Dutch Birding volume 26 (2004) no 4

Melanistic Common Tern near Deventer in April 2001

In late April 2001, an unusually dark Common Tern Sterna hirundo was photographed among normally coloured Common Terns near Deventer, Overijssel, the Netherlands. Melanism in terns is rare and has only been recorded in Common Tern (including a similar bird in the Netherlands in June 1995) and Forster's Tern S forsteri. Melanistic Common Terns may be confused with White-cheeked Tern S repressa and Whiskered Tern Chlidonias hybrida but these have a grey rump and uppertail. Eastern Common Terns S h longipennis/tibetana are darker in plumage than European birds and show dark reddish-brown (S h tibetana) to all-dark bare parts (S h longipennis). The possible occurrence of such dark eastern birds in western Europe should not be excluded but may be hard to prove.

Edwin Winkel, Het Laar 217, 7414 BP Deventer, Nederland
(Leifmiecs.com)