Cooperative Wildlife Research Unit Research Articles

An Improved Propulsion System for Short-Range Projection of Immobilization Darts

An adapter and pipe were fitted onto the barrel of a .38 caliber revolver. Powered with a shotshell primer fitted into a modified cartridge case, the device was used to fire 2-cc darts to immobilize captive and trapped collared peccaries (Pecari tajacu). Performance and impact were uniform up to about 10 ft and there was no injury to the animals. The mechanism can be made by a machinist from materials easily available. The immobilization dart manufactured and sold by the Palmer Chemical Co.2 has become a useful and necessary piece of equipment in wildlife research. A lack of uniformity of performance and an unpredictable force of impact have been two serious shortcomings of the dart when fired from the gas-operated pistol or rifle. This has been especially true when captive or trapped animals have been immobilized. We have found that at close range the impact of the dart was difficult to adjust and damage to flesh often resulted. Darts have often bounced out of an animal unless barbed darts were used. To minimize these difficulties when working with captive and trapped animals, we have devised and successfully used a simple adaptation for firing immobilization darts with a uniform impact force up to about 10 ft. The new dart propulsion mechanism includes a metal sleeve adapter which fits over the muzzle of a .38 caliber revolver, a 6-inch length of %-inch galvanized pipe which has been reamed out to about /%inch diameter, and an empty .38 caliber pistol cartridge with a hole in the base into which is inserted a Winchester No. 209 shotshell primer to furnish the power charge. Fig. 1 shows the parts and their arrangement when the gun is ready for firing. The slotted metal sleeve slides back over the muzzle of the revolver. The forward end of the adapter is threaded inside so that the 3/s-inch galvanized pipe can be screwed into it. A turn of the adapter into a wider recess locks the adapter over the front sight of the revolver. The loaded 2-cc dart is then inserted into one end of the 3/8-inch pipe. The pipe is then screwed into the adapter so that the rear end of the dart is just ahead of the muzzle of the revolver. All of the parts necessary for this propulsion system are readily available or can be easily made by a machinist. Because individual revolvers vary in barrel taper, the adapter sleeve should be made by an experienced machinist to fit each gun. It can be made from round, cold finished screw stock or similar machine steel. The galvanized pipe can be reamed out by using any '/2-inch steel power drill. The cartridge case is prepared by first knocking out the spent primer and boring a 1/4-inch hole through the base of the cartridge case. This hole is then reamed out by lightly applying the tip of a '/2-inch high-speed steel countersink drill to the hole to obtain the proper smoothness and bevel. The 345 1 Contribution of the Arizona Cooperative Wildlife Research Unit: University of Arizona, Arizona Game and Fish Department, Wildlife Management Institute, and U. S. Bureau of Sport Fisheries and Wildlife, cooperating. 2 No endorsement of the Palmer Chemical Co. is being given by any of the cooperating agencies. This content downloaded from 157.55.39.144 on Mon, 25 Jul 2016 05:07:00 UTC All use subject to http://about.jstor.org/terms 346 Journal of Wildlife Management, Vol. 31, No. 2, April 1967

Beaver Productivity in Idaho

Data on the productivity of beavers (Castor canadensis), including sex and age ratios, litter size, and rate of pregnancy, were gathered from livetrapping and fur-trapping operations in 1953-56 and 1962-64. Standard methods were used for determining sex and age of both live beavers and carcasses. Uteri hardened and discolored by preservatives were cut longitudinally to expose breaks on the internal ridge of tissue which pointed out sites of placentation. Counts of placental scars and fetuses indicated average litter size to be 3.1 and 3.4, respectively. The percentage of yearling and older females with placental scars dropped from 46.2 in the mid-1950's to 32.3 in the 1960's in southeastern Idaho, possibly owing to increased disturbance of colonies from accelerated fur trapping. Males consistently outnumbered females in kit and yearling age-classes while females were more abundant among the adults. The sex ratio of 352 beavers examined was 113 males per 100 females. Twenty-one percent of these animals were kits, 23 percent yearlings, and 56 percent adults. A disturbed (trapped) beaver population had a lower percentage of kit and yearling beavers than did an undisturbed population (35 percent vs. 49 percent). A highly migratory population consisted of 38 percent late yearlings, supporting the belief that beavers leave their home colony when almost 2 years old. This paper summarizes data on beaver productivity collected in Idaho in two separate periods, 1953-56 and 1962-64, and adds comparable data to the beaver literature from many other states. A method is also described for delineating placental scars on uteri that have been hardened and discolored by preservative solutions. Gratitude is expressed to the many beaver trappers who collected uteri and counted fetuses and to conservation officers and other personnel of the Idaho Fish and Game Department who distributed preservatives and solicited trappers' cooperation. Thanks are extended to Dr. Paul D. Dalke for his counsel during the portion of the work done by the senior author and for reviewing this manuscript. Dr. Edson Fichter and Levi L. Mohler also reviewed the manuscript and contributed editorial suggestions. Statistical assistance was provided by Drs. Robert Giles and Dale Everson. MATERIALS AND METHODS Collection of Materials and Data State trappers collected uteri of beavers during the fall trapping seasons of 1953 through 1956. They counted fetuses during the spring trapping season in 1956. The materials and data were collected throughout the state and sent to the junior author for analysis. During the 1962-63 fall through spring trapping season, two beaver trappers in southeastern Idaho, John Kindall and Warren Moore, collected uteri and counted fetuses preliminary to a study of productivity and movements by the senior author (Leege 1964). In the 1963-64 season, additional reproductive tracts, fetus counts, and data on sex and age ratios were gathered by Leege with the assistance of these two trappers. Beavers were livetrapped during the summer months in 1962 and 1963 in portions of Bear Lake and Caribou counties in southeastern Idaho. One hundred ninety1Contribution from the Idaho Cooperative Wildlife Research Unit; The College of Forestry, Wildlife and Range Sciences, University of Idaho; the Idaho Fish and Game Department; the Wildlife Management Institute; and the U. S. Fish and Wildlife Service, cooperating; and Idaho Fish and Game Department P.-R. Project W-108-R. 2 Present address: Idaho Fish and Game De-

Parasites of Ovis canadensis canadensis in Montana, with a Checklist of the Internal and External Parasites of the Rocky Mountain Bighorn Sheep in North America

