Second North American Sea Duck Conference - Patuxent Wildlife ...

SECOND NORTH AMERICAN SEA DUCK CONFERENCE
FINE-SCALE SPATIAL AND TEMPORAL SEGREGATION
IN FORAGING OF BARROW’S GOLDENEYES,
EASTERN POPULATION, WINTERING IN THE
ST. LAWRENCE RIVER ESTUARY, QUEBEC, CANADA
Helene Laforge¹, Jean-Francois Ouellet¹, Magella Guillemette¹, and Michel Robert²
¹Departement de biologie, Universite du Quebec a Rimouski, 300 allee des Ursulines, Rimouski, QC,
G5L 3A1, Canada; helenelaforge@hotmail.com
²Canadian Wildlife Service (Quebec Region), 1141 Route de l’Eglise, Ste-Foy, QC, G1V 4H5,
Canada
The Eastern North American population of Barrow’s goldeneye (Bucephala islandica) is legally
considered “at risk” by the Canadian and Quebec Governments. For six months a year, greater
than 50% of the population, estimated at no more than 4,500 birds, congregate along 300 kilometers
of coastline in the St. Lawrence Estuary, making it their major wintering ground. This important
concentration of individuals and its gregarious nature in winter make this population highly vulnerable
to any degradation of its coastal habitat. There is an important lack of knowledge regarding factors
that may control the species distribution (e.g. macro- and microhabitats, tide levels, ice cover, and
food preferences), as well as factors that may constrain survival of the population (e.g. energy content
of preys, short daylight, and cold weather) in the harsh winter conditions of this area. This poster
presents a first attempt to describe, at micro-scale, spatial and temporal segregation in foraging of
Barrow’s goldeneyes. These are the preliminary results of a multi-year study addressing winter habitat
selection, diet, and time-activity budgets of the Eastern North American population of Barrow’s
goldeneyes. Spatial and temporal segregation in foraging are compared from January to April 2005 for
two wintering sites, St-Irenee (47°34’ N; 70°12’ W) and Godbout (49°19’ N; 67°36’ W), in Quebec.
Flocks were positioned by in-site observation using laser binoculars. The polar coordinates (azimuth
and distance) of the birds from the observer’s location (recorded with a GPS receiver) were converted
by trigonometry in UTM coordinates and mapped with the help of a geographic information system.
Time budgets were simultaneously quantified, using both scan and focal sampling. Categories of
foraging intensity, based on a diving frequency index, were later derived and coupled with the birds’
locations. Preliminary results from our first year of study show dynamics of habitat use of wintering
Barrow’s goldeneyes in relation to foraging, tide oscillations, and period of day.
NOV. 7-11, 2005 ANNAPOLIS, MARYLAND, USA
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