The Little Tern Sterna albifrons and Fairy Tern S. nereis are largely allopatric breeders, but the incidence of
breeding sympatry and hybridization appears to be increasing as the breeding range of the Fairy Tern expands
northward. During the summer of 1996-97, a mixed pair comprising a female Little Tern and a male Fairy Tern
nested on Towra Spit Island, Botany Bay. Species identification was confirmed by both plumage characteristics
and morphometric measurements. The mixed pair successfully hatched two young from a clutch of three eggs.
Hybridization may ultimately threaten the continued survival of one or both species.