Eighteen Rocky Mountain bighorn sheep in Montana were examined for parasites at necropsy. Twelve came from the National Bison Range, five from Wildhorse Island (Flathead Lake), and one from the Sun River area. The parasites recovered were: Cysticercus tenuicollis, Wyominia tetoni, Marshallagia marshalli, Ostertagia circumcincta, 0. lyrata, 0. occidentalis, 0. ostertagi, Cooperia oncophora, C. surnabada, Nematodirus archari, N. davtiani, N. helvetianus, N. lanceolatus, N. spathiger, Trichostrongylus sp. (unidentified females), Protostrongylus rushi, Dermacentor albipictus, and D. venustus. Gastrointestinal nematodes recovered from the National Bison Range sheep ranged in number from 275 to 5,300 per host and those from the Wildhorse Island sheep from 670 to 3,510. The species recovered from the National Bison Range sheep were totally different from those recovered from the Wildhorse Island and Sun River sheep. The parasites recovered represent several new host and distribution records. Included in this report is a checklist of 51 species from Ovis canadensis, based on the present report, unpublished records of specimens in the U. S. National Museum Helminthological Collection, and from the literature. Seventy per cent of these 51 species are known parasites of domestic sheep and 35% of cattle in North America. During a study of the Rocky Mountain bighorn sheep, Ovis canadensis canadensis Shaw, 1804, by the staffs of the Department of Zoology and the Montana Cooperative Wildlife Research Unit of the University of Montana, parasites were recovered from 18 animals. Twelve rams were obtained by P. L. Wright and V. B. May from the National Bison Range at Moiese, Montana, through the cooperation of John Schwartz and C. J. Henry, former managers of the Range. Five sheep were obtained from Wildhorse Island on Flathead Lake, Lake County, Montana, and one pregnant ewe was obtained from the Sun River area in Teton County, Montana, with the assistance of personnel of the Montana State Game and Fish Department. The Sun River ewe was trapped at Scattering Springs. It was killed and necropsied at the Rocky Mountain Laboratory, Hamilton, Montana, by W. Hadlow. Some of the parasites recovered from the 18 sheep have been the subject of previous reports; namely, lungworms (Forrester and Senger, 1964), Bovicola jellisoni (Emerson, 1962), and Oestrus ovis (Capelle, 1966). The remaining parasites collected are reported herein, together with a checklist of the external and internal parasites of Ovis canadensis. Received for publication 18 July 1966. MATERIALS AND METHODS One ram was killed and necropsied each month for 12 consecutive months at the National Bison Range. The first ram was necropsied in May 1958, and the 12th in April 1959. The rams ranged in age from 2 to 7 years. They were first examined for ectoparasites, then the lungs, liver, omasum, abomasum, and small intestines were removed and taken to the laboratory for examination. The general method of recovering and estimating total numbers of gastrointestinal worms was similar to the procedure used by Porter (1942), with the exception that the fine plant debris in each container of organ contents and washings was reduced by means of a process of repeated suspensions in water, sedimentations, and decantations prior to taking samples. For most sheep, the total worm counts were determined from various small samples of the washings from the abomasums and small intestines of the sheep. In some instances, however, all the washings from the gastrointestinal tracts were examined and the total counts were made directly. Sheep 13, 14, and 15 from Wildhorse Island (Table II) were found dead or were accidentally killed in the field. They were not subjected to as thorough an examination for gastrointestinal parasites as were the other sheep from Wildhorse Island and the National Bison Range (Table I), and their worm counts are probably incomplete. Only qualitative determinations were made on the parasites recovered from sheep 18 from Sun River (Table II), as the procedures used in collecting these specimens are unknown. Fecal samples were collected from sheep 1 to 11 (Table I) from the National Bison Range, but not from the other seven sheep, and the nematode

Stump and Tree Nesting by Mallards and Black Ducks

Studies conducted 1961-65 at the Montezuma National Wildlife Refuge in New York demonstrated that mallards (Anas platyrhynchos) and black ducks (Anas rubripes) make extensive use of stumps and dead snags for nest sites. Nest densities in timbered habitats compared favorably with those in untimbered habitats. Nest success was generally higher in timbered than in untimbered areas, except for a newly flooded impoundment where nest success was poor. A simple artificial nest structure was used to increase the number of available nest sites in some of the timbered habitats. Development of stump-nesting populations of ducks may furnish a means of increasing waterfowl production in forested areas. The use of stumps and dead snags as nest sites for black ducks and mallards was noted during the course of several studies of waterfowl ecology at the Montezuma National Wildlife Refuge, Seneca Falls, New York. The purpose of this paper is to bring together and present observations of stump nesting, a habit which may have valuable management implications. Studies of waterfowl nesting at Montezuma were initiated by Cummings in 1961 and continued until 1964. Cowardin (1965) made a detailed study of waterfowl production on habitat types containing dead flooded timber during 1963 and 1964. Reed (1966) reported preliminary findings concerning waterfowl production in green timber impoundments. Stump nesting is more common in mallards than in black ducks at Montezuma. Instances of stump nesting were also observed for the blue-winged teal (Anas discors), redhead (Aythya americana), wood duck (Aix sponsa), and Canada goose (Branta canadensis). Nest sites included stumps, tall snags, mounds between clumps of red maple (Acer rubrum), hollow logs, and crotches in both living and dead trees. With the exception of the wood duck and Canada goose, there are few recorded instances of tree and stump nesting by the species mentioned above. Bent (1962:52, 53) described a number of tree nest sites used by black ducks. Wright (1954:34) stated that, In the lowlands of the St. John River, and no doubt in other areas in eastern Canada, the nest [of black ducks] frequently is placed in holes and crotches in mature hardwoods. Stotts and Davis (1960:138) found black duck nests in wooded areas and on offshore duck blinds on the Eastern Shore of Maryland. Bent (1962:37) cited one instance of a mallard nesting in a hollow stump. Burger (1964) described the use of nest boxes by mallards. We have found no recorded instance of tree nesting by redheads or blue-winged teal. Canada geese often nest in trees or in nesting tubs placed in trees. Brakhage (1965) reviewed the literature describing tree nesting in geese. O. H. Hewitt and D. Q. Thompson fur1This study was supported by the New York Cooperative Wildlife Research Unit and the Division of Wildlife Refuges of the U. S. Bureau of Sport Fisheries and Wildlife. 2 Present address: Northern Prairie Wildlife Research Center, Bureau of Sport Fisheries and Wildlife, Jamestown, North Dakota.

