘projects of farm bureaus and of county agents in the territory now ‘districted. The definiteness and value of the results accomplished ‘and the promptness with which these returns on the effort and investment are secured have made this work one of outstanding im- ‘portance in the movement to increase crop, forage, and live- ‘stock ‘production. Detailed plans for the organization and conduct of ‘these cooperative campaigns are prepared i in consultation between the district representatives of the Biological Survey, the State extension director, and the county agents. The bureau assumes the cost of operations on Federal lands, the State officials on State lands, and the farmers and stockmen pay the cost of work on private lands either directly or through taxes levied by the counties. Concerted campaigns systematically organized to destroy rodent pests over large areas of Federal, State, and private lands are proving an entir ely practic al way of coping with rodent pests, and have made it possibie for the first time in the history of the country to make effective headway against them on a large scale. ~ In addition to the advantage derived by individual landowners from these concerted attacks under the guidance of bureau experts, farmers and stockmen have been saved many thousands of dollars a year by a plan of cooperative purchase of strychnine and other materials used in the poison operations. This was devised and put into effect by the bureau, and by it the enormous quantity of over ‘4 tons of strychnine has been arranged for and supplied at a very ‘Material saving in cost. In Idaho officials report that not only has this saving in that State alone amounted to $21,000 during the year, but also they have been enabled to secure the large quantities required “promptly at the time needed for the most effective prosecution of the ampaign. This latter feature has been most important in the de- velopment, without serious interruption or delay, of the extensive ‘rodent eradication campaigns during the last three years. The areas seriously infested by rodent pests in the States west of he Mississippi River comprise more than 200,000,000 acres. Field 6 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. : operations during the last four years have shown that the worst of these pests, as prairie dogs, certain species of ground squirrels, and pocket gophers, can be eradicated from a great part of the farming — and best forage-producing regions of the West at a cost which is _ merely nominal as compared with the annual increase in the produe- tion of the land. The large and constantly growing expenditure of — funds and application of labor by cooperating farming and stock- raising communities are conclusive evidence of the practical char- acter of these campaigns. Under the modern methods of the bureau, the first time the rodents are poisoned over a large area from 85 to 98 per cent of the animals are killed. This accomplished, follow-up measures to complete the work are organized as needed during the same and subsequent seasons. PRAIRIE DOGS AND GROUND SQUIRRELS. Prairie dogs and ground squirrels are the most widespread and conspicuously destructive rodents affecting cultivated crops and range grasses in the States west of the Mississippi River. They — do their damage by digging out the planted seeds and cutting down the growing grain until harvested, by eating off alfalfa, clover, bean, pea, and similar legume and hay crops, and by feeding on forage grasses and digging out their roots, thus destroying the stand. Lands thus denuded of native grasses are often subject to serious erosion, resulting in permanent damage to the soil. Prairie dogs occur from Texas north to North Dakota and Montana and from Kansas west to Utah and Arizona. Ground squirrels of several species live in vast numbers over all of the States west of the Missis- sipp1 River, involving all of the area occupied by prairie dogs, but becoming most conspicuously destructive in the Northern and West- ern States, including the Dakotas, Montana, Wyoming, Idaho, north- ern Utah and Nevada, Washington, Oregon, and California. The plans of organization, the seasonal work, and the methods of extermination for eradication campaigns against both these groups of rodent pests are essentially the same. The details differ some- what, however, both with respect to the species concerned, the sea- sonal, weather, and crop conditions, and the topography of the country. The local representatives of the Biological Survey care- fully observe and study these features and apply the measures which have proved most effective and economical. Particularly notable results are now being secured on a large scale in the campaigns against prairie dogs in New Mexico and Arizona. An illustration of this work is furnished in one especially valuable range area in Sulphur Springs Valley, Cochise County, Ariz., a tract 12 miles long and 4 miles broad, involving 30,700 acres, which was completely cleared of prairie dogs last spring. Adjoming range occupants then appealed to the inspector in charge to assist them in conducting the work over their areas, with the result that by June 30 three-fourths of the area in both Cochise and Graham Counties was_ completely cleared of prairie dogs. Work to clear the remaining” portions of these counties is progressing rapidly. The progress made in eradicating a very heavy infestation of prairie dogs from the raluable range areas of Moreno Valley, northern New Mexico, is an= other good example of the advance which is being made in the or-— ? BUREAU OF BIOLOGICAL SURVEY. 