• Life history and management of the grayling in interior Alaska

      Wojcik, Frank J. (1955-04)
      Field work on the Arctic grayling was conducted from September, 1951, to May, 1953; data on movements, spawning, food habits, sex ratios, and population dynamics were obtained. Returns on 1,222 tagged grayling varied from 0 to 20 per cent with areas. No returns were obtained from 165 fin-clipped fish. Fish entered the streams in the spring as soon as water started flowing, the dates varying from March 15 to May 9, 1952. Spawning in the Little Salcha River during 1952 is believed to have occurred between June 12 and June 16, Of 262 grayling checked for maturity, 18.7 per cent were mature in their fourth summer, 45 per cent in their fifth summer, and all by their sixth summer. Sex ratios obtained for adults varied with areas. The average sex ratio found for all areas was 79 males per 100 fem ales. The rate of growth was determined for grayling from six areas. The average increment for class V fish varied from 2.7 to 4.6 cm. per year. Aquatic insects were the main food organisms taken by grayling. Some terrestrial insects, fish, fish eggs and vegetable, matter were also taken. In view of the findings made in this study, overfishing appears to be the major cause of the decline in the sizes of grayling populations along the highways in the Fairbanks area. A twelve-inch minimum size limit is apparently the best management procedure, although an area closure is advisable for overfished spawning runs.
    • Range, movements, population, and food habits of the Steese-Fortymile caribou herd

      Skoog, Ronald O. (1956-05)
      The Steese-Fortymile caribou (Rangifer arcticus stonei Allen) form one of the most economically important herds in Alaska. This study of the herd took place from September, 1952, to December, 1955, under the auspices of the Alaska Cooperative Wildlife Research Unit at the University of Alaska and of the Federal Aid in Wildlife Restoration branch of the United States Fish and Wildlife Service, Project W3R. The Steese-Fortymile range occupies about 35,000 square miles of east-central Alaska and the Yukon Territory, lying mainly between the Tanana and Yukon Rivers. The terrain is mountainous, but not rugged; roads and towns are scarce, and a maximum of 60,000 people live on the fringes. Seven major plant communities comprise the range vegetation, three of them covering 60 to 70 per cent of the area and furnishing the bulk of the food for caribou. The carrying capacity is computed to be 70,000 to 90,000 caribou. The erratic and continual movements of caribou characterize this game species. Their movements vary from day to day and season to season. Most of the traveling takes place during the early morning and late afternoon; major seasonal movements take place in the spring and fall. Past and present data provide a general picture of the movement pattern of this herd throughout the year. The Steese-Fortymile herd dwindled from a peak of about 500,000 animals in the late 1920's to a low of 10,000 to 20,000 in the early 1940's. The decline is attributed to a population shift. The present population contains at least 50,000 animals and is increasing steadily. Reproduction was high during the years 1950 to 1955. The rut takes place during the first two weeks of October; most of the calves are born during the latter half of May, following a gestation period of about 33 weeks. Valuable information on caribou behavior during the calving period is presented. Counts taken in May show that at least 50 per cent of the calves survive the first year. Wolf and man are the most important mortality factors affecting this herd. The total annual mortality, excluding calves, is estimated at eight per cent. Sex and age data from composition counts and hunter-checking-station operations indicate that this herd is young and that the sex ratio approaches 100:100. The annual increment for the herd is computed to be 10 to 15 per cent. Caribou are cursory feeders and eat a wide variety of plants. The main periods for resting and feeding occur during the middle portions of the day and night. The caribou’s diet hinges upon the available food supply, and thus varies with the seasons. In winter, the diet consists mostly of lichens, grasses, and sedges, with browse plants of some importance; data from 23 stomach-samples are presented. In spring, the new shoots of willow, dwarf birch, grass, and sedge are most important; information is based only on field observations. In summer, a wide variety of plants are eaten; willow and dwarf-birch foliage are of greatest importance, followed closely by grasses and sedges; data from 27 stomach-samples are presented. In fall, the diet shifts from a predominance of woody plants and fungi in late August to one of lichens, grasses, and sedges in late September; data from 70 stomach-samples are presented. The problems of data-gathering are discussed, as related to management practices. The contributions made by this report are outlined, and the important information still needed for proper caribou management is listed.
    • A review of waterfowl investigations and a comparison of aerial and ground censusing of waterfowl at Minto Flats, Alaska

