Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. - Deaiiaat ro REPORT OF CHIEF OF BUREAU OF BIOLOGICAL SURVEY Unirep States DEPARTMENT oF AGRICULTURE, Bureau or BroLrocicat SuRVEY, Washington, D. C., September 15, 1924. Sir: I have the honor to submit herewith a report of the opera- tions of the Bureau of Biological Survey for the fiscal year ended June 30, 1924. Respectfully, Hon. Henry C. WaAuLLaAce, EK. W. NE son, Chief of Bureau. Secretary of Agriculture. GENERAL ACTIVITIES AND ORGANIZATION The work of the Bureau of Biologi- cal Survey has to do with the conser- vation of the useful and otherwise yaluable wild bird and mammal life of the country, including species classed as game and as fur bearers. This involves the administration of certain Federal laws, including among others the migratory bird treaty act and laws for the protection of land fur animals in Alaska. The bureau is charged also with the duty of con- trolling certain species which, through their feeding habits or excessive in- crease in numbers, have become seri- ously injurious to agriculture, includ- ing many kinds of crops, horticulture, forestry, and stock growing on the western ranges. In addition, with its efforts to conserve and build up the wild life of Alaska, the bureau con- ducts investigations and experiments to develop the reindeer industry, and to utilize some of the numerous is- lands in the Great Aleutian Reserva- tion for stock-growing purposes, These activities are all based on scientific investigations, which include extended field and laboratory studies. _ The only change in organization during the year has been the sepa- ration of the section having to do with the development of fur produc- tion, including fur farming, from the 13371—24 1 Division of Economic Investigations, and its establishment, effective July 1, 1924, as the Division of Fur Re- sources, in charge of Frank G. Ash- brook. ¥ The work during the year was con- ducted under six divisions, as follows: 1. Economic Investigations, Dr. A. K. Fisher, in charge. Necessary investigations of injurious wild mam- mals and methods for their control are conducted by this division and the leadership and organization fur- nished for cooperative and other cam- paigns against predatory animals and destructive rodents throughout the country. Through experiments in fur farming, and in other ways, studies have been made of problems in fur production and the development of the fur industry. 2. Food Habits Research, W. L. Me- Atee, in charge. In this division are investigated the food habits and eco- nomic relations of birds, reptiles, and amphibians, the food resources of water areas for migratory wild fowl, and methods of control of injurious birds, and basic recommendations are made in these particulars. 3. Biological Investigations, TE. A. Goldman, in charge. Field and labo- ratory studies are made of the wild life of the country, including mam- mals, birds, reptiles, amphibians, and the more characteristic native plants. This includes technical investigations 2 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE to determine the classification of spe- cies, also their life habits and distri- bution, ificluding the migratory move- ments of birds, for the purpose of mapping the natural life zones of the country and of supplying fundamen- tal scientific information as the nec- essary basis for the economie, regula- tory, and other activities of the bu- reau. 4. Alaska Investigations, the chief of bureau and W. F. Bancroft, in charge. All problems affecting the improvement and management of rein- deer herds are studied in this unit; fur production is encouraged through advice to fur farmers and the enforce- ment of laws and regulations for the protection of land fur animals in the Territory; and possibilities of utiliz- ing certain islands for stock grazing are investigated. 5. Game and Bird Refuges, Smith Riley, in charge. This division super- vises the maintenance of 69 Federal large game and bird refuges and the warden service on them, including the production of hay for feeding elk on the Winter Elk Refuge at Jackson, Wyo. 6. Migratory Bird Treaty and Lacey Acts, George A. Lawyer, Chief United States Game Warden, in charge. Under this division are administered laws for the protection of migratory game and other birds, and laws gov- erning interstate shipments and im- portations from abroad of wild birds and mammals. WILD ANIMAL PESTS The widespread destruction by such stock and game killing animals as wolves, coyotes, mountain lions, and bobeats, as well as by the numerous crop, forage, and tree damaging ro- dents, including prairie dogs, ground squirrels, pocket gophers, rabbits, and others, especially in the Western States, has resulted in defensive or- ganizations on a large scale to limit the losses from these sources. A con- stant, desultory warfare had been conducted against these animals by the payments of bounties and other- wise since early in the occupation of this continent by Europeans, and the lack of results from such sporadic ef- forts was amply demonstrated. As a result, during the past 10 years there has been a steady growth of correla- tion of Federal, State, and local ef- forts. Well-organized campaigns have resulted and have been vigorously con- ducted during the past year. For the destruction of these wild- animal pests on the public domain and for cooperative work elsewhere during the year, an appropriation of $447,666.42 was made by Congress. Of this sum, $287,951.81 was used in the destruction of predatory animals and $159,714.61 for the control of rodents. The work was conducted in 19 of the Western States and several Eastern States, which provided cooperative funds totaling $894,922 either by di- rect State appropriations or from other sources. Approximately $387.