Tree cavity availability across forest, park, and residential habitats in a highly urban area

摘要: Tree cavities are used by a wide variety of species for nesting, food storage, and cover. Most studies on cavity availability have been conducted in forests, little is known about urban areas. With urbanization, that excavate may be less abundant, natural tree-decay processes managed, tree densities reduced, all which influence tree-cavity availability. We investigated three questions: 1) What the prevalence different habitats Chicago area? 2) How do characteristics woodpecker-excavated cavity-trees differ across habitats? 3) does landscape cavities? tested capacity large parks residential areas to provide at levels similar forested surveyed 1,545 trees these excavated (caused decay) cavities. Cavities were most available where density was highest. found proportion forests had cavities, but rare Trees containing larger than control more decay, with decay trees. Canopy cover main variable influencing Our results suggest not limiting factor wildlife, however contingent use currently unknown.