      Rowinski, Ludwig J. (1958)
      The Minto Flats is one of the important waterfowl concentration areas of interior Alaska. Aerial surveys and ground studies were initiated in this area in 1950 and have continued in succeeding years. This study began in September, 1955, as a research project of the Alaska Cooperative Wildlife Research Unit. The study was financed largely by Pitman-Robertson Project Alaska W-3-R. The Minto Flats is an area of about 450 square miles, located about 35 miles west of Fairbanks. The important nesting species are scaup, pintail and widgeon. The Minto Lakes area serves as an important molting and flocking area for these and other species. Climatically the Minto Flats resemble the rest of interior Alaska. Water levels in the area are highly variable and influence the vegetation and breeding. Minto Lakes, Big Lake, and the Tolovana Flats were selected for concentrated study in 1956. During the 1956 field studies, data were collected for comparison with data available from previous years. Waterfowl production in the Minto Flats area is affected principally by weather, changes in water level, and predation. Among the factors influencing censusing are the census methods, stratification, and sample size. Enumeration of waterfowl is affected by differences in the visibility of birds, population composition, environmental conditions, and the accuracy of observers in relation to the other variables and in regard to individual partiality and talent. The difference between observers, when analyzed statistically points out the need for continuity of observers with known levels of ability. Breeding bird census figures from aerial surveys from 1950 t o 1956 are not comparable due to differences in census methods. Aerial brood surveys are valuable for determining year to year production trends while ground surveys provide data on brood species composition. Together they are the best guide to waterfowl production. Nesting studies have provided some data on nesting terrain, clutch size, and nesting success. The effect of nest hunting on the breeding population and the time necessary for obtaining an adequate sample indicates that nest hunting is not an economical or accurate means of measuring yearly productive success. Aerial surveys are recognized as the most feasible way of measuring production if the accuracy of the information gathered from the air can be increased.
    • Red squirrel (Tamiasciurus hudsonicus) ecology during spruce cone failure in Alaska

      Smith, Michael C. T. (1967-05)
      Observations were made on a red squirrel (Tamiasciurus hudsonicus) population in a mature white spruce (Picea glauca) forest near Fairbanks, Alaska, during two years of spruce cone crop failure (July, 1964, to April, 1966). An adequate supply of old spruce cones, cached in previous years, was available during the first winter. A 67% drop in numbers of the squirrel population followed the second crop failure with the remaining squirrels utilizing spruce buds as their primary food during the winter. Stomach analyses revealed that when present, spruce seed is the major constituent in the diet. In its absence, heavy utilization of mushrooms in summer and spruce buds in winter occurs. Feeding trials conducted with captive red squirrels in March, 1965, and April, 1966, showed that about 194 old cones per day were necessary to sustain a squirrel, approximately 35% more than for cones from the current year's crop. Three squirrels survived for eight days on a diet of only white spruce buds. Analysis of old spruce cones showed that 31% of the seed was potentially viable (filled), but that only 1.4% of the seed germinated. Calorimetric determinations of old seed (minus coat), spruce buds, and mushrooms yielded values of 5,976, 4,986, and 4,552 cal/g respectively. Excavation of middens revealed up to 8,518 old, cached cones per midden, despite a crop failure. In years of normal cone production, squirrels may cut and cache 12,000 to 16,000 cones; the excess accrues each year and eventually a sufficient supply exists to maintain the squirrels through a winter following a cone crop failure.
    • Some aspects in the ecology of the black bear (Ursus Americanus) in interior Alaska

      Hatler, David F. (1967-05)
      Research during 1964 and 1965 revealed that black bears in interior Alaska are active only 5 to 5.5 months each year. Emerging from winter dens in early May, the animals spend most of the first 3 months in river bottom and other lowland situations where green vegetation, especially Equisetum spp., composes the bulk of their diet. From the last half of July until mid-September bears are observed most commonly in alpine areas where fruits, especially Vaccinium uliginosum, are the important food. Animal food, constituting less than 15 percent (volume) of the animal's diet, is apparently taken whenever it is obtainable. Most animal food occurrences involve insects. Litter size averaged 1.73 for 30 litters observed during the 2 years studied. Litters larger than two do not seem to be common in interior Alaska. Intestinal parasites were found in 12 of 16 bears. Two heavy infestations of ascarids, 249 worms in one bear and 53 in another, were observed. Serious predation by interior Alaskan black bears upon the nests of some waterfowl has been recorded; predation upon most other wildlife species appears to be negligible. Evidence gathered during this study suggests that the rash of black bear problems experienced by interior Alaskans in 1963 was due largely to the widespread lack of blueberries during that year.
    • Reindeer Range Appraisal In Alaska

      Pegau, Robert Elwyn (1968)
    • Aspects of red squirrel (Tamiasciurus Hudsonicus) population ecology in interior Alaska

      Krasnowski, Paul Vincent (1969-05)
      Red squirrel (Tamiasciurus hudsonicus preblei) population ecology was investigated in a field study conducted between 21 September 1967 and 30 October 1968 near College, Alaska. Population density on the 21 ha study area was one squirrel per 1.1 ha during the spring 1968 and one per 1.2 ha during the fall 1968. Territoriality appears to be somewhat relaxed during the spring, and there are non-territorial squirrels present at that time. Young of the year squirrels can be distinguished from adults, at least through October, according to the degree of closure of the epiphyses of the radius and ulna. Immature males can be distinguished from adults on the basis of testis weight during the fall. Immature squirrels constituted 57.1% of the population sample during the fall 1967 and 51.3% during the fall 1968. Males formed 66.7% of the sample of adults and 64.0% of the sample of immature squirrels. Males were not significantly heavier or larger than females. Mean tail length of immature squirrels exceeded that of adults. Fall molt commences for all red squirrels during late August and September. The spring molt commences for females during March, whereas males do not molt until May. Testes measurements and female reproductive condition indicate that there is a single annual reproductive season, from late February through April. Squirrels breed during their first spring at about 10 to 11 months of age. Estimated mean litter size was 4.20 based on embryo counts and 3.92 based on placental scars. The most frequent litter size was four.