- 424 of the cooperative funds was ex- pended for the destruction of preda- tory animals and $507.498 in the ro- dent-control campaigns. The general range of most of these animal pests has been determined. The fierce destructiveness of large wolves and of mountain lions, both to domestic animals and game, is so great that it becomes a necessity to elimi- nate them from certain areas. This, however, does not mean the actual de- struction of these species, since they range over such a vast area in both North and South America that the possibility of their actual extermina- tion undoubtedly lies many centuries. in the future. The coyote is one of the most wide- spread of all predatory animals and is so numerous in the aggregate that it is probably the most destructive of them all, both as to domestic stock and game. Enormous numbers of coyotes are killed each year, but they have so many young to the litter that, except in restricted areas, little more than the increase is destroyed an- nually. In parts of the West, how- ever, the campaigns against them have materially reduced their num- bers. The effect of this reduction in the numbers of coyotes is well indicated by a marked decrease in losses of sheep and other livestock and by a very notable increase of game, in- cluding such ground-nesting birds as the quail. Coyotes are so cunning and adapt themselves so readily to changing conditions of environment, including the warfare against them by man, that they are showing as great persistence in maintaining themselves as the red fox, which still occurs in the eastern United States despite the centuries of pursuit by its human enemies. The big wolves have been reduced to a relatively small number over much of the West. Since 1915 more than 5.400 of them are known to have bee BUREAU OF BIOLOGICAL SURVEY 3 killed, in addition to many which have been poisoned and not found. In northern Mexico, Canada, and Alaska these animals still occur in consider- able numbers and will long persist as picturesque elements of the fauna. They will undoubtedly continue to in- vade the United States along the border for a long time in the future and only vigilant efforts will prevent them from vreinfesting vast areas where the losses caused by them are now bringing about their destruction. The numbers of both predatory ani- mals and harmful rodents depend mainly on the food supply. The gen- eral distribution and abundance of livestock, together with widespread crop production, furnishes so depend- able a food supply that, without or- ganized control work, the aggregate losses from these pests would become appalling and successful stock grow- ing and agriculture would become im- possible over great areas. The success of the long-continued educational work of the bureau to bring the public to a realization of the heavy annual losses from house rats and the possibility of eliminating most of them at a reasonable cost is becom- ing evident. Appeals for aid to con- trol these pests have come from 45 States, and as much assistance as pos- sible has been given with the men and funds available, and experts of the bureau have aided in organizing more or less extensive campaigns in 22 States. The hearty cooperation of States, local organizations, and individuals has made possible the systematically conducted operations under the leader- ship of bureau representatives for the control of the various destructive ani- mals. In addition to the funds con- tributed, more than 66,000 farmers and stockmen took active personal part in the rodent field work, con- tributing time and labor in operations on Federal and State lands as well as on their own holdings. Thousands of farmers and stockmen joined in the organized work of trapping and poi- soning coyotes, and this has added greatly to its scope and effectiveness and made it possible to conduct opera- tions at a minimum cost to the public. PREDATORY ANIMALS Field work against predatory ani- mals was conducted during the year in Arizona, Arkansas, California, Colorado, Idaho, Michigan, Missouri, Montana, Nevada, New Mexico, Okla- homa, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming in cooperation with organizations and in- dividuals. State agencies participat- ing included departments of agricul- ture, livestock commissions or boards, game commissions, extension depart- ments, county organizations, and stockmen’s and farmers’ associations, Cooperating Federal agencies that control areas of Federal lands in- cluded the Forest Service of the De- partment of Agriculture and the Office of Indian Affairs and the National Park Service of the Department of the Interior. The Bureau of Plant Industry and the Bureau of Chem- istry of this department also have aided in consultations and laboratory investigations, and the survey field men have effectively cooperated in operations of the Bureau of Animal Industry to eradicate foot-and-mouth disease in California, which is not only destructive to domestic stock but also is a menace to deer and other hoofed game. In addition to the thousands of co- operating stockmen a force of 