Photo courtesy of apalca
Over the last four years, a white blackbird has taken up residence in a Nottinghamshire country park. There have been further reports of hundreds of blackbirds with strangely arranged white feathers seen in suburban gardens and parks around the country.
The birds in question are leucistic, a condition characterised by reduced pigmentation in animals and humans. The genetic mutation prevents pigments from being deposited as normal in the bird’s feathers. The condition differs from albinism as it is caused by a reduction in all types of skin pigment, not solely melanin and does not result in the individual’s eyes turning pink.
The all-white blackbird has been attracting bird watchers to a Nottinghamshire country park, taking up residence in the woodland of Rufford Abbey Country Park. Over the past few years, bird watchers have reported the individual losing its pigmented feathers, steadily replacing them with bright white plumage. During the summer of last year the blackbird was photographed with no black feathers at all.
Generally, leucistic and albinistic birds have a shorter lifespan than non-mutated individuals simply because they are more conspicuous and subsequently more vulnerable to predators in the wild. The park’s manager, John Clegg, has said the bird “has become quite a character at the park in recent years” and is urging birdwatchers to keep an eye out for this particularly unusual all-white specimen.
It is not uncommon that other species with all-black, or mostly black, plumage have some white feathers, with reports of 49 carrion and 40 jackdaw showing some degree of leucism. Bird colouring is important and can have a direct impact on the individual’s mating success, said Dr Tim Harrison of the BTO Garden Ecology Team. Dr Harrison commented on a report of a white breasted robin which seemed to have a shy temperament, “birds often communicate with each other using their feathers” and the robin’s characteristic red breast is “important in territorial disputes”.
The first national survey of birds with unusual colouring began after people sent in reports of unusual looking birds in their gardens. “The diversity of species recorded through the survey is impressive, ranging from common garden birds, such as house sparrow and chaffinch, to less frequent visitors, such as an all-white buzzard in Aberdeenshire and a leucistic coot in Norfolk” Dr Harrison said.
By Lucas Lowe