Saturday, September 19, 2009

Variable Wheatear (capistrata) and Mourning Wheatear

(Aloke Gupta's post at birds-chandigarh google group and telephonic affirmation by S.S. Poonia (the man who has made Tal Chhapar the hottest birding spot in the Thar) about the sighting of a Mourning Wheatear generated lot of discussions. However, the wheatear in question turned out tobe a Variable Wheater (capistrata). Krys puts to end to the confusion by his following comemnts:

"First of all I'd like to make the small point that in my field guide Oenanthe lugens is given in square brackets with status symbol X, clearly explained in the introductory section as indicating that the species is extralimital (has not occurred in the Indian Subcontinent). It was only included on the basis that it is a potential vagrant to Pakistan.

In order to be an acceptable new record for the Subcontinent, any sighting must be completely incontrovertible. I'm afraid, my diagnosis is that your bird is a male of the capistrata morph of Oenanthe picata. The rufous wash on the vent I feel is an artefact of the lighting and photography. If you examine the photo attached (originally sent by you) VS-TC(7)-060909-LR (one of the better shots), it shows no such rufous wash at all. The same bird in another shot on the same perch in VS-TC(8)-060909-LR appears to show a rufous wash on the vent, but if you look at this carefully, you will see that it is distinctly asymmetrical and caused by the lighting/shadow and a perhaps a photographic effect called fringing. You can see this fringing if you look at the broken part of the branch the bird is sitting on. The top side of the broken part has a reddish fringe, not actually there in nature, but an effect of fringing.

One of the main differences between lugens and capistrata is that the black bib of lugens is smaller and does not extend onto the upper breast. To show this I am including a composite photo with lugens on the left and capistrata on the right. The patern of your bird is clearly that of capistrat and not lugens.

The best confirmation would be to have a shot showing the spread wings. Lugens shows a prominent whitish panel on the open wing. A good photo of the spread tail would also confirm one way or the other since, although the basic tail pattern is similar, the black on the outer edges of the outer tail feathers on lugens is even with the other outer tail feathers, but on capistrata extends distinctly upwards.

I hope that closes this issue since I don't have time for further consideration of it.

Kind regards


--Krys Kazmierczak

OBI Editor