406 trappers and poisoners was employed under bureau supervision during the year. Part of the men employed were paid from Federal funds and_ part by the States and other cooperating agencies. Skins or scalps of 38,591 predatory animals were taken, of which 562 were wolves, 34,092 coy- otes, 3,507 bobeats and Canada lynxes, 237 mountain lions, and 193 bears. In addition to these animals, it is estimated that about 100,000 coyotes were killed in the extended poison- ing operations, of which neither skins nor scalps were taken. Bears are re- garded as game animals, and the offi- cial hunters have strict instructions not to kill them except individuals known to be destructive to livestock. State game departments and sports- men’s associations in many States have cooperated heartily in the preda- tory animal work on account of its very evident favorable influence on the game supply, Wolves—When the organized work against predatory animals was started in 1915, wolves were regarded by cat- tlemen and other experienced obsery- ers as the wild animal by far the most destructive to livestock. Wolves had previously subsisted on buffalo, elk, deer, and other large game animals which they were able to pull down in- dividually or by operating in packs. The development of the livestock busi- ness throughout the West afforded them an abundance of readily obtain- able food among the calves, yearlings, 4 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE and even adult cattle, sheep, and other domestic animals. enormous sums paid in bounties on predatory animals, which sometimes almost bankrupted counties, and the great but unorganized efforts of ranch- men and their employees and of pro- fessional trappers, wolves maintained themselves in large numbers and ex- acted a heavy toll from the livestock industry. In some districts they ren- dered impossible the growing of sheep and hogs. Economic pressure due to restricted ranges and the necessity for closer attention to every item that re- duced the margin of profit finally made intolerable this drain upon the possible output of livestock. Inauguration by the Biological Sur- vey of carefully planned organized operations aud constant improvement of methods threugh investigations con- ducted by trained experts have made possible effective headway toward the extermination of these exceedingly de- structive animals in livestock-produc- ing areas. Concentrated efforts have been made to take promptly the more notoriously destructive individuals. Already 5,478 wolves have been de- stroyed and their skins ov scalps se- cured. Many others are known to have been killed by poison, and in ad- dition, numbers of pups and unborn young have been accounted for. In many sections where wolves formerly occurred in packs of 12 to 15, not a sign of a wolf has been seen during the past two or three years. These animals have disappeared from their well-known ranges following the plac- ing of poison about their haunts, and have become so scarce that in a num- ber of instances solitary wolves have been detected trying to lure dogs away from ranches as mates. This is not infrequently successful, and.the hybrid young resulting often prove to be no- toriously destructive nnimals. One female wolf in Arizona that had been endenyoring to lure away a ranch dog was killed within 30 yards of the door of the ranch house through poisoned baits. Few young wolves have been permitted to escape during the past two or three years, and the adults that now remain are, for the most part, wily individuals that have thus far evaded capture by exercising extraordinary cunning. Throughout most of the western range country the losses from wolves should be practically eliminated in the near fu- ture. The wolves crossing the interna- tional boundary from Canada and Mexico into the United States’ present swine, Despite an international problem that will be difficult to solve. Of the 22 wolves killed in Arizona during the past year, 17 had recently crossed from Mexico. Of 39 wolves killed in New Mexico, 19 were taken by one hunter close to the Mexican border. This hunter, after returning to a locality which had ‘previously been eleared of wolves, in two days found 14 calves killed and 21 mutilated by wolves which had crossed the border. Some cooperation has already been secured from Ameri- can ranchmen in Mexico. They have worked in consultation with our lead- ers in border States and report having taken 70 wolves during the past two years. Notable kills during the year in- clude an old white wolf in Arizona, known for the past eight years on the Aguila range and reported by stock- men to have killed about $25,000 worth of cattle and sheep in that time. On one occasion this wolf was definitely known to have killed 65 sheep in one night and 40 in another. It averaged a calf about every four nights. Coy- otes had learned to follow this old wolf, sometimes as many as 12 or 15 at a time, in order to feast on the leav- ings after it had made a kill. Stock- men had placed a bounty of $500 on its scalp, and many private hunters and trappers had worked for it months at a time without results. Its range was most unusual for a wolf, being in the low, hot desert at an alti- tude of not more than 3,000 feet above sea level and in a district overgrown with the typical desert vegetation, such as palo verdes and mesquites. This wolf succumbed in’ October to skill- fully placed poisoned bait distributed by one of the