The breeding ecology of ruddy turnstones (Arenaria interpres) in the eastern Canadian Arctic

Abstract

In 2002 and 2003, studies were made of the breeding phenology, nesting success, nesting density, and rates of nest predation of ruddy turnstones (Arenaria interpres) at East Bay, Southampton Island, Nunavut, Canada. Previous data from East Bay were used to compare nesting chronology and nest success across years. Bird banding data were used to examine migration routes and rates of return. In all years, ruddy turnstones initiated nests within 7 days of arrival at the study area. The median date of incubation onset was the same in 2002 and 2003, despite different spring snow conditions. Snow remained later in the season in 2003 and the overall range of incubation onset was greater than in 2002. Ruddy turnstones at East Bay nested at high densities and in semi-colonial groups with a significantly aggregated distribution. In both years, nest success was low, predation was high, and lemmings were scarce. These data (and data from earlier East Bay studies) support the ‘alternative prey hypothesis’. Resighting rates of breeding adults between 2002 and 2003 were also low. Individuals banded at East Bay were resighted at Delaware Bay on the Atlantic coast of the United States, the Caribbean Islands, and in southern Brazil. This study increases our knowledge of this understudied species about which there is conservation concern.