Physiological Changes Associated with Shock in Confined Gray Squirrels

Shock resulting from confinement of certain individual gray squirrels (Sciurus carolinensis) in live-traps was characterized by convulsions, and unconsciousness, leading to death. Confined-comatose squirrels (in shock) were compared physiologically to confined-stressed squirrels and to an unstressed control group. Physiological changes in the confined-comatose animals included severe hypoglycemia, slight leukopenia, a reduction in adrenal glucocorticoids, and elevated packed-cell volume. Studies made near Blacksburg, Virginia, have revealed that gray squirrels are susceptible to shock, and frequently die when they are confined in live-traps. The shock condition is characterized by muscular incoordination, inability to maintain orientation in space, convulsions, and unconsciousness, leading to death. For one to several hours before death, the animals exhibit variable respiratory and heart rates, and are cold to the touch, with rectal temperatures as low as 80 F. Some squirrels are quite resistant to confinement-stress, while others are extremely susceptible. Preliminary behavorial studies indicate that susceptibility to confinementstress may be related to an animal's early experiences and hierarchial position. According to this premise, stress from social contacts with others of the species would decrease the individual's ability to withstand the additional stress of confinement. This study was undertaken to describe the normal physiological values and to measure the changes that occurred in these parameters as a consequence of fear-shock that appeared in some confined gray squirrels. Grateful acknowledgment is made to the Virginia Commission of Game and Inland Fisheries for fellowship funds to support this investigation. MATERIALS AND METHODS Three groups of experimental animals were compared in this study: control squirrels, collected by shooting in the head with a .22 caliber rifle; confined-stressed squirrels which did not display symptoms of shock after 12-48 hours of confinement in live-traps; and confined-comatose animals which were in shock as a result of confinement in live-traps for 12-24 hours. Food and water were available to the trapped animals. Each of the groups was composed of 5 male and 5 female squirrels. Animals in the two latter groups were killed by a blow on the head. All animals were collected between September and March, and all the animals, except two males, were in a nonreproductive condition (that is, females were neither pregnant nor lactating and males had small testes and few sperm). Cardiac blood, 1 to 5 ml in volume, was collected in a heparinized syringe immediately after death. A portion was removed for cytological study; the remainder was centrifuged, and the supernatant plasma 1Release No. 65-4 of the Virginia Cooperative Wildlife Research Unit (Virginia Polytechnic Institute; Virginia Commission of Game and Inland Fisheries; Wildlife Management Institute; and U. S. Fish and Wildlife Service, cooperating). 2 Present address: Department of Zoology, University of British Columbia, Vancouver.

An Observation of Parturition in The Pronghorn Antelope

Journal Article An Observation of Parturition in The Pronghorn Antelope Get access Volney W. Howard, Jr. Volney W. Howard, Jr. Idaho Cooperative Wildlife Research Unit, Moscow Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 47, Issue 4, 2 December 1966, Pages 708–709, https://doi.org/10.2307/1377902 Published: 02 December 1966 Article history Accepted: 07 September 1966 Published: 02 December 1966

Autumn Roosting Flight Counts as an Index to Wood Duck Abundance

Roosts and roosting flights of wood ducks (Aix sponsa) were studied during autumn, 1959-64. Observations were made during 768 flight periods at 52 roosts. The primary study area was a 100-mile segment of Mississippi River bottoms in northeastern Iowa. Roosts were in many species of emergent vegetation. Barring major changes in habitat, autumn roost sites were usually the same each night and each year. Autumn migrants used roosts established in late summer by local birds. Seasonal changes in roosting populations were similar each year. September 20 is recommended for making roosting flight counts to be used as an index to annual changes in abundance of wood ducks. Evening counts were superior to morning counts. Numbers at a roost ranged up to 5,400. Sampling units, sampling schemes, sensitivity, and use of roosting flight counts for estimating abundance of wood ducks are discussed. The Mississippi Flyway Council stated that adequate information on population levels of wood ducks was not provided by techniques used to census other waterfowl (Yancey et al. 1958). In response, the Iowa Cooperative Wildlife Research Unit initiated a study of some methods of censusing wood ducks. This is a report of an investigation of wood duck roosting phenomena in northeastern Iowa and adjacent areas during August-November, 1959-64. The main objective was to evaluate roosting flight counts as a method of estimating abundance of wood ducks. We are grateful to Refuge Manager Don Gray and his staff on the Upper Mississippi River Wildlife and Fish Refuge for their assistance and support of this study.

Marking Mule Deer with an Automatic Tagging Device

Automatic tagging devices were used to mark mule deer (Odocoileus hemionus) in Colorado. Deer entered 16.9 percent of 749 devices set on the winter range and 32.5 percent of 83 devices set on the summer range. Reliability of the devices was increased from 43.3 percent (winter range) to 70.4 percent (summer range) by modifying the snap mechanism. This paper reports the use of a modified automatic tagging device to mark mule deer for a study of seasonal movements. Devices of this general type were first used to mark white-tailed deer (Odocoileus virginianus) in Michigan by Verme (1962). The study was conducted within the Cache la Poudre River drainage west of Fort Collins, Colorado, where tagging devices were used on winter and summer ranges. Topography of the winter range was generally rugged. North-facing slopes were covered by mixed stands of ponderosa pine (Pinus ponderosa) and Douglas fir (Pseudotsuga menziesii); other slopes were covered by shrubs, forbs, and grasses. The summer range was characterized by glacial U-shaped valleys covered by dense stands of Engelmann spruce (Picea engelmanni) and lodgepole pine (Pinus contorta). Wet meadows bordered major stream courses. Acknowledgment is made to Dr. Fred A. 1 Contribution from the Colorado Cooperative Wildlife Research Unit, the Colorado Game, Fish, and Parks Department, Colorado State University, the Wildlife Management Institute, and the Bureau of Sport Fisheries and Wildlife, cooperating. 2 Present address: Illinois Natural History Survey, Urbana. 631 not be determined. No variation between the sexes was observed. The chronologic data are not applicable statistically to any population of mule deer because of the improbability of a random sample, the wide span of time over which the collection was made, the methods of age determination, and the difference in sources. However, the regularity of development and the similarity of eruption times observed in this study with those reported by Robinette et al. (1957) are significant biologically. Differences of not more than 1 month occurred for all teeth except the permanent premolars in which a difference of 3 to 4 months existed. It is presumed that these results are representative for postnatal wild deer from the Cache la Poudre River drainage in Larimer County, Colorado.

