Selection of lake habitats by waterbirds in the boreal transition zone of northeastern Alberta

Abstract

We examined habitat characteristics associated with presence or absence of 16 waterbird species on 113 lakes during 2001–2006. We found that piscivorous species such as pelicans, loons, and mergansers were found on fish-bearing lakes, while birds that typically nest in emergent vegetation (e.g., coots, grebes) strongly preferred water bodies with moderate to high levels of emergent macrophytes. The presence of a riparian buffer was important for loons and several species of waterbird that nest on the backshore. Moderate to deep lake depth and high water clarity also were important for some species and likely associated with hunting habits and (or) fish availability. Breeding-occurrence models were developed for a few conspicuous species that could be sampled using aerial surveys. Surprisingly, changes in water levels were not important predictors for most species, and associations between waterbirds and high levels of recreational activity were unexpected. Common Loon ( Gavia immer (Brunnich, 1764)) and Great Blue Heron ( Ardea herodias L., 1758) were most sensitive to anthropogenic activities, with fewer of these species detected on lakes with more disturbed shorelines.