Alan B. Sargeant

Dispersal patterns of red foxes relative to population density

Factors affecting red fox (Vulpes vulpes) dispersal patterns are poorly understood but warranted investigation because of the role of dispersal in rebuilding depleted populations and transmission of diseases. We examined dispersal patterns of red foxes in North Dakota based on recoveries of 363 of 854 foxes tagged as pups and relative to fox density. Foxes were recovered up to 8.6 years after tagging; 79% were trapped or shot. Straight-line distances between tagging and recovery locations ranged from 0 to 302 km. Mean recovery distances increased with age and were greater for males than females, but longest individual recovery distances were by females. Dispersal distances were not related to population density for males (P = 0.36) or females (P = 0.96)

Observed interactions between coyotes and red foxes

Etude des interactions entre Vulpes vulpes et Canis latrans. Des descriptions de rencontres entre individus de ces deux especes sont realisees pour comprendre les relations qui existent entre elles

Evaluation of Mark-Recapture for Estimating Striped Skunk Abundance

The mark-recapture method for estimating striped skunk (Mephitis mephitis) abundance was evaluated by systematically livetrapping a radio-equipped population on a 31.4-km2 study area in North Dakota during late April of 1977 and 1978. The study population was 10 females and 13 males in 1977 and 20 females and 8 males in 1978. Skunks were almost exclusively nocturnal. Males traveled greater nightly distances than females (3.3 vs. 2.6 km, P < 0.05) and had larger home ranges (308 vs. 242 ha) although not significantly so. Increased windchill reduced night-time activity. The population was demographically but not geographically closed. Frequency of capture was positively correlated with time skunks spent on the study area. Little variation in capture probabilities was found among trap-nights. Skunks exhibited neither trap-proneness nor shyness. Capture rates in 1977 were higher for males than for females; the reverse occurred in 1978. Variation in individual capture rates was indicated among males in 1977 and among females in 1978. Ten estimators produced generally similar results, but all underestimated true population size. Underestimation was a function of the number of untrapped skunks, primarily those that spent limited time on the study area. The jackknife method produced the best estimates of skunk abundance. J. WILDL. MANAGE. 49(2):332-340 The estimation of animal abundance is often difficult. Mark-recapture is used commonly to estimate the abundance of secretive mammals, including striped skunks (Verts 1967, Bailey 1971, Lynch 1972). Although there are many estimators available (Cormack 1968, 1979; Otis et al. 1978; Pollock 1981; Seber 1982), there are few data on their application to populations of known size. This paper assesses the applicability of several estimators with data for populations of striped skunks of known size in 2 years and discusses aspects of skunk biology that influence capture probability. Although captures in this s udy are fewer than desired for most markrecapture evaluations, the approach represents a practical application of the mark-recapture method. W. B. Bicknell and J. L. Piehl provided field assistance. Radiotelemetry equipment was obtained from the James Ford Bell Mus., Cedar Creek Natl. Hist. Area, Univ. of Minnesota, St. Paul. D. R. Anderson and G. C. White provided the CAPTURE computer program. Appreciation is extended to D. W. Sparling, who verified This content downloaded from 157.55.39.201 on Sat, 17 Dec 2016 05:24:49 UTC All use subject to http://about.jstor.org/terms J. Wildl. Manage. 49(2):1985 STRIPED SKUNK MARK-RECAPTURE * Greenwood et al. 333 some of the calculations and reviewed the manuscript, and to D. R. Anderson, K. P. Burnham, R. M. Cormack, L. L. Eberhardt, D. L. Otis, K. H. Pollock, and G. C. White, who provided constructive comments on the manu-

