Influence of pool habitat characteristics on Red-throated Loon Gavia stellata occupancy and reproduction in a Boreal forest landscape

Abstract

We investigated the occupancy of alternative breeding pools for Red-throated Loon Gavia stellata and the reproductive output in relation to a selection of habitat characteristics in a coniferous forest inland area in South-central Sweden, using generalized linear mixed models. Models provided good support for the conclusion that small-sized pools with high coverage of floating vegetation were preferred. The survival of pre-fledged chicks was higher when foraging waters were located closer, and open mires around the breeding pool were more extensive. We propose that these habitat characteristics should be considered in nature conservation planning and management, as well as in environmental impact assessments. We found that with the current data, predicting pool occupancy and chick survival based on the selected habitat characteristics was not sufficiently accurate to replace field surveys and can only be used as a complementary method. We also emphasize the importance of freshwaters, potentially to be used for foraging in the surrounding landscape, which is an often-overlooked aspect in management and impact assessments.