at $17 per acre. In the South preliminary experiments have shown that small mammals destroy practically all southern pine seeds planted. Later studies will be directed toward methods of control.

The national forests in the South are being systematically covered to determine wildlife conditions. Studies are under way to evaluate the longleaf pine and loblolly pine-hardwood forests of the South as wildlife range.

The effect of free-ranging hogs on acorn crops and forest reproduction is being determined in Louisiana.

The effect of big game or beaver on vegetation was studied in Glacier Park, Mont.; Acadia National Park, Maine; Zion National Park, Utah; and Isle Royale National Park, Mich. At the request of the Forest Service in Montana an analysis was made of the effect of deer on the reproduction of western yellow pine. Five year's cooperative effort on a national forest in Nevada have shown that a deer herd about to destroy the range vegetation can be prevented from dying off and the range preserved through management.

The role of small mammals in range management is being investigated at the Santa Rita Range Experiment Station in Arizona. This is considered by the Forest Service to be one of the biggest factors in handling the southwest ranges. A cooperative study of big game-livestock-range_relationships is centered on national forest land in Utah. The Forest Service, Bureau of Land Management, State fish and game department, State agricultural college, and experiment station are the other cooperators. This study is an attempt to determine the actual degree of competition for food between deer and livestock. This is one

of the most pressing problems in the management of western big game herds. While the study was begun with three Fish and Wildlife Service field men and a clerk, a cut in funds has left only one man to carry on our part of the project. Work on Indian lands includes beaver surveys and stocking, regulation of commercial fishing, wild turkey studies, and game management plans. A good example is the Grand Portage Reservation in Minnesota where, over a 5-year period, stocking and protection have built up a beaver population, the pelts of which are worth $4,000. During the war studies of fish production in the Red Lake Reservation in Minnesota showed that the Indians could maintain a commercial catch of a million pounds of fish. The catch figures are being analyzed each year to make sure the fishery is not being overutilized.

A comprehensive monograph on the elk was completed for publication during the year.

A method was developed in the Northwest for controlling moles with an earthworm bait poisoned with "1080." Loss from these moles often runs to thousands of dollars per acre in bulb fields and heavy damage also is suffered in nurseries. In the South a study is in progress on the ecology of the armadillo, a species which is spreading rapidly across the region.

STUDIES ON METHODS OF CONTROLLING INJURIOUS ANIMALS

Studies on methods of controlling harmful rodents, and preventing damage to food and other agricultural products, have constituted an important phase of the work of the Denver and Patuxent laboratories of the Fish and Wildlife Service. The problem is of paramount importance for two reasons: first, the presence of large rodent populations in inhabited areas presents a serious menace to health; and second, rats and other rodents annually destroy or damage food and property valued at $200,000,000. The first reason, public health, is a cogent one at all times, and the second becomes particularly important at this period of world-wide shortage of food and feedstuffs.

Rodenticides: The primary approach to the solution of the problem of rodent control consists of finding suitable toxic agents whereby the rodent populations may be maintained within safe limits. This approach has been followed for many years, and a number of more or less effective rodenticides have been developed. According to estimates based on figures compiled by the Department of Commerce, approximately 600,000 pounds of rodenticides, valued at nearly $500,000, are used in this country each year. These figures do not include some of the newer and more effective toxicants, such as the widely publicized ANTU and 1080.

The importance of studies leading to the development of more effective methods of rodent control was accentuated during World War II when sources of supply of some of the then known rodenticides, such as red squill and thallium, were cut off. The wartime research led to the development within the Service laboratories of the extremely effective rodenticide sodium fluoroacetate (known as compound 1080), as well as the development by outside agencies of the widely publicized

ANTU. Since the close of the war, the efforts of the Service have been directed both toward the discovery of still more effective, or safer, toxic agents, and toward the development of more effective methods for the use of the known rodenticides. One product of this postwar research has been the discovery of the rodenticidal merits of some of the organic phosphates, notably tetraethyl pyrophosphate. This extremely toxic material has given very striking results in some of the limited field trials against rats and mice, and appears to offer promise as one of the most effective rodenticides yet discovered. It possesses the unique property of hydrolyzing on exposure to water or atmospheric moisture, hence baits would lose toxic properties on standing and would not present a hazard to humans or domestic animals. However, the extreme toxicity of the compound, and the fact that it may be absorbed through the intact skin, makes its use hazardous to an undetermined degree. Additional work on this compound will be necessary before it should be released to the public for general use as a rodenticide.

