Comparison of Breeding and Postbreeding Movements and Habitat Requirements for the Scarlet Tanager (Piranga Olivacea) in Virginia

Abstract

AbstractWe investigated movements and habitat use during breeding and postbreeding periods in Scarlet Tanagers (Piranga olivacea) during June-September 1998 in northern Virginia deciduous forest. Nine birds (8 males and 1 female) remained on the same home range during both breeding and postbreeding periods, whereas 11 birds (9 males and 2 females) shifted home range (>300 m) between periods. Breeding season home-range size ranged from 2.6 to 5.6 ha (95% kernel), and core area from 0.61 to 0.93 ha (50% kernel). Postbreeding home ranges were similar in size to home range during the breeding period for birds that remained in the vicinity of nesting areas, but were larger for birds that moved away from the nesting area. Scarlet Tanagers occurred in both mature and successional forest during breeding and postbreeding periods, with some indication of increased use of earlier successional stages during the postbreeding period. Needs for Scarlet Tanagers during the postbreeding period (molt, premigratory fattening) differ from those during the breeding period (pair formation, nest placement, rearing of young). Those differences provide a plausible explanation that all tanagers changed focal areas between breeding and postbreeding periods. These findings confirm the need for taking the postbreeding period into account, both for understanding migrant life history and successful conservation.