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Geology topics

A.B. Sargeant

Publications and source records attributed to A.B. Sargeant.

At least 19 recordsLinked to original sources
USGS1999

Foods and foraging of prairie striped skunks during the avian nesting season

Food habits of prairie skunks are not well understood, yet such knowledge might provide insight into factors influencing nest depredation. We studied food habits of radiocollared adult striped skunks (Mephitis mephitis) during 1976-78 in North Dakota, where skunks are regarded as important predators of ground-nesting birds. Plant foods, primarily grain and sunflower seeds, occurred in a larger percentage of scats in spring (15 Apr 31 May) than summer (1 Jun 15 July, P=0.04), but overall, plant foods were a minor part of skunk diets. Animal foods, primarily birds (including eggs), small rodents, and insects occurred annually in a large percentage of scats of all skunks. These foods were acquired nearly exclusively in grasslands. Percentage of scats containing animal foods was similar, irrespective of sex, season, or year (P>0.45). In spring, vertebrates occurred in a smaller percentage of scats of females than males (P<0.01). Among females, vertebrates also occurred in a smaller percentage of scats in spring than summer (P<0.01). Among all skunks, birds occurred in a smaller percentage of scats in spring than in summer (P<0.01). Both birds (P<0.02) and mammals (P<0.01) occurred in a smaller proportion of scats when wetland conditions were poor. Percentage of scats containing insects, the primary invertebrate food of skunks, did not vary by sex, season, or year (P>0.15). Insects were mostly adult and larval Coleoptera, larval Lepidoptera, and adult and nymph Orthoptera.

Wildlife Society Bulletin↗
USGS1995

Seasonal predator removal relative to hatch rate of duck nests in waterfowl production areas

These authors report that hatch rates of duck nests were related to removal of predators from waterfowl production areas. Cost effectiveness of such efforts is questioned. The prairie pothole region (PPR) is the primary breeding ground of several species of North American ducks (Bellrose 1980). Much habitat of breeding ducks in the PPR has been destroyed or degraded by intensive agriculture (e.g., Kiel et al. 1972, Bellrose 1980, Sugden and Beyersbergen 1984, Boyd 1985), resulting in high predation rates on duck nests (Sargeant and Raveling 1992). Because of predation, hatch rate (HR) of duck nests in Waterfowl Production Areas (WPA's) in the PPR is often less than the 15-20% suggested for stability of populations of the 5 most common species of dabbling ducks (e.g., Cowardin et al. 1985, Greenwood 1986, Klett et al. 1988, Greenwood et al. 1990). Managers seek ways to reduce depredations of duck clutches in WPA's, but little information is available concerning effects of predator removal. We evaluated seasonal (spring and early summer) removal of predators from WPA's in Minnesota and North Dakota. Our objectives were to compare HR in uplands of WPA's with and without predators removed and to determine functional aspects of conducting predator removal.

Wildlife Society Bulletin↗
USGS1993

Distribution and abundance of predators that affect duck production--prairie pothole region