In the course of the experiments with tetraethyl pyrophosphate, it was observed that the material was exceedingly toxic on contact. This toxicity, coupled with the characteristic instability of the compound, indicated the possibility of using the compound in the control of other injurious species, such as starlings. It was postulated that the compound, or a solution, could be spread on roosting areas in the late afternoons, and the birds would acquire a lethal dose during the roosting period. The decomposition of the compound would render the roosts innocuous within 48 hours, or less, while the birds themselves would be relatively harmless to handlers, or to domestic pets which might pick them up.

In order to explore the possibilities of this method for the control of starlings, a series of carefully controlled laboratory tests, and a limited field trial, were conducted. It was found in the laboratory that a very high percentage of kills could be obtained in this manner, while the results of the field trial were less promising. It should be noted, however, that a number of variables may have entered into the field trial, and that it appears that this toxicant might offer some promise as a means of starling control. The hazards connected with such use have not been determined, and no recommendations for use of this compound outside of the laboratory are made at this time.

Repellents: A second phase of the work on methods for rodent control has been directed toward the development of methods for the protection of stored foods and feeds through the use of rodent repellents. Although the most desirable means of rodent control is through the use of toxic agents, it is impractical to use such materials in areas where undue hazard to other forms of animal life may result. Under such conditions, the use of repellent impregnates in packaging materials may serve to prevent rodent damage.

Much of the emphasis in the field of control-methods research was placed on projects sponsored by the Quartermaster Corps. These included the advanced testing of rodenticides previously screened by the Patuxent laboratory and the perfecting of application techniques in the field.

A method of coloring compound 1080 as a safeguard against its accidental ingestion by human beings was perfected. A compact unit for packaging and disposal of 1080 solutions in rat control also was developed. The latter procedure has long attracted the attention of rat-control operators in the Navy, and it bids fair to be a useful procedure in general rat control. Specifications also have been drawn up for the manufacture of suitably inscribed paper cups for the disposal of 1080 solutions by the Quartermaster Corps and other public agencies.

Pharmacological studies of 1080 included work aimed to determine the toxicity of this compound to domestic sheep, a project carried out in cooperation with the Colorado A. and M. College at Fort Collins. A paper summarizing the accumulated information on the toxicity of 1080 to numerous wild and domestic mammals and birds also was published in a technical journal.

Continued research and field experimentation with a number of the newer materials that may be useful in rodent control, have brought out both advantages and disadvantages with respect to those now in use. The hazards of some of these to human beings, domestic livestock and beneficial wildlife precludes their general application in populated areas. On the other hand, there may be opportunity to employ some of them on pine mice and gophers which feed largely underground.

Research in red squill has emphasized the need for a faster and more accurate method of appraising the toxicity of red squill powders and extracts. It appears that the creation of a "standard" material againt which the efficiency of powders of unknown toxicity may be appraised is the most logical procedure. Through the cooperation of a large processor of red squill, progress has been made in that direc

tion. In the meantime a paper summarizing the current information on red squill has been published in a botanical journal. Advice also has been given on the construction of a red squill "fortification" plant in Louisiana through which our Service will obtain much of its higher quality of squill.

In the search for effective repellents against rodents the Denver laboratory has continued its advanced testing of material screened at the Patuxent laboratory. To facilitate this a division of the work has been effected whereby the Patuxent laboratory will concentrate on materials that are chemical in origin while the Denver laboratory will place emphasis on those that possess repellent characteristics of a physical nature. This work, sponsored largely by the Quartermaster Corps, has objectives that have a bearing on many aspects of the battle against rodents.

Predators: The development of new toxicants has had an emphatic impact on matters connected with predator control. While these new materials are effective as killing agents they also possess certain definite hazards to beneficial or harmless wildlife. The problem of making them selective with respect to the creature being controlled is an important one now holding the attention of the Denver laboratory. As a result much is being done in the high country during the winter months to determine the effect on fur-bearer populations of poison stations exposed for the control of coyotes. Likewise further studies are being made of the selectivity, effectiveness and economy of various types of cyanide guns now on the market.

Of continued importance is the study being made in and adjacent to Yellowstone National Park aimed to determine the nature and extent of coyote drift out of or into the park and its relation to the livestock interest nearby.

THE COOPERATIVE WILDLIFE RESEARCH UNIT PROGRAM

Since 1935 the Service has been cooperating with certain land-grant colleges, State game departments, and the Wildlife Management Institute in cooperative research and training. At present there are cooperative wildlife research units in 13 land-grant colleges, 3 of which (Oklahoma, Colorado, and Idaho) were established during the year under a special appropriation item earmarked by Congress for them. The units are now located across the country in all major land type

areas.