cooperative Federal- State hunters. A wolf locally known by forest rang- ers and stockmen as the “ butchering wolf” was trapped in Eagle County, Colo., during July, 1928. In addition to its record of animals killed out- right it had an unusual reputation for biting off the ears and tails or other- wise mutilating young calves and even full-grown cattle. The hunter who was detailed to the task of getting this renegade rode thoroughly over the country, noting signs where the animal ranged, and then carefully placed his traps. On his first visit to these traps he found the wolf awaiting him in one of them. The head of this wolf was mounted and now adorns the office of the State Board of Stock Inspection Commissioners in Denver, this board being the cooperating agency in Colo- rado. BUREAU OF BIOLOGICAL SURVEY 5 A notorious she wolf was taken in December south of Pueblo, Colo., which had been known for a long time in that section and was responsible for the killing of many cattle. The hunter rode the range frequented by this wolf and succeeded in killing it within three weeks. It had been in traps several times previously, but had escaped, losing a toe on each front foot. The wounds had healed so com- pletely as to give the appearance of a naturally three-toed animal. The man- ager of the ranch on which this wolf was taken writes: I am taking this means to thank you for the services of your hunter in this neigh- borhood for the last two months. While there may be a few coyotes left, he has re- duced them greatly in number, and it is a great satisfaction to know that we are rid of probably the last wolf in this part of the country. A hunter north of Fruita, Golo., finally succeeded in December in trap- ping an old wolf with seven unborn young, It had preyed heavily on deer, cattle, and sheep in the section, and its dens had yielded the trappers a total of 21 pups in three consecutive years. In one locality along the Oklahoma- Arkansas border, where no predatory- animal work had previously been done, 14 wolves were killed within a few days during October on an area less than 10 miles square, 11 being poi- soned and 3 trapped. These wolves appeared to have a rather extensive range, and their depredations were heavy on calves, colts, and hogs, espe- Cially hogs, practically all of which had been destroyed by them in several neighborhoods in both States. In southwestern Missouri 93 wolves were killed during the year the work has been in progress. In northern Michigan, where the work has been in progress for three years and where wolves have been very materially re- duced in numbers, a hunter discovered Signs that a small pack of wolves had recently passed. Four traps were set close together, and the following morning the trapper was rewarded by finding an adult wolf in each. Coyotes—At present coyotes, which in the aggregate in the United States must number several million ani- mals, are unquestionably the most destructive predatory animals in this country. One of the most difficult problems of predatory animal control is raised by them. They are widely distributed and well endowed by their mental qualifications to protect them- selves and secure food under a great variety of conditions. To insure their perpetuation they are prolific breeders, sometimes having 14 young in a litter. Contrary to their former habits, coy- otes may now be found throughout high and rugged mountain ranges and in dense forests. Not only have they occupied prac- tically all the available territory in the Western States, but they have moved northward into Alaska and to the delta of the Mackenzie River in Canada. They have successfully maintained themselves in such States as Illinois, Indiana, and Michigan, and continually invade new territory. Coyotes persistently follow livestock and game in their seasonal movements between summer and winter ranges, constantly preying upon the young and even adult cattle, sheep, goats, and swine, and deer and antelope. Coy- otes are also notorious destroyers of the eggs and young of ground-nesting birds, including such important species as sage hens, prairie chickens, quail, grouse, and many kinds of ducks. They also destroy great numbers of full-grown birds and are probably the most seriously destructive enemy of our game resources. Because of their foxlike skill in concealing themselves and in escaping pursuit, they often successfully locate their dens and rear their young in close proximity to ranches and farms. A recent study of denning activities in a limited area surrounding a single ranch revealed a group of 8 coyote dens, from which 48 pups were taken. It has long been recognized by the Biological Survey that the only hope of coping suecessfully with these ani-. mals is thrpugh the development of effective poisoning procedure and its application on a wide scale throughout their range. With this in view, con- stant effort has been made to devise poisoning materials that would prove palatable and not arouse the suspicion of these alert animals and to devise methods of distributing poisoned baits in such a way that the infested area might be systematically covered. Successful plans of organization and vigorous prosecution of the campaigns, including the use of these improved methods of poisoning, supplemented by a limited amount of trapping, shooting, and den hunting, have made remarkable progress possible in the control of these animals during the past year. The total number