Hybridisation in terns
Hybridisation in terns is not as frequent as in gulls; however, some mixed pairings have been noted.
Hybridisation between white-winged black tern and black tern has been recorded from Sweden and the Netherlands. Two juvenile birds at Chew Valley Lake, England, in September 1978 and September 1981, were also believed to be hybrids; they showed mixed characters of the two species, specifically a combination of a dark mantle (a feature of white-winged black) with dark patches on the breast-side (a feature of black tern, not shown by white-winged black).
- (in Swedish) Alexandersson, H. (1979) En hybridisering mellan vitvingad tärna Childonias leucopterus och svarttärna Childonias niger på Öland 1978 Calidris 8: 151-53
- (in Dutch) Van IJzendoorn, E. J. (1980) Broedgeval van Zwarte Childonias niger × Witvleugelstern C. leucopterus Dutch Birding 2: 62-65
- Vinicombe, Keith (1980) Tern showing mixed characters of Black Tern and White-winged Black Tern British Birds 73(5): 223-25
- Davis, A. H. (1980) Tern showing mixed characters of Black and White-winged Black Tern British Birds 75(12): 579-80