No abstract

As a contribution to Partners in Flight–Canada, the Canadian Wildlife Service developed a ranking system to help set priorities for landbird species. Two complementary species lists were generated: one with scores for “concern” representing vulnerability and population trend, and one for “responsibility” for regionally characteristic fauna. The concern score gave equal weight to vulnerability, a composite score based on abundance and breadth of range, and population trend, because its purpose was to give early warning of potential problems. Responsibility scores were scale‐free and were assigned for the season in which the species is most abundant. Other systems for identifying species of concern may be more appropriate for other jurisdictions or organisms, but the responsibility ranking is widely applicable. This system is a coarse filter that generates preliminary ranks; additional information should be considered in deciding how to allocate scarce resources for conservation. Unrefined results are nonetheless useful for a variety of purposes, as illustrated by the scores for Canadian landbirds. About 25% of Canada's high‐responsibility species are also of high concern. These high‐concern species are not associated with specific habitats or migration patterns. Conservation of species ranking high on concern and responsibility merits cooperation with the United States and Mexico in particular. The scores identified improved monitoring as a priority conservation activity for Canada.

Effects of spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks on boreal mixed-wood bird communities. Avian Conservation and Ecology-Écologie et conservation des oiseaux 4(1): 3.

No abstract

1996. Relationships of bird community Structure and species distributions to two environmental gradients in the northern boreal forest. -Ecogriphy 19: 194-208.Few studies have explicitly examined avian community structure in the North Americin northern boreal forest. Herein we report upon the results of bird surveys in mature stands of boreal forest in the Great Clay Belt, Ontario. Canada. We related trends in avian community structure and individual bird species' abundance to two environmentiil gradients described in a landbase classification scheme called the Forest Ecosystem Classificationa moisture and a nutrient-richness gradient.Variation in environmental characteristics is limited in the Ontario Clay Belt and this wils reflected in short environmental gradient lengths. However, major trends in avian community structure were strongly associated with the nutrient-richness gradient axis summarized by this scheme. Analyses of avian community composition indicated a continuum from moist, coniferous habitats to drier aspendominated mixed woodlands with several bird species occurring in varying abundances across the width of both gradients. 48 of the 58 species examined showed statistically significiant associations with at Irit one of the two multivariate gradient axes. A smaller proportion of shortdistance migrant species were associated with these gradients than were species in either the neotropial migrant or resident categories. We used a multivariate variable ("habitat breadth") to compare degree of habitat spefiiliwtion across diHerent migratory groups. A large proportion of neotropical migrants showed a hlgh degree of habitat specialization in mature Clay Belt forests. and neotropial species with small habitat breadths were more commonly a+xiited with habitats dominated by broad-leaved deciduous tree species than either shortdistance or permanent resident species. We discuss our findings in relation to the post-glacial history of the Clay Belt region.