The Bird Vital Sign tells us about the health of populations of native resident and migratory bird species associated with Puget Sound. Each winter, thousands of seabirds, sea ducks, and waterfowl converge in the relatively calm and food-rich waters of Puget Sound. In summer, colonies of seabirds are busily raising and attending their young. In spring and fall, the mudflats bustle with shorebirds that stop to feed and rest during migration. During the non-breeding season, large flocks of marine waterfowl and seabirds aggregate to rest and feed in nearshore waters. Because it draws such a variety of bird life, Puget Sound supports over a dozen Important Bird Areas and offers ample birdwatching opportunities.

The Bird Vital Sign is measured with two indicators: marine population abundance and terrestrial population abundance. Each indicator integrates population information from multiple species that represent different prey bases and habitats. Currently, only the marine indicator species is being assessed by tracking breeding season at-sea densities of Marbled Murrelet, Rhinoceros Auklet, and Pigeon Guillemot, and non-breeding season at-sea abundance trends for Surf, White-winged and Black Scoters. Each of these species are considered highly dependent on the marine environment of Puget Sound and the greater Salish Sea.


Key Vital Sign Messages

 Rhinoceros auklet with herring. Photo P. Hodum
  • Marbled Murrelet, Rhinoceros Auklet, and Pigeon Guillemot breed locally in Puget Sound and the Strait of Juan de Fuca, whereas the three scoter species overwinter here and breed elsewhere.
  • Population conservation status and trends vary among the Vital Sign indicator species, (either unchanged or declining) and therefore show mixed signals. Summer at-sea surveys in Puget Sound show that Marbled Murrelets, a federally-listed species, have declined by nearly 5 percent per year since surveys began in 2000. Scoter density (Surf, Black, and White-winged Scoter species combined) has also declined by 2.8 percent per year in that time. In contrast, Sound-wide trends for Pigeon Guillemots and Rhinoceros Auklets suggest stable populations.
  • Changes in marine bird abundance and distribution may result from a number of factors, including habitat alteration/degradation, changes in fish prey populations, and disease and contamination from toxic chemicals. Human and environmental pressures in other parts of species’ ranges can also lead to changes in the number of birds we see locally in Puget Sound.
  • Changing ocean and climate conditions associated with climate change can:
    • disrupt historical patterns of prey abundance and diversity, resulting in inadequate food or changes to the food quality having impacts of unknown severity if sustained for multiple years; and
    • increase the prevalence of disease in seabird breeding colonies in Puget Sound through increases in sea surface temperatures.
  • Volunteer opportunities for marine bird monitoring in Puget Sound include the Puget Sound Seabird Survey, COASST, and Pigeon Guillemot breeding colony monitoring with the Guillemot Research Group in north Puget Sound and Nisqually Reach Nature Center in south Puget Sound.

Other Resources

Contributing Partners

The following organizations contribute marine bird monitoring data to the Birds Vital Sign for Puget Sound:

The Guillemot Research Group on Whidbey Island



PSEMP Marine Bird Work Group (coordinator is Trina Bayard)
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