Dispersal and Survival of Red-Shouldered Hawks Banded in Suburban Southern Ohio, 1996–20181

Abstract

We used banding data to investigate dispersal and survival of Red-shouldered Hawks (Buteo lineatus) in two study areas in southern Ohio from 1996 to 2018. Of the 2448 nestlings we banded, 167 (6.8%) were encountered (dead or alive) some time after banding. Mean distance from the natal nest at the time of encounter was 31.6 ± 6.2 km (median = 10.0, range = 0.1–568.6 km, n = 163); natal dispersal distance averaged 16.0 ± 1.9 km (median = 9.0, range = 1.4–117.1 km, n = 110), and was significantly greater for females than for males. Most hawks dispersed 100 km from their natal nest. Of these long-distance dispersers, nine (82%) were 0.05); however, dispersal direction of long-distance dispersers was not uniform (P < 0.05) but bimodal, with hawks encountered either to the south or to the northeast of the study area. Mean age at recovery was 2.6 ± 0.3 yr (median = 1.5 yr, range = 0.2–10.3 yr). As in other raptor species, apparent annual survival varied between age classes, with young birds (hatch-year and second-year) having lower apparent annual survival (0.49 ± 0.03) than adult birds (0.76 ± 0.03). Our study provides information on dispersal, survival, and causes of mortality of Red-shouldered Hawks, demographic data that are important for evaluating population trends and the sustainability of urban/suburban populations.