Hoodie / Carrion Crow hybrid identification

There is a link below to the paper  published in the Orkney Bird Report 2013. This is very much a work in progress and I am currently (time permitting) working to update and revise this paper.

(Sorry, problems getting the link to work, I'll try and remedy this later, however, illustrations for id are below)

Many thanks to everyone who has helped with this paper and the continuing work, and given advice, especially Julain Branscombe, Eric Meek, Stuart Sexton and Jim Williamson. Many thanks also to Morris Rendall for his excellent photographs. Thanks to Mollie Forsyth for technical help with the illustrations.

I am always happy to receive photographs of crows, please email me at badseawatcher at gmail.com if you have some interesting hybrid photographs or would like to comment on the views expressed here.

The illustrations below are from the paper, the illustrations give an idea of the range of plumage variation of hybrids. As stated in the paper I have categorised hybrid crows into seven broad types in order to draw attention to the difficulty observers may encounter in deciding on the identification of crows seen in the field. This is particularly relevant to extra-limital crows, Carrion Crows in the north and west of Scotland and in Ireland, and Hooded Crows in the remainder of Scotland and England. Records committees should be aware that the separation of Hooded Crow from potential hybrid crows is subtle and requires an excellent view, and preferably photographs to eliminate confusion with pale hybrid crows.

In Scotland hybrid crows are common in Orkney and Caithness and in the south-west on Arran. The hybrid swarm, the so-called hybrid zone, extends at least to Neath (photographs to be posted).

Carrion and Hooded Crow distribution in Europe. The hybrid zones are centred on the black line. (Haas and Brodin 2005)


Hooded Crow, Note especially grey undertail coverts, clean border at the nape, lack of black feathering on the body at the shoulders.

Grey hybrid crow. Note black feathers within the undertail coverts. This can be more subtle than the bird illustrated and can be difficult to see in the field, very careful observation is required. 

Grey hybrid, Scapa, Orkney (Alastair Forsyth)

Mid-grey Crow. Note the black on the back and the blurred border between grey and black on the nape. Often the grey plumage can appear darker due to the black in the centres of the feathers being more diffuse than the very fine black line on the feathers of pure Hooded Crow.

Mid-dark crow. This is what observers generally expect hybrids to look like.

Dark crow These can be quite subtle from Carrion Crow., however, Carrion Crow has grey bases to the body feathers so beware wind ruffled feathers.

Near black crow. Theses are very subtle from Carrion Crow, very careful observation is required, the grey feathers are typically found in the undertail coverts and on the belly and lower flanks.

Carrion Crow is not illustrated. Beware juvenile Carrion Crows in July and August, these can show quite a bit of grey feathering and are often claimed as hybrids.


Mid-dark hybrid crow (Morris Rendall)

I will post some more photographs later.




2 comments:

unclefish said...

http://www.nature.com/news/two-crows-kept-separate-by-their-looks-1.15436

Alastair said...

Martin,

Thank you. I have a very long paper which I still need to read which I think is on the same track, just a bit more long-winded. All references and additional info greatfully received. I am still, but very slowly, working on a new version of the paper, to update and improve it.