Foods of Lesser Scaups on Breeding, Migration, and Wintering Areas

This food habits study was based on stomach contents of 164 lesser scaups (Aythya affinis): 39 from a breeding area in Manitoba, 88 from a fall concentration area on the Mississippi River in Illinois, and 37 from two wintering areas on the Louisiana coast. Animal foods made up the bulk of the diet of all three groups: 91.1 percent on the breeding area, 93.5 percent on the fall concentration area, and 63.7 percent on the wintering areas. The most important animal foods were amphipod crustaceans on the breeding area, molluscs on the fall concentration area, and fishes on the wintering areas. The percentages of animal foods are similar to those found in other recent investigations, but they differ from earlier findings which show the lesser scaup to be chiefly vegetarian. Additional collecting is needed, especially in early spring, for a more accurate picture of seasonal food habits but present information shows that lesser scaups feed chiefly, and sometimes almost exclusively, on animals most of the year. Animal foods decrease in the diet from summer to winter and probably reach a low point in late winter and early spring. Food habits data reflect the close relationship of the lesser and the greater scaup and show that they differ sharply from other North American members of their genus, which are chiefly vegetarians. A general picture of the food habits of the lesser scaup was given by Cottam (1939:38-46) who presented data on 1,051 stomachs from various localities in North America and reviewed the findings of earlier investigators. Since then, additional information has been obtained from scaups collected along fall migration routes (Korschgen 1955, Anderson 1959) and on wintering areas (Cronan 1957, Harmon 1962), but little attention has been given to food habits on the breeding ground. Munro (1941:134-137) reported the foods of 45 lesser scaups from British Columbia breeding areas. Cottam's (1939) data also included specimens from breeding areas but they were not discussed separately, except for 17 juveniles collected in western Canada. No information from other parts of the breeding range was found in the literature. This paper reports the foods eaten by adult lesser scaups on a breeding area in southwestern Manitoba, a fall concentration area on the Mississippi River in Illinois, and two wintering areas in Louisiana. Comparisons are made with previously published studies. Data from breeding and wintering areas were derived from 76 stomachs taken from specimens collected primarily for a study of the reproductive organs. Nineteen specimens in 1959 and 20 in 1960 were obtained in the pothole country around Erickson, Manitoba, during spring and summer. The other 37 were collected in marshes around Lake Borgne near New Orleans, Louisiana, in December, 1959 (20 specimens), and f om roadside ditches and ponds near Grand Chenier, southwestern Louisiana, in late February and early March, 1960 (17 specimens). Data from the fall concentration area are based on 88 stomachs taken from lesser scaups shot by hunters at Keokuk Pool on the Mississippi River, Hancock County, Illinois, during fall, 1948. Illinois specimens were provided by George C. Arthur, Illinois Department of Conservation, who generously contributed them to this study. The authors are in1 Contribution from the Gaylord Memorial Laboratory, the Delta Waterfowl Research Station, the Missouri Department of Conservation, and the Missouri Cooperative Wildlife Research Unit.

Breeding Ecology of the Redhead Duck in Western Montana

The habits of the redhead duck (Aythya americana) were studied in the Flathead Valley of western Montana in 1960 and 1961 to determine their habitat preferences in this pothole breeding ground. The 2,600-acre study area, surrounding the Ninepipe Reservoir, contained 686 potholes. Redheads usually were paired by the time they arrived on the study area in March. The average density of redhead breeding pairs was 25 pairs per square mile. For all spring activities except nesting, the birds used large, deep, open potholes or breeding-pair potholes. The several breeding-pair potholes and the nesting pothole utilized by the pair comprised their home range. Starting in late April, the pairs moved about the home range as the hens selected nesting sites, usually in the dense emergent vegetation of small, shallow potholes. Hard-stem bulrush (Scirpus acutus) and cat-tail (Typha latifolia) were preferred nesting cover. Redhead nesting success was only 15 percent, a low rate apparently caused by degenerate nesting behavior complicated by high redhead density, a lack of suitable nest hosts, and certain habitat deficiencies. By late June most drakes and unsuccessful hens had moved from the potholes to nearby reservoirs. All successful hens led their newly hatched broods from the nesting potholes to larger brood potholes and many eventually moved to the reservoir. By mid-July virtually all redheads had moved from the potholes to the reservoirs, where they remained until fall migration. 1A contribution from the Montana Cooperative Wildlife Research Unit (U. S. Fish and Wildlife Service, Montana Fish and Game Department, University of Montana, and Wildlife Management Institute cooperating). 2 Present address: Northern Prairie Wildlife Research Center, Jamestown, North Dakota. The redhead duck is an important nesting species in the Flathead Valley of western Montana. A study of redhead habits was conducted in 1960 and 1961 to determine breeding behavior, habitat preferences, and This content downloaded from 207.46.13.129 on Wed, 29 Jun 2016 04:41:10 UTC All use subject to http://about.jstor.org/terms BREEDING ECOLOGY OF REDHEAD * Lokemoen 669 nesting success. Ecological information was gathered on each pothole in the study area and then correlated with redhead use to determine habitat preferences. Nesting success and production, as affected by habitat conditions, redhead parasitism, weather, and other environmental factors were included as major features of the study. Williams and Marshall (1938:46) who studied a large number of redhead nests at Bear River, Utah, noted a 62 percent nesting success but only a 26 percent hatching success. Many eggs were lost from unknown causes, plus flooding, predation, desertion, or being knocked from the nest. Redheads preferred to nest in hard-stem bulrush, phragmites (Phragmites communis), and cat-tails, in that order. Nests were generally located over shallow water, in dense emergent vegetation, and near an opening. To improve the Bear River marshes for nesting redheads, C. S. Williams and M. C. Nelson (Unpublished report, 1943. Management of the redhead duck in Utah. Filed with U. S. Fish and Wildl. Serv., Washington, D. C. 85pp.) suggested stable water levels, predator control, and good interspersion of nesting cover with open

