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At least 217 records · Page 12Linked to original sources
USGS1984

Home-range formation and dispersal of deer in northeastern Minnesota

Eleven white-tailed ( Odocoileus virginianus ) does and their offspring (10 male and 6 female fawns) were radio-tracked for up to 56 months (2,725 total deer locations) in Minnesota's Superior National Forest from November 1974 through August 1983. All fawns wintered in yards with their does and migrated in spring to their does' summer ranges where they then separated from the does. By 17 months of age, seven males had established new summer ranges up to 9.6 km away, whereas the other three used the same summer ranges as their does, up to at least 29 months of age. One male established a new winter range, but six others continued to use the winter ranges of their does. The female fawns used the same summer range as their does, or areas immediately adjacent, and migrated to and from the same winter ranges, some with their does, for up to 3 years of age. The one female that we followed beyond this age migrated separately to and from the same winter yard during her fifth year. The data fit a hypothesis that non-incestuous inbreeding is common in vertebrates.

Journal of Mammalogy↗
USGS1986

Habitat use and terrestrial activity by red tree voles ( Arborimus longicaudus ) in Oregon

Several species of vertebrates may find optimal habitat for breeding, nesting, or foraging in old-growth (>200 years old) confierous forests in the Pacific Northwest. Old-growth forests are economically valuable, however, and most unprotected stands will be cut within 40 years (Franklin et al., 1981). Meslow et al. (1981) and Raphael (1984) identified a critical need to document habitat use and establish the relationship of wildlife species in these forests. In 1983, we operated arrays of pitfall traps for six months to investigate habitat use by terrestrial herpetofauna and small mammals in four age classes of Douglas-fir ( Pseudotsuga menziesii ) forest in and near the H. J. Andrews Experimental Forest, Linn and Lane counties, Oregon. Red tree voles, Arborimus longicaudus , were among the mammals captured. This species is considered to find optimum habitat in old-growth forests (Franklin et al., 1981; Meslow et al., 1981), but quantitative data on the local occurrence of the species are lacking. Here we report on habitat use by A. longicaudus and document terrestrial activity for this presumably arboreal species. A pitfall array was located in each of 18 stands dominated by Douglas-fir. Each array consisted of two sets of three 5-m aluminum drift fences each with pitfall traps (No. 10 tin cans; 6.4 l in volume) at the ends of the fences (see Bury and Raphael, 1983). The 18 stands represented four successional stages based on estimated age: 3 pre-canopy (clear cuts 5-9 years old), 3 young (30-69 years), 4 mature (76-150 years), and 8 old-growth (195-450 years). Additionally, old-growth stands were ranked on a general moisture gradient (wet, mesic, or dry) based on aspect, topographic position, and presence of indicator plant species. Pitfall traps were operated continuously for 180 days from late May to late November, 1983.

Oregon↗
USGS1985

The effects of catastrophic ecosystem disturbance: the residual mammals at Mount St. Helens

Individuals that survive the direct effects of community- or ecosystem-level disturbances, i.e., "residuals", can have major roles in determining the rate and pathway of subsequent secondary succession. The explosive eruption of the Mount St. Helens volcano on 19 May 1980 resulted in severe damage to a cast array of animal and plant populations (Edwards and Schwartz, 1981; MacMahon, 1982; Hayward et al., 1982). We apply the term "catastrophic" to this event because of its intensity and the large area (>600 km 2 ) over which successional processes were initiated. We present here the results of surveys for mammals, particularly small mammals (excluding bats), conducted in the Mount St. Helens region during the 40 months following the eruption. Our purpose was to elucidate any patterns in species representation that might exist along a gradient of disturbance "intensity", and thus document which species could potentially influence early plant successional patterns there. We infer whether individuals captured were more likely to have been residuals (or their descendants), or immigrants from areas less affected by the eruption, from consideration of the time span between the eruption and the capture date, the trapping location, and life history data. We also make inferences concerning the animal-environment relationships that led to our survey results, and thereby address the question of the likelihood of other types of disturbance, either natural or anthropogenic, producing similar results. Data concerning survival of Thomomys talpoides , the northern pocket gopher, have been presented elsewhere (Andersen, 1982). Initial results from our studies of the relationships among residual small mammals and plant population dynamics are detailed in MacMahon and Warner (1984), Allen et al. (1984) and Andersen and MacMahon (in press).

Washington↗
USGS1985

Deposition of anal-sac secretions by captive wolves (Canis lupus)

Deposition of anal-sac secretions by captive wolves was investigated by a labelling technique using protein-bound iodine 125 and food dye. Wolves deposited secretions on some but not all scats. Adult males, especially the alpha male, deposited anal-sac secretions more frequently while defecating than did females or juveniles. Secretions sometimes also were deposited independently of defecation, suggesting a dual role in communication by these substances.

