Colony guardian programme improves the recruitment of the critically endangered hooded grebe Podiceps gallardoi in Austral Patagonia, Argentina

Abstract

The critically endangered hooded grebe Podiceps gallardoi has suffered a population reduction of 80% in the last 25 years. Although climatic conditions have been mentioned as important causes of this decline, invasive species are also playing a main role. Hooded grebes have the lowest recruitment rate within the Podicepodiformes, but this is compensated by high adult survival. Considering these life history traits and threats, we designed the "colony guardian programme", which ed to protect nesting grebes. We describe the methods used to reduce the negative impacts of American mink and kelp gull on breeding colonies of grebes in central-western Santa Cruz Province, Argentina. Since the breeding season of 2011-2012, 10 colonies were protected using a total of 755 fieldwork days. Colonies guarded throughout the breeding season had higher recruitment (0.64 juveniles/breeding pair) than colonies with no or little protection (0.39 juveniles/breeding pair).