During 1983-88, the relative abundance of 18 species and species-groups of mammalian and avian predators affecting duck production in the prairie pothole region was determined in 33 widely scattered study areas ranging in size from 23-26 km2. Accounts of each studied species and species-group include habitat and history, population structure and reported densities, and information on distribution and abundance from the present study. Index values of undetected, scarce, uncommon, common, or numerous were used to rate abundance of nearly all species in each study area. Principal survey methods were livetrapping of striped skunks (Mephitis mephitis) and Franklin's ground squirrels (Spermophilus franklinii), systematic searches for carnivore tracks in quarter sections (0.65 km2), daily records of sightings of individual predator species, and systematic searches for occupied nests of tree-nesting avian predators. Abundances of predators in individual areas were studied 1-3 years.The distribution and abundance of predator species throughout the prairie pothole region have undergone continual change since settlement of the region by Europeans in the late 1800's. Predator populations in areas we studied differed markedly from those of pristine times. The changes occurred from habitat alterations, human-inflicted mortality of predators, and interspecific relations among predator species. Indices from surveys of tracks revealed a decline in the abundance of red foxes (Vulpes vulpes) and an albeit less consistent decline in the abundance of raccoons (Procyon lotor) with an increase in the abundance of coyotes (Canis latrans). Records of locations of occupied nests revealed great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) tended to nest 0.5 km apart, and American crows (Corvus brachyrhynchos) tended to avoid nesting 0.5 km of nests of red-tailed hawks. Excluding large gulls, for which no measurements of abundance were obtained, the number of predator species averaged 12.2 (SD = 1.60) per study area; common or numerous predator species averaged 6.0 (SD = 1.54) per study area (minimal because the abundance of weasels [Mustela erminea; M. frenata] in all areas and of minks [Mustela vison] and raptors in some areas was not rated). Major changes in relative abundance of individual predator species studied >1 year were few. Predator species most restricted to the aspen parkland were the Franklin's ground squirrel, black-billed magpie (Pica pica), American crow (Corvus brachyrlus), and red-tailed hawk; species most restricted to the prairie were the badger (Taxidea taxus), Swainson's hawk (Buteo swainsoni), and ferruginous hawk (B. regalis). The coyote, black-billed magpie, and American crow were most numerous in Canada, whereas the red fox, raccoon, mink, ferruginous hawk, and great horned owl were most numerous in the United States. The number of common or numerous egg-eating predator species (excludes large gulls and weasels, which were not rated) averaged 4.6 (SD = 0.90) per study area. The average numbers of common or numerous egg-eating species per study area did not differ among provinces and states, but birds gradually replaced mammals from southeast to northwest across the region. Investigators are urged to assess composition of predator populations and relative abundance of predator species for evaluations of waterfowl recruitment.

Resource Publication↗
USGS1987

Responses of three prairie ground squirrel species, Spermophilus franklinii, S. richardsonii, and S. tridecemlineatus, to duck eggs

Franklin's Ground Squirrels (Spermophilus franklinii) preyed on eggs in 29 of 30 tests in which they were exposed to two Mallard (Anas platyrhynchos) or two Blue-winged Teal (A. discors) eggs and their discovery of eggs was confirmed. No Richardson's (S. richardsonii) or Thirteen-lined (S. tridecemlineatus) ground squirrels preyed on eggs in 104 and 54 similar tests, respectively. Franklin's Ground Squirrels exposed to clutches of six duck eggs placed in simulated nests preyed on all such clutches. Predation on simulated nests began soon after eggs were discovered, but predation of all eggs often took more than one day to complete.

Canadian Field-Naturalist↗
USGS1986

Commercial sunflowers: food for red foxes in North Dakota

Stomach contents of 70 red foxes (Vulpes vulpes) shot in east-central North Dakota during January 1982 and January 1983 were examined. Commercial sunflower seeds were the most frequently found food item, occurring each year in three-fourths of the stomachs and composing about half of the contents. The remainder of the diet was primarily mammals, but included birds, insects, amphibians, and refuse.

Prairie Naturalist↗
USGS1982

Behavioral interactions of penned red and arctic foxes

Expansion of the geographical distribution of red foxes ( Vulpes vulpes ) into the far north tundra region may lead to competition between arctic ( Alopex lagopus ) and red foxes for space and resources. Behavioral interactions between red and arctic foxes were evaluated during 9 trials conducted in a 4.05-ha enclosure near Woodworth, North Dakota. Each trial consisted of introducing a male-female pair of arctic foxes into the enclosure and allowing them to acclimate for approximately a week before releasing a female red fox into the enclosure, followed by her mate a few days later. In 8 of 9 trials, red foxes were dominant over arctic foxes during encounters. Activity of the arctic foxes decreased upon addition of red foxes. Arctic foxes tried unsuccessfully to defend preferred den, resting, and feeding areas. Even though the outcome of competition between red and arctic foxes in the Arctic is uncertain, the more aggressive red fox can dominate arctic foxes in direct competition for den sites and other limited resources.

