No abstract

Moose, Alces alces, occur naturally throughout most of Canada but successful introductions of known numbers of animals have been made to the islands of Newfoundland and Cape Breton. Five microsatellite loci were used to investigate the population genetic structure and any change in genetic variability due to founder events of moose in Canada. Comparisons of allele frequencies for moose from 11 regions of the country suggested that there are at least seven genetically distinct populations (P < 0.05) in North America, namely Alberta, eastern Ontario, New Brunswick, Cape Breton, Labrador, western Newfoundland, and the Avalon Peninsula of Newfoundland. The average population heterozygosity was approximately 33% (range from 22 to 41%). upgma analysis of Nei’s genetic distances produced phenograms similar to what would be expected when geographical location and population history are considered. The loss of heterozygosity due to a single founder event (n = 3; two introductions and a natural colonization) ranged from 14 to 30%, and the cumulative loss of heterozygosity due to two successive founder events (an introduction followed by a natural colonization) was 46%. In these examples loss of genetic variability has not been associated with any known phenotypic deviances, suggesting that populations may be established from a small number of founders. However, the viability of these founded populations over evolutionary timescales cannot be determined and is highly dependent upon chance.

Predator species identification is an important step in understanding predator-prey interactions, but predator identifications using kill site observations are often unreliable. We used molecular tools to analyse predator saliva, scat and hair from caribou calf kills in Newfoundland, Canada to identify the predator species, individual and sex. We sampled DNA from 32 carcasses using cotton swabs to collect predator saliva. We used fragment length analysis and sequencing of mitochondrial DNA to distinguish between coyote, black bear, Canada lynx and red fox and used nuclear DNA microsatellite analysis to identify individuals. We compared predator species detected using molecular tools to those assigned via field observations at each kill. We identified a predator species at 94% of carcasses using molecular methods, while observational methods assigned a predator species to 62.5% of kills. Molecular methods attributed 66.7% of kills to coyote and 33.3% to black bear, while observations assigned 40%, 45%, 10% and 5% to coyote, bear, lynx and fox, respectively. Individual identification was successful at 70% of kills where a predator species was identified. Only one individual was identified at each kill, but some individuals were found at multiple kills. Predator sex was predominantly male. We demonstrate the first large-scale evaluation of predator species, individual and sex identification using molecular techniques to extract DNA from swabs of wild prey carcasses. Our results indicate that kill site swabs (i) can be highly successful in identifying the predator species and individual responsible; and (ii) serve to inform and complement traditional methods.

1993. Responses of woodland caribou (Rangifer tarandus caribou) to clear-cutting in east-central Newfoundland. Can. J. Zool. 71: 487-493. 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][1988][1989][1990]. We 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. Four males and 10 females maintained similar mean distances from clearcuts, 3 males and 12 females were farther away, and 2 females were closer. Three other females and one male were assumed to be too distant to be affected by clear-cutting. Of those found farther away from clearcuts, females were 2 -3 times farther away than males. Among female caribou that maintained similar mean distances to clearcuts, habitat use during clear-cutting was similar to that before and afterwards. Females displaced by clear-cutting avo.ided open burns and hardwoods and selected mature black-spruce forest, whereas prior to cutting they used habitats in proportion to their availability. Sex and age ratios indicated that significantly fewer females and calves were present near clearcuts than elsewhere in the study area. Our results demonstrate that clear-cutting mature forests on summer range may affect the movements and distribution of woodland caribou. CHUBBS, T. E., KEITH, L. B., MAHONEY, S. P., et MCGRATH, M. J. 1993. Responses of woodland caribou (Rangifer tarandus caribou) to clear-cutting in east-central Newfoundland. Can. J. Zool. 71 : 487-493. Les dkplacements, la rkpartition des sexes, la distribution des ages et le choix des habitats chez des adultes du Caribou des bois (Rangifer tarandus caribou) ont Ct C mis en relation avec la coupe B blanc sur leur aire d'CtC dans le centre-est de Terre-Neuve en 1987 -1990. Trente-cinq caribous, 8 miles et 27 femelles, porteurs d'kmetteurs-radio B collier ont Ct C repCrCs B 2473 reprises sur au moins deux CtCs consCcutifs. Les distances entre la position des animaux et les zones de coupe B blanc ont Ct C mesurCes. Les positions des animaux par rapport aux sites de coupe ont pu Ctre comparCes un an avant et un an aprks la coupe. Quatre males et 10 femelles n'ont pas changC leur position vis-B-vis les zones de coupe, 3 males et 12 femelles s'en sont CloignCs et 2 femelles s'en sont rapprochCes. Les 3 autres femelles et I'autre male Ctaient probablement trop loin pour Ctre affect& par la coupe. Parmi les animaux qui s'Ctaient distanciCs de la zone de coupe, les femelles s'en CtaientCloignCes de 2 B 3 fois plus que les males. Les femelles qui n'avaient pas changC de position continuaient B exploiter les mCmes habitats qu'avant la coupe. Cependant les femelles, qui avai~nt modifiC leur position, Cv...

