Geographic Variation of Yellow Warblers Killed at a Television Tower

摘要: -Prairie and aspen parkland Yellow Warblers are brighter in color larger bill length than those from the boreal forest. MacKenzie River Delta near arctic coast terminate clines of birds with smaller to north darker plumage forested or coastal habitats. Statistically significant differences wing among killed at a TV tower western Minnesota conform patterns geographic variation demonstrate that individuals this species originating perhaps as far apart 3,220 km (2,000 mi) were migrating southward together.-Minnesota Museum Natural History, University Minnesota, Minneapolis, 55455. Present address offirst author: Division Wildlife Fisheries Biology, California, Davis, California 95616. Accepted 13 May 1976. DESCRIPTIONS subspecies for most bird commonly towers during migration inadequate confident estimation areas their origin, only few attempts racial identification have been made (Tordoff Mengel 1956, Johnston Haines 1957, Stoddard 1962, Raveling 1965). A sample 74 (Dendroica petechia) was obtained kill Westport, Stearn's County, on night 9-10 September 1962 (see Kemper et al. 1966). Obvious coloration adults within suggested different populations over location same night. We analyzed midcontinent museum specimens compared results recorded birds.