| Abstract: | North American populations of northern pintails (Anas acuta) declined between 1979 and the early 1990s. To determine if low survival during winter contributed to declines, we estimated winter (last week of Aug-Feb 1987-90) survival for 190 adult (after hatching yr [AHY]) female radio-tagged pintails in late summer in Sacramento Valley (SACV), California. Survival rates did not vary by winter (P = 0.808), among preseason, hunting season, or postseason intervals (P = 0.579), or by body mass at time of capture (P = 0.127). Premolt (wing) pintails (n = 10) tended to survive at a lower rate (0.622, SE = 0.178) than pintails that had already replaced flight feathers (0.887, SE = 0.030) (P = 0.091). The pooled survival (all years) estimate for the 180-day winter was 0.874 (SE = 0.031). Hunting mortality rate (0.041-0.087) and nonhunting mortality rate (0.013-0.076) did not differ among years (P = 0.332) or within years (all P > 0.149). Legal hunting (n = 7), predation (n = 4), cholera (n = 2), illegal shooting (n = 2), botulism (n = 1), and unknown cause (n = 1) accounted for all mortality. Nonwintering survival (annu. survival/winter survival = 0.748) was lower than winter survival; thus, if gains in annual survival are desired for this population, managers should first examine the breeding-migration period for opportunities to achieve increases. |
| Genre: | Article |
| ProdID: | 1001339 |
| Citation Author: | Miller, M. R.; Fleskes, J. P.; Orthmeyer, D. L.; Newton, W. E. |
| Citation Contributing Office: | Northern Prairie Wildlife Research Center |
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| Citation End Page: | 486 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Wildlife Management |
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| Citation Number Of Pages: | 8 |
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| Citation Phsyical Description: | p. 478-486 |
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| Citation Search Results Text: | Survival of adult female northern pintails in Sacramento Valley, California; 1995; Article; Journal; Journal of Wildlife Management; Miller, M. R.; Fleskes, J. P.; Orthmeyer, D. L.; Newton, W. E. |
| Citation Start Page: | 478 |
| Citation Volume: | 59 |
| Citation Year: | 1995 |
| Type: | citation/reference |
| Text: | Survival of adult female northern pintails in Sacramento Valley, California; 1995; Article; Journal; Journal of Wildlife Management; Miller, M. R.; Fleskes, J. P.; Orthmeyer, D. L.; Newton, W. E. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DOCUMENT): | http://www.npwrc.usgs.gov/resource/birds/npsurviv/index.htm |
| Date Other: | Sun, 1 Jan 1995 00:00 -0600 |
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