Fitness and Implications of Reproductive Decisions for Black Brant Nesting on the Yukon-Kuskokwim Delta, Alaska
type: CreativeWork
description: Cost of breeding is influenced by numerous decisions during reproduction. In black brant (Branta bernicla nigricans; hereafter brant), an arctic goose, I studied effects of choices individual female brant which influence numerous life history traits. For birds maintaining long-term monogamous relationships, mate loss might be expected to reduce fitness, either through reduced survival or reduced future reproductive investment. In the second chapter, human harvest of male brant was used as an experiment to examine effects of mate loss on fitness of female brant. Nineteen years of recapture/resighting and nesting data were used from 2338 marked pairs of brant from the Tutakoke River colony in southwest Alaska. The Barker model in program MARK was used to examine effects of mate loss on annual survival, reporting rate, and permanent emigration. The best supported CMR model allowed survival to differ between females that lost their mates versus those that did not lose mates, reporting rate and fidelity to remain constant, and recapture probabilities at and away from the study area to be year specific. Survival rates decreased from 0.847 ± 0.004 for birds that did not lose their mates to 0.690 ± 0.072 for birds that lost mates. Ring reporting rate for females that lost their mates were two times higher than those that did not lose mates, 0.12 ± 0.086 and 0.06 ± 0.006 respectively, indicating that mate loss increased vulnerability to harvest and possibly other forms of predation. Little support was found for effects of mate loss on fidelity. Linear mixed models were used to examine variation in clutch size and nest initiation date within individuals relative to treatment (mate loss), number of years delay in breeding following treatment and number of years since resuming breeding. Females that formed new pair bonds and bred following loss of a mate enhanced their clutch size by approximately 0.83 eggs (compared to pre-loss size) when compared to the colony wide mean clutc…
abstract: Cost of breeding is influenced by numerous decisions during reproduction. In black brant (Branta bernicla nigricans; hereafter brant), an arctic goose, I studied effects of choices individual female brant which influence numerous life history traits. For birds maintaining long-term monogamous relationships, mate loss might be expected to reduce fitness, either through reduced survival or reduced future reproductive investment. In the second chapter, human harvest of male brant was used as an experiment to examine effects of mate loss on fitness of female brant. Nineteen years of recapture/resighting and nesting data were used from 2338 marked pairs of brant from the Tutakoke River colony in southwest Alaska. The Barker model in program MARK was used to examine effects of mate loss on annual survival, reporting rate, and permanent emigration. The best supported CMR model allowed survival to differ between females that lost their mates versus those that did not lose mates, reporting rate and fidelity to remain constant, and recapture probabilities at and away from the study area to be year specific. Survival rates decreased from 0.847 ± 0.004 for birds that did not lose their mates to 0.690 ± 0.072 for birds that lost mates. Ring reporting rate for females that lost their mates were two times higher than those that did not lose mates, 0.12 ± 0.086 and 0.06 ± 0.006 respectively, indicating that mate loss increased vulnerability to harvest and possibly other forms of predation. Little support was found for effects of mate loss on fidelity. Linear mixed models were used to examine variation in clutch size and nest initiation date within individuals relative to treatment (mate loss), number of years delay in breeding following treatment and number of years since resuming breeding. Females that formed new pair bonds and bred following loss of a mate enhanced their clutch size by approximately 0.83 eggs (compared to pre-loss size) when compared to the colony wide mean clutc…
author: Nicolai, Chris A.
keywords: Black Brant, Fitness, Mate loss, Recruitment, Survival
date published: 2010
date modified: 2026-07-27T21:45:34Z
provider: University of Nevada - Reno
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Nevada - Reno

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property ID: Handle
value: http://hdl.handle.net/11714/4389