The so-called black-headed gull

A question readers often ask is about one of our increasingly common birds that seems badly named. These rather precocious gulls with bright red legs and bill are the so-called black-headed gulls.

However, as the picture shows, after the end of the breeding season the dark head-markings are lost entirely but for a small brownish patch; and this state lasts for several months. Then, during the breeding season, the black-headed gull sports a dark brown head.

Nevertheless, the name has stuck and we have a very confusing situation. Black-headed gulls were common before the widespread drainage of fenlands and sometimes nested in such large inland colonies that their eggs were harvested as food. With drainage and land ‘improvement’, their numbers declined but in recent times, populations increased once more.

Wetland nature reserves and similar habitat creation has produced extensive areas of suitable nesting and wintering sites. Throughout the winter months large numbers of these birds gather to loaf at afternoon ‘pre-roosts’ on the short grass of parks and playing fields. Then, towards late afternoon, they head off in small groups to roost overnight on open waterbodies such as reservoirs or nature reserve lakes.

Professor Ian D. Rotherham, researcher, writer and broadcaster on wildlife and environmental issues, is contactable on ianonthewildside@ukeconet.org; follow ‘Ian’s Walk on the Wildside’ blog, www.ukeconet.org for more information.