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Sea Duck Projects
| Characterization
of annual migration
Primary objectives of this study include:
Black Scoters were captured, using floating mist-nets (Paton et al. 1991, Kaiser et al. 1995), in April 2003 at Nelson Lagoon, located on the Bering Sea side of the Alaska Peninsula. A population of 15,000 to 20,000 Black Scoters stage at Nelson Lagoon each spring. Seventeen individuals were implanted with satellite transmitters following the technique initially described by Korschgen et al. (1996) and later adapted for sea ducks. Transmitters were programmed to optimize the amount of location data received in order to characterize cross-seasonal associations and habitat use throughout an annual cycle. Duty cycles of all transmitters were scheduled to provide location information for 6 hours during an 84-hour period extending approximately 12-18 months. Preliminary data are filtered for best approximating locations using SAS (D. Douglas, USGS) and depicted on maps generated via ArcView software. Maps posted on this website represent movement of 14 individuals from time of capture to current date. Literature cited: Bordage, D. and J. P. L. Savard. 1995. Black Scoter. In The birds of North America, No. 177. (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia and The American Ornithologist Union, Washington D.C. Conant, B. and D. J. Groves. 2002. Waterfowl breeding population survey: Alaska-Yukon, 2002. Unpubl. Report, U.S. Fish and Wildlife Service, Juneau, Alaska. Kaiser, G. W., A. E. Derosher, S. Crawford, M. J. Gill, and I. A. Manly. 1995. A capture method for marbled murrelets in coastal inlets. J. Field Ornith. 66:321-456. Korschgen, C. E., K. P. Kenow, A. Gendron-Fitzpatrick, W. L. Green and F. J. Dein. 1996. Implanting intra-abdominal radiotransmitters with external whip antennas in ducks. J. Wildl. Manage. 60:132-137. Paton, P. W. C., C. J. Ralph and J. Seay. 1991. A mist net design for capturing marbled murrelets. N. Am. Bird Bander 16:123-126. U.S.F.W.S. 1999. Population status and trends of sea ducks in Alaska. U.S. Fish and Wildlife Service, unpublished report. Migratory Bird Management, Anchorage, Alaska 99503. Funding sources for this project:
US Fish and Wildlife Service, Migratory Bird Management with in-kind support from: US Fish and Wildlife Service, Izembek NWR For additional information concerning this study, please contact:
Jason Schamber
Latest Locations of Black Scoters marked in April 2003 at Nelson Lagoon, Alaska This map includes current locations of 14 Pacific Black Scoters marked in April 2003 at Nelson Lagoon, on the Alaska Peninsula. Transmitters provided locations approximately every three days from time of marking (6 hours ON: 78 hours OFF) until batteries expire, estimated to be June 2004. Of the 17 individuals that were marked at Nelson Lagoon, two birds died and one transmitter discontinued transmitting (no signal) within two weeks of capture. Individual Scoter Spring/Summer Movements (by transmitter number) |
Black
Scoters (Melanitta nigra) breeding in Alaska have been
listed as a ‘species at risk’ by the U. S. Fish and
Wildlife Service (USFWS) in response to a persistent population
decline in recent decades (USFWS 1999). It has been difficult
to gauge the severity of and identify factors underlying this
decline because basic information regarding life-history, ecology
and distribution of this species is lacking (Bordage and Savard
1995). Further, the ability to monitor trends for this population
is hampered by improper timing of surveys and incomplete coverage
of breeding areas by the Waterfowl Breeding Pair and Habitat Survey,
which provides the only long-term index to population size (Conant
and Groves 2002).
Difficulties researching and surveying breeding Black Scoters
can be attributed to their extremely dispersed nesting habits
and delayed breeding phenology (Bordage and Savard 1995); most
sympatric nesting waterfowl are well into incubation, while Black
Scoters are either arriving on or migrating to breeding areas
(Flint unpubl. data). Broad-scale studies describing patterns
of migration and identifying critical habitats, including wintering/staging
and breeding areas, have not been conducted and are needed for
biologists to begin to identify factors contributing to population
decline and more accurately assess population trends.
This satellite telemetry project will provide important new information,
helping biologists delineate population structure and identify
cross-seasonal associations among critical habitats. Further,
data gathered on timing and patterns of migration will allow managers
to assess the utility of historic aerial survey data and develop
an appropriate coastal-wide survey platform in Alaska to effectively
monitor long-term population trends of Black Scoters. Information
leading to effective research and management strategies is necessary
to reverse decline in this species.