7 ganized campaigns against these pests. In Kansas, after years of ffort, extermination of prairie dogs was accomplished except for a few scattering small towns; through neglect of landowners to com- plete the work, reinvasion of adjoining cleared areas is beginning to occur. Effort is now being concentrated upon these small areas of infestation, involving 25 to 40 acre tracts, which are widely scattered ‘throughout the middle and Ge counties. Similar illustrations may be cited of effective work in the enor- “mous campaigns now being waged against ground squirrels. In Camas Prairie, a fertile valley “inclosed by “Mountains in Camas County, Idaho, where a heavy infestation of Columbia ground squirrels. was on the point of driving out the settlers, relief was afforded through the organization of a campaign against the pests, with the result that at present scarcely a ground squirrel can be found in this area, involving 59,000 acres. In ‘North Dakota the Rich- -ardson ground squirrel, commonly known as “ gopher,” formerly caused an annual crop loss estimated by State officials at $6,000,000 to $9,000 000, depending upon seasonal conditions. The er adication compaigns have now progressed to a point where in many counties these ground squirre!s are no longer looked wpon as a menace by the landowners, but merely as occasional objects of interest and curiosity. There is a strong tendency under these circumstances for landowners to discontinue the concerted campaign to complete their eradication. Every effort, however, is being made to have this work continued in such counties in order to prevent any possibility of the animals increasing to a point where they may again become destructive of crops. Indolence and neglect can be the only possible ‘reason for such a condition arising, as under the leadership of the bureau and county agents the farmers have become thoroughly fa- miliar with and experienced in effective measures for destroying these animals. i In the campaigns against prairie dogs and ground squirrels dur- ‘ing the year, 19,117 737 acres of Federal, State, and private lands Were given a first poison treatment, and follow-up work was done on 15,172,709 acres. Through State and county appropriations and funds expended by individual landowners, cooperative, funds were contributed amounting to $841,909. The quantity of poisoned grain ‘distributed amounted to 1 610 tons, while the number of farmers ‘and stockmen actively cooperating numbered 121,435. The work ‘resulted in a saving of crops for the year estimated at $10,000,000. POCKET GOPHERS. Extensive work has been done during the year in demonstrating “met! 10ds of destroying pocket gophers “and organizing community “campaigns against them in Kansas, Nebraska, Tdaho, Oregon, New Mexico, and Arizona. Many farmers report killing as high as 95 per cent of the pests with one application of poison. The animals occur in every State west of the TS pees River, and are especially jurious to alfalfa and grazing lands, hay meadows, orchards, and oot crops. They often ruin the stand of alfalfa by cutting off the fap roots, and in Kansas, State officials estimate the annual loss to e alfalfa growers alone from this source at $5,000,000. Pocket gophers greatly reduce the quantity of hay that can be harvested, 8 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. both by injuring the stand and by piling up mounds of dirt over considerable portions of the crop; these mounds interfere with cut- ting the hay and frequently damage the harvesting machinery. In Kansas and Ne braska, where the pocket gopher is the most serious rodent pest affecting’ the producers, the efforts of the bureau representatives are concentrated particularly upon the organization of effective community campaigns for its eradication from farming districts. Excellent progress has been made and a foundation laid for more extensive operations during the coring year. In Arizona pocket gophers caused very serious losses in orange and grapefruit orchards by gnawing the roots of trees and thus killing them. The burrows of pocket gophers in the banks of irrigation ditches have resulted in great damage in parts of Arizona, Idaho, and other irrigation States “by causing breaks, which were followed by serious loss of water at critical periods, by the inundation and destruction of crops, and by large expenditures for repair of the ditch banks. Extensive poisoning “operations were organized with a view to de- stroying the pests in such situations and preventing damage of this character. In Arizona chambers of commerce, associations of orange and grapefruit growers, water users’ associations, and others joined actively with bureau representatives in conducting these campaigns. The Office of Indian Affairs cooperated by poisoning these animals on considerable areas of the Moqui and Parker Indian Reservations in Arizona. The Forest Service also has given active cooperation in Nebraska, Oregon, and other States. The same general lines of procedure are followed in initiating and organizing campaigns for the destruction of pocket gophers as in the case of other rodents, and, with a like cordial response by the people interested, important results were attained in protecting crops and property from damage by these animals. JACK RABBITS AND COTTONTAILS. Jack rabbits are seriously destructive in many of the Western States. They frequently concentrate in enormous numbers in grain fields, orchards, vineyards, and other cultivated areas by moving in from surrounding sagebrush or range. In such instances they com- pletely devastate ‘large fields of growing grain, eat off the crowns of the young alfalfa, and entirely destroy valuable orchards and vine- yards that have been built up only after large expenditures and years of unremitting toil. Pathetic instances have occurred where orchards representing the work and savings of a lifetime and constituting the sole reliance of the owners for future support, have been brought to a bearing age only to be destroyed in a single night by jack rabbits, During the ‘winter these animals also congregate ‘about otek of hay and grain provided for winter stock feed, and frequently eat around and undermine them to such an extent that the stacks topple over and become practically a complete loss. The rabbits also make heavy inroads on the crop of long staple cotton, an important and rapidly developing feature of production under irrigation in Arizona. Last year one producer near Chandler, Aviz., lost from this source his en- tire cotton crop valued at $2,500. This year a campaign was organ- ized in this vicinity to destroy the rabbits, and in it many thousands BUREAU OF BIOLOGICAL SURVEY. 