On the Grand Canal in Dublin this morning I noticed what seemed to be a black- headed gull in full summer plumage of chocolate brown head in a flock of winter plumage birds. Is this unusual? - Paul Bregazzi, Dublin.
For no apparent reason, a few adult black- headed gulls retain parts of their brown hood all winter. This is not an isolated phenomenon.
There are two magpie nests on two differ- ent trees about 10 metres off the ground in my back garden. Despite two major storms gusting 70mph, during which the trees bent and swayed 45 degrees off the perpendicular, both nests survived intact. Do magpies have some instinctive knowledge of architecture or nest construction to enable them to construct such durable nests? - Aidan A Larkin, NCR, Limerick
Yes, like all birds, they do.
Edited by Michael Viney, who welcomes observations sent to him at Thallabawn, Carrowniskey PO, Westport, Co Mayo. email: viney@anu.ie.