Habitat selection by breeding Black-throated Blue Warblers at two spatial scales

摘要: New Hampshire, U.S.A. I found different responses to shrub density at two spatial scales (plot and territory). At the scale of 15 ha study plots, number breeding birds on seven plots was positively related density, suggesting that areas having a high shrubs were selected by birds. Selection further supported an experiment in which Black-throated Blue Warblers declined zero three years after leaves removed from 14 plot. In contrast plot results, territory analysis demonstrated not greater inside than outside territories any 11 analyses (five each studied for or years). Thus, within located where high. No other vegetation variable consistently differed between plots. The provide example how vertical structure habitat can affect distribution bird species. conflicting results point out importance considering several studies abundance, but they also raise question why would preferentially select with dense then locate its so is maximized. argue all average above threshold level will contain enough small patches birds, especially if these are important nesting rather foraging. If this argument valid, selection may be necessary Warblers.