Dispersal, interpatch movements, and survival in a shrubland breeding bird community

Abstract

Dispersal events can affect the distribution, abundance, population structure, and gene flow of animal populations, but little is known about long‐distance movements due to the difficulty of tracking individuals across space. We documented the natal and breeding dispersal of shrubland birds among 13 study sites in a 1000 km2 area in southeastern Ohio. In addition, we radio‐marked and tracked 37 adult males of one shrubland specialist, the Yellow‐breasted Chat (Icteria virens). We banded 1925 juveniles and 2112 adults of nine shrubland species from 2002 to 2005. Of these, 33 (1.7%) juveniles were encountered in subsequent years (2003–2006) as adults (natal dispersal) and 442 (20.9%) birds initially banded as breeding adults were re‐encountered in subsequent years (breeding dispersal). Apparent survival of juvenile shrubland birds on their natal patches was 0.024 (95% CI 0.016–0.036). After accounting for the probability of detection, we found that 21% of birds banded as juveniles and recaptured as adults returned to their natal patches, whereas 78% of adult birds showed fidelity to the patch where they were originally captured. Moreover, natal dispersers tended to move farther than breeding dispersers (corrected natal median = 1.7 km ± 0.37; corrected breeding median = 0.23 km ± 0.10). We used our estimates of natal dispersal and annual apparent survival to estimate true survival at 0.11 (95% CI 0.07–0.18) for juveniles in their first year. However, this estimate was only applicable for birds dispersing within 7 km of their natal patches. Interpatch movements of radio‐marked Yellow‐breasted Chats were not uncommon, with 13 of 37 males located in more than one habitat patch. Overall, we observed low natal philopatry, but high adult site fidelity for shrubland birds in our study area. Considering the frequency of short‐distance movements observed (median = 531 m, range = 88–1045 m), clustering of patches within 1 km might facilitate use of shrubland habitat.

Site Fidelity and Annual Survival of the Western Yellow-breasted Chat (<em>Icteria virens auricollis</em>) at the Northern Edge of its Range

“…Return rates of resident males for the study area (18 ha) and the additional fields (49 ha) were still only 13%, much lower than in the southern Okanagan valley. In southeastern Ohio, the return rate for Yellow-breasted Chats (males and females combined) during a five-year study (2002)(2003)(2004)(2005)(2006) in regenerating shrubland patches 4 to 18 ha in size within a 1000 ha state forest was 19.8% (Lehnen and Rodewald 2009). Our detected return rates might also be higher because there is little riparian habitat left in the southern Okanagan valley and our population is relatively concentrated.…”

“…This contrasts with Eastern Phoebes (Sayornis phoebe), where the average dispersal distance for females (3115 m, SD 958) was slightly greater than for males (1486 m, SD 340) (Beheler et al 2003). In southeastern Ohio, the dispersal distances for nine shrubland species (males and females combined) tended to be larger in natal dispersers (second-year birds returning) than breeding dispersers (after-second-year birds returning) (Lehnen and Rodewald 2009). This contrasts with our study, where, on average, breeding males moved farther than natal males and females that dispersed, but our sample size for females is small.…”

“…None of the Eastern Yellow-breasted Chat nestlings banded in Indiana returned to their natal site in subsequent years (Thompson and Nolan 1973). In southeastern Ohio, 0.8% of banded Eastern Yellow-breasted Chat juveniles returned in subsequent years (Lehnen and Rodewald 2009).…”

“…There has been very little study of the demography of I. virens, and most research has been done on the eastern subspecies (e.g., Thompson and Nolan 1973;Burhans and Thompson 1999;Ricketts and Ritchison 2000;Lehnen and Rodewald 2009). The objective of this study was to fill data gaps on demography of this endangered population to better understand the potential for the population to persist in this fragmented landscape.…”

Demographic response of a shrubland bird to habitat creation, succession, and disturbance in a dynamic landscape

“…For example, the sequence in which different bird species colonize shrubland habitats has been understood for decades (Johnston and Odum, 1956); however, whether birds colonizing new habitat http://dx.doi.org/10.1016/j.foreco.2014.10.016 0378-1127/Ó 2014 Elsevier B.V. All rights reserved. originate from within the local area or from populations within a larger landscape is largely unknown (Dale et al, 2006;Lehnen and Rodewald, 2009). Furthermore, the success of management efforts should include consideration of reproductive success (Sallabanks et al, 2000), but the rate at which newly created habitats become productive after disturbance is not understood.…”