Use of genetic mark-recapture to estimate breeding site fidelity and philopatry in a threatened sea duck population, Alaska-breeding Steller’s eiders

Abstract

The Steller’s eider Polysticta stelleri is a sea duck that breeds in Arctic tundra regions of Russia and Alaska (USA). The Alaska-breeding population is listed as ‘threatened’ under the US Endangered Species Act because of a perceived contraction of the breeding range in North America. Understanding demography of the listed population is critical for evaluating measures that can lead to increased abundance and thus, long-term viability. Specifically, estimates of return rates to breeding areas by adult females and natal areas by juvenile females are needed for planning effective recovery actions. We used a suite of polymorphic loci to genotype individuals and generated genetic profiles of nesting females and female offspring from nest materials collected between 1995 and 2016 in a ~170 km2 study area near Utqiagvik, Alaska. We analyzed capture histories of genetically identified individuals to estimate breeding site fidelity, temporary emigration, and philopatry. From a sample of 365 nests, we found that breeding site fidelity of adult females was high (0.91 ± 0.07 SE), and temporary emigration was also high (0.77 ± 0.06) and annually variable (range 0.34-0.97). From egg shell remains of 124 hatched females, we observed 9 recaptures as nesting adults, suggesting that philopatry was also high (range 0.6-1.0). Given the relatively high rates of adult female breeding site fidelity and female philopatry that we estimated, management actions that reduce mortality of adult females and increase annual productivity are likely to help maintain the population of a few hundred breeding Steller’s eiders on the Arctic Coastal Plain of Alaska.

Predators of Cackling Goose (Branta hutchinsii) eggs on the Alaska Coastal Plain are variable and inconsistent across years

“…In Arctic Canada, Arctic foxes were responsible for the majority of snow goose depredations from 1996 to 1999 and 100% of shorebird nest depredations captured on camera from 2009). Even in Utqiagvik, Alaska, where foxes were removed for predator control, Arctic foxes were still the primary egg predator of sea ducks in several years (Safine 2011. Conversely, in our camera study, we found red foxes and wolverines were responsible for most nest losses in 2017 and 2019, respectively.…”

Prey availability and foraging activity by tundra‐nesting sea ducks: Strong preference for specific wetland types

“…While this study focused only on use of wetlands during the prenesting period, Arctophila wetlands continue to be used by sea ducks throughout the summer. Indeed, within our study area in 2011–2012, 48%–50% of locations of Steller's eider broods, and 34%–47% of spectacled eider broods, occurred within Arctophila wetlands (Safine, 2013 ). For Steller's eiders specifically, in 6 years from 1995 to 2012, 43%–85% of brood locations were in wetlands dominated by Arctophila (Safine, 2013 ).…”

“…Indeed, within our study area in 2011–2012, 48%–50% of locations of Steller's eider broods, and 34%–47% of spectacled eider broods, occurred within Arctophila wetlands (Safine, 2013 ). For Steller's eiders specifically, in 6 years from 1995 to 2012, 43%–85% of brood locations were in wetlands dominated by Arctophila (Safine, 2013 ). Thus, Arctophila wetlands provide critical resources not only for females upon arrival at the breeding grounds but also for the rearing of young.…”

Climate change and coastal wetland salinization: Physiological and ecological consequences for Arctic waterfowl

“…Because Steller's eider breeding is rare on the YKD, no comparable information is available although Flint and Herzog (1999) did document a single female that returned to breed in multiple years. Further, analyses by Safine et al (2020) suggest breeding site fidelity and moderate to high degree of natal philopatry for Steller's eiders near Utqiagvik, Alaska. In the U.S., the spectacled eider was listed as threatened by the U.S.…”