9 f them were killed; as a result, no damage has since resulted to the otton crops in this locality. _ Campaigns for the destruction of jack rabbits were organized on large scale in Idaho, Oregon, Washington, Nevada, Utah, and Ari- ona under the leadership of bureau representatives and along co- “operative lines similar to those employed in combating other rodents. In some instances the destruction of these animals was accomplished through extended poisoning operations. In Lincoln County, Idaho, farmers reported an average of 400 rabbits killed with each ounce of “strychnine used, while two farmers in Gooding County reported killing 1,000 rabbits with each ounce. Minidoka County reported ‘killing 40,000 rabbits in their poisoning campaign. Great numbers of jack rabbits were also destroyed by organized drives in these ‘States. In some instances the animals were shot as the drive pro- -gressed toward a point of concentration made by converging fences or natural barriers. In others they were driven into fenced in- ‘closures and killed. The destruction of as many as 10,000 jack rab- Dits resulted from individual drives of this character. Farmers re- port practically complete protection of their crops the present season in localities where these campaigns were conducted. _ Many thousands of skins of the rabbits thus killed were cured and ‘marketed at good prices. Wherever it was practicable to do so the carcasses of unpoisoned rabbits were also prepared and shipped to ‘city markets for human consumption; in other cases they were util- ized as feed for chickens and hogs. In some localities it was possible to keep jack rabbits under control merely by bringing the market “value of the skins and carcasses to the attention of the people. Complaints of damage by cottontail rabbits were received from peany localities throughout the country. As an example of the de- “structiveness of cottontails may be cited a new 3-acre vineyard ‘planted during April, 1920, in a foothill location in Tulare County, Calif. Before the end of May the vines had been completely de- ‘stroyed, the rabbits even digging down to get at the tender sprouts. This delay of a year in establishing the vineyard, together with the money expended on it, involves the loss of hundreds of dollars and is an illustration of the kind of damage done in numberless places on a great variety of garden truck and or rehard er ops. Advice covering methods of control by means of properly built woven-wire fences and the employment of poisons and traps has been given numerous in- uirers desiring to eliminate losses from this source. MICE, WOOD RATS, AND COTTON RATS. Damage by various kinds of meadow and pine mice in orchards as been very widespread, extending from the orcharding sections of Virginia, Maryland, Pennsylv ania, and New York west to Washing- on, Oregon, and Idaho. In the last three States assistance was ren- dered the orchardists through the bureau’s regular force of experts ngaged in local rodent-eradication work, and effective measures of destroying these pests were demonstrated. In the Eastern States orchardists, florists, and truck farmers were aided through circulars nd bulletins describing methods of eradication. In a few instances it was possible to detail representatives from the Washington office 0 near-by points to demonstrate effective procedure. d1622—20——2. — 10 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. Wood rats have continued to do damage in some localities, es- pecially in forest and nursery plantations throughout the West. As cases of this kind were reported they were dealt with by representa- tives of the bureau in tie territory affected by means of written in- structions or demonstrations. Cotton rats and rice rats have been responsible for considerable damage in Florida to the sugar-cane crop. Effective methods of poisoning these animals were “determined and the planters advised regarding practical procedure. BEAVERS AND WOODCHUCKS. In some localities, especially in the State of Washington, beavers caused considerable damage to orchards and farm crops as well as to timber in areas along streams where they construct their dams and houses. Investigation disclosed that in many cases the damage was sufficiently serious to warrant removal of the animals. Arrange- ments were made with State game officials for the necessary captures and for the removal of the beavers to other places where they could be permitted to multiply without endangering valuable timber sup- plies or cultivated crops. Mountain beavers, or sewellels, also have continued to do con- siderable damage in Washington and Oregon to crops and vines planted on areas adjacent to timber lands occupied by these animals, and bureau representatives have demonstrated methods for their control. Woodchucks have been a source of annoyance and loss to gardeners, truck growers, and farmers throughout New E ngland and the North- ern States west to Oregon and W ashington. Following the introduc- tion of alfalfa, clover, and succulent root crops in the Northwestern States, woodchucks have concentrated about these new sources of food supply, frequently traveling considerable distances to feed upon them. Their depredations have caused heavy losses, wide strips along the borders of fields often being completely destroyed. As the