Fidelity and breeding probability related to population density and individual quality in black brent geeseBranta bernicla nigricans

Abstract

Summary 1.Patterns of temporary emigration (associated with non-breeding) are important components of variation in individual quality. Permanent emigration from the natal area has important implications for both individual fitness and local population dynamics. 2. We estimated both permanent and temporary emigration of black brent geese ( Branta bernicla nigricans Lawrence) from the Tutakoke River colony, using observations of marked brent geese on breeding and wintering areas, and recoveries of ringed individuals by hunters. We used the likelihood developed by Lindberg, Kendall, Hines & Anderson 2001 (Combining band recovery data and Pollock's robust design to model temporary and permanent emigration. Biometrics , 57 , 273-281) to assess hypotheses and estimate parameters. 3. Temporary emigration (the converse of breeding) varied among age classes up to age 5, and differed between individuals that bred in the previous years vs. those that did not. Consistent with the hypothesis of variation in individual quality, individuals with a higher probability of breeding in one year also had a higher probability of breeding the next year. 4. Natal fidelity of females ranged from 0·70 ± 0·07-0·96 ± 0·18 and averaged 0·83. In contrast to Lindberg et al . (1998), we did not detect a relationship between fidelity and local population density. Natal fidelity was negatively correlated with first-year survival, suggesting that competition among individuals of the same age for breeding territories influenced dispersal. Once females nested at the Tutakoke River, colony breeding fidelity was 1·0. 5. Our analyses show substantial variation in individual quality associated with fitness, which other analyses suggest is strongly influenced by early environment. Our analyses also suggest substantial interchange among breeding colonies of brent geese, as first shown by Lindberg et al . (1998).

Robust estimation of survival and contribution of captive‐bred Mallards Anas platyrhynchos to a wild population in a large‐scale release programme

“…, Sedinger et al . ) or to monitor endangered long‐lived species (Kendall et al . , Peñaloza et al .…”

To breed or not: a novel approach to estimate breeding propensity and potential trade‐offs in an Arctic‐nesting species

“…First, we assumed that birds not going to Bylot Island for one summer skipped breeding. This assumption is based on the fact that geese are highly faithful to their breeding site (Rohwer and Anderson 1988, Reed et al 2003b, Sedinger et al 2008, see Discussion for possible violation of this assumption). Secondly, we assumed that even though some nonbreeding adults could come to the study site early during the breeding season before migrating to distant molting areas (Reed et al 2003a), they could not be resighted.…”

Are there trade‐offs between pre‐ and post‐fledging survival in black brent geese?

“…This restriction increased the likelihood that we would encounter these individuals as adults if they survived and bred (Lindberg et al. 1998; Sedinger et al. 2008).…”

“…Because we were interested in estimating survival for the period from hatch to ringing and the associated encounter probability for the first ringing occasion, we pooled all subsequent encounters following the initial ringing period (the second encounter occasion) into a single, third encounter occasion. Because most individual brent do not return to TRC as breeders until age two or three (Sedinger et al. 2008), we restricted our analyses to individuals from the 2005 cohort and earlier.…”