Abby Powell, PhD (Former Employee)

Most king (Somateria spectabilis) and common eiders (S. mollissima v-nigra) breeding in the northwestern Nearctic migrate past Point Barrow, Alaska. Spring migration counts have been conducted there since 1953; during 1976–1996, both species declined > 50% for unknown reasons. To evaluate population trends, counts in 2003, 2004, 2015, and 2016 were compared to earlier counts. King eider...

Hatch-year Semipalmated Sandpipers (Calidris pusilla) use river deltas along the Beaufort Sea as their first stops during fall migration. However, these sites are subject to extreme changes in water levels that affect available foraging habitat. We examined relationships between timing of fall migration and storm surges, with respect to forage availability, using different water level...

Most of the king (Somateria spectabilis) and common eiders (S. mollissima v-nigra) nesting in northern Alaska and northwestern Canada migrate past Point Barrow, Alaska, during the spring and fall migration. Yellow-billed loons (Gavia adamsii) also migrate past Point Barrow and are a species of international conservation concern. Spring migration counts of eiders have been conducted...

Deep-sea sponge grounds are relatively understudied ecosystems that may provide key habitats for a large number of fish and invertebrates including commercial species. Glass sponge grounds have been discovered from the tropics to polar regions but there are only a few places with high densities of dictyonine sponges. Dictyonine glass sponges have a fused skeleton, which stays intact when...

The quantification of prey remains is a common method for estimating the diet of a variety of birds. However, these estimates may be subject to biases based on prey body type, nesting habitat, and collection date. To better understand biases and limitations associated with this method, we compared it with two others commonly used to characterize diet: direct observation of parents...

River deltas along Alaska’s Beaufort Sea coast are used by hatch-year semipalmated sandpipers (Calidris pusilla) after leaving their terrestrial natal sites, but the drivers of their use of these stopover sites on the first “hop” of fall migration are unknown. We quantified sandpiper temporal distribution and abundance as related to food resources at three river deltas during the...

Despite changes in shrub cover and weather patterns associated with climate change in the Arctic, little is known about the breeding requirements of most passerines tied to northern regions. We investigated the nesting biology and nest habitat characteristics of Smith's Longspurs (Calcarius pictus) in 2 study areas in the Brooks Range of Alaska, USA. First, we examined variation in...

Breeding ecology studies of boreal waders have been relatively scarce in North America. This paucity is due in part to boreal habitats being difficult to access, and boreal waders being widely dispersed and thus difficult to monitor. Between 2008 and 2014 we studied the nesting ecology of Whimbrels Numenius phaeopus hudsonicus in interior Alaska, a region characterized by an active...

Implanted biologging devices, such as satellite-linked platform transmitter terminals (PTTs), have been used widely to delineate populations and identify movement patterns of sea ducks. Although in some cases these ecological studies could reveal transmitter effects on behavior and mortality, experiments conducted under controlled conditions can provide valuable information to understand...

Unlike lower latitude coastlines, the estuarine nearshore zones of the Alaskan Beaufort Sea are icebound and frozen up to 9 months annually. This annual freezing event represents a dramatic physical disturbance to fauna living within intertidal sediments. The main objectives of this study were to describe the benthic communities of Beaufort Sea deltas, including temporal changes and...

Shifts in the distribution of benthivorous predators provide an indication of underlying environmental changes in benthic-mediated ecosystems. Spectacled Eiders (Somateria fischeri) are benthivorous sea ducks that spend the nonbreeding portion of their annual cycle in the Bering, Chukchi, Beaufort, and East Siberian seas. Sea ducks generally molt in biologically productive areas with...

Four species of threatened or declining eider ducks that nest in the Arctic migrate through the northeast Chukchi Sea, where anticipated industrial development may require prioritizing areas for conservation. In this nearshore corridor (10–40 m depth), the eiders’ access to benthic prey during the spring is restricted to variable areas of open water within sea ice. For the most abundant...