Float Counts vs Flight Counts as Indices to Abundance of Nesting Wood Ducks

Counts of wood ducks (Aix sponsa) made during canoe float trips on Mississippi River tributaries in northeast Iowa were less useful than counts made at mouths of those streams as flights passed from scattered roost sites in the bottoms to nesting, feeding, and loafing areas in tributary valleys. Coefficients of variation were 0.29 for float counts and only 0.08 for flight counts. River float counts and flight counts of wood ducks were made in northeast Iowa during April, 1962. This paper compares the usefulness of these two methods for estimating abundance of nesting wood ducks. River float counts are widely used to measure breeding populations and production of wood ducks. However, there is disagreement concerning reliability of this method. Mumford (1952) conducted a 3-year study of river float counts in Indiana and concluded that they gave usable estimates of wood duck production when made under favorable conditions. In Ohio, Stewart (1958) found that river float counts made with one trip in each of the three months, April, May, and June, were not sufficiently sensitive to show anything but major changes in numbers. He added that if all three trips were made within a short period, a measurement of variation could be obtained. Martin (1959) discussed spring and summer float counts and concluded that the technique was unsuitable in Iowa. Hein (1962) found that fall float counts were unreliable in Iowa owing to variation in counts according to time of day, length of float trip, and nature of the stream. Wood duck flight counts have not been used during spring, although fall roosting flight counts have been investigated by Smith (1958), Stewart (1958), Martin (1959), and Hein (1965). Data were collected along the Mississippi River in northeast Iowa. Most of the bottomland habitat was part of the Upper Mississippi River Wildlife and Fish Refuge administered by the Bureau of Sport Fisheries and Wildlife. The bottoms were 1 to 3 miles wide and consisted of wooded islands, sloughs, and marshes interspersed with open 1 Journal Paper No. 5089 of the Iowa Agricultural and Home Economics Experiment Station, Ames. Project No. 1391. A contribution from the Iowa Cooperative Wildlife Research Unit, U. S. Bureau of Sport Fisheries and Wildlife, Iowa State University, Iowa State Conservation Commission, and the Wildlife Management Institute, cooperating. 2 Present address: Department of Biology, Wake Forest College, Box 7325, Reynolda Station, Winston-Salem, North Carolina. 13 JORDAN, J. S. 1953. Consumption of cereal grains by migratory waterfowl. J. Wildl. Mgmt. 17(2):120-123. MARTIN, A. C., H. S. ZIM, AND A. L. NELSON. 1951. American wildlife and plants. Dover Publications, Inc., New York. ix + 500pp. McFARLAND, L. Z., H. GEORGE, AND H. MCKINNIE. 1963. Grain preference of captive waterfowl. California Fish and Game 49(3):207-209. MoRRISON, F. B. 1956. Feeds and feeding. 22nd ed. The Morrison Publishing Company, Ithaca, New York. vi + 1165pp. Received for publication August 4, 1965. This content downloaded from 40.77.167.34 on Fri, 01 Apr 2016 05:05:30 UTC All use subject to http://about.jstor.org/terms 14 Journal of Wildlife Management, Vol. 30, No. 1, January 1966 water. Wooded bluffs rose as high as 600 feet on each side of the floodplain. Numerous tributary valleys were important extensions of habitat for wood ducks. Before the incubation period of the nesting season, most pairs roosted each night at scattered locations in the Mississippi River bottoms. At dawn more than half of these birds left the bottoms and entered tributary valleys and ravines to spend the day searching for nesting cavities, egg laying, feeding, and loafing before returning to the bottoms at dusk to roost. These flights became unpredictable after hens began incubating.

Natural Variation in the Blood Proteins of White-Tailed Deer

Starch gel electrophoretic patterns of blood from 200 white-tailed deer (Odocoileus virginianus), mostly from the DeSoto Bend area of the Missouri River on the Io*a-Nebraska border, disclosed two hemoglobin patterns and three presumed transferrin patterns which were compared with each other and with sex and age. This technique disclosed presumptive genetic variation and might be used with blood grouping or alone to characterize different populations of one species or even to estimate mixtures of stocks. To test the feasibility of identifying possible strains or subspecies of deer, the technique of starch gel electrophoresis was applied to 200 blood samples collected for other purposes from wild white-tailed deer in December of 1962 and 1963. The horizontal starch gel electrophoresis was used as described and demonstrated by Mikael Braend to the senior author (1962); it much resembled the method of Smithies (1955) and Poulik (1957). Another detailed description of the technique is given by Manwell (1963). Almost all parts of the serum as well as the hemoglobin (Ingram 1963) can show patterns which vary among individuals within a species, prealbumins (pre), Kristjansson (1963), Shreffler (1964); albumins, Braend (1964), Desborough and Irwin (1964); postalbumins (pa), Gahne (1963); beta globulins or transferrins (Tf), Smithies (1955), Parker and Beam (1962), and Braend and Stormont (1964); and haptoglobins (Hp), Giblett (1961). Genetic studies of these variations wherever made so far have shown simple, or easonably simple, hereditary control (codominance of alleles at one or two loci for each category of variation, Smithies and Hickman (1958), Popp (1963), and previously cited references). One may assume, even in the absence of family data, that similar variation disclosed in related species is likely to have a simple genetic control. Besides disclosing presumptive genetic variation in wild species of animals, such techniques, used with blood grouping (Marr and Sprague 1963) or alone, might enable one to characterize different populations (strains or subspecies) of one species and even to estimate mixtures of stocks. Deer blood from four geographical areas was checked. Most samples, however, came from the DeSoto Bend area of the Missouri River. Deer from this area may be of the subspecies O. v. dacotensis, since deer reintroduced into this area are reported to have been secured from northwestern Nebraska in the 1880's. Samples from northeast Iowa (Lansing) are likely to be of the northern variety (0. v. borealis); the samples from Lucas County in south-central Iowa and 'Journal Paper J-4953 of the Iowa Agricultural and Home Economics Experiment Station, Ames. Projects 1551 and 1395. A joint contribution of the Department of Genetics, Iowa State Unive sity, and Iowa Cooperative Wildlife Research Unit, which is sponsored jointly by Iowa State University, the Iowa State Conservation Commission, the Bureau of Sport Fisheries and Wildlife, and the Wildlife Management Institute. 2 Leader, Iowa Cooperative Wildlife Research Unit, Ames.

Corpora Lutea Variations of White-Tailed Deer

The reproductive tracts of 404 female white-tailed deer (Odocoileus virginianus) were studied for information on size, shape, and coloration of corpora lutea. Corpora lutea in fawns are regarded as regressing if they are less than 4.0 mm in diameter at the time when the rut for that age-class is nearing its end. In all age-groups of does where fetal membranes or embryos are present, corpora lutea smaller than 6.0 mm are regarded as regressing. These small ones are regarded as corpora lutea of an earlier heat and not as corpora lutea of the current pregnancy. Regressing corpora lutea of a previous ovulation also appear to have an irregular surface shape. Color is not a dependable criterion for differentiation of the two types of corpora lutea. During an investigation of reproduction in white-tailed deer in Iowa, information was obtained on the physical characteristics of their corpora lutea. In attempting to correlate fertilization rate with ovulation rate, difficulty has been encountered in differentiating corpora lutea of ovulation of a previous heat from corpora lutea of pregnancy. In sheep, corpora lutea of ovulation are formed in ruptured follicles within 4 days following ovulation (Asdell 1946:366-367) and are fully developed by the eighth day following ovulation (Harrison 1962:169). In deer, corpora lutea of ovulation begin regressing after about 14-15 days (Cheatum 1949:285) if fertilization does not occur. When fertilization and implantation take place, corpora lutea of ovulation persist as corpora lutea of pregnancy (Amoroso and Finn 1962:454). The corpus luteum has a glandular function, secreting progesterone hormone which is essential for implantation and early development of the fertilized ovum. This hormone also suppresses further follicular development and ovulation. After parturition, corpora lutea of pregnancy regress and become corpora albicantia. Ability to identify corpora lutea of ovution of a previous heat from those of pregnancy of a later heat would eliminate a possible source of error when using corpora lutea counts as an index to reproductive rates of deer. Golley (1957) found the use of the corpora lutea dependable for determining the ovulation incidence of the black-tailed deer (Odocoileus hemionus columbianus) but detected an error when using the corpora albicantia to indicate ovulation. Golley used histological techniques to determine the differences between the two types of tissue. This paper will discuss gross size, shape, and color variations of corpora lutea in white-tailed deer ovaries as a possible means for distinguishing the two types. The assistance of Eldie Mustard, former Iowa State Conservation Commission Biologist, is appreciated. Several of Iowa's Conservation Commission officers and biologists also assisted materially by collecting reproductive tracts from wild deer. The cooperation of deer hunters who saved tracts for the study was indispensable. Calvin Rayburn, Ronald Schara, Harold Prince, and David Bolton, students 1Journal paper J-4604 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa. A contribution from the Iowa Cooperative Wildlife Research Unit, which is jointly sponsored by Iowa State University of Science and Technology, U. S. Bureau of Sport Fisheries and Wildlife, the Iowa State Conservation Commission, and the Wildlife Management Institute. Financial support for Trauger was provided by the National Science Foundation Undergraduate Research Participation Program.

