INFLUENCE OF AGE AND DISPERSAL ON REPRODUCTIVE SUCCESS OF CLIFF SWALLOWS (PETROCHELIDON PYRRHONATA)

We examined age-related reproductive success and the short-term consequences of dispersal by known-aged Cliff Swallows (Petrochelidon pyrrhonota) breeding in Texas from 1975–86. Clutch size increased with age in females, and males and females ≥2 yrs old fledged more young than yearlings. Sixteen percent (76/463) of birds dispersed between breeding seasons and we observed female-biased dispersal. Birds that dispersed to a different colony at age...