Odd Mag­pie colours ex­plained

Bird Watching (UK) - - Your View -

We’ve re­ceived two queries about strangely coloured Mag­pies. From Steve Parker in Nuneaton comes a pic­ture of a very pale Mag­pie with brown ac­cents, while Jane Ham­bling has sent us a rather more colour­ful pic­ture from St David’s in Pem­brokeshire. Both ask how th­ese birds ac­quired their rather dif­fer­ent plumage. Pink Mag­pies, while un­usual, have been re­ported be­fore, in­clud­ing a nearly brick-red one in York­shire sev­eral years back. The usual ex­pla­na­tion is that the pink hue is caused by diet, in the same way that flamin­gos pick up their colour­ing from the food they eat. This col­oration is usu­ally caused by carotenoids trans­ferred to the feather dur­ing moult­ing. But this may not be the whole story. For a start, if this pink colour is diet-re­lated, it begs the ques­tion as to why the diet of the pink Mag­pie is so dif­fer­ent from any other lo­cal Mag­pies. Stud­ies of a yel­low and black Mag­pie in Scan­di­navia showed that the un­usual colour­ing was caused by the bird bathing in a pond con­taining an iron com­pound, and we’re of the opin­ion that this par­tic­u­lar bird (and the York­shire ones) has been ex­posed to some sort of chem­i­cal stain­ing. Or it be due to a ge­netic de­fect. We can be more cer­tain about the pale Mag­pie – this bird is clearly has a form of schhi­zochro­ism which is pre­vent­ing pig­ments such as me­lanin from be­ing de­posited in the feath­ers, which can lead to feather weak­ness.

Fe­male Kestrel Rook Male Kestrel Schizorchroic Mag­pie Pink Mag­pie

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