Primeval Deer Hunting Pressures Revealed by Remains from American Indian Middens

Deer jaws from Indian middens were available from five populations in Missouri--three from the prehistoric period, two from the historic. Two contemporary samples from areas where any deer is legal game were used for comparison. Findings led to three conclusions: (1) The Indian kill of fawns was very light, never exceeding 8 percent of the total sample (in modern times fawns make up 30 percent of the hunting bag), which may have been a voluntary conservation practice among a people dependent upon deer as an important item of food and clothing. (2) Modern deer populations are being more closely cropped than were those hunted by Indians. (3) The proportion of old deer in the harvest (61/2 years or more) is declining. At the three prehistoric sites this proportion ranged from 20 to 26 percent; at the two historic sites it was 3 and 11 percent; modem white man's kill is only 2 percent old deer. The more rapid population turnover in contemporary deer populations indicates that white man's equipment and rapid transportation enable him to exert greater hunting pressure during a 1-week hunting season than Indians did by hunting the year round. In 1947, Leopold et al. (1947:165-170) listed 30 states suffering from overpopulations of deer; many other states could have been added to the list since that time. These overpopulations have led to many interesting speculations as to the causes and to the belief that irruptions of deer are a modem phenomenon, man-made through mismanagement of the herds. Most states with problem deer herds have been forced to legalize the hunting of does; this means that any deer is legal, and fawns as well as does are shot. It becomes of interest, therefore, to compare contemporary deer harvest pressures with those maintained by Indians under primeval conditions. The principal tool used by the modem game biologist to evaluate hunting intensity is the age compostion of the kill, determined by examination of deer rami and comparison with a standard set of rami (commonly called a jaw board). Criteria for age-classes are based on premolar replacement, third molar eruption, and degree of enamel wear, as established by Severinghaus (1949). In the present study, deer jaws from Indian middens in Missouri were available in sufficient numbers from five populations -three from the prehistoric period, two from the historic. Each jaw was compared with the same standard jaw board, and both right and left rami were included. Many of the tooth rows were so broken or in'A contribution from the Missouri Cooperative Wildlife Research Unit: U. S. Bureau of Sport Fisheries and Wildlife, The Wildlife Management Institute, Missouri Conservation Commission, and the University of Missouri, cooperating. This content downloaded from 157.55.39.107 on Wed, 30 Mar 2016 06:36:34 UTC All use subject to http://about.jstor.org/terms DEER REMAINS IN INDIAN MIDDENS * Elder 367 complete as to preclude their use, and it was quite impossible to match right with left sides because the distal ends of the rami were nearly always missing. Contemporary samples were from states in which a deer of any sex or age is legal game. From Iowa, the 1953 data were used for comparison because 1953 was their first open season in many years (Sanderson and Speaker 1954). In Missouri, any deer had been legal game for 7 years prior to 1958, the year I chose for comparison. Thus biases arising from bucks-only seasons were avoided. There were some possible sources of error. It may be argued that jaws of fawns were comparatively scarce in material from middens because of poor preservation, the softer bone of the younger animal being less likely to persist. I do not believe this to be true, because rami of fawns were found in good preservation from every village site studied and were accompained by well-preserved bones of a much more delicate nature from many small mammals. Since jaws from Indian middens were not all taken during a brief, restricted fall season, they were more difficult to classify as to age than were jaws from contemporary kills. This makes possible an error of a year either way in classifying some jaws, but it does not introduce a consistent bias, and hence each jaw was placed with the age-class it most resembled. Indian midden material is not stratified sufficiently for any one year's harvest to be distinguishable; each site represents a deer kill extending over a considerable number of years and is thus an average sample. Fawns, for instance, might have been killed in time of famine but not in intervening

Body Condition and Response to Pesticides in Woodcocks

Response of woodcocks (Philohela minor) to heptachlor dosage was closely related to the physical condition of the birds, as reflected by body weight and by body weight in relation to capture weight: in a series of tests with underweight birds, nearly all woodcocks died at dosage levels well below those at which nearly all the birds in a normal-weight series lived. Heptachlor residues in tissues were determined and their loss with time was estimated. Dieldrin proved more toxic than heptachlor to birds of similar weight. Birds in good weight survived massive doses of DDT; some succumbed to smaller spaced serial doses, but only when these were accompanied by starvation rations. When birds were placed in foil-lined boxes after doses of heptachlor added to butter oil or corn oil, it became evident that they passed quantities of oil in about 3 hours, thus very likely ridding themselves of a large part of the heptachlor dose. It was concluded that other methods than dosage with encapsulated chemicals would be needed for appraisal of field effects of toxicants on woodcocks. Investigations of the effects of heptachlor on woodcocks were begun in 1959 because of the potential hazard of this chemical on the southern wintering grounds, which are within the area treated extensively for control of the imported fire ant (Solenopsis saevissima). As a first step, exploratory tests of acute toxicity of heptachlor were made at the Massachusetts Cooperative Wildlife Research Unit at Amherst. DDT and dieldrin dosages were tried also, because they, too, are chemicals to which woodcocks may be exposed in many areas. Additional tests with heptachlor were made at the Patuxent Wildlife Research Center, Maryland, in 1960. The purposes of this paper are (1) to show the relationship between weight, time in captivity, and effect of toxicant; (2) to demonstrate the resistance of woodcocks to large doses of encapsulated toxicant; (3) to record residue content of dosed birds and to approximate the loss rate of heptachlor residues; and (4) to record mortality data-these are given in some detail, for, although they are not in standard LD50 form, they provide the only available data for a species that offers unusually difficult problems in xperimentation. For the studies of both years, woodcocks were caught in mist nets near Amherst. Housing and care of the birds were as described by Stickel, Sheldon, and Stickel (1965). Assistance was received from several people in various parts of the work. John L. Buckley facilitated and encouraged the tests in 1960 and the analyses that followed; Don W. Hayne helped plan the 1960 tests and provided critical analysis of data from the entire study. Allyn Coombs helped perform the experiments at Amherst in 1959. Residue analyses were made at the Patuxent Wildlife Research Center by Vyto Adomaitis, Calvin Menzie, and William Reichel. EXPERIMENTS WITH HEPTACHLOR Tests in 1959 explored the lethal levels of capsule dosages of heptachlor to captive woodcocks. With this rangefinding as background, tests in 1960 were planned to refine the 1959 determinations, using a stepwise procedure recommended by Hayne for obtaining an LD50 determination with the most economical use of birds. When it was

