Energetics and vulnerability to human impacts of molting Surf and White-winged Scoters in the Puget Sound-Georgia Basin

Project Number: 120

Year Funded: 2009

Lead Institution(s): Simon Fraser University

Project Lead: Eric Anderson

Email:

Collaborator(s): Dan Esler (SFU) Joseph Evenson (WDFW)

Location: Salish Sea

Focal Species: Surf Scoter (Melanitta perspicillata), White-winged Scoter (Melanitta delgandi)

Project Description: Scoters aggregate during wing molt to a greater extent than at most other times of year, increasing the risk to scoter populations of localized human disturbances. Recent observations indicate that many thousands of scoters molt in the Puget Sound-Georgia Basin (PSGB) of Washington and British Columbia (BC). Many heavily-used molting sites in the PSGB are subject to diverse and extensive human impacts, particularly when compared to molting sites further north. Padilla Bay, a major molting site in Washington, is bordered by two major oil refineries, is subject to extensive diking and dredging that alter food availability, and is open to hunting in mid-October when breeding females may not have completed molt. In BC, many thousands of Surf and White-winged Scoters molt in the Fraser River Delta. Rapid urbanization in the lower reaches of the Fraser River has likely increased contamination in the Fraser River Delta (Hall and Schreier 1996), although related effects on molting scoters and foods on which they may depend are unknown. To clarify the value of coastal molting habitats, we are evaluating the nutritional condition of scoters during molt and thus their vulnerability to human impacts using data available through concurrent studies and comparisons with captive sea ducks. These results are a substantial response to the SDJV priority to identify and inventory important sea duck coastal habitats.

Project Reports:

SDJV120 Final Report FY09

Related Publications:

Anderson EM, Lovvorn JR. 2012. Seasonal dynamics of prey size mediate complementary functions of mussel beds and seagrass habitats for an avian predator. Mar Ecol Prog Ser 467:219-232. https://doi.org/10.3354/meps09943

Anderson, E. M., D. Esler, W. S. Boyd, J. R. Evenson, D. R. Nysewander, D. H. Ward, R. D. Dickson, B. D. Uher-Koch, C. S. VanStratt, and J. W. Hupp. 2012. Predation rates, timing, and predator composition for Scoters (Melanitta spp.) in marine habitats. Canadian Journal of Zoology 90: 42-50. https://doi.org/10.1139/z11-110

Anderson, E. M., and J. R. Lovvorn. 2011. Contrasts in energy status and marine foraging strategies of White- winged Scoters (Melanitta fusca) and Surf Scoters (M. perspicillata). Auk 128:248−257. https://doi.org/10.1525/auk.2011.10088

Anderson, E. M., J. L. Bower, D. R. Nysewander, J. R. Evenson, and J. R. Lovvorn. 2009. Changes in avifaunal abundance in a heavily used wintering and migration site in Puget Sound, Washington, during 1966–2007. Marine Ornithology 37:19–27. http://www.marineornithology.org/PDF/37_1/37_1_19-27.pdf

Anderson, E. M., and J. R. Lovvorn. 2008. Gray whales may increase feeding opportunities for avian benthivores. Marine Ecology Progress Series 360:291–296. https://doi.org/10.3354/meps07359

Anderson, E. M., J. R. Lovvorn, and M. T. Wilson. 2008. Reevaluating marine diets of Surf and White-winged scoters: interspecific differences and the importance of soft-bodied prey. Condor 110:285–295. https://doi.org/10.1525/cond.2008.8458

Dickson, R.D., D. Esler, J.W. Hupp, E.M. Anderson, J.R. Evenson, and J. Barrett. 2012. Phenology and duration of remigial molt in surf scoters (Melanitta perspicillata) and white-winged scoters (M. fusca) on the Pacific coast of North America. Canadian Journal of Zoology 90:932-944. https://doi.org/10.1139/z2012-061

Lewis, T.L., D. Esler, B.D. Uher-Koch, R.D. Dickson, E.M. Anderson, J.R. Evenson, J.W. Hupp, and P.L. Flint. 2017. Attaching transmitters to waterbirds using one versus two subcutaneous anchors: retention and survival trade-offs. Wildlife Society Bulletin 41:691-700. https://doi.org/10.1002/wsb.833

Uher-Koch, B.D., D. Esler, R.D. Dickson, J.W. Hupp, J.R. Evenson, E.M. Anderson, J. Barrett, and J.A. Schmutz. 2014. Survival of surf scoters and white-winged scoters during remigial molt. Journal of Wildlife Management 77:1189-1196. https://doi.org/10.1002/jwmg.774

Energetics and vulnerability to human impacts of molting Surf and White-winged Scoters in the Puget Sound-Georgia Basin