Effect of white-tailed deer on songbirds within managed forests in Pennsylvania

摘要: White-tailed deer (Odocoileus virginianus) populations have been maintained at high densities in Pennsylvania for several decades with unknown effects on songbirds and their habitats. I evaluated of white-tailed density songbird species richness, abundance, habitat. simulated 4 (3.7, 7.9, 14.9, 24.9 deer/km2) within individually fenced enclosures 65-ha forest areas northwestern Pennsylvania. Within all enclosures, 10% the area was clear-cut 30% thinned. Enclosures were subjected to 10 years browsing, 1980-90, densities. conducted bird counts 1991. Varying had no effect (P > 0.1) ground- or upper canopy-nesting habitat, but richness intermediate declined 27% = 0.01) abundance 37% 0.002) between lowest highest did not observe eastern wood pewee (Contopus virens), indigo bunting (Passerina cyanea), least flycatcher (Empidonax minimus), yellowbilled cuckoo (Coccyzus americanus), cerulean warbler (Dendroica cerulea) >7.9 /km2, phoebe (Sayomis phoebe), American robin (Turdus migratorius) observed deer/km2. Threshold habitat managed (100-yr rotation) forests 7.9 14.9