Metapopulation Dynamics and Multi-Scale Habitat Selection of a Montane Forest Songbird

摘要: Variations in species occurrence and distribution across the landscape over time provide fundamental information concerning population dynamics. How this relates to habitat characteristics at multiple scales can elucidate process of selection. I evaluated these processes for a montane fir (Abies) forest specialist, Bicknell’s Thrush (Catharus bicknelli) Vermont. This is threatened by suite anthropogenic disturbances on its breeding grounds quantifying effects environmental change level songbird has not been addressed. The naturally fragmented varying size, quality, connectivity warranted metapopulation approach robust occupancy analysis. Detection/non-detection data was collected 88 sites during seasons 2006 2007. Local were measured each site landscape-level features calculated using predictive model. six local variables combined principal component Principal 1 (PC1) described gradient increasing coniferous shrub density proportion dominated with decreasing canopy height. covariate dividing patch size isolation creating continuum small, isolated patches large, less patches. Thus characterized single metric. From data, 67 models considering all combinations scores (univariate, additive interaction) individual estimates following parameters: (1) probability detection, (2) initial occupancy, (3) colonization, (4) extinction. AIC model selection techniques used rank models, which represented ecologically plausible hypotheses that compared strength large-scale features. Models within 4 AICc points top considered plausible. eight Landscape alone significant driving relative importance + highest both Probability increased extinction decreased combination (landscape) density, height (local habitat). colonization driven mainly quality. These results indicate complex system intricate links between scales. Preserving large tracts may be sufficient assuring future persistence, but could minimize risk. Careful consideration should given fragments, particularly maintain adequate rates. Because important from are correlated, intact patches, landscape-scale attributes serve as surrogate identifying quality habitat, assuming natural disturbance maintained. ii DEDICATION To Erika, whose friendship love will forever source light my life. strive role you me.