of coy- otes killed and their scalps secured was 34,092, but animals actually found is not a measure of the number de- stroved in poisoning campaigns. Skilled men are now employed during 6 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE six to nine months or more of the year working in cooperation with stock- men’s associations and other local or- ganizations in the systematic prosecu- tion of the poisoning work. They spend practically their entire time in establishing poison stations, distrib- uting baits, demonstrating methods to stockmen, and aiding them to estab- lish and maintain effective poison lines. Relatively little time is now spent in searching for animals killed, as the value of the skins collected commonly would not pay for the time lost. This procedure is strongly urged by stockmen, who have become fully convinced as to the effectiveness of the poisoning operations, and whose first concern is to have the poison dis- tributed carefully and on the largest possible scale. 7 Effective noisoning operations are conducted in summer, especially about watering places, but the work is done chiefly from October to April. Careful study is made of coyote conditions by experienced men stationed in each of the States, and, so far as practicable, the campaigns are launched chiefly after the livestock leave the summer or winter ranges, in close cooperation with the stockmen using the range. By systematically placing feeding sta- tions and poisoned baits, and by post- ing notices and otherwise notifying the residents of the district, valuable dogs or other animals are protected. In settled country or other places where such action is desirable extended lines of feeding stations are often estab- lished and maintained until the coy- otes become accustomed to feeding at them, and then small, specially pre- pared poisoned baits are placed, and a short, intensive campaign carried on, often resulting in the destruction of practically all the coyotes in the ter- ritory. Any poisoned material left uneaten is then picked up and de- stroyed or used elsewhere. Livestock losses over large areas have been practically ended by systematic work on summer and winter ranges and on lambing grounds. The total area cov- ered in this work during the past year has been much greater than in any preceding year. During the year more than 3,567,000 especially prepared poisoned baits were methodically put out in accord- ance with definite plans, and these poisoning operations covered an area of about 284,400 square miles. One hunter and a cooperating stock- man established a line of poison sta- tions in Oregon, and the first time they returned over it found 29 dead coyotes. A ranchman in Texas re- ports finding 57 dead coyotes along part of a 100-mile poison line which he established in accordance with di- rections given him. A rancher in ’ Arizona reports that his men found 140 coyotes which they had poisoned by following instructions and, al- though coyotes had been abundant formerly, little trouble was experi- enced after using the poison. Another “eooperator and his herder maintained a poison line in Oregon during the winter and picked up 87 dead coyotes. This practically rid his range of coy- otes before spring. Over great areas of range the de- struction of coyotes has been so thor- ough that stockmen have been able to reduce the number of men required to handle their flocks. Many stock- men now report carrying their flocks through the lambing period with abso- lutely no losses from coyotes in locali- ties where previously they were heavy. In addition to the direct say- ing of lambs, growing stock, and breeding animals, stockmen by this service can handle their herds at less expense and utilize the pasture more fully. Freedom of the range from predatory animals eliminates the need for long drives to bedding grounds and permits the use of the open-herding system, which is bene- ficial both to the sheep and to the range. Similar savings accrue also to producers of other kinds of live- stock and of poultry. The destruc- tiveness of coyotes to sheep was em- phasized in a poster issued during the year for cooperative work in South Dakota (No. Bi-701), the chief feature of which was the direct ques- tion, ‘‘ Why feed coyotes?” Poultry production is becoming an increasingly extensive business in large parts of the country now occupied by coyotes, and with the destruction of these pests it can be developed on a more profitable scale. Their destruc- tion has greatly benefited cattlemen also, as it has become evident that coyotes are exceedingly destructive to calves on farms and ranges, often ma- terially reducing the calf crop and thus cutting down at a vital point the possibility of profitable livestock pro- duction. In California, where an outbreak of foot-and-mouth diserse resulted in great losses of livestock, Biological Survey representatives cooperated ef- fectively with the Bureau of Animal Industry by conducting poisoning op- erations to eliminate coyotes or other possible carriers of the disease, and BUREAU OF BIOLOGICAL SURVEY 7 so planned and organized the work that experienced men could be placed promptly in any locality where the dis- ease might make its appearance or where this work would afford added protection against its spread. In addition to beneficial results of this work accruing to the livestock in- dustry, for which it is primarily con- ducted, the benefits to game resulting from