Effects of lake development on common loons (gavia immer) in southwest New Hampshire

Wohlfort, Kathleen A.
Jon Atwood, PhD
Department of Environmental Studies
Previous research indicates that natural features of a water body are more important predictors of loon occupancy than development (Caron and Robinson 1994; Christenson and Sherburne 1981; Heimberger et al. 1983; McIntyre 1975; Ruggles 1994; Smith 1981; Stockwell and Jacobs 1993). This study differs from previous studies by selecting 53 water bodies in southwest New Hampshire and examining various measures of human activity and shoreline development, as well as physical characteristics of the lakes themselves, as potential predictors of Common Loon presence and reproductive success. Then I applied the resulting statistical model to all lakes > 2 ha in area in southern New Hampshire to identify those sites most likely to be occupied by breeding loons. Of the 11 variables used to predict loon presence, Area: perimeter ratio was the only variable found to significantly affect the presence of adult loon pairs; area: perimeter ratio and other were found to significantly affect the presence of chicks. This study was 56% accurate in predicting pair presence and 83% accurate in predicting chick absence. I conducted this study to create a list that may predict loon occupancy and be useful for prioritizing future monitoring and management efforts in the region.

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