Avian Conservation and Ecology (Jun 2019)
Estimating the conservation value of protected areas in Maritime Canada for two species at risk: the Olive-sided Flycatcher (Contopus cooperi) and Canada Warbler (Cardellina canadensis)
Abstract
The Olive-sided Flycatcher (Contopus cooperi) and Canada Warbler (Cardellina canadensis) are threatened landbirds in Canada and parts of the U.S. Both species are subjects of recent conservation and management interest. Protected areas are a key tool for managing populations of species at risk, and Canadian national parks may serve as important refuges in an increasingly fragmented landscape. However, the potential role that Canadian national parks may play in the recovery of these species is unclear. We used the Boreal Avian Modelling Project point count database to build Poisson log-linear models using forward stepwise variable selection to predict population density and distribution of these two threatened species in four national parks in Maritime Canada. We also predicted population density in areas of equivalent size in the same ecoregions outside the parks for comparison. Because forested wetlands, a key habitat for these species in this region, are difficult to represent with available spatial data, we tested the effectiveness of different remote sensing products. We tested GIS layers based on aerial photography wetlands (WETLANDS), depth to water table (WETNESS), and WETNESS as interacted with forest cover from aerial photography (WETxFOR). The best-performing models for the Olive-sided Flycatcher used WETxFOR, whereas WETNESS performed best for the Canada Warbler. Anthropogenic disturbance and proximity to roads had a negative effect on predicted density for both species. Protected areas showed slightly higher Olive-sided Flycatcher population densities than nearby areas, but not so for the Canada Warbler. Our results provide the first population density and population size estimates for these species in these parks, and novel information on the impacts of anthropogenic disturbance on predicted population density. These results can inform conservation and management in this region and our approach can be replicated in other regions to support ongoing recovery efforts.