Journal of Mammalogy↗
USGS1985

Observation of a wolf killed by a deer

Wolves (Canis lupus ) probably risk injury while attempting to kill large prey (Muie, 1944; Rausch, 1967; Mech, 1970; Peterson, 1977). Rausch (1967) found that numerous wolf skulls collected in a control program had sustained injuries, probably inflicted by severe blows from moose (Alces alces ). Wolves killed by prey seldom if ever are found. The authors located only three such published records, two involving moose (MacFarlane, 1905; Stanwell-Fletcher and Stanwell-Fletcher, 1942), and one involving deer (Odocoileus virginianus ) (Frijlink, 1977). In the latter case, the wolf was rabid and apparently was killed by a blow to the head, presumably by a hoof.

Journal of Mammalogy↗
USGS1987

Power and speed of swimming dolphins

The belief that dolphins have an extraordinary ability to generate propulsive power or can modify the water flow over their bodies to the low-resistance laminar flow is pervasive in the perception of the animals by the public and by some of the biology communities. I analyzed measured swimming speeds for dolphins of the Stenella-Delphinus morphology. A conservative hydrodynamics model equivalent to 119% of the drag of a rigid fusiform body (the added 19% compensates for the drag induced by propulsion) and a metabolic rate of 13.4 times the projected resting metabolic rate are consistent with measured maximum steady-state speeds. Measured routine swimming speeds are also consistent with this same hydrodynamics model and with metabolic rates for routine activity of other swimming and terrestrial homeotherms. Energy expenditure for swimming dolphins is entirely within expected ranges and no extraordinary mechanisms are necessary to explain observations.

Journal of Mammalogy↗
USGS1984

Species groups in Proechimys (Rodentia: Echimyidae) as indicated by karyology and bullar morphology

The genus Proechimys is divisible into four groups of species on the basis of bullar septal patterns. Each of the four groups can be further characterized by distinctive distributions and karyotypes. The subgenus Trinomys and the guairae species group each are comprised of phylogenetically closely-related species. The semispinosus - and brevicauda -groups, although generally distinctive on the basis of bullar septa, are not phylogenetically equivalent to the first two groups. The brevicauda -group, for example, consists of at least three separate species complexes. The taxonomy used in this report reflects several nomenclatural changes from that used in the recent literature. In addition, previously unreported karyotypes are described for P. quadruplicatus, P. gularis, P. decumanus, P. oris, P. oconnelli , and P. mincae .

Journal of Mammalogy↗
USGS1988

Genetic variability in the Florida manatee ( Trichechus manatus )

Tissue was obtained from 59 manatee ( Trichechus manatus ) carcasses salvaged from 20 counties in Florida. Allozyme phenotypes at 24 structural loci were determined by gel electrophoresis. Averages for the proportion of polymorphic loci and mean heterozygosity were 0.300 (range, 0.167-0.417) and 0.050 (range, 0.028-0.063), respectively. These estimates are equivalent to or higher than those generally reported for other species of marine mammals and do not support the hypothesis that body size and heterozygosity in mammals are related inversely. Among-region gene diversity accounted for only 4% of the total diversity. High rates of gene flow probably account for genetic homogeneity across regions. An F-statistic analysis revealed a general tendency toward excess homozygosity within regions. Management efforts to prevent future reductions in population size that would erode existing genic diversity should continue.

Journal of Mammalogy↗
USGS1988

Tunnel-construction methods and foraging path of a fossorial herbivore, Geomys bursarius

The fossorial rodent Geomys bursarius excavates tunnels to find and gain access to belowground plant parts. This is a study of how the foraging path of this animal, as denoted by feeding-tunnel systems constructed within experimental gardens, reflects both adaptive behavior and constraints associated with the fossorial lifestyle. The principal method of tunnel construction involves the end-to-end linking of short, linear segments whose directionalities are bimodal, but symmetrically distributed about 0°. The sequence of construction of left- and right-directed segments is random, and segments tend to be equal in length. The resulting tunnel advances, zigzag-fashion, along a single heading. This linearity, and the tendency for branches to be orthogonal to the originating tunnel, are consistent with the search path predicted for a "harvesting animal" (Pyke, 1978) from optimal-foraging theory. A suite of physical and physiological constraints on the burrowing process, however, may be responsible for this geometric pattern. That is, by excavating in the most energy-efficient manner, G. bursarius automatically creates the basic components to an optimal-search path. The general search pattern was not influenced by habitat quality (plant density). Branch origins are located more often than expected at plants, demonstrating area-restricted search, a tactic commonly noted in aboveground foragers. The potential trade-offs between construction methods that minimize energy cost and those that minimize vulnerability to predators are discussed.

Journal of Mammalogy↗