Over 500 reports of research findings have been published in book, bulletin, popular and technical papers, and thesis form by the units. Approximately 600 men and women have obtained college training in wildlife management in this program. One hundred and ninety-three men have received postgraduate training. These graduates are now employed in 43 of the States, Alaska, Canada, Hawaii, and Puerto Rico by State, Federal and private wildlife agencies. The training program has made available trained personnel that has led to better management of the wildlife resource throughout the country.

During the past year the program of research and training has been particularly heavy at the various units because of the enforced lull in activities during the war, and because the enrollment of students is now at an all time peak. The unit organization is engaged at present in summarizing the available information on white-tailed deer, to be published as a book by the Wildlife Management Institute, but this manuscript will not be ready for publication until 1949. A book on the prong-horn antelope, the product of research at the Oregon unit, is expected off the press in April 1948.

STUDIES OF BIRD DISTRIBUTION AND MIGRATION

Bird-banding: Investigation of the migration routes of definite waterfowl breeding populations through the analysis of the banding records is being stressed because of the particular interest in the management of this group of birds. Many of the findings which would be impossible to determine except through the birdbanding program have been of great value in management.

Mr. and Mrs. Joseph Hickey spent the entire year under a grant from the Guggenheim Foundation making detailed statistical analyses of the bird-banding records available at the Patuxtent refuge. This is the most extensive use by cooperators to date of these files.

Distribution, abundance, and migration of birds: The cooperator program of obtaining information on the current status of the abundance, distribution and migration of birds is being revised and expanded to obtain greater coverage through the participation of bird clubs. Special studies of exact numerical status of birds on breeding areas treated with DDT have been emphasized. Also a coop

erator program to obtain basic numerical information by habitats of both breeding and winter populations is being developed. Extensive survey of birdlife of the North American Arctic regions was undertaken through cooperation with a naval task force operating in far northern waters. Reports on intensive studies of the birdlife of the States of Georgia, and Washington, and the British Colony of Newfoundland are under way.

WILD FUR ANIMAL INVESTIGATIONS

One important responsibility of the office is compilation of statistics on the fur take in the United States. During the past 10 years the estimated annual catch of fur animals in the United States has been exceedingly large. The muskrat take ranges from 18,000,000 to 20,000,000 pelts; the opossum 2,500,000 to 3,000000; the skunk 2,000,000 to 2,500,000; raccoon, 1,000,000 to 1,500,000; fox, 900,000 to 1,000,000; mink, 700,000 to 800,000, and so on. The data suggest that domestic production of raw fur at the present time is at least 20,000,000 to 30,000,000 fur animal skins per year. After the domestic crop of raw furs and those imported for 1947 were processed, manufactured into fur garments and sold the turn-over was $425,000,000.

The income to the Government from the retail excise tax on fur apparel during the past 3 years averaged more than $85,000,000. From the sale of fur seal skins, seal byproducts, blue-fox pelts, furs from Federal refuges and predatory animal hunters the return to the Treasury annually is about $1,600,000.

Everyone generally agrees that the supply of wild fur has decreased greatly since 1910. The shrinkage is estimated at 20 to 50 percent during the past 10 to 15 years. A review of fur sales recently held in the United States shows that the pelts disposed of were brought from all parts of the world to supply the American trade. Manufactured furs cost much more now than the same grade of furs did 10 or 15 years ago, and the demand for fur is far greater than ever before. The time is overdue when steps should be taken to increase and improve the fur supply.

Fur from refuges: More than $100,000 was returned to the Treasury of the United States from the sale of furs produced on Federal wildlife refuges during 1946-47. The trappers who worked on these areas received an equal amount for their services and the counties in those States where the refuges are located also received 20 percent of this. At the present time there are 50 refuges on which wild fur animals are taken annually on a share-cropping basis, the trappers receiving 50 percent.

All furs taken on Federal refuges and by predatory animal hunters are sold at public auction. The statistical data accruing therefrom is naturally compiled and analyzed. Furs sold from each Federal refuge and predatory animal district by species and prices received for same are recorded. In 1946-47 about 500,000 animals were taken and the return to the Government was over $150,000. Predatory animal skins for the same period amounted to $5,000. The trend of fur prices paid for long-haired furs during the past 3 or 4 years has been constantly downward. Today it is almost impossible to move them.

Since 1937 on Blackwater National Wildlife Refuge, muskrat houses were counted to correlate pelt production_and house density per acre, a basis for determining number to be trapped. For six consecutive years brown and black muskrat skins counted-brown 55 percent, black 45 percent; blacks bring more money than brown. Pelts taken at 10-day intervals to determine primeness. Best quality skins trapped late winter and early spring. These and other problems studied to furnish information for managing fur animals on refuges.