coyote eradication have been very marked. In areas where coyotes have been destroyed, deer and antelope are reported to have raised a much larger proportion of the fawns than was known in recent years, and a marked ‘increase of quail, grouse, and other ground-nesting game birds has been reported from many points in the West where the poisoning campaigns have been conducted. Mountain lions still occur in numbers throughout much of the mountainous country in the West and are chiefly destructive to colts, calves, and sheep among domestic animals and to deer, elk, mountain sheep, and mountain goats among the larger game animals. During the year 287 mountain lions were killed by employees and coop- erators of the Biological Survey in the Rocky Mountains and Pacific Coast States, making a total of 1,236 moun- tain lions killed since this work was organized in 1915. Individually these animals range over great areas, apparently making more or less regular rounds in pursuit of their prey, and are hunted eagerly by sportsmen. The animals killed in this way, coupled with the work done in the organized campaigns, has led to a marked reduction in their numbers. At present the distribution of moun- tain lions is somewhat local, only a few usually oceurring in a given local- ity. They are ordinarily hunted with dogs and rifle, but at times are suc- cessfully trapped and poisoned. One herder in Arizona, after having 80 sheep killed one night by a moun- tain lion, put out poison according to instructions and the following day found the offender dead. Two private hunters in Arizona were instructed in methods of poisoning mountain lions and later reported killing 14 of them during the winter. One of the regular hunters in Arizona killed 15 during February following a heavy snow- storm which had driven the animals down out of their usual range into an area that had previously been practi- cally cleared of them. In the State of Washington 11 adult mountain lions were killed, among which were 3 that had nearly ex- terminated the mountain goats in Mount Rainier National Park. During March a lion hunter in Colorado suc- ceeded in killing a large male in the Pike National Forest just inside the Denver Mountain Parks Game Refuge. He had previously trailed this lion during December, but it made its es- cape after killing his leading dog. While trailing it in the Tarryall Mountains the hunter found that it had made serious inroads on the moun- tain sheep of this section, and while tracking it in the Denver Parks Game Refuge he found two deer which it had killed but a short time before. Another mountain lion, killed in Colo- rado in April, had recently killed a fine five-point buck. One of the experienced hunters in Montana made a snowshoe trip of 400 miles and only secured 1 adult lion where two years before he took 23. In another section of western Montana where one of the bureau hunters caught several mountain lions two years ago, two men who knew the country well were only able to take two of them during the past winter, and the evi- dence indicated that but few are left in this section, although formerly it was heavily infested. Larger herds of deer have been reported in these localities recently than for years, a fact which sportsmen attribute mainly to the destruction of the mountain lions. Relatively few of these animals now occur in sections where livestock is being produced, and their control ean be effected readily through the as- signment of skilled hunters as condi- tions require. Oil of catnip, the first use of which as a bait was mentioned in the re- port of last year, continued to be used effectively by hunters trapping mountain lions and bobeats, and ar- rangements have been made to obtain an additional supply from this year’s crop. Bobcats and lynxes.—During the year 3,448 bobcats and 59 Canada lynxes were taken by our official hunters. Bobcats occur in considerable numbers throughout the mountainous sections of the West, while lynxes are con- fined to the more northern regions and the higher mountains. Both feed to a large extent upon rabbits and other rodents, but are often exceedingly de- structive to sheep, goats, antelopes, pigs, calves, and poultry. In certain parts of Arkansas, where bobcats are common, their destructiveness makes hog raising impracticable. Many deer, especially the fawns, and wild turkeys, quail, and other ground-nesting birds 8 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE are destroyed by them. They are taken readily by the use of trained dogs and are easily trapped. The use of oil of catnip has proved to be a particularly effective bait. Some hunt- ers report that they have succeeded in taking every bobcat that came into the vicinity of traps baited with cat- nip oil. Bobcats are far less success- ful than coyotes in maintaining them- selves in the face of civilization and rarely, if ever, regain territory from which they have once been eradicated. They are eagerly hunted by private hunters for sport and for the value of their furs. Bears.