Cumming, Steven G.

21 items:

Conservation of future boreal forest bird communities considering lags in vegetation response to climate change: a modified refugia approach Aim Species and ecosystems may be unable to keep pace with rapid climate change projected for the 21st century. We evaluated an underexplored dimension of the mismatch between climate and biota: limitations to forest growth and succession affecting habitat suitability. Our objective was to inform continental-scale conservation for boreal songbirds under disequilibria between climate, vegetation and fauna. Location Boreal and southern arctic ecoregions of North America. Methods We used forest inventory and avian survey data to classify 53 species by seral-stage affinity and applied these to generate alternative projections of changes in species' core habitat distributions based on different vegetation lag-time assumptions.... Categories: Publication; Types: Citation; Tags: Monitoring 1-Changes in Plant and Animal Distribution: Ecosystems
Assessing the spatial variability of density dependence in waterfowl populations Population models commonly assume that the demographic parameters are spatially invariant, but there is considerable evidence that population growth rate (r) and the strength of density dependence (?) can vary over a species? range. To address this issue we developed a spatially explicit Gompertz population model based on the spatially varying coefficients approach to assess the spatial variation in population drivers. The model was fit to spatially stratified time series population estimates of the Mallard (Anas platyrhynchos) in western North America. We included precipitation during the previous year and spring maximum temperature in the current year as environmental factors in the density dependent population... Categories: Publication; Types: Citation; Tags: M1-Birds
Assessing the spatial variability of density dependence in waterfowl populations Population models commonly assume that the demographic parameters are spatially invariant, but there is considerable evidence that population growth rate (r) and the strength of density dependence (?) can vary over a species? range. To address this issue we developed a spatially explicit Gompertz population model based on the spatially varying coefficients approach to assess the spatial variation in population drivers. The model was fit to spatially stratified time series population estimates of the Mallard (Anas platyrhynchos) in western North America. We included precipitation during the previous year and spring maximum temperature in the current year as environmental factors in the density dependent population... Categories: Publication; Types: Citation; Tags: Birds, Monitoring 1-Changes in Plant and Animal Distribution: Fauna
Assessing the spatial variability of density dependence in waterfowl populations Population models commonly assume that the demographic parameters are spatially invariant, but there is considerable evidence that population growth rate (r) and the strength of density dependence (?) can vary over a species? range. To address this issue we developed a spatially explicit Gompertz population model based on the spatially varying coefficients approach to assess the spatial variation in population drivers. The model was fit to spatially stratified time series population estimates of the Mallard (Anas platyrhynchos) in western North America. We included precipitation during the previous year and spring maximum temperature in the current year as environmental factors in the density dependent population... Categories: Publication; Types: Citation; Tags: M1-Birds
Using binomial distance-sampling models to estimate the effective detection radius of point-count surveys across boreal Canada We used binomial distance-sampling models to estimate the effective detection radius (EDR) of point-count surveys across boreal Canada. We evaluated binomial models based on 0-50 m and >50 m distance categories for goodness-of-fit and sensitivities to variation in survey effort and habitats sampled. We also compared binomial EDRs to Partners in Flight's maximum detection distances (MDD) to determine differences in landbird population sizes derived from each. Binomial EDRs had a small positive bias (4%) averaged across 86 species and a large positive bias (30-82%) for two species when compared with EDRs estimated using multinomial distance sampling. Patterns in binomial EDRs were consistent with how bird songs attenuate... Categories: Publication; Types: Citation; Tags: M1-Birds

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