Movements of Common Tern (Sterna hirundo) Chicks from the Nest with Age

Abstract

Common Tern (Sterna hirundo) chicks are highly mobile, as they are semi-precocial. However, they generally stay in the territories near their nests until soon after fledging. In the salt marsh-breeding population in Barnegat Bay, New Jersey, USA, Common Tern chicks were recorded far from their nests before fledging. Movements from the nest were quantified at two islands in Barnegat Bay. For the first 1-3 days, chicks stayed very close to the nest. By 4 to 6 days of age, no chicks were within the nest cup, but they typically remained nearby, at a median distance of 0.45 m from the nest. From 1 to 3 weeks of age, median distance from the nest steadily increased from about 1 to 4 m. Among those chicks older than 3 weeks, the median distance away from the nest was 6.45 m, and none were found closer than 1.75 m. Common Tern chicks older than one week were usually not present in their territories, despite continuing to rely on their parents for care. The contrast between this and previous studies of the Common Tern may relate to habitat differences.