The effect of siblings on nest site homing by Common Tern chicks: A benefit of kin recognition

Bg. Palestis et J. Burger, The effect of siblings on nest site homing by Common Tern chicks: A benefit of kin recognition, WATERBIRDS, 24(2), 2001, pp. 175-181
Citations number
Categorie Soggetti
Animal Sciences
Journal title
ISSN journal
1524-4695 → ACNP
Year of publication
175 - 181
SICI code
Studies of kin recognition in birds have rarely tested its adaptive value. We tested whether sibling recognition helps Common Tern (Sterna hirundo) ch icks find their nests. The ability to discriminate the natal nest from neig hboring nests is critical to survival in chicks of ground-nesting, colonial birds, such as the Common Tern. We temporarily moved 70 four-day old chick s 1 to from their nests and compared their ability to return home across th e following treatments: siblings in natal nest, no chicks in nest, siblings in neighboring nest, and non-siblings in test chick's nest. With a sibling in the natal nest, test chicks returned within 20 min in 14 of 20 trials. In all other treatments, fewer than half of the chicks returned. When chick s did return, they typically did so within 5 min. Several additional factor s may affect nest site homing, such as parental behavior, aggression by nei ghboring adults, and habitat type. To control for these factors, we restric ted the dataset for analysis to 27 nests by excluding chicks led back to th e nest by a parent, chicks attacked by neighboring adults, and nests on a r ocky beach (most experiments were performed in grassy habitat). In the rest ricted dataset, seven of nine chicks with siblings in the nest returned. Tw o of five returned in the empty nest treatment, none of six with siblings a t a neighboring nest returned, and one of seven with non-siblings in the ne st returned. There was significant variation among treatments in the final distance of test chicks from their nests. Siblings appeared to affect nest site honing, even though parents usually returned quickly to the nest and w ere least likely to search for displaced chicks if siblings were home. We a lso tested the ability of singletons to return to the nest, using air ident ical protocol. Singletons returned to the nest in only two of 14 trials, in none of the six cases when the dataset was restricted.