You are here:
HABITAT CHARACTERISTICS ASSOCIATED WITH THE DISTRIBUTION AND ABUNDAANCE OF HISTRIONICUS HISTRIONICUS (HARLEQUIN DUCKS)WINTERING IN SOUTHERN NEW ENGLAND
Citation:
MCKINNEY, R. A., S. R. MCWILLIAMS, AND M. A. CHARPENTIER. HABITAT CHARACTERISTICS ASSOCIATED WITH THE DISTRIBUTION AND ABUNDAANCE OF HISTRIONICUS HISTRIONICUS (HARLEQUIN DUCKS)WINTERING IN SOUTHERN NEW ENGLAND. NORTHEASTERN NATURALIST. Humboldt Field Research Institute, Steuben, ME, 14(2):159-170, (2007).
Impact/Purpose:
We studied patterns of habitat use by Harlequins at 12 known wintering sites in southern New England that supported greater than 4 individuals.
Description:
Harlequin ducks that winter along the east coast of North America are listed as an endangered population in Canada, and they use several coastal wintering sites in southern New England, USA that are subject to varying degrees of urbanization. We studied patterns of habitat use by Harlequins at 12 known wintering sites in southern New England that supported greater than 4 individuals. An average of 327 114 Harlequins were found at the sites during the winters of 2001-2003. More Harlequins wintered at sites south of Cape Cod, Massachusetts that had greater mollusk (709,133 504,568 versus 97,154 72,427 kcal ha-1) and crustacean (27,907 16,312 versus 1,412 1,675 kcal ha-1) prey energy density, and a higher index of hunting activity (2.4 1.2 versus 1.4 0.5), than sites to the north. We identified habitat characteristics that best explained Harlequin distribution in southern New England using 1) an existing model that was developed for waterfowl in Narragansett Bay, RI, and 2) logistic regression analysis to compare habitat characteristics at 12 sites inhabited by Harlequin ducks and 12 nearby sites of similar geomorphology that did not support Harlequins. The existing model of habitat characteristics correctly predicted the presence of ducks at only 3 of the 12 inhabited sites. Logistic regression analysis identified 1) the proportion of residential, commercial, and industrial land use within a 100 m radius of the perimeter of the site, and 2) distance to the nearest harlequin duck wintering site as potentially affecting habitat use by Harlequins. Our findings suggest that urbanization may be affecting habitat use by east coast Harlequin ducks. However other factors, including those related to their extremely low population size, will need to be investigated before recommendations can be developed for the conservation of east coast Harlequins.