animals live under a ereat variety of conditions throughout the infested area, it has been necessary to develop methods adapted to neet the different conditions prevailing. Demonstrations are given or circulars outlining procedure issued as required by individuals or communities. | HOUSE RATS AND MICE. . The educational campaign to acquaint the public with the serious- ness of the drain on the Nation’s food resources through depredations of house rats and mice has been continued. This has involved con- siderable investigational work with a view to improving methods of © poisoning and trapping the animals, devising effective means of ex-_ cluding them from buildines and places where they could damage food or other stored property, and employing deterrents where other means of exclusion are impracticable. In response to inquiries from points throughout the United States, bulletins, circulars, and other information regarding practical meas- ures for ‘destroying ‘ats and excluding them “thr ough rat-proof con- struction and the use of deterrents have been supplied. Requests have | BUREAU OF BIOLOGICAL SURVEY. ea been received from military and naval officers in charge of camps, rsenals, and storage warehouses for the inspection of these places by ¢ perienced representatives of the bureau and for specific directions regarding procedure in destroying the rats or protecting property from their depredations. This was done at the naval base, Norfolk, ‘Va.; at the arsenal and military camp located at Amatol, N. J.; and at the Picatinny Arsenal, Dover, N. J., where effective control meas- ures were inaugurated and carried out. In other instances the situa- tion was met by sending bulletins and furnishing other necessary information. ‘State officials and public health officers of cities also appealed to the bureau for practical plans of organizing extended eradication campaigns and for suggestions regarding legislation or ordinances which should be put into effect with a view to complete and permanent rat control. Interest on the part of State and municipal public health officials was stimulated by the appearance of bubonic plague at Beaumont and Galveston, Tex., and at Pensacola, Fla., with the possibility con- fronting them of its further spread. The rat serves as a carrier of fleas responsible for the transmission of the plague to human beings, ‘and because of its extended movements from place to place within a city and from point to point throughout the country it becomes an active agent in disseminating this malignant disease. This situa- tion, together with the fact that the rat is a notorious carrier of filth-borne diseases and a destroyer of property by contamination, also of food, feed, clothing, farm machinery, and harness and other leather goods, has emphasized the importance of carefully planned, thoroughly organized, and vigorously conducted campaigns for the destruction of all rats. Attention has been called to the fact that State laws and city ordinances should require all new buildings to be made rat-proof, and should also require the adoption of practi- cable measures for rat-proofing existing buildings, sewers, and water mains. Such action is of the utmost importance in any plan to eliminate the enormous losses of property and to remove the constant menace from disease due to the widespread abundance of house rats and mice. Representatives of the bureau were detailed to visit Norfolk and Portsmouth, Va., and Baltimore, Md., to advise and assist the local officials in working out comprehensive plans for the organization of Campaigns to destroy rats. Considerable assistance has also been rendered in urban and farming communities by local representativ es of the bureau in connection with their regular field operations against rodent pests in the organized districts of the West. [Empha- sis has constantly been placed upon the absolute necessity for the rat-proof construction of buildings and storage places in both urban and rural communities as a means of obtaining permanent relief from rats, and upon the necessity for preventing the pests from finding harborage and having ready access to food supplies, as an essential preliminary step to ‘the carrying out of effective measures for destroying them. } MOLES. te __ Many reports have been received from the Eastern and Middle States of damage by moles to lawns, garden and truck crops, and ower nurseries. While not rodents, "moles are frequently confused * 4 " 12 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. with them because of certain superficial resemblances in size, general outline, color, and pelage. Damage caused by moles has been, as in~ other years, closely associated with the work of mice, which fre- : quently follow the mole runways. This damage by moles is often very serious, particularly in hght sandy situations, where their lift-_ ing up of the surface soil injures the roots of plants and permits — them to dry out, resulting in their death. The Townsend mole, the— distribution of which is limited to the coast counties of Washington, Oregon, and northern California, has been destructive in vineyards, gardens, hay meadows, and lawns through its habit of burrowing near the surface of the ground and piling up mounds of dirt on the surface. ‘Trapping moles with specially designed traps has proved to be the most practical way of combating them. Information re- garding suitable traps and trapping procedure has been disseminated through bulletins and the press. The value of moleskins was established among fur dealers through efforts of the Biological Survey, and methods of tra apping the animals and preparing their pelts for market have been widely demonstrated throughout the infested territory. These demonstrations were con- ducted in cooperation with the “public schools, the State extension services, and other agricultural