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 wa s recorded in six broods and was maintained throughout the observed fledgli ng care period. Chicks were capable of short flights (up to 25 in) by fledg ling day 6 and longer flights (to 100 m) by fledgling day 13. During the fi rst three weeks after fledging, juveniles moved as far as 800 in from nests . Nine of 23 (39%) monitored fledglings died within 15 days of fledging, pr imarily due to predation by raptors. Daily survival rates were 0.953 +/- 0. 019 for fledgling days 0-9, 0.955 +/- 0.038 for fledgling clays 10-20, and 0.953 +/- 0.015 for fledgling days 0-20. The probability of surviving fledg ling days 0-20 was 0.367. More quantification of juvenile survival is clear ly needed to understand the role of post-fledging mortality in source-sink dynamics.