Movement and persistence by Ross’s Geese (Chen rossii) in Canada’s arctic

Abstract

We have been studying population biology of Ross's Geese south of Queen Maud Gulf (QMG) in Canada's central arctic from 1989 to 2008. Many Ross's Geese there nest in a small number of discrete colonies which form the QMG metapopulation. In addition to capture and marking of geese, we have used ground-based sampling of nests to estimate the annual rate of population growth at Karrak Lake, one of the largest colonies within the QMG metapopulation. Between 1993 and 2008, Ross's Geese at Karrak Lake have been growing in an uninterrupted fashion at about 11% per year and numbered about 726,000 ± 91,000 (95% CL) breeders in 2008. In addition, substantial numbers of Ross's Geese had colonized an area about 750 km southeast of QMG at McConnell River on the west coast of Hudson Bay (WHB) in 1994. We have been marking Ross's Geese at WHB from 2001 to 2006. In addition, we used complementary ground-based methods similar to those at QMG to estimate annually the abundance of nesting geese at WHB. The population increased at WHB by 11% per year between 2003 and 2007, a rate very similar to that observed at Karrak Lake near QMG. In 2007, the population of nesting Ross's Geese at WHB was about 81,000 ± 12,000. In addition to contributions through local recruitment, we wished to better understand the role of movement and source-sink dynamics between QMG and WHB. We used joint multistate-dead recovery mark-recapture models to estimate movement probability of adults between these two regions. The greater likelihood of movement (0.24 ± 0.18) from WHB to QMG, compared to the inverse (0.05 ± 0.04) was restricted to males; there was virtually complete philopatry by females at both study areas. The high rate of philopatry by adult females suggested that population growth in each study area was most likely sustained by in situ recruitment. We also tested and confirmed the assumption that movement probability between regions was unrelated to marker type.

Harvest, survival, and abundance of midcontinent lesser snow geese relative to population reduction efforts

“…Uninterrupted banding operations in arctic regions that support large numbers of highly clumped distributions of snow geese would allow researchers to address population parameters that are estimable from mark‐recapture of individual geese (Cooch and White 2009). Such an approach would allow a focus on facets of metapopulation biology, such as local dynamics in abundance, survival, and recruitment, as well as the exchange of geese among breeding subpopulations (Alisauskas et al, in press) while continuing to allow an assessment of the role that exploitation by hunters may play in population dynamics.…”

Factors influencing emigration of Ross's and snow geese from an Arctic breeding area

“…The movement of organisms among populations can influence individual fitness (Nevoux et al ), genetic structure (Rockwell and Barrowclough ), and spatio‐temporal variation in population dynamics (Ruxton , Alisauskas et al , Schaub et al ). The difficulty in tracking individuals across large spatial scales has impeded more rapid advances in understanding the factors that influence probabilities of immigration and emigration for most taxa (Koenig et al , Doherty et al , Cam et al ).…”

“…The extent of dispersal typically differs between sexes for birds and mammals, related to the ability to defend mates and resources (Greenwood , Pusey , Lawson Handley and Perrin ). Female‐biased dispersal is the norm among birds, but exceptions include most waterfowl (Clarke et al , Blums et al , Alisauskas et al ). Regardless of which sex exhibits greater movement, dispersal probabilities are generally higher for juveniles, as they move from natal to first breeding sites, than for adults that have bred previously (Greenwood , Paradis et al ).…”

“…We examined inter‐specific variation in probabilities of fidelity and survival by adult Ross's geese ( Chen rossii ) and lesser snow geese ( Chen caerulescens caerulescens , hereafter snow geese), from a study near Karrak Lake south of Queen Maud Gulf (QMG) in central Nunavut, Canada (Alisauskas et al , b ; Traylor et al ). The abundance of light geese has increased rapidly across much of Arctic Canada over the past 4 decades (Kerbes et al ).…”

Demographic consequences of translocation of overabundant Canada geese breeding in urban areas

“…Changes in local population size could arise from effects of local survival and movements of immature and adult geese among sites (Alisauskas et al , Norris et al ). Translocation of immature and adult geese could reduce a nuisance population of geese, but this effect may be dampened if a large number of geese return to the original site the following year (Surrendi , Fritzell and Soulliere , Sanders and Dooley ).…”