—The hunters of the Biological Survey are. instructed to consider bears as game animals and not to kill them except in cases where they are known to be destructive to livestock or where, in cooperation with State game departments, they are to be killed be- cause of their destructiveness to game. They are protected by the game laws of practically all the Western States. Large numbers are killed by sports- men during the open season, and this ordinarily serves to keep them well un- der control. In some localities the animals are reported as becoming over- abundant and at times are excessively destructive to livestock, especially when there is a shortage of their nat- ural food. Individuals, particularly grizzly bears, also become addicted to such killing and then it is necessary to destroy them as predatory animals. In the 17 States in which predatory animal work was conducted 193 bears were killed by official hunters during the year. One notable kill was made in the Okanogan Forest Reserve in Washing- ton. This bear, a grizzly, had been re- sponsible for heavy losses during the past three years, and was definitely known to have killed 85 head of cattle and 150 head of sheep during the sum- mer of 1923. The latter part of July it appeared near a camp after dusk and attacked a 4-year-old steer. Hear- ing the noise, the camp foreman in- vestigated and found the grizzly hold- ing the steer with its forefeet and biting at its neck. A shot failed to take effect and the bear ran away. At the request of livestock owners, an ex- perienced hunter with trained dogs was assigned to the task and effected the capture of this notorious animal in about three weeks. This bear weighed over 1,100 pounds. The utmost care is exercised to avoid killing bears through mistaken identity as to the culprit responsibie for livestock losses. The following ease illustrates the careful diserimina- tion exercised by our hunters: A re- port that a bear was killing sheep in Nevada near Lake Tahoe was person- ally investigated by the inspector. It | was found that 15 sheep had been killed and tracks showed where a bear had been eating from the ear- casses. Close inspection, however, showed where a large coyote had dug his claws into the ground in making a turn to catch one of the sheep. Fur- ther investigation showed places where a coyote had been sitting and had made short runs to the various places where the kills had been made. Acting on this evidence as to- the ani- mal responsible for the killing, pois- oned baits were distributed along a trail traveled by the coyote, and the herder reports no further losses “ from bears ”’ during the season. RABIES In Washington, Oregon, northern California, Nevada, Utah, and Idaho rabies was of widespread local occur- rence for several years among coyotes and bobeats and has resulted in heavy losses of livestock and the biting of many people. The measures employed have brought it so fully under control that only occasional outbreaks were reported during the year. Whenever an outbreak was reported experienced hunters were concentrated and prompt- ly destroyed the wild animal carriers of the disease and the spread of the disease was quickly checked. In Washington two serious outbreaks oc- curred, but prompt and effective co- operation between Federal and State officials ultimately controlled the sit- uation. Similarly effective cooperation in cases where rabies made its appear- ance among domestic animals in Ari- zona and New Mexico, and the prompt destruction of coyotes and other pos- sible wild carriers in zones surround- ing the points where the disease ap- peared,.made it possible to prevent its spread. A most serious situation developed in Colorado, where apparently the dis- ease was introduced on the San Isa- belle Forest by a rabid dog. The case was not reported for several months, and a large number of cattle and other domestic animals were bitten and died. Five people also were bitten and promptly took the Pasteur treat- ment. One of these was bitten by a bobeat, two by coyotes, and two by dogs. Responding to the emergency thus created, the bureau made a spe- ; ‘ fi a BUREAU OF BIOLOGICAL SURVEY 9 cial detail of men to conduct a vig- orous poisoning campaign against pos- sible wild carriers in this district with the cooperation of stockmen and local officials. Large numbers of coyotes were killed in the poisoning campaign, as many as 16 being found at a single poisoning station. As a result, the range was thoroughly freed from coy- otes and bobeats and the disease effec- tively controlled. Rabies later appeared among dogs and coyotes on the eastern edge of the San Luis Valley in Colorado and spread rapidly. When the disease was reported to the Denver ‘office prompt action was taken. The evidence in- dicated that it had been brought in by rabid coyotes ‘or dogs which had crossed the Sangre de Christo divide in the vicinity of Pass Creek. A meet- ing of representative citizens was held and the San Luis Valley Anti-Rabies Association was formed and presented the situation to the county commis- sioners of six counties. County funds were promptly appropriated to coop- erate with the bureau and the State board of stock inspection commission- ers for carrying on a thorough eradi- cation campaign against worthless dogs and coyotes and other predatory ani- mals that might serve as carriers. Regulations regarding the muzzling of dogs and cats also were enforced. Ten hunters were placed in the terri- tory under the immediate supervision of a field assistant, and at the close of the year the situation was well in hand. Occasional outbreaks may be expected, however, and effort must be continued to prevent further spread of the disease. Without such prompt control measures rabies might spread over the entire West, with appalling results. RODENT PESTS Steady progress has been made in the control of those