Effects of backpack radiotags on female northern pintails wintering in California

摘要: To test whether backpack radiotags impacted the wintering biology of northern pintails (Anas acuta), I attached spear-suture (SSU, n=82 in 1993) or harness (HAR, n=337 1991-1993) to female Hatch-Year(HY) and After-Hatch-Year (AHY) after their autumn arrival California. evaluated impacts on 1) population distribution; 2) flock status, size, body mass at harvest; 3) August-March survival. also compared retention SSU HAR following attachment. Distribution, size harvest HAR, SSU, unmarked (UMK) were similar. However, averaged 133 g (SE=25 g) less than UMK pintails; loss tended be greatest for heavier HY females 1993. Daily survival rates during 1993-1994 vs. similar both (0.9979 0.9974) AHY (0.9988 0.9986) pintails. Retention ranged from 30-158 days (x=81 d, SE =5 d) 37 that confirmed as being shed; all other failed 1-month studies due poor past a month.