Chemical Inhibitors of Ovulation in the Pigeon

The recent increase in the numbers of several species of native blackbirds as well as the increasing concern over the numbers of such exotic birds as starlings (Sturnus vulgaris), house sparrows (Passer domesticus), and pigeons (Columba livia) has prompted widespread study of control methods. This paper reports the results of a 4-year search for a practical oral contraceptive for nuisance birds. Most substances found effective in inhibiting ovulation in other animals proved to have effect on pigeons, even in nearly lethal doses. Compounds used included: tranquilizers, gametocides, antithyroid compounds, hypophyseal inhibitors, insecticides, fungicides, and coccidiostats. Only provera at 0.1 percent or more in the diet and arasan at 0.35 percent inhibited ovulation without severe debilitation of the birds; the effect was lost as soon as the materials were withdrawn from the diets. Practical results were obtained with the anticholesterol compound SC-12937 (22, 25-diazacholestanol dihydrochloride). When this compound constituted 0.1 percent of the diet for 10 days in early November, no eggs were laid for 3 months, full fertility among some birds was not reached for 6 months, and some remained anovulatory for 12 months. Following spring feeding, ovulation was almost completely inhibited for 3 months, and after 6 months remained 75 percent inhibited. As man expands his numbers he comes in conflict with the few species of animals that are adaptable enough to thrive and even increase despite alteration of their environment or sometimes as a result of a new environment artificially created for them. The coyote's (Canis latrans) spread eastward over half the United States and the tremendous increase in blackbirds are examples of problems caused by species that seem to have profited by man's alteration of habitat. The gradual spread of exotic birds such as the house sparrow, European starling, and domestic pigeon is obviously the result of man's providing food and nesting sites. Each of these birds occasionally becomes so abundant as to require control; and the problems caused by excess feral animals are usually relegated to the field of wildlife management, whether or not we welcome them. The use of poisons to eliminate nuisance birds has many repugnant if not hazardous aspects, particularly in cities. It is opposed by well-organized groups and, in any case, simply makes room for more birds to move in and occupy the same territories. The employment of a multitude of frightening devices from noisemakers and artificial owls to such witch doctory as little black boxes and silvered ropes serves only to move bird concentrations from one building to another. A new approach seems necessary. Successful control of the screwworm fly (Callitroga hominivorax) in Florida by releasing sterile males (Bushland and Hopkins 1951, Simpson 1958, Knipling 1960) prompted my attempt to find a means of inhibiting reproduction in birds. With avian populations it is neither desirable nor practical to attempt to swamp out normal fertile males by releasing sufficient numbers of hand-reared, infertile male birds. Therefore, leads were sought in the medical literature devoted to birth control through inhibition of ovulation, in poultry literature dealing with side effects of drugs used in control of poultry diseases, in cancer research sidelines (gametocides, mutagens, or cytotoxins), and in wildlife sources revealing effects of insecticides and fungicides on reproduction in birds. 1A contribution from the Missouri Cooperative Wildlife Research Unit: U. S. Bureau of Sport Fisheries and Wildlife, Wildlife Management Institute, Missouri Conservation Commission, and the University of Missouri, cooperating.

Sex- and Age-Ratio Bias of Cannon-Netted Geese

Age ratios of Canada geese (Branta canadensis), derived from catches in cannon traps, are of questionable value unless time on bait is taken into account. Findings were based on examination of 2,879 geese caught in 46 timed catches at Swan Lake National Wildlife Refuge in 1961 and 1962. The proportion of adults in the catches increased with length of time on bait. No significant differences were found in sex ratios as time on bait increased. This study was designed to determine whether any measurable sexor age-ratio biases are obtained in the cannon-net trapping of Canada geese. It has been speculated that the period of time geese spend on the bait at the trap sites, before the catch is made, may influence sex and age ratios obtained. Correct interpretation of band recoveries is important in analysis of population dynamics. One problem that plagues wildlife research is the difficulty of obtaining random samples from wild populations. If sex and age ratios from trap samples contain biases of unknown magnitude, we cannot accurately determine flock composition or predict productivity and turnover from these samples. Until we know the magnitude of bias involved, we cannot make corrections and must assume that present trap samples and band recoveries are indicative of the populations. This study was carried out at Swan Lake National Wildlife Refuge in north-central Missouri during October, November, and December of 1961 and 1962. Financial assistance was supplied by the Missouri Conservation Commission and an Edward K. Love Fellowship from the University of Missouri. Dr. W. H. Elder, Rucker Professor of Zoology at the University of Missouri, guided the study. I am also grateful to the following: Dr. Donald H. Hazelwood, Department of Zoology, University of Missouri, for advice on statistics; Richard Vaught, Waterfowl Biologist, and Fred Veach, Area Manager, Missouri Conservation Commission; Leo Kirsch, Manager, and Howard Thornsberry, Wildlife Technician, Swan Lake National Wildlife Refuge. Richard Thompson, from the Savannah National Wildlife Refuge, Georgia, and Earl Cunningham, of the Carolina Sand Hills National Wildlife Refuge, South Carolina, also assisted with observations and handling of geese for several days during the fall of 1962. MATERIALS AND METHODS Determination of time on bait before each catch necessitated observation of the bir s from the time they came near the trap site until the actual shot was fired for the catch. The two trap sites used during this study were located on opposite sides of Swan Lake. The points of concealment and detonation control were an old silo, now an observation tower, and a storage barn. The silo is about 400 yards from one site, the barn only 30 yards from the other. Nets and cannons were laid out parallel to the shoreline in conventional fashion 'Contribution from the Missouri Cooperative Wildlife Research Unit, U. S. Fish and Wildlife Service, Wildlife Management Institute, Missouri Conservation Commission, Edward K. Love Foundation, and the University of Missour , cooperating. 2 Present address: Bureau of Sport Fisheries and Wildlife, 403 Perlstein Bldg., Beaumont, Texas.