North Dakota↗
USGS1982

Recurrence, mortality, and dispersal of prairie striped skunks, Mephitis mephitis, and implications to rabies epizootiology

Detailed study of radio-equipped individuals of the Striped Skunk (Mephitis mephitis) in a North Dakota population provided insight into possible mechanisms for spread of rabies during spring and summer. Annual recurrence rates of 138 skunks marked on a study area averaged 11% for adult males, 43% for adult females and 9% for kits. Population changes were from mortality (including rabies) and dispersal. Five instances of adult dispersal (four by males) were recorded; maximum straight-line distance was 119 km. Some males initiated dispersal in spring. Communal denning by adults occurred rarely after whelping began but resulted in intraspecific conflict. Evidence of intraspecific and interspecific strife leading to kit mortality and some adult mortality was found at dens of 9 of 40 litters studied.

Canadian Field-Naturalist↗
USGS1982

A case history of a dynamic resource--the red fox

Red fox (Vulpes vulpes) population trends in midwestern North America since 1800 were examined. During 1801-1900, the red fox expanded its range south to include most of the region, but populations remained low in most areas. During 1901-30, it became scarce or absent in many northern areas but was common in southern areas. During 1931-45, populations in most of the region increased to high levels. From 1946 to 1980 populations remained high and westward range expansions occurred on the northern plains. Three factors appear primarily responsible for major population changes. Habitat conditions improved after settlement, but in many areas population buildup was delayed. Interspecific canid competition, especially from expanding coyote (Canis latrans) populations, held red fox populations at low levels, especially in the west. Excessive harvest for fur contributed to holding populations down in many areas, especially during the early 1900's when pelt values were exceptionally high. Major population increases during the 1930's and early 1940's coincided with declining pelt prices and resulted in widespread implementation of fox bounties. In the 1960's, bounties were gradually discontinued, pelt prices increased, and restrictions on season length and harvest methods were implemented in most states.

Book chapter↗
USGS1978

Red fox prey demands and implications to prairie duck production

Experiments were conducted during spring and summer with 33 red foxes ( Vulpes vulpes ) to determine prey demands, feeding characteristics, and growth rates using natural foods. Pups began eating prey the 4th week after birth. Then, prey consumption averaged 1.38 and 1.90 kg/pup/week for weeks 5-8 and 9-12 of the denning season respectively, and 2.54 kg/pup/week for the postdenning period. Feeding by adults averaged 2.25 kg/adult/week. Free water was not needed by either pups or adults. About 90 percent of the prey offered to pups on simulated natural diets was consumed, remains varied with prey availability and prey type. Prey biomass required by a typical fox family was estimated at 18.5 kg/km2 for the 12-week denning season and 2.4 kg/km2/week for the postdenning period. Because of the large prey demands, ducks could represent a small part of the foxes' diet and yet be of consequence to the productivity of particular species. An example is provided for the mallard ( Anas platyrhynchos ).

Journal of Wildlife Management↗
USGS1975

A spring aerial census of red foxes in North Dakota

Systematic aerial searches were flown on transects to locate adult red foxes ( Vulpes vulpes ), pups, and rearing dens on 559.4 km2 (six townships) in eastern North Dakota during mid-May and mid-June each year from 1969 through 1973 and during mid-April 1969 and early May 1970. The combined sightings of foxes and fox dens from the mid-May and mid-June searches were used to identify individual fox families. The number of fox families was used as the measurement of density. Dens, highly visible during the mid-May searches, were the most reliable family indicator; 84 percent of 270 families identified during the study were represented by dens. Adult foxes second in importance, were most observable during the mid-May searches when 20 to 35 percent of those estimated to be available were sighted. Adult sightings during other search periods ranged from 4 to 17 percent of those available. Pup sightings were the most variable family indicator, but they led to the discovery of some dens. Sources of error for which adjustment factors were determined are: den moves exceeding criterion established for the spacing of dens in a single family, overestimation of the number of fox families living near township boundaries, and the percentage of fox families overlooked during the aerial searches. These adjustment factors appeared to be largely compensatory.

North Dakota↗
USGS1975

A rural mail-carrier index of North Dakota red foxes

Rural mail-carrier sightings of red foxes (Vulpes vulpes) during mid-April, -July, and -September of 1969-73 were compared to spring fox family estimates derived by aerial searches of six townships. The mid-April mail-carrier index reflected annual fox density changes on the six townships (correlation coefficient = 0.958) . Random exclusions of individual mail-carrier reports indicated participation could decline 40 percent without affecting index accuracy.

Wildlife Society Bulletin↗