agencies. Many successful boys’ and cirls’ clubs were organized to trap moles and prepare their pelts for market, for the combined purpose of ridding the land of a pest and obtaining profits from the sale of the skins. As a result large num- bers of these animals have been taken and their pelts marketed at good prices. Reports received from leading fur dealers indicate that the number of American moleskins marketed during the year showed an increase of approximately 20 per cent over the preceding year, representing a value of about $60,000 for the raw furs. PRODUCTION OF DOMESTIC RABBITS. By the development in this country of a well-sustained interest in the production of domesticated rabbits there has been a rapid increase in the number of people who are raising them and in the number of animals produced. Many of the animals are used for home con- sumption, as the meat compares favorably with that of the domestic fowl and possesses high nutritive value. Rabbit meat has also come to be a popular item on the menu of hotels and restaurants wherever its good qualities have been demonstrated and an adequate supply can be furnished. - The cost of rearing rabbits is so low that they have been found a_ profitable adjunct to other lines of farm production. Many extensive” plants have been established to raise them for the larger city mar- kets, and great numbers also are being produced in the back yards of city residences. The pelts of these animals also have considerable value for felting and other manufacturing purposes. There has been a marked increase in the quantity of rabbit skins marketed and in the use of these skins by manufacturers of hats and of trimmings for coats and olen wearing apparel. They are used in their natural color and are also clipped and dyed in imitation of more expensive grades of fi National and State rabbit breeders’ associations are now well organ- ized and are working actively for the development of the rabbit — ae: ie | BUREAU OF BIOLOGICAL SURVEY. 13 dustry as an important feature of the meat-production program of he country. Rabbit raising has also proved a popular phase of the ctivities of boys’ and girls? clubs in many sections of the country. he Biological Survey has endeavored to stimulate this rapidly rowing phase of animal production and guide it along practical lines. Farmers’ Bulletin 1090, covering breeds of rabbits, plans for Riutches, methods of feeding, breeding, “marketing, and dressing rab- its and cooking the meat for food, with a section devoted to the treatment of the diseases of rabbits, was issued during the year. In order that inquirers might know ere to obtain breeding stock -and where to dispose of their output, lists of the principal. rabbit breeders in the different States, and buyers of rabbits and rabbit skins have been maintained by the bureau. _ Representatives of the bureau have kept in close touch with lead- ding rabbit producers throughout the country and have inspected a “number of the more impor tant rabbitries and visited establishments devoted to the dressing and dyeing of rabbit skins. At the request of officials in charge, a representative of the bureau was also in attend- “ance at the annual convention of the American Breeders and Fanciers’ Association, held at Cleveland, Ohio, and at the rabbit show held at Baltimore, Md. FUR-BEARING ANIMALS, THEIR PROTECTION AND PROPAGATION, _ Many interesting features regarding the status of the fur industry have been dev eloped as a result of investigations conducted during the year. Representatives of the bureau have visited the principal raw fur markets, including those in St. Louis and New York and in Montreal, Canada; and also have visited establishments engaged in the dressing and dyeing of furs and in the manufacture of fur garments. ‘Studies have been made of conditions prevailing throughout the country as to abundance of wild fur-bearing animals, and mainte- nance of adequate breeding stock of the more valuable forms, with a vview to the development of sound State and National policies i im re- gard to trapping that would maintain the number of fur bearers at the maximum consistent with other agricultural and commercial in- “terests. On invitation of Canadian officials, a representative of the bureau was detailed to attend a conference of the Commission of Conservation and the Advisory Board on Wild-Life Protection, at Montreal, February 19-20, for the purpose of discussing matters re- lating to the rearing, registration, and importation of silver and Dlack foxes and other fur bearers in Canada and the United States, sand of considering plans for the conservation, increase, and proper “utilization of fur- ‘bearing animals. The value of pelts taken from fur bearers throughout the United States runs to a total of many millions of dollars annually without taking i into consideration the large amount of labor and capital em- ployed i in their manufacture or the value of the product as it goes to the wearer. North America has long been one of the most important regions of the world for taking the pelts of wild fur-bearing animals. More ‘recently it has become one of the greatest world centers for the marketing and manufacture of furs. As illustrative of the extent of he fur business, it: is estimated that there are approximately 18,000 14 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. people in New York City engaged in the various branches of the fur industry and that the capital invested there amounts to about $200,- 000,000. During a period of 12 days in February, 1920, one firm in St. Louis sold peltries valued at $27,000,000. A few days later a New York firm sold furs having only slightly less value, while in May the St. Louis firm listed furs for sale valued at $30,000,000. A survey of conditions throughout the country indicates that the supply of wild fur-bearing animals has