asbostaff's picture

Leucistic Carrion Crow

Observed: 31st March 2010 By: asbostaffasbostaff’s reputation in Birdsasbostaff’s reputation in Birdsasbostaff’s reputation in Birds
Leucistic Crow
Leucistic Crow 2
Description:

Carrion Crow with white and grey wing feathers

Identifications
Species interactions

No interactions present.

Species with which Carrion Crow (Corvus corone) interacts

Comments

Norwichnaturalist's picture

Not Leucistic

Pied. Leucistic is a pale buff colour this is just pied, Common in Black birds. Crows are not entirly black either and can show grey in the primaries esp after moult

Colin Jacobs.
Wild Flower Society member
Norwich
Norfolk
vc27
http://www.thewildflowersociety.com/

RoyW's picture

Pied Crows are showing leucism!

Leucism is the effect of a problem with the deposition of pigments which results in abnormal pale, or white, colouration. This means that pied crows (and Blackbirds) are leucistic.
Normally Carrion Crows should be black, if they have grey or white patches in their wings after a moult it is due to a problem with the deposition of pigment (ie. leucism).

A summary about albinism/leucism can be found here;
http://www.birds.cornell.edu/pfw/AboutBirdsandFeeding/Albinism_Leucism.htm

asbostaff's picture

No leucistic

Thanks,BecclesNature. That hadn't occurred to me.

John O'D

Kluut's picture

Leucism/albinism

Leucism is actually the reduction or absence of all pigments, so the birds is partially leucistic, but as it has only melanin pigments, it is also albino (which does not mean entirely white, merely reduced melanin).

White feathers in crows is common and usually temporary - it is often due to dietary problems and/or stress. In years when spring is dry, young rooks, which are normally reared largely on earthworms and other soil invertebrates, commonly have white or grey flight feathers in particular.