No evidence for sex bias in winter inter‐site movements in an Arctic‐nesting goose population

Weegman, Mitch D.; Fox, Anthony D.; Bearhop, Stuart; Hilton, Geoff M.; Walsh, Alyn; Cleasby, Ian R.; Hodgson, David J.

doi:10.1111/ibi.12246

Cited by 6 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Geese occupying northern high latitudes exhibit life‐history traits that may facilitate population structure and restrict interflyway genetic exchange, such as high philopatry in both sexes along with long‐term pair bonds and familial associations and delayed reproduction (Ely & Scribner, ; Scribner et al., ; Ely, Wilson, & Talbot, ). In contrast to ducks, pair‐bonding in some goose species is thought to occur primarily during the spring and summer when genetically similar individuals are segregated (Ely & Scribner, ; Leafloor, Moore, & Scribner, ; Weegman et al., ), and this would provide an additional mechanism to further limit gene flow among breeding areas. The greater white‐fronted goose ( Anser albifrons, Figure ) is only one of two goose species with a nearly circumpolar distribution (the other being brant, Branta bernicla ), and is comprised of populations that utilize five major flyways (Figure ).…”

Section: Introductionmentioning

confidence: 99%

Flyway structure in the circumpolar greater white‐fronted goose

Wilson

Ely

Talbot

2018

Ecology and Evolution

View full text Add to dashboard Cite

Dispersal and migratory behavior are influential factors in determining how genetic diversity is distributed across the landscape. In migratory species, genetic structure can be promoted via several mechanisms including fidelity to distinct migratory routes. Particularly within North America, waterfowl management units have been delineated according to distinct longitudinal migratory flyways supported by banding data and other direct evidence. The greater white‐fronted goose (Anser albifrons) is a migratory waterfowl species with a largely circumpolar distribution consisting of up to six subspecies roughly corresponding to phenotypic variation. We examined the rangewide population genetic structure of greater white‐fronted geese using mtDNA control region sequence data and microsatellite loci from 23 locales across North America and Eurasia. We found significant differentiation in mtDNA between sampling locales with flyway delineation explaining a significant portion of the observed genetic variation (~12%). This is concordant with band recovery data which shows little interflyway or intercontinental movements. However, microsatellite loci revealed little genetic structure suggesting a panmictic population across most of the Arctic. As with many high‐latitude species, Beringia appears to have played a role in the diversification of this species. A common Beringian origin of North America and Asian populations and a recent divergence could at least partly explain the general lack of structure at nuclear markers. Further, our results do not provide strong support for the various taxonomic proposals for this species except for supporting the distinctness of two isolated breeding populations within Cook Inlet, Alaska (A. a. elgasi) and Greenland (A. a. flavirostris), consistent with their subspecies status.

show abstract

Section: Introductionmentioning

confidence: 99%

Flyway structure in the circumpolar greater white‐fronted goose

Wilson

Ely

Talbot

2018

Ecology and Evolution

View full text Add to dashboard Cite

show abstract

“…individuals that fledged and migrated from breeding areas in Greenland to wintering areas in Ireland and Scotland). Weegman et al (2015) found no bias in sex ratio in adult or juvenile Greenland White-fronted Geese; we therefore halved the adults and juveniles in the counts and based our model structure on females. We interpolated the per-capita production of young in 1986 by calculating the mean from 1985 and 1987, because the observed production recorded for that year (0.46) was conspicuously more than twice that in any other year (see Fig.…”

Section: Methodsmentioning

confidence: 99%

Adult survival and per‐capita production of young explain dynamics of a long‐lived goose population

Weegman

Walsh

Ogilvie³

et al. 2021

Ibis

Self Cite

View full text Add to dashboard Cite

Population growth rates in geese can be sensitive to small changes in survival and/or production of young, and understanding which demographic rates explain more variation in population change can be crucial for implementing effective conservation actions. Here, we show that annual adult survival and production of young (assessed in winter) explained most variation in annual population growth rate across 36 years in Greenland White-fronted Geese Anser albifrons flavirostris, during which time the population showed a sustained increase followed by a decline. In contrast, there was no strong relationship between annual population growth rate and juvenile survival following autumn migration, suggesting that variation in this demographic parameter contributed little to the population trajectory over the same period. Quantifying the influence of decisions made by Greenland White-fronted Geese throughout the annual cycle will improve our ability to target seasonal conservation actions that reduce adult mortality and/or increase production of young where possible.

show abstract

“…Previous analyses suggest an even sex ratio (Weegman et al . ); thus, we halved census‐based estimates of adult and juvenile abundances and based our modelling framework on females only.…”

Section: Methodsmentioning

confidence: 99%

Integrated population modelling reveals a perceived source to be a cryptic sink

Weegman

Bearhop

Fox

et al. 2016

Journal of Animal Ecology

Self Cite

View full text Add to dashboard Cite

Summary1. Demographic links among fragmented populations are commonly studied as source-sink dynamics, whereby source populations exhibit net recruitment and net emigration, while sinks suffer net mortality but enjoy net immigration. It is commonly assumed that large, persistent aggregations of individuals must be sources, but this ignores the possibility that they are sinks instead, buoyed demographically by immigration. 2. We tested this assumption using Bayesian integrated population modelling of Greenland white-fronted geese (Anser albifrons flavirostris) at their largest wintering site (Wexford, Ireland), combining capture-mark-recapture, census and recruitment data collected from 1982 to 2010. Management for this subspecies occurs largely on wintering areas; thus, study of sourcesink dynamics of discrete regular wintering units provides unprecedented insights into population regulation and enables identification of likely processes influencing population dynamics at Wexford and among 70 other Greenland white-fronted goose wintering subpopulations. 3. Using results from integrated population modelling, we parameterized an age-structured population projection matrix to determine the contribution of movement rates (emigration and immigration), recruitment and mortality to the dynamics of the Wexford subpopulation. 4. Survival estimates for juvenile and adult birds at Wexford and adult birds elsewhere fluctuated over the 29-year study period, but were not identifiably different. However, per capita recruitment rates at Wexford in later years (post-1995) were identifiably lower than in earlier years (pre-1995). The observed persistence of the Wexford subpopulation was only possible with high rates of immigration, which exceeded emigration in each year. Thus, despite its apparent stability, Wexford has functioned as a sink over the entire study period.5. These results demonstrate that even large subpopulations can potentially be sinks, and that movement dynamics (e.g. immigration) among winters can dramatically obscure key processes driving subpopulation size. Further, novel population models which integrate capture-markrecapture, census and recruitment data are essential to correctly ascribing source-sink status and accurately informing development of site-safeguard networks.

show abstract

No evidence for sex bias in winter inter‐site movements in an Arctic‐nesting goose population

Cited by 6 publications

References 24 publications

Flyway structure in the circumpolar greater white‐fronted goose

Flyway structure in the circumpolar greater white‐fronted goose

Adult survival and per‐capita production of young explain dynamics of a long‐lived goose population

Integrated population modelling reveals a perceived source to be a cryptic sink

Contact Info

Product

Resources

About