More muskrats are taken on Federal refuges than any other animal. This is also true for the entire United States. To conduct research and manage the fur-animal production on these areas, a count is taken of the muskrat houses. This is correlated with production per acre and the number trapped. Effect of sex and season on quality of fur and market classification of pelts is also studied. Impoundments and land-management practices are investigated to maintain and improve proper habitat for muskrats, raccoons, beavers, minks, and other fur animals; also fur production and grazing and competition between fur animals and waterfowl is studied and comparisons made.

Fur-animal research at the Patuxent Research Refuge is to determine the fur productivity of submarginal farm land situated along the western border of the Atlantic coastal plain about midway between the heavily populated areas of Washington, D. Ĉ., and Baltimore, Md. This work has demonstrated that parttime trapping or hunting about 2 or 3 months each year on such worn-out land could yield about 40 cents per acre in wild fur as a side line to farming and timber

growing operations. Modifying agricultural practices increases productivity of fur animals. A 3-year study of this problem has just been completed, and the results will be published.

Annually since 1915 an abstract of fur laws of the States, Alaska, and Canada has been published. It has been invaluable to trappers, lawmakers, fur tradesmen, and publishers in these fields. (Wildlife Leaflet No. 297, Abstract of Fur Laws, 1947-48, published September 1947.)

In 1934 attempts were made to collect fur statistics. Less than 12 States kept records. Annually since 1939 the Service has issued Annual Fur Catch of the United States, an innovation which encouraged more and more States to gather such information. In 1939, only 37 States were doing so; in 1946 the number was 43. (Wildlife Leaflet 298, Annual Fur Catch of the United States, published September 1947.)

ALASKA FUR SEAL INVESTIGATIONS

In managing the Alaska fur-seal herd the Division of Alaska Fisheries encounters many biological problems. This managing agency is in immediate need of a simple but accurate means of estimating the size of the seal herd and each age class component, an accurate estimate of the size of the herd which will yield the maximum number of marketable sealskins on a sustained basis. Other objectives are to determine the effects of present and proposed killing programs on the production rate of the herd, determine mortality rates and causes on land and, in general, devise recommendations for increased production for greater sustained revenue to the Government.

The rate of reproduction in different age classes, mortality of pups and older seals, value of pelage and byproducts resulting from various age classes and the efficiency of certain sealing operations are other problems for study.

Fur-seal pups have been tagged on the Pribilof Islands prior to and since World War II. During 1947, 20,000 fur-seal pups were tagged as a basis for an estimate of the pup crop in 1950 when the 1947 pups reach killable age. Information on

migration of the seals is required and this will be accomplished through cooperation with the Coast Guard weather stations. Men on these weather ships will report fur seals seen 500 to 1,000 miles at sea in water hitherto unexplored by Service personnel. Further data on seal migrations southward are being gathered by means of studies from the motorship Black Douglas, which conducted three cruises during 1947.

THE HATCHERIES, STOCKING AND MANAGEMENT ACTIVITIES

The fishing pressure upon our inland waters has continued to increase and is greater today than at any time in the history of this country. For the year ending June 30, 1947, 12,620,464 angling licenses were sold in the United States. This, however, does not represent the total number of fishermen. In some States women are not required to obtain a license, and in other States anglers under certain age do not need licenses to fish. Land owners and tenants in some States may fish on their own lands without a license. Altogether, there were probably 20,000,000 people fishing the waters of this country during 1947. Last year more than 3,120,000 anglers fished in waters on lands under the control of the United States Forest Service. Of the visitors to Yellowstone Park in 1947, about 150,000 went fishing. The demands for hatchery-reared fish for stocking purposes have continued to increase. The current application load is about 300 percent greater than the prewar level.

The Service foresaw the need for a tremendous increase in the production if it were to meet the demand. The indications were that the greatest demands would be for salmon, legal-sized trout, black bass, and bluegill sunfish.

Though the production was increased in some instances by means of changes in technique, the greatest handicap was insufficient funds. The funds allotted for hatchery operations have not kept pace with increased costs of fish food, and other material, fertilizer, and manpower. To produce as many fish as possible, it has been necessary to neglect the maintenance of buildings, facilities, and equipment. Nearly all the trucks in operation, purchased before the war, have high mileages. The average load of fish is worth several hundred dollars, and the lack of first-class equipment for distribution may permit a break-down involving a total loss of the fish carried. Many of the hatcheries in operation were among the first built by the Government, and the buildings are from 50 to 75 years old. Many of the buildings are of frame construction and should be replaced. The neglect of buildings, facilities, and equipment represents an important loss in capital investments; funds should be provided for the proper rehabilitation of the stations and the maintenance of the equipment and facilities.