Yellow-nosed moorhen at WWT in London

30/11/2010 18:08:05 Yellow-nosed moorhen and leucistic birds at London Wetland Centre

November 2010. A moorhen with an unusual beak has become a bit of a star at WWT London Wetland Centre.

The shiny yellow bill stands out like a beacon amidst the other moorhens that have made their home at this wildlife reserve in Barnes, south west London.

Staff at the WWT Centre are unsure why she has a pure yellow beak, rather than a red proboscis like ‘normal' moorhens. We're not sure what has caused her unusual facial colour said Idris Bhatti, Senior Grounds & Aviculture Supervisor. The shield on her face should be red so it's some sort of genetic mutation but we have no idea where she came from or what caused it. (ED note. Wildlife Extra suspects that the yellow bill has been caused by leucism, or even Xanthocroism, see text box below left.)

Leucism (or Leukism) Leucism is a very unusual condition where the pigmentation cells in an animal or bird fail to develop properly. This can result in unusual white patches appearing on the animal, or, more rarely, completely white creatures.  Albinism is a different condition. The easiest way to tell the difference between the two is that in albinism the eyes are usually pink or red, and albinism affects the entire animal, not just patches. This occassionaly causes very excited biologists to think they have discovered a new species, when in fact leucism is the cause of the unusual markings they have seen. Click here to see more leucistic birds and animals.  Xanthochroism Birds can show this condition in one of two ways: either there is an excess of yellow in the plumage or the yellow replaces another colour (in this instance the red). The condition has been reported in a number of species, including woodpeckers and in many instances the colour replaced is red. Photo credit M R Honey

Resident at WWT for 2 years
The yellow billed moorhen has lived at London Wetland Centre for a couple of years now. She is one of the more aggressive moorhens on the reserve, constantly chasing her larger, more placid cousins, pecking them and stealing their food. However she's very wary of humans and, unlike the other wild birds, doesn't come forward to eat when the wardens feed the Hawaiian Geese in whose pen she has taken up residence.

 

Moorhen sexes are difficult to tell apart but the wardens know the bird is female as she's given birth to chicks in the past two years, some of which have had the same pure yellow facial shield as their mother.

White coot seen at the  London WWT in 2009.

Leucistic coot and Greylag
Last year a white coot spent the winter on the reserve, and a very pale greylag goose appeared late in the winter of 2008. Unfortunately neither of these leucistic birds has returned to London Wetland Centre this year yet, but the wardens are keeping their eyes peeled.

Staff at London Wetland Centre are keen to hear from anyone who has also seen a moorhen with a yellow face, to see how far Daphne's offspring might have travelled. They would also like to hear from anyone who knows where the white coot and Greylag goose are spending the winter. Records of sightings preferably with a photo should be sent to editor (@) wildlifeextra.com.

White greylag at WWT London in 2008