Several thousand black brant breed and molt along the arctic coast of Russia. The eastern portion of the Russian population, which nests from the Lena River Delta in the west to the Anadyr River lowlands in the east, winters in North America. The western portion of the Russian breeding population (approximately 5,000 birds) winters in Japan, Korea, and northeastern China, near recent outbreaks of the Asian H5N1 virus (e.g., Hong Kong). Mixing of flocks likely occurs between these two Russian breeding populations, and potentially with birds wintering in northern Europe. Also, molt migrants from Russia may come to the arctic coast of Alaska (King and Hodges 1979) and conversely molters from Alaska may migrate to Russia (e.g., Wrangel Island; Ward et al. 1993). Finally, Brant marked in Alaska have been observed staging and wintering in Japan (Derksen et al. 1996), indicating that there is interchange between birds from Alaska and those that winter closest to infected areas. The highest probability of Asian H5N1 transmission would be at Izembek Lagoon, Alaska, in the fall, when the Russian-breeding and molting birds make landfall in North America in largest numbers. Izembek Lagoon and adjacent embayments support virtually the entire population of black brant during fall and significant numbers of birds in winter. The individuals most vulnerable to Asian H5N1 would likely be goslings, which are especially susceptible to new virus after their maternal immunity fades (at about 30 days) and they might act to amplify the virus (Hon Ip, pers. comm.).

Brant segregate into breeding populations (colonies) during nesting, to which they show fidelity. There may be mixing among colonies during brood rearing. Molting flocks at Teshekpuk Lake are non-breeders and failed breeders from many colonies across North America and possibly Russia. During the fall staging period at Izembek Lagoon nearly the entire world population of black brant comes together. For the most part, Brant nest in high concentrations (colonies) and during brood rearing, molting, and staging, they concentrate in flocks. Thus, they are relatively easy to capture both on nests with nest traps, and during brood rearing and molting using corral traps. Brant are much more difficult to capture in spring and fall but they are hunted both for subsistence in the spring and fall, and for sport in the fall.

We propose a 4-stage sampling design targeting birds that may be arriving from Asia. The first level will be stratified based on timing and breeding status: arrival/early nesting, molting, brood rearing, and fall staging. Further stratification or cluster sampling will occur within each of these strata as Hollmén et al. (2003) found that the prevalence of a virus may vary greatly among spatially segregated segments of a population.

Arrival / Early Nesting

Spring subsistence killed birds could be sampled from the Seward Peninsula (Shishmaref), Saint Lawrence Island, and Yukon Delta NWR. At Izembek NWR samples could also be obtained through collections and fecal samples. Spring sampling will be spread across two broadly defined breeding areas: the Yukon-Kuskowkim Delta (YKD) and the Arctic Coastal Plain. Within each of these areas brant typically nest in colonies which we will sample as clusters. Thus, on the YKD where colony sizes are large, we will sample 70 females from each of 3 major colonies: Kigigak Island, Baird Inlet, and Tutakoke River. Conversely, on the Arctic Coastal Plain, nesting colony sizes are small and samples of 10 females will be taken from 4 distinct colonies. Sampling of nesting females will occur in conjunction with other nesting studies. Females will be captured on nests in incubation and samples will be taken as cloacal swabs.

Molting

Failed and non-breeding birds from a variety of breeding colonies concentrate in the vicinity of Teshekpuk Lake for molt. Large flocks of birds are regularly found dispersed across a series of large lakes. We will sample lakes as clusters, 50 birds per lake from each of 4 lakes, live capturing birds in corral traps and taking cloacal swabs.

Molting flocks of non-breeding birds have also been observed in the vicinity of the Black River on the YKD, however, little is known about their abundance and distribution. Two hundred birds will be sampled to replicate the design used at Teshekpuk Lake if the distribution of birds allows.

Brood-Rearing

Goslings will be sampled from the major breeding colonies on the YKD by driving brood flocks into corral traps. Samples of 200 goslings from each colony will be sampled by cloacal swab.

Fall Staging

Fall staging birds will be sampled at Izembek Lagoon, Morzhovoi, and Bechevin lagoons in late September and October. Samples will be taken as cloacal swabs from sport hunter harvested birds when possible. Collections and fecal samples will be used to supplement hunter samples. A total of 200 samples will be obtained.

U.S. Fish and Wildlife Service

Izembek NWR (Izembek Lagoon and adjacent embayments)

U.S. Geological Survey

Alaska Department of Fish and Game (Izembek State Game Refuge)

University of Nevada, Reno (Tutakoke River)

Derksen, D.V., K. S. Bollinger, D. H. Ward, J. S. Sedinger, and Y. Miyabayashi. 1996. Black brant from Alaska staging and wintering in Japan. Condor 98:653-657.

Hollmén T. E., J. C. Franson, P. L. Flint, J. B. Grand, R. B. Lanctot, D. E. Docherty, and H. M. Wilson. 2003. An adenovirus linked to mortality and disease in long-tailed ducks (Clangula hyemalis) in Alaska. Avian Diseases 47:1434-1440.

King, J. G. and J. I. Hodges. 1979. A preliminary analysis of goose banding on Alaska’s arctic slope. Pages 176-188 in R.L. Jarvis and J. C. Bartonek (eds). Management and Biology of Pacific Flyway Geese. Oregon State University Bookstores, Corvallis.

Ward, D. H., D. V. Derksen, S. P. Kharitonov. M. Stishov, and V. Baranyuk. 1993. Status of Pacific black brant Branta bernicla on Wrangel Island, Russian Federation. Wildfowl 44:39-48.