Movements and habitat use of Franklin's ground squirrels in duck-nesting habitat

We used radio telemetry to determine the movements and habitat use patterns of adult Franklins ground squirrels (Spermophilus franklinii) on a 152-ha Waterfowl Production Area (WPA) in central North Dakota. The squirrels were diurnal. Mean total distance traveled daily was 213 and 153 m for males and females, respectively. Movements of females decreased during gestation and lactation; those of both sexes decreased prior to immergence. Annual home ranges averaged 24.6 and 8.7 ha for males and females, respectively; biweekly home-range sizes exhibited seasonal patterns. Ground squirrels restricted their activities almost exclusively to the WPA. Use of blocks of herbaceous cover on the WPA could not be explained by vegetation height, density, or litter depth. Ground squirrel movements were influenced by locations of burrow systems and patchily distributed food resources. Periodic cultivation or removal of herbaceous vegetation may inhibit use of upland duck-nesting habitat by ground squirrels. J. WILDL. MANAGE. 53(2):324-331 Planting dense nesting cover (DNC) to provide upland-nesting ducks with increased security from nest predators is a common practice on areas managed for duck production in North Americas prairie pothole region (Duebbert and Kantrud 1974, Duebbert and Lokemoen 1976, Higgins and Barker 1982). Although DNC is attractive to some duck species, its importance to the activities of predators of duck eggs is undetermined. The Franklins ground squirrel inhabits dense cover throughout much of the prairie pothole region (Hall 1981). It is a predator of duck eggs (Sargeant et al. 1987) and has been implicated in severe predation on duck nests in fields of DNC in east-central North Dakota (Greenwood 1986). Past studies of Franklins ground squirrels have emphasized natural history (Sowles 1948, Haggerty 1968, Haberman and Fleharty 1971, Iverson and Turner 1972, Murie 1973), but little information is available on their movements and use of habitat. Our objective was to describe the movements and use of habitat by Franklins ground squirrels on a federally owned WPA where upland habitat was primarily DNC fields of different ages. We thank D. H. Johnson and J. N. Burroughs for help with data processing, R. J. Greenwood, M. A. Sovada, and D. J. Norris for field assistance and helpful suggestions throughout the study, and H. F. Duebbert and D. H. Johnson for comments on manuscript drafts. The study was funded by the U.S. Fish and Wildlife Service, Northern Prairie Wildlife Research Center; the Missouri Cooperative Fish and Wildlife Research Unit; and the Edward K. Love Foundation. The U.S. Fish and Wildlife Service, Missouri Department of Conservation, University of Missouri-Columbia, and the Wildlife Management Institute contribute to the Missouri Cooperative Fish and Wildlife Research Unit. This is Journal Series 10008, Missouri Agricultural Experiment Station Project 189.

Foods of American Badgers in West-central Minnesota and Southeastern North Dakota During the Duck Nesting Season

Abstract Although the American badger (Taxidea taxus) is common in grasslands and preys on a wide diversity of foods including birds, little is known about badger diet in areas where nesting ducks are common. Small mammals, primarily Muridae and Geomyidae, were the most common food items in the diet of badgers collected from west-central Minnesota and southeastern North Dakota during April–July 1987 through 1990, based on analysis of gastrointestinal tracts of 47 adult (≥1-y-old) and 5 juvenile (<6-mo-old) badgers. Remains of mammals occurred in 98% of samples from adult badgers. Small quantities of insects were found in 40% of adult samples. Bird remains were in 32% of adult samples, most birds identified as Anatidae; ducks or ducklings occurred in 27% and duck eggs in 60% of those samples. Remains of reptiles, amphibians and mollusks were present, but were less common than other foods. Insects and bird eggs were more common during spring (April–May) than summer (June–July). Birds were more frequent in diets of adults than juvenile badgers.

Determination of Age and Whelping Dates of Live Red Fox pups

COWAN, W. F. 1973. Ecology and life history of the raccoon (Procyon lotor hirtus Nelson and Goldman) in the northern part of its range. Ph.D. Thesis. Univ. North Dakota, Grand Forks. 161pp. FRITZELL, E. K. 1978a. Habitat use by prairie raccoons during the waterfowl breeding season. J. Wildl. Manage. 42:118-127. . 1978b. Aspects of raccoon (Procyon lotor) social organization. Can. J. Zool. 56:260-271. GREENWOOD, R. J. 1979. Relating residue in raccoon feces to food consumed. Am. Midi. Nat. 102:191-193.

A Telemetry Technique for Monitoring Diel Waterfowl Activity

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