No abstract

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). Although woodland caribou inhabiting Newfoundland have been exposed to moderate levels of timber harvesting, black bears (Ursus americanus), not wolves, are the principal large predator in this system, and moose represent the alternative large prey species. During a 4-year period of timber harvesting, we monitored the location and status of 24 adults and 46 calves to determine coarse-scale habitat selection and survival rates of a nonmigratory and demographically isolated woodland caribou herd in Newfoundland. We also estimated pregnancy and recruitment rates and determined potential causes of mortality. Habitat selection significantly varied among seasons but was consistent with the hypothesis that caribou avoid habitats where the likelihood of contact with a predator or alternative prey was high. Population growth rate (rs = –0.01 ± 0.06 (mean ± 1SD)), calf recruitment (percentage of 10-month old calves = 13%), and adult survival rate (0.87) indicated that the population was stable. Mean pregnancy rate (96%), parturition date, and the lack of evidence for malnutrition in 22 carcasses suggested that the availability of quality forage is not a key factor limiting population growth. Although predation could not be linked to the death of adult caribou, black bears were responsible for 5 of 15 calf fatalities. This study suggests that black bears need to be considered more seriously as a factor influencing coarse-scale habitat selection and demography in woodland caribou herds.

No abstract

In many vertebrates size is one of the most influential and variable individual characteristics and a strong determinant of reproductive success. Body size is generally density dependent and decreases when intraspecific competition increases. Frequent and long‐distance movements increase energy expenditures and, therefore, may also influence body size, particularly in highly mobile species. Caribou (Rangifer tarandus, also known as reindeer) exhibit tremendous variation in size and movements and thus represent an excellent candidate species to test the relationships between body size, population size, and movements. We analyzed body measurements of adult female caribou from 7 herds of the Québec‐Labrador Peninsula, Canada, and we related their morphology to population size, movements, and annual ranges. The herds represented 3 ecotypes (migratory, montane, and sedentary). Ecotypes and herds differed in size (length), shape (roundness), and movements. The sedentary ecotype was larger and moved 4 to 7 times less than the migratory ecotype in the 1990s. At the start of a demographic growth period in the early 1960s, migratory caribou from the Rivière‐George (hereafter George) herd had longer mandibles than caribou of the sedentary ecotype. Mandible length in the George herd declined in the 1980s after rapid population growth, while individuals performed extensive movements and the herd's annual range increased. Migratory caribou then became shorter than sedentary caribou. After the George herd decline in the 1990s, mandible length increased again near levels of the 1980s. Caribou from the migratory Rivière‐aux‐Feuilles herd later showed a similar decline in mandible length during a period of population growth, associated with longer movements and increasing annual range. We hypothesize that the density‐dependent effect observed on body size might have been exerted through summer habitat degradation and movement variations during herd growth. Our study has 2 important implications for caribou management: the distinctiveness of different populations and ecotypes, and the correlations between population trajectories and changes in body condition and habitat.