Foraging-Related Activity of Bald Eagles at a Washington Seabird Colony and Seal Rookery

  title={Foraging-Related Activity of Bald Eagles at a Washington Seabird Colony and Seal Rookery},
  author={James L. Hayward and Joseph G. Galusha and Shandelle M. Henson},
Abstract From 1980 to 1998, Washington's Bald Eagle (Haliaeetus leucocephalus) population increased at an annual rate of 10%. Over the same time period, foraging activity of Bald Eagles at marine bird breeding colonies also increased. From 1993 to 2008, we observed foraging-related behavior of Bald Eagles on Violet Point, Protection Island. This island hosts more than 70% of the breeding seabirds in Washington's inner seaways and serves as an important rookery for harbor seals (Phoca vitulina… 

Predator–prey dynamics of bald eagles and glaucous‐winged gulls at Protection Island, Washington, USA

The results suggest that the effects of bald eagle activity on the dynamics of a large gull colony were explained by a predator–prey relationship that included the possibility of coexistence but also the possible of gull colony extinction.

Migration and Winter Habitat Use of Glaucous-Winged Gulls (Larus glaucescens) from Triangle Island, British Columbia

Abstract. Understanding the movements and habitat use of marine birds is essential to inform conservation and marine spatial planning. Here, satellite transmitters were used to study the migration

Spatiotemporal Responses of Wintering Bald Eagles to Changes in Salmon Carcass Availability in the Pacific Northwest

Abstract Each winter, thousands of bald eagles (Haliaeetus leucocephalus) from across western North America migrate to Pacific Northwest rivers to feed on the carcasses of post-spawning chum salmon

Bald Eagle Predation on Sitka Black-Tailed Deer Fawns

  • S. Gilbert
  • Environmental Science
    Northwestern Naturalist
  • 2016
Bald Eagles (Haliaeetus leucocephalus) are known predators, but records of predation on large mammals are limited and highly seasonal. During winter, Bald Eagles are known to scavenge but not predate

Bald Eagle Predation on Double-Crested Cormorant and Herring Gull Eggs

Repeated Double-crested Cormorant (P. auritus) and Herring Gull egg predation events by Bald Eagles on a Double- cormorant–Herred Gull rookery in Rainy Lake along the U.S.–Canada border between Voyageurs National Park (VNP), MN, and Ontario, Canada is reported.

Density-Dependence in the Survival and Reproduction of Bald Eagles: Linkages to Chum Salmon

It is suggested that eagle populations in the Pacific Northwest are currently partially limited by density on the breeding grounds and partially by adult mortality in late winter, likely due to reduced late winter salmon stocks forcing eagles to exploit more marginal prey supplies.

Negative Interspecies Interactions in a Glaucous-Winged Gull Colony on Protection Island, Washington

Together, the tall grass and eagle predation appear to be carrying out a pincer movement which may be forcing the gulls into suboptimal nesting habitat and driving the decline of the gull colony on Protection Island.

Fitting in with the crowd: the role of prospecting in seabird behavioural trends

Although prospectors typically spent more time on the colony surface than adults, prospectors rarely socialized with conspecifics during their visits to the colony, possibly due to the absence of a citrus-like feather odour used in olfactory communication.

Modeling climate change impacts on overwintering bald eagles

Future climate-driven declines in winter food availability, coupled with a growing bald eagle population, may force eagles to seek alternate prey in the Puget Sound area or in more remote ecosystems.

Landfill Use by Bald Eagles in the Chesapeake Bay Region

Abstract We examined patterns in the use of landfills (rubbish dumps) in the Chesapeake Bay by Bald Eagles (Haliaeetus leucocephalus). Sites of solid waste landfills (n  =  72) were located using



Nesting Population, Nest Sites, and Prey Remains of Bald Eagles in Barkley Sound, British Columbia

The size of the present population of bald eagles throughout Barkley Sound was assessed, to determine which islands and sites these eagles selected for nesting, and to identify prey remains of eagles beneath nests, to compare the population density, nest site seleciton and prey of the Barkley Sound population with those of e Eagles nesting in the Gulf Islands, British Columbia.

Seasonal Timing of Bald Eagle Attendance and Influence on Activity Budgets of Glaucous-winged Gulls in Barkley Sound, British Columbia

Investigation of changes in Bald Eagle abundance in relation to gull breeding phenology over 6 years at Seabird Rocks and compare activity budgets of gulls shows that Bald Eagle attendance patterns at gull colonies coincide with hatching of gull chicks and can influence time-activity budgets ofulls, suggesting Predator-induced changes in gull behavior during the breeding season may influence reproductive success.

Bald eagles and sea otters in the Aleutian Archipelago: indirect effects of trophic cascades.

The results provide further evidence of the wide-ranging indirect effects of sea otter predation on nearshore marine communities and another apex predator, the Bald Eagle, and the food-web pathway transcended five species and several trophic levels in linking one apex predator to another.

Factors Influencing Great Blue Heron Nesting Productivity on the Pacific Coast of Canada from 1998 to 1999

Abstract Surveys were conducted at 35 Great Blue Heron (Ardea herodias) colonies in urban and rural landscapes of south-coastal British Columbia, Canada, to investigate low nesting productivity


Dietary preferences of bald eagles reflect local prey availability in many parts of the United States; depending on time and place, eagles prey upon fish, marine birds, gull eggs, and sea otter pups and they scavenge cow, sheep, deer, salmon, and seal carcasses.

Rhinoceros Auklet (Cerorhinca monocerata) Burrow Counts, Burrow Density, Occupancy Rates, and Associated Habitat Variables on Protection Island, Washington: 2008 Research Progress Report

Unlike many species of seabirds that use the Salish Sea (Puget Sound, Georgia Basin and Strait of Juan de Fuca) during migration or for over-wintering, rhinoceros auklets (Cerorhinca monocerata)

Breeding Biology of the Rhinoceros Auklet in Washington

Investigation of the breeding biology of the Rhinoceros Auklet at three main colony sites on the coast of Washington found that early-hatched young grew more rapidly than chicks hatched at a later date and breeding success was higher on the inland colony sites.

Bald Eagle Predation on Harbor Seal Pups

Roosting and thermoregulatory of male Gould's long-eared bats, Nycto philus gouldi: energetic benefits of thermally un stable tree roosts and benefits of living in a building versus buildings.


To explore the contribution of eagles to the observed population decline of the Common Murre, a wide range of plausible models of murre demography are developed, finding that the match between the projected and observed murre numbers is generally much improved by the inclusion of eagle effects.

Influence of group size and habitat type on reproductive success in Common Murres (Uria aalge)

As a function of size, nesting colonies dilute the risk of predation and also may provide members with early warning of predator presence, and whether colonial nesting confers advantages on the adults, with respect to predation, depends on the numerical response of predators to colony size and location.