decreased very materially during the last decade. This is doubtless due to the large number of people who, during a portion of the year at least, engage in trap- ping fur bearers, as a means of increasing their incomes. The exceed- ingly high prices which have prevailed for furs during the last few years have stimulated trapping activities to a remarkable degree, re- sulting in a serious depletion of the supply of wild fur-bearing ani- mals in many sections of the country. The fur industry from trap- per to manufacturer has developed to a point where it is worthy of the most careful consideration and the employment of all practicable measures to maintain the supply on a basis which will meet the re- quirements of the future and lay the foundation for the permanency and growth of the industry. Trappers, raw fur dealers, manufac- turers, and Federal and State officials concerned with wild-life con- servation work should unite in working out and establishing policies directed toward this end. This affects. in a very material way present and future financial interests, besides providing fur garments to meet the demands of the constantly increasing number of persons who use them for physical comfort and for the satisfaction and enjoyment coming from wearing the more luxurious articles of apparel. While prices declined considerably at spring sales, it appears probable that owing to the world-wide decrease in the natural supply, prices will continue in future at a high level. With a view to fostering and guiding the production of fur- bearing animals under conditions of domestication, the bureau has initiated and conducted experimental and practical studies of silver, black, blue, cross, and red foxes, fishers, martens, minks, skunks, and raccoons, and of animals which may be reared under semicontrolled conditions, including beavers and muskrats. ‘These investigations have been conducted in part at the Experimental Fur Farm, near Keeseville, N. Y., on the ranches of successful fur breeders, and on marshes and streams under patrolled and natural conditions. Carefully outlined studies are in progress of diseases that affect fur-bearing animals, both those of bacterial and those of parasitic origin. ‘The specific causes and also the course and symptoms of such diseases are being investigated, and studies are being made of means of prevention and methods of treatment, practical ways of disin- fecting pens, dens, and houses, and means by which they may be maintained in a sanitary and healthful state. Studies were con- tinued of feeds and feeding practices with a view to economy of production and maintenance of health and vigor in the animals, and of soil, climatic, housing, and other conditions favorable to the production of furs having the highest marketable qualities. Studies are also in progress of fur quality and grade and the characteristics upon which these are based, including means of identifying accurately the kinds of fur that are now placed on the market under a great variety of trade names. The latter feature is of much importance : - BUREAU OF BIOLOGICAL SURVEY. 15 Wa because of the skill with which inferior furs are now dressed and dyed in imitation of more valuable peltries. _ During the year much information has been furnished inquirers ‘through correspondence and the issuing of circulars and bulletins. An article entitled “Trapping on the Farm” was published in the Yearbook of the Department of Agriculture for 1919, and a manu- script for a department circular completed for publication on “ Main- tenance of the Fur Supply.” ECONOMIC ORNITHOLOGY. As in the previous fiscal year, investigation of damage by various birds protected under treaty between Great Britain and the United “States was a special feature of the work. Provisions of the migra- tory-bird treaty act authorize the Secretary of Agriculture to issue permits to kill any of the protected birds when found seriously injurious to agricultural or other interests. This is a wise and beneficent arrangement, for there is no doubt that the true interests of both bird protection and agriculture are furthered by facilities for the constant adjustment of the numbers of birds in relation to the supplies of food they may consume without detriment to man. When birds increase to such an extent that these supplies no longer suffice for them, and they make serious inroads on cultivated crops, control measures are justified, and it is fortunate that the department has at its command this indispensable part of a well-balanced pro- gram in economic ornithology. Investigations of the economic relations of various groups of birds were continued during the year, the birds receiving most attention ‘being the English sparrow, the vireos, yellow-legs, Wilson snipe or jacksnipe, hawks, and owls, and the redhead and scaup or bluebill ducks. A number of manuscripts were+ prepared for publication, those not mentioned elsewhere in this report being “The Crow in Its Relation to Agriculture” and “Community Bird Refuges,” pre- pared for publication as farmers’ bulletins; and as department bulle- tins, a report on the “ Fish-eating Birds of the United States,” “ Food and Economic Relations of North American Grebes,” “Food of rican Phalaropes, Avocets, and Stilts,” and “ Food Habits of the Jireos.”” MEADOWLARKS AND DOVES IN SOUTHERN STATES. An investigation conducted during the year having demonstrated that meadowlarks are seriously destructive of sprouting oats and corn in South Carolina, an order was issued by the Secretary of Agri- culture permitting aggressive measures against the birds from No- yember 1, 1919, to April 30, 1920. Investigations of similar com- _ plaints against mourning doves were not conclusive. ROBINS DESTROYING CHERRIES IN NEW YORK. - Complaints that robins do considerable damage in the commercial _cherry-growing regions of New York, received both from individual fruit growers and from horticultural organizations, led to an investi- gation of the trouble. It was found that during the ripening season of small fruits robins were securing most of their sustenance from ges we a lie cl 16 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE them and the damage done amounted to about 10 per cent of the crop in the case of sour cherries and to 75 and even 100 per cent of sweet cherries. no Ei TEEN : BUREAU OF BIOLOGICAL SURVEY. 