Animal Sciences Commons^™

Population Regulation In Wolves, Jane M. Packard, L. David Mech

USGS Northern Prairie Wildlife Research Center

The possibility of social regulation of wolf populations has been discussed in the literature for several years. Some of the first ecological studies of wolves indicated that their populations did not increase as rapidly as was theoretically possible, and that they reached a saturation point apparently not set by food. Subsequent captive studies demonstrated the existence of social mechanisms possibly capable of regulating population growth. However, the importance of these factors in wild populations has not been established. This paper has four objectives: (1) to evaluate the existing concept of "intrinsic limitation," (2) to propose that wolf population dynamics may …

Wolf Howling And Its Role In Territory Maintenance, Fred H. Harrington, L. David Mech

USGS Northern Prairie Wildlife Research Center

The wolf (Canis lupus) is a wide-ranging social carnivore with a complex spatial organization (MECH, 1972; 1973). The precise manner in which this organization is maintained is unknown, but territory advertisement using olfactory and acoustic modes seems to be involved.

The acoustic mode includes primarily howling. Within a wolf pack, howling may be useful to reassemble separated members (MECH, 1966; THEBERGE & FALLS, 1967), and may communicate information on individual identity, location, and other behavioral and environmental contingencies (THEBERGE & FALLS, 1967). Between packs, however, howling may serve to advertise territory, communicating the locations of packs and thus …

A Mid-Continent Irruption Of Canada Lynx, 1962-63, Harvey L. Gunderson

University of Nebraska State Museum: Mammalogy Papers

There was a mid-continent irruption of the Canada lynx (Felis lynx) population and subsequent extensive movement into non-lynx habitats during the years 1962-1963. Lynx were found in the prairie provinces of Canada and the prairie areas of Minnesota, and North and South Dakota. They were also found in urban areas such as Minneapolis and St. Paul, Minnesota: Winnipeg, Manitoba: and Calgary, Saskatchewan, Canada. Causes for the irruption remain unknown but speculations include primarily a change in snowshoe hare population, disease, extensive forest fires and extensive spraying. Unusual behavior seemed to be most often reflected by a lack of …

Relating Wolf Scat Content To Prey Consumed, Theodore J. Floyd, L. David Mech, Peter A. Jordan

USGS Northern Prairie Wildlife Research Center

In 9 trials, captive wolves (Canis lupus) were fed prey varying in size from snowshoe (Lepus americanus) to adult deer (Odocoileus virginianus), and the resulting scats were counted. collectible scats were distinguished from liquid, noncollectible stools. In collectible scats, the small prey occurred in greater proportion relative to the prey's weight, and in lesser proportion to the prey's numbers, than did the remains of larger prey. A regression equation with an excellent the data (r² = 0.97) was derived to estimate the weight of prey eaten per collectible scat for With this information …

Productivity, Mortality, And Population Trends Of Wolves In Northeastern Minnesota, L. David Mech

USGS Northern Prairie Wildlife Research Center

Population parameters, mortality causes, and mechanisms of a population decline were studied in wolves (Canis lupus lycaon) from 1968 to 1976 in the Superior National Forest. The main method was aerial radio-tracking of 129 wolves and their packmates. Due to a decline in white-tailed deer (Odocoileus virginianus), the wolf population decreased during most of the study. Average annual productivity varied from 1.5 to 3.3 pups per litter, and annual mortality rates from 7 to 65 percent. Malnutrition and intraspecific strife accounted equally for 58 percent of the mortality; human causes accounted for the remainder. As wolf …

Wolf-Pack Buffer Zones As Prey Reservoirs, L. David Mech

USGS Northern Prairie Wildlife Research Center

Abstract. In a declining herd, surviving deer inhabited overlapping edges of wolf- pack territories. There, wolves hunted little until desperate, in order to avoid fatal encounters with neighbors. Such encounters reduce wolf numbers and predation pressure and apparently allow surviving deer along territory edges to repopulate the area through dispersal of their prime, less vulnerable offspring into territory cores.

Comparison Of Coyote And Coyote × Dog Hybrid Food Habits In Southeastern Nebraska, Brian R. Mahan

University of Nebraska State Museum: Mammalogy Papers

The recent taxonomic study by Mahan et al. (1978) documented the occurrence of coyote (Canis latrans) x dog (c. familiaris) hybrids in Nebraska. This study, and those by Freeman (1976) in Oklahoma and Gipson et al. (1974) in Arkansas show coyote x dog hybrids, though not abundant, to be numerous in some areas. The purpose of the present study was to compare the stomach contents of coyote x dog hybrids collected by Mahan et al. (1978) from southeastern Nebraska with those of contemporary coyotes.

Stomachs of 12 coyote x dog hybrids and 16 coyotes collected November 1975 …

Visual Detection Of Cryptic Prey By Blue Jays (Cyanocitta Cristata), Alexandra T. Pietrewicz, Alan Kamil

Avian Cognition Papers

Blue jays learned to respond differentially to the presence or absence of Catocala moths in slides. This detection of the moths by the jays was affected by the background upon which the moth was placed and its body orientation, thus providing an objective measure of crypticity. These procedures are useful for the study of visual detection of prey.

Canis Lupus., L. David Mech

USGS Northern Prairie Wildlife Research Center

Order Carnivora, Family Canidae. The genus Canis includes eight species. Approxi- mately 24 New World and eight Old World subspecies of C. lupus are recognized, the number depending on authorities accepted. For summary, see Mech (1970); for full synonymy, see Pocock (1935), Goldman (1944), Ellerman and Morrison- Scott (1951), Novikov (1956), and Hall and Kelson (1959).

The Role Of Adventitious Reinforcement In Operant Discrimination, Alan Kamil, John W. Davenport

Avian Cognition Papers

Rats were trained in 2 S^D-S^Δ discrimination experiments in which the effects of an S^D-postponement contingency during S^Δ and temporal regularity of S^Δ duration were assessed. Experiment I showed that discrimination is markedly facilitated by the presence of an S^D-postponement contingency of either fixed or variable duration. Experiment II showed that variable-duration S^Δ periods in a noncontingent schedule can also greatly enhance formation of an operant discrimination. These effects were attributed to differences in the probability of adventitious reinforcement of S^Δ behavior by S^D events.

Factors Affecting Nesting Success Of The Canvasback In The Aspen Parklands, Jerome H. Stoudt

USGS Northern Prairie Wildlife Research Center

The Minnedosa study area is located in the southwestern portion of Manitoba just south of the town of Minnedosa. It is 90 square miles in size and roughly square in shape. The Aspen Parkland, in which the study area is located, is characterized by gently rolling terrain and black soils. Mixed farming is the rule with emphasis on small grain production consisting of wheat, barley, and oats. Roughly 50 percent of the water areas in the parkland are ringed with aspen, Populus tremuloides, and large blocks of aspen are interspersed throughout the area. The Minnedosa area differs because of …