We tested the hypothesis that regional spatial organization of Adélie, emperor, chinstrap and gentoo penguin colonies is dependent on proximity and size of adjacent colonies, availability of breeding habitat, and proximity of polynyas and submarine canyons. We tested previously the hypothesis that large colonies affect sizeof adjacent colonies of seabirds, before the availability of extensive biologging results to quantify colony foraging areas and when assessments of colony size was a compendium of historical counts. Results were problematic but interesting. The critical data sets, updated, are now available following 20 years of biologging and real-time satellite assessment of colony locations and sizes continent-wide. Indeed, except for emperor penguins, colonies occur in clusters. In general large colonies do not exist adjacent to one another, within a zone characteristic of the outer edge of the foraging area of large colonies. Foraging area increases with colony size. Therefore, inter-and intraspecific competition importantly affects geographic structure, as does access to polynyas and canyons among Antarctic penguins. Results are relevant to assessing effects of climate and other factors on penguin population trends, it being necessary to evaluate trends in entire colony clusters rather than individual colonies.
Speaker: David Ainley, Senior Ecologist 2, H. T. Harvey & Associates
Contact:Website: Click to Visit
Save this Event:iCalendar
Windows Live Calendar
Bay Conference Center, South Bay Room
Tiburon, CA 94920
Website: Click to Visit