rodents which have persisted and, in many instances, increased excessively in the face of ordinary agricultural and stock-rais- ing conditions. Because of their num- bers and widespread distribution they cause heavy losses of farm crops and’ forage grasses, also in orchards, vine- yards, truck farms, and nurseries. Investigations by the Biological Survey have determined successful methods of reducing the number of rodent pests, and plans have been devised for large-scale organization of systematic field operations to this end. Federal, State, and local agencies are so correlated that the work of clear- 13371—24——2 ing great areas can be conducted in an orderly way. The work has _ been supported consistently by farmers and stockmen, aS the direct benefits evi- dent from it appeal to their business judgment. Large-scale operations have been greatly facilitated through the hearty cooperation of the Office of Cooperative Extension Work and the State extension service organizations, including the county agricultural agents and State and county farm bureaus. A poster (No. Bi-761), is- sued for use in the cooperative work with the Wyoming Extension Service, was helpful in drawing attention to the enormous losses caused by rodent pests in the State and to the compara- tively simple method of deriving profits through increased stock production on areas where losses are suffered from range-destroying rodents. State de- partments of agriculture, county com- missioners, and many agricultural, horticultural, and livestock organiza- tions have taken an increasingly active part in the undertaking, and Officials of the Forest Service, the Office of In- dian Affairs, and the Reclamation Service cooperated most helpfully on their lands. The bureau continued to cooperate with the United States Pub- lic Health Service of the Treasury Department, and with State, county, and municipal health organizations in lines of work where rodents are im- portant agencies in the dissemination of such diseases as bubonic and pneu- monic plague, Rocky Mountain spotted fever, and tularaemia. Prairie dogs and ground squirrels—Krom the earliest settlement of the mid- West and the Western States the ground-squirrel and prairie-dog prob- lems have confronted the farmer and stockman. Production of farm crops made conditions all the more favor- able for constant increase in the num- bers of these pests through the pro- vision of a nutritious and readily available food supply. Especially in dry weather, when their natural food is scarce, these animals congregate on the cultivated areas, dig up the planted seeds, and sometimes the roots of the plants, and feed upon growing or harvested crops. They make seri- ous inroads into grain fields and often completely devastate large areas, So long as there was an abundance of free pasturage little heed was given to the destructiveness of these ani- mals to forage grasses. With the more complete occupation of the land by flocks and herds, and a growing necessity for giving greater attention to management details in order to ob- 10 tain a profit, there has developed a more persistent demand for eliminat- ing the competition from these pests. Prairie dogs often completely de- nude productive grazing lands of all the valuable forage grasses. It is common for prairie dogs and ground squirrels to reduce the forage ayail- able for livestock from 25 to 50 per cent. By selecting the more fertile lands their competition with livestock is rendered especially serious, because they feed upon the same nutritious grasses that are most sought by live- stock. Occurrence of such animals in large numbers results in a marked decrease in the numbers of livestock that can be maintained on a given area. Their presence also interferes with the suecess of deferred grazing or grazing rotation practices, as they continue to feed upon the grasses dur- ing the period that stock are kept off and, finding such areas more favor- able for their feeding, increase in numbers and destructiveness. Campaigns organized to combat prairie dogs and ground squirrels dur- ing the past year covered 8,000,000 acres of Federal and private lands, which were given a first treatment with poisoned baits, and follow-up work with poison or fumigants on previously treated areas was done on 6,000,000 acres. This makes approxi- mately 12,000,000 acres of Federal and 105,000,000 acres of State and pri- vate lands on which a large percent- age of these pests have been poisoned since 1916 in Arizona, California, Colo- rado, Idaho, Kansas, Montana, Ne- braska, Nevada, New Mexico, North Dakota, Oklahoma, Oregon, South Dakota, Utah, Washington, and Wyo- ming. The Biological Survey and co- operating Federal agencies assume the cost of operations on the Federal lands. Owners of adjacent lands, however, continue to contribute much of the labor required to distribute the poison, and furnish much of the grain used as bait, in order to cover the largest possible acreage with the lim- ited Federal funds and thus reduce the numbers of the animals migrating from the Federal to the adjacent pri- vate lands. State officials and county commissioners have provided for work on State lands, and farmers and stock- men have borne the cost on their own holdings. Except in California, where the occurrence of the foot-and-mouth dis- ease prevented the usual progress of field operations during the spring, there has been a_ steady advance in the work accomplished.