| Abstract: | Midwinter inventories of total numbers, population-age ratios in the autumn, and estimates of the total numbers of and age ratios in hunter-killed birds were used to develop a population budget for Atlantic Brant - Lightbellied Brent Geese - Branta bernicla hrota for the period 1968-84. Substantial fluctuations in productivity and survival occurred even in the absence of hunting seasons for 9 of the 17 years. Annual survival estimates ranged from 0.41 to 0.97 for birds> I year of age; mean annual survival for the 17-year period was 0.77, little different from an estimate of 0.78 recently obtained from ringing records. This summary confirms high adult survival for Atlantic Brant as in other long-lived birds with delayed sexual maturity and irregulur breeding failure. The combinution of these factors results in unequal age-cohort representation from year to year. Population size alone, therefore. is not an indicator of population resilience. Proper management should aim to maintain Atlantic Brant at a level sufficient to rebound from sequential breeding and wintering failure. We propose management by age-cohort as the best scheme for tbese geese. |
| Genre: | Article |
| ProdID: | 5222015 |
| Citation Author: | Kirby, R.E.; Barry, T.W.; Kerbes, R.H.; Obrecht, H.H., III |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
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| Citation End Page: | 52 |
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| Citation Language: | English |
| Citation Larger Work Title: | Wildfowl |
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| Citation Number Of Pages: | 4 |
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| Citation Phsyical Description: | 49-52 |
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| Citation Public Comments: | 3196_Kirby.pdf |
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| Citation Search Results Text: | Population dynamics of North American light-bellied brent geese as determined by productivity and harvest surveys; 1985; Article; Journal; Wildfowl; Kirby, R.E.; Barry, T.W.; Kerbes, R.H.; Obrecht, H.H., III |
| Citation Start Page: | 49 |
| Citation Volume: | 36 |
| Citation Year: | 1985 |
| Type: | citation/reference |
| Text: | Population dynamics of North American light-bellied brent geese as determined by productivity and harvest surveys; 1985; Article; Journal; Wildfowl; Kirby, R.E.; Barry, T.W.; Kerbes, R.H.; Obrecht, H.H., III |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 16 Jun 2010 12:18 -0500 |
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