Tuesday 20 January 2015

Mystery wader photo.

Recently on our facebook page we posted a photo of a bird feeding with half of its head and all of its bill underwater which we have reproduced here. Bills are very important in identifying waders and so making this bird's ID a little tricky. If you didn't see that post have a guess what this bird is before scrolling down.

Our mystery bird.

Of course straight away we were asked "Where was the picture taken?" This is the first question I always ask in these situations too as bird identification is all about narrowing the options if you don't automatically recognise the bird straight away. In this case that would have made life too easy. Lets look at some of the suggestions made; Curlew Sandpiper, Sharp-tailed Sandpiper, White-rumped Sandpiper, Baird's Sandpiper and Great Knot.

The slim shape of this bird and lack of flank markings can rule out Great Knot fairly quickly and its relative lack of breast-heavy stature would also seem to exclude Sharp-tailed Sandpiper. Curlew Sandpiper would be greyer and would not show the breast markings. So that would leave us with just two.

Sharp-tailed Sandpiper Calidris acuminata. Cairns esplanade, Queensland, Australia. 22/09/2013.
Note the heavy structure of this bird compared to the mystery bird.

With those long primaries it could be either White-rumped Sandpiper and Baird's Sandpiper. As suggested in the comments on the post, you would expect that a white-rump would be greyer. The same comment went on to add a note of caution, mentioning that the light can alter colours in photographs; however the observation about the colour is correct and the bird is indeed quite brown in real life.

Baird's Sandpiper Calidris bairdii (Left) and White-rumped Sandpiper Calidris fuscicollis. Laguna Verde, Tierra del Fuego, Chile. 06/11/2013. Note the slightly warmer tones of the Baird's compared to the White-rumped even in dull, overcast conditions. (This is most noticeable if you flick your eyes back and forth from the head and neck of one to the other quickly.)

With the combination of the warm tones, breast markings, lack of any dark flank markings and long pointed back-end we think it is possible to identify this bird as Baird's Sandpiper even without knowing where it was photographed which, just happens to be Laguna Chaxa, Antofagasta, Chile.

Our mystery bird is a Baird's Sandpiper Calidris baridii. Laguna Chaxa, Antofagasta, Chile. 31/10/2013

Well done to all those who thought this was a Baird's Sandpiper and thanks very much for making the effort and having the courage to have a stab at what was a tricky ID conundrum.

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