Movements and survival of lark bunting fledglings

We quantified post-fledging pre-independence behavior and survival in Lark Buntings (Calamospiza melanocorys) using radio-telemetry. Brood division was recorded in six broods and was maintained throughout the observed fledgling care period. Chicks were capable of short flights (up to 25 m) by fledgling day 6 and longer flights (to 100 m) by fledgling day 13. During the first three weeks after fledging, juveniles moved as far as 800 m from nests. Nine of 23 (39%) monitored fledglings died within 15 days of fledging, primarily due to predation by raptors. Daily survival rates were 0.953 +/- 0.019 for fledgling days 0a??9, 0.955 +/- 0.038 for fledgling days 10a??20, and 0.953 +/- 0.015 for fledgling days 0a??20. The probability of surviving fledgling days 0a??20 was 0.367. More quantification of juvenile survival is clearly needed to understand the role of post-fledging mortality in source-sink dynamics.