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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.

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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.

Interactions between Lipophrys pholis and its amphipod prey Echinogammarus marinus were used to investigate the effect of changing water temperatures, comparing current and predicted mean summer temperatures. Contrary to expectations, predator attack rates significantly decreased with increasing temperature. Handling times were significantly longer at 19 ∘ C than at 17 and 15 ∘ C and the maximum feeding estimate was significantly lower at 19 ∘ C than at 17 ∘ C. Functional-response type changed from a destabilizing type II to the more stabilizing type III with a temperature increase to 19 ∘ C. This suggests that a temperature increase can mediate refuge for prey at low densities. Predatory pressure by teleosts may be dampened by a large increase in temperature (here from 15 to 19 ∘ C), but a short-term and smaller temperature increase (to 17 ∘ C) may increase destabilizing resource consumption due to high maximum feeding rates; this has implications for the stability of important intertidal ecosystems during warming events.

The distribution of radar-estimated precipitation from lake-effect snowbands over and downwind of Lake Ontario shows more snowfall in downwind areas than over the lake itself. Here, two nonexclusive processes contributing to this are examined: the collapse of convection that lofts hydrometeors over the lake and allows them to settle downwind; and stratiform ascent over land, due to the development of a stable boundary layer, frictional convergence, and terrain, leading to widespread precipitation there. The main data sources for this study are vertical profiles of radar reflectivity and hydrometeor vertical velocity in a well-defined, deep longlake-axis-parallel band, observed on 11 December 2013 during the Ontario Winter Lake-effect Systems (OWLeS) project. The profiles are derived from an airborne W-band Doppler radar, as well as an array of four K-band radars, an X-band profiling radar, a scanning X-band radar, and a scanning S-band radar.The presence of convection offshore is evident from deep, strong (up to 10 m s 21 ) updrafts producing bounded weak-echo regions and locally heavily rimed snow particles. The decrease of the standard deviation, skewness, and peak values of Doppler vertical velocity during the downwind shore crossing is consistent with the convection collapse hypothesis. Consistent with the stratiform ascent hypothesis are (i) an increase in mean vertical velocity over land; and (ii) an increasing abundance of large snowflakes at low levels and over land, due to depositional growth and aggregation, evident from flight-level and surface particle size distribution data, and from differences in reflectivity values from S-, X-, K-, and W-band radars at nearly the same time and location.

Our purpose in writing this paper is to stimulate discussion about new concepts and approaches to forest management for Canada. This paper is designed to introduce the concept to Canadian foresters. The authors are working on an expanded technical edition that will deal in more detail with the practical concerns of forest resource managers.