Guillaume Bastille-Rousseau, Nathaniel D. Rayl, E. Hance Ellington, James A. Schaefer, Michael J.L. Peers, Matthew A. Mumma, Shane P. Mahoney, and Dennis L. Murray
Generalist predators typically have broad diets, but their diets may become constrained when one species of prey becomes disproportionately available. Yet there is poor understanding regarding whether generalist predators exhibit stereotypic relationships with pulsed prey resources.
Understanding the relationship between abundance and distribution is central to ecology but may require broad-scale observations, especially for long-lived, mobile animals like caribou (Rangifer tarandus (L., 1758)). The authors tested the link between demography and spatial ecology of Newfoundland caribou, coincident with their numerical growth (1980s, 1990s) and decline (2000s). The authors analysed site fidelity, rate of movements, timing of migration, and population organization from telemetry observations of more than 600 adult females.
Tony E. Chubbs, Lloyd B. Keith, Shane P. Mahoney, and Michael J. McGrath
Movements, sex and age structure, and habitat selection of adult woodland caribou (Rangifer tarandus caribou) were examined in relation to clear-cutting on summer range in east-central Newfoundland during 1987–1990. The authors obtained 2473 locations of 35 radio-collared caribou during at least two consecutive summers. Locations relative to clearcuts were determined for eight males and 27 females. Distances to existing clearcuts were compared with distances to those same geographic points prior to and following the summer in which clear-cutting occurred.
Shane P. Mahoney, John A. Virgl, and Kim Mawhinney
Phenotypic variation in body size and degree of sexual size dimorphism of North American black bears (Ursus americanus) was quantified for populations from New Brunswick, Quebec, Ontario, Maine, Alaska, and the island of Newfoundland. Based on a model of island biogeography developed by Case, we predicted that body size should be larger in Newfoundland bears than in mainland populations.
Several studies have shown that habitat selection and population limitation of woodland caribou (Rangifer tarandus caribou) is typically associated with the interaction among human-induced habitat alteration, wolf predation (Canis lupus), and the availability of alternative prey such as moose (Alces alces) and white-tailed deer (Odocoileus virginianus).
Mark C. Ball, Murray W. Lankester, and Shane P. Mahoney
Elaphostrongylus rangiferi was introduced to caribou (Rangifer tarandus caribou) of Newfoundland by infected reindeer (R. t. tarandus) from Norway and has caused at least two epizootics of cerebrospinal elaphostrongylosis (CSE), a debilitating neurologic disease. In an attempt to understand the conditions necessary for such outbreaks, the authors examined the effects of herd density and climatic factors on parasite abundance. The abundance of E.
Sixty ducks (34 Anas rubripes, 26 Bucephala clangula), collected at three localities in Ontario and eastern Canada, were examined for helminth parasites. Twenty-three genera of parasites (17 of Digenea, 5 of Nematoda, 1 of Acanthocephala) were recovered. Eighteen of the recoveries represent new host records (11 digeneans, 5 nematodes, 2 acanthocephalans). Eighty-eight percent of both host species were infected. The number of parasite species per infected bird ranged from 1–9 (mean 4) for A. rubripes and 1–7 (mean 2) for B. clangula.