Comparative Ecology of Bobwhite and Scaled Quail in the Oklahoma Panhandle

Bobwhite quail were encountered primarily in the riparian habitat in Cimarron County while the scaled quail occupied parts of the short grass, sandsage grassland, and pifion-juniper vegetation types. During a severe drought period, 1954-56, scaled quail populations remained at a high level while bobwhite quail numbers diminished. The early winter diet of bobwhite and scaled quail was similar. Scaled quail mingled in larger coveys during the winter period than did bobwhites. INTRODUCTION The Oklahoma Panhandle area provided an ideal opportunity to study simultaneously two species of quail, bobwhite (Colinus virginianus L.) and scaled (Callipepla squamata (Vigors)), at the overlapping peripheries of their respective geographic ranges. Furthermore the two species sometimes intermingled closely as members of the same covey. This suggested a certain degree of ecological equivalency between the two species. Odum (1954) defined ecological equivalents as organisms which occupy the same ecological niche in similar communities. The similarities and differences in some of the ecological and behavioral attributes of these two common quail will be considered in detail. This paper is based on 18 months of field observations made in Cimarron County extending from June, 1954 to November, 1957. The specific ecology of the scaled quail is treated in more detail by Schemnitz (1961). Acknowledgments.-This research (Contribution No. 359 of the Department of Zoology) was supported by the Oklahoma Cooperative Wildlife Research Unit (Oklahoma State University, Oklahoma Department Wildlife Conservation, Wildlife Management Institute, and U. S. Fish and Wildlife Service, cooperating). Dr. A. M. Stebler, Unit Leader, provided essential advice and counsel during this study. Dr. F. M. Baumgartner offered many helpful sug-

Breeding Age of Canada Geese

This study was designed to determine what percent of 1-, 2-, and 3-year-old wild geese (Branta canadensis moffitti) nest in a population of limited size; to compare results with similar information from captive flocks; and, by applying the breeding-age data obtained, to determine the percent of breeding geese in the Flathead Valley population. Five hundred forty-eight known-age Canada geese in the Flathead Valley population were color-marked during four breeding seasons, and the survivors were observed for breeding activity over a 5-year period. Most of the marked known-age geese were located prior to nesting; then the number of nesting birds in each age group was determined by censuses throughout the breeding seasons. A similar experiment was conducted on two captive flocks. No 1-year-old birds nested in either the wild or the captive populations. Between 27 and 36 percent of the 2-year-old wild geese nested, but only 17 percent of the captive 2-year-olds did so. All of the 3-year-old wild birds nested, but only 64 percent of the captives nested. Since the proportion of birds breeding in captive and in wild flocks appears to be markedly different, the breeding data from captive flocks cannot be used to determine the breeding age or the percent of breeding birds in a wild population. The breeding-age statistics obtained from the wild population, when applied to life-table data, showed that during a population-turnover period of 5 years only 10.2 percent of a generation of geese in the Flathead Valley, Montana, attained breeding age and survived to nest. This calculation was made on the assumption that one-third of all 2-year-old geese nest. In order to understand the population dynamics of Canada geese and to interpret more accurately life equations and life tables constructed for the species, it is essential to evaluate breeding-age data on captive flocks and to obtain more precise information on the breeding age of wild birds. Various authors have studied the breeding age of Canada geese in captive and semicaptive flocks. Elder (1946:105) stated that none of the pinioned geese in the flock at Bright Land Farm, Illinois, nested in their first or second years and only 25 percent nested in their third year. Kossack (1950:628), studying the same flock, found that none nested as 1-year-olds, 7.8 percent nested as 2-year-olds, and 20 percent nested as 3-year-olds. Kossack apparently included in his findings both wing-clipped and full-winged birds. Balham (1954), working with a flock in Manitoba, stated that only a small percentage of geese nested as 2-year-olds. Hanson (1949:181-182), working with captured wild geese (Branta canadensis interior) on the Horseshoe Lake Game Refuge in Illinois, separated 1-year-old females from older females by determining the presence or absence of an occluding membrane over the opening of the oviduct. All but one of 2/2-year-old females had open oviducts. If this was an accurate way of judging whether these females had nested, then about 94 percent had nested at 2 years. In his most recent publication, Hanson (1962:15) indicates uncertainty as to breeding among 2-year-olds and points out the need to determine more precisely what percent of the 2-year-old females nest in their third spring. He says, however, At the present stage of our knowledge, predictions of populations must be based on the assumption that all females attempt to nest 1Contribution from the Montana Cooperative Wildlife Research Unit, U. S. Fish and Wildlife Service, Montana State Fish and Game Department, Montana State University, and Wildlife Management Institute cooperating. The study was partially supported with Federal Aid in Wildlife Restoration funds under Pittman-Robertson Project W-71-R, Montana State Fish and Game Department.

Management of Ptarmigan in North America

Ptarmigan are monogamous, territorial game birds of arctic and alpine tundras. They are gregarious and migratory or nomadic from late summer until spring. Sex-segregation occurs in winter. Populations of rock (Lagopus mutus) and willow ptarmigan (L. lagopus) fluctuate widely from year to year; whether the fluctuations are rhythmic is not known. Breeding densities commonly range from 1 to 10 pairs per square mile. Ptarmigan habitat is unusually free from human disturbance. Most ptarmigan harvested in North America now are killed primarily for food; the main harvest occurs in winter. Sport hunting exists on a small fraction of ptarmigan range. The only active management of ptarmigan is through regulation of harvest. Present regulations are set with no knowledge of ptarmigan numbers, the kill, or the effect of one on the other. Lack of access to ptarmigan range restricts the harvest. Greater future demand for ptarmigan as a recreational resource is expected; research is needed to establish a basis for an intelligent management program. This paper discusses the management of rock and willow ptarmigan in North America exclusive of Newfoundland. The questions examined are: (1) To what extent do people utilize ptarmigan? (2) What management procedures have been applied to ptarmigan? (3) What trends in utilization can be expected in the next few decades? (4) What problems may arise from these trends? Familiarity with Alaska has led me to present more details of ptarmigan use and management there than in other regions. Thanks are extended to Robert A. Rausch, Alaska Department of Fish and Game, and David R. Klein, Leader, Alaska Cooperative Wildlife Research Unit, for their excellent critical reviews of this manuscript. I am grateful to the Alaska Department of Fish and Game and to the United States Fish and Wildlife Service, Branch of River Basin Studies, for the use of unpublished data on the harvest of ptarmigan. Various federal and provincial conservation agencies in Canada gave prompt and courteous attention to requests for information on management practices. SOME CHARACTERISTICS OF PTARMIGAN AND THEIR ENVIRONMENT