23 “birds occurs every winter in Mexico, but conditions in that country have not been propitious for a migr atory- -bird treaty. A considerable number of our “important waders and shorebirds, especially golden and black-bellied plovers, winter in Argentina and adjacent countries, and their future conservation may “depend on conditions attending the rapid development of agriculture in that remote region. In ‘order to have the necessary first-hand informa- tion regarding this, an assistant biologist was detailed to proceed to Argentina and adjacent countries in time to witness the arrival there of our migratory wild fowl during their southern migration in the summer of 1920 and to continue his investigations relating to these birds in their winter home until they return northward again in the spring of 1921. He sailed for Buenos Aires on May 29 and should bring back much valuable information bearing on the future of many of our well-known species. WILD LIFE IN-NATIONAL PARKS AND NATIONAL FORESTS. Late in September, 1919, a representative of the bureau visited the Black Hills of South Dakota to investigate the topography and food resources of an area which has been proposed as a game and bird refuge, to determine its fitness as a reservation for the protection of wild life. An investigation was begun late in October in cooperation with the Forest Service to ascertain the conditions affecting the herd of elk at different seasons on the Sitgreaves National F orest, Ariz., variously estimated to contain from 300 to 500 animals. These, are the progeny of a number of elk introduced from the Yellowstone Park region several years ago. The work was resumed in January, when the winter ra nge and ‘the approximate number of elk compos- ing the herd were determined. Another trip was made to the region during the latter part of June to ascertain the summer range of the herd and to secure data on which to base final recommendations re- garding the extent and approximate boundaries of a proposed game refuge. This investigation was still in progress at the close of the fiscal year. During the first half of April an investigation of the condition of the elk wintering in the Jackson Hole region was made, special atten- tion being given to certain areas in the Hoback Valley, along the slopes of ‘the foothills bordering Jackson Valley on the east and in the valley of the Gros Ventre, all within the confines of the national forests, on which, by virtue of arrangements made in 1917 with the Forest Service, grazing by cattle was restricted in order to conserve sufficient forage for wintering elk. Further joint investigation by this bureau and the Forest Service is planned during the summer. The National Park Service will also have men in the field in order that the three bureaus interested in the Yellowstone elk herds may work effectively for their conservation. A new edition of the cir- cular of information concerning Yellowstone National Park, which is issued annually by the N Yational Park Service and which appeared in the spring of 1920, contains revised lists of the mammals and birds of this area, contributed in part by a field naturalist of this bureau. In addition, a comprehensive treatise on the niammals of _ Yellowstone National Park is in the hands of the National Park i 24 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. Service for publication, and a large manuscript map showing the life zones of the Yellowstone National Park and the region adjoining it on the south was prepared for the use of the National Park Service. Lists of a few characteristic birds and mammals of Mount Rainier National Park have already been published by the National Park Service in its circular of information, and, as already stated, a detailed report on the region is well advanced in preparation. RELATION OF RODENTS TO FOREST PRODUCTION. Progress was “made in experiments being conducted to secure in- formation concerning damage to crops and forage by injurious ro- dents, instituted in the spring of 1918 in several western States, notably Arizona and Colorado. By means of quadrats established on grazing areas, some of these plats being fenced and others un- fenced, the damage inflicted by the rodents which abound there is measured. A= preliminary report on the results of these investiga- tions is in preparation. A department circular (No. 59) entitled “Field Studies of Mammalian Life Histories,” which ee: the pro- cedure to be followed in studying the habits of these important ani- mals in order to obtain the best results, was issued in October. BIG-GAME AND BIRD RESERVATIONS. Federal big- game and bird reservations in charge of the Biological Survey are now 75 in number. Tour are big-game preserves, 70 are bird reservations, and 1, the Niobrara, created as a bird reser vation, is used for both birds and big game. Included in the number is a small bird reservation near Fort Myers, Fla., of two islands contain- ing rookeries and breeding grounds of sev “eral species of herons, established by Executive order of July 1, 1920, and known as the Caloosahatchee bird reservation, in the river of the same name. On June 30, 1920, the big-game reservations contained a total of 427 buffalo, 384 elix, 60 antelope, and 27 deer, an increase in each species over last year. The total number of buffalo now in the Government’s various herds exceeds a thousand head, of