Densities and Biomass Relationships of Birds Nesting in Boreal Forest Habitats

A spot-mapping technique was applied to obtain quantitative data on bird populations on 25-acre (10 hectare) plots in northern boreal forest habitats. The number of breeding passerines varied from 15 to 42 pairs per plot. The number of species varied from 6 to 11 breeding passerines and 4 to 8 non-passerines and non-breeding passerines. Biomass of the breeding passerines ranged from 3100 to 5496 grams per 100 acres (40 hectare). Members of the Fringillidae family contributed the highest percentage of the total avian biomass, followed by Turdidae, Parulidae, Bombycillidae, Sylviidae, Paridae and Tyrannidae.Densités et rapports de biomasse chez des oiseaux nichant sur des aires d’étude.  Dans des habitats de forêt boréale nordique, on a appliqué, sur des aires de 25 acres (10 hectares), une technique de cartographie ponctuelle pour obtenir des données quantitatives sur les populations d’oiseaux.  De 15 à 42 paires de passereaux couvaient sur chaque aire.  Le nombre d’espèces variait de 6 à 11 pour les passereaux.  D’une aire à l’autre, la biomasse des passereaux couvant variait de 3100 à 5496 grammes par 100 acres (40 hectares).  Le plus grand pourcentage de la biomasse aviaire totale était formé par les membres de la famille des Fingillidés, suivis par les Turdidés, les Parulidés, les Bombycillidés, les Sylviidés, les Paridés et les Tyrannidés

Descriptions of Wolf Attacks on Bison Calves in Wood Buffalo National Park

Wolf predation on bison in Wood Buffalo Park and adjacent areas in late spring/early summer season was observed to be directed toward cow/calf herds. While hunting, wolf packs in early summer developed a strong preference for herds with calves. Packs of four to six individuals were observed. Of 14 interactions recorded, 12 were made from ground observations and 2 were made from the air. Five apparent defense strategies to protect calves were noted. These were: (1) to run to the cow, (2) to run to a herd, (3 ) to run to the nearest bull, (4) to get out in front and center of a stampeding herd and (5) to run through water bodies. When fleeing from wolves in open areas, cow with young calves took the lead, while bulls often were seen at the rear of the herds. When under attack from wolves, cows and particularly bulls were sometimes seen to defend the calves. Killing attempts observed in this study lasted from a few minutes to 11 hours.Key words: wolf predation, bison, wolves, antipredator defense, Wood Buffalo National ParkMots clés: prédation des loups, bisons, loups, défense contre les prédateurs, parc national Wood Buffal

Evaluating trade-offs between forage, biting flies, and footing on habitat selection by wood bison (Bison bison athabascae)

Habitat selection is a behavioural process that ultimately affects animal fitness. Forage availability and predation risk are often studied in the context of habitat selection for large ungulates, while other biological and environmental factors such as insect harassment and footing are less studied. Here we examine trade-offs in summer habitat selection between forage availability for wood bison (Bison bison athabascae Rhoads, 1898) with that of biting fly harassment and soil firmness, which affects activity budgets and predation risk, respectively, and contrast this to winter when flies are absent and soils frozen. Using path analysis, we demonstrate that graminoid availability was not related to summer habitat selection, but was positively related to selection in winter. Habitat selection in summer was negatively related to biting fly abundance and positively related to firmer footing. Our results suggest that bison observe trade-offs in summer between maximizing forage intake and minimizing harassment from that of biting flies, while avoiding areas of soft substrates that affect locomotion and vulnerability to predators. In contrast, during the winter bison focus on areas with greater graminoid availability. While forage is a key aspect of habitat selection, our results illustrate the importance of considering direct and indirect effects of multiple biological and environmental factors related to ungulate habitat selection.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Native Great Lakes wolves were not restored

Wolves from the Great Lakes area were historically decimated due to habitat loss and predator control programmes. Under the protection of the US Endangered Species Act, the population has rebounded to approximately 3000 individuals. We show that the pre-recovery population was dominated by mitochondrial DNA haplotypes from an endemic American wolf referred to here as the Great Lakes wolf. In contrast, the recent population is admixed, and probably derives also from the grey wolf (Canis lupus) of Old World origin and the coyote (Canis latrans). Consequently, the pre-recovery population has not been restored, casting doubt on delisting actions