Parent Recognition in Chicks of the Ground-Nesting, Nidifugous Saunders's GullSaundersilarus saundersi

Abstract

In birds, offspring-parent interactions play an essential role in facilitating offspring survival at nest-leaving. In contrast to nidicolous nestlings, nidifugous chicks are expected to hatch in ground nests, leave the nest soon after hatching, and presumably exhibit precise parent-offspring recognition during this time. Yet, some studies document variation in nidifugous behavior and offspring-parent recognition of semi-precocial chicks during the nest-leaving stage in the family Laridae. We examine patterns in nest-leaving age, mobile capacity, and parent recognition in wild and captive chicks of the Saunders's Gull Saundersilarus saundersi that is one of ground nesting and colonially breeding species. Our results indicated that the development of locomotor activity in nidifugous chicks coincided with the nest- leaving age. Soliciting behavior of experimental chicks increased with age, but they strongly discriminated vocalizations of pseudo-parents against unfamiliar adults only at the early stage of nest-leaving. We suggest that parent recognition by chicks during this short period may play a key role in facilitating their own survival while moving to a new environ- ment with their parents after leaving the nest. More studies using a comparative approach are needed to understand how nesting ecology, nest-leaving behavior, and parent-offspring interaction are interconnected in the members of the family Laridae.