which about half are under the charge of this department. The boundaries of the Niobrara Reservation were modified during the year by the inclusion of a narrow strip of bottom land on the west boundary along the Niobrara River. A bill affecting the boundaries of the Klamath Bird Reservation, approved on May 2 1920, among other things authorizes the Secretary of the Interior to determine which lands are chiefly valuable for a bird preserve and which are chiefly valuable for agriculture, and to eliminate and open to settlement the agricultural areas. The measure is likely to result in the modification of the southern boundaries of the reserva- tion and in the elimination of swamp lands, which, however, have not been utilized by the birds for several years pe the summer an investigation was made by a representative of the bureau, in cooperation with the secretary of the American Bison Society, for the purpose of selecting a tract in eastern Oregon suitable for a refuge for sage grouse and antelope, and as a result one was selected east of Warner Lake and extending from Lake County, Oreg., to Washoe County, Nev. Some opposition to the- ; BUREAU OF BIOLOGICAL SURVEY. 25 ereation of this reservation having developed, reexamination of the project indicates that the area may be materially reduced without serious injury to the purpose for which it is intended. The unusual drought of 1919 was responsible for several fires, particularly on the National Bison Range, in Wind Cave Park, and on the Klamath Bird Reservation. No serious damage was done on any of the big-game refuges, but on the Klamath Reservation the fires burned over a considerable area of tule land before they were extin- guished by autumn rains. BIG-GAME RESERVATIONS. Winter Elk Refuge, Jackson, Wyo.—This reservation thoroughly justified its existence this year in saving the southern Yellowstone elk herd from practical extermination by starvation. Throughout the summer of 1919 a severe dr ought prevailed in the northern Rocky Mountain States, which prevented the growth of forage on the range and greatly reduced the output of hay. This was followed by an almost unprecedentedly long and severe winter, beginning with fierce snowstorms, which drove the ellc out of the high mountains the last of October, and continuing until the end of April. The hay crop for 1919 on the elk refuge, with hay held over from the previous year, made a total of about 850 tons on hand at the beginning of “winter. The State game warden of Wyoming pro- vided about 500 tons and a carload of vottonseed-oil cake. As it became necessary to feed elk on the refuge much earlier than usual, it was plain that unless more hay was provided the last months of winter would see the animals perish by thousands. The Secretary of Agriculture granted the Biological Survey authority to expend the sum of $45, G00, if necessary, in the purchase of hay to meet this emergency. Owing to the urgent need of hay for stock, it was dif_i- cult to secure any ~ for the ell, but early in ‘January 573 tons were ‘purcha ised, hauled 30 miles on sleds, and fed to the elk during the Jater months of winter, at a total cost of $36,271.50. This provided “sufficient hay to feed until the end of the emergency, April 20. About 8,000 elk were reported as having been fed on the refuge and in the “valley below during a considerable period late in the season. The availability of the necessary hay to feed the animals at this critical time kept them off the winter range in that district, leaving the “scanty forage on it to maintain the elk which did not descend to the feeding ¢ erounds. _ Early in the fall it was estimated that there were about 17,000 elk in the southern herd, of which approximately 2,000 were killed by hunters. About 15,000 entered the winter, and a careful estimate gives 13,00 10 as the number of survivors which were doing well late in May. The loss of approximately 2,000 during the winter of 1919- 20 was only a little above normal despite the severity of the winter gy the scantiness of forage. In connection with the maintenance of the elk on the Winter Elk Refuge it may be stated that the hay crop for 1919 amounted to only 314 tons, which was grown, cut, and stacked at an average cost of $4.09 aton. This is a higher cost than the average in ordinary seasons, owing to the scanty crop caused by the dr ought. Hay land added to that on the refuge sufficient to raise the total yield in ordinary seasons 26 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. to from 1,000 to 1,200 tons would provide a surplus sufficient to meet any emergency and insure the perpetuation of the southern elk herd. It is imperative if the interests of the southern herd are to be reason- ably safeguarded that additional hay land adjoining the present refuge be purchased at an early date. National Bison Range, Moiese (near Dixon), Mont—During the past year substantial improvements were made at’the National Bison ange, including the construction of a residence for an assistant warden. At certain times of the year, particularly during the months when there is danger from fires, it 1s essential to have an assistant warden regularly employed on the range, and at other times extra assistance is necessary to enable the warden to perform his duties efficiently. Owing to the drought of 1919 unusual pressure was brought to bear on the department to open up part of the range for grazing, but on account of the danger of communicating cattle diseases to the buffalo it was considered unwise to assume the risk of jeopardizing the herds for which the range was established. Grass fires in August and September at first threatened to do considerable damage, but through the activity of the warden and the assistance furnished by the Reclamation Service and the Indian Agent they were extinguished after a few hours with only slight losses.