I would described the detail in Baird’s as looking like the profile of a person whose bottom lip protrudes slightly. Looking at many photos on the internet and in books, although this is not absolutely diagnostic in all individuals and the angle the bird is seen at can make a difference, it does seem to hold true in general. There is also a feature that I have not seen written anywhere, but looking at the base of the bill where the feathers end, on the lower mandible of Baird’s Sandpiper it seems to extend much further forward along the bill then on the upper mandible on White-rumped, although the lower feathering is further forward it is much less markedly so.
#White rumped sandpiper Patch#
If you can compare the two it is fairly obvious, but again a lone bird may not be so easy and there is some degree of individual variation, however you may find another useful feature often apparent on the bill of White-rumped Sandpiper, is a brownish patch at the base of the lower mandible. That of the Baird’s is straighter and finer than White-rumped’s with a narrower tip. Baird’s Sandpiper, Antofagasta, Chile – White-rumped Sandpiper Rio Grande do Sul, Brazil. Here the flank markings can be seen on the White-rumped Sandpiper (right) quite clearly whilst the Baird’s Sandpiper (left) has unmarked flanks. Although Baird’s will sometimes show one or two fine feather shaft-streaks high up on the rear of the flanks there is one on this bird. In Baird’s it will normally be clear white, whereas on White-rumped you will usually be able to detect some dusky streaks. So what do we look for? Well we often start with looking at the flanks of the bird. Baird’s Sandpiper, Antofagasta, Chile – White-rumped Sandpiper São Paulo, Brazil I has not moulted any of the coverts which it will keep until it moults again and it still retains one or two of the bright rufous scapulars from its attractive juvenile plumage. For interest the White-rumped Sandpiper is a juvenile bird moulting into its first non-breeding plumage. If they had been taken in the same light the difference could well be even less marked. Side by side you can see that the White-rumped Sandpiper on the right is greyer than the Baird’s on the left, but alone this difference is too subtle to detect easily and bear in mind that the Baird’s is in the clear Andean sunshine, while the White-rumped is on a beach in Brazil on an overcast day. Naturally we do not encourage anyone to flush a feeding or roosting bird to make it fly, but if your bird does fly or preen itself conveniently, as one did for us at Cley on the first day of Wader Quest back in 2012, then you will not find it hard to spot the white uppertail coverts on the White-rumped Sandpiper, or, if your bird is a Baird’s, that this feature is absent. So, we have seen the projecting wing tips so we know we have a Baird’s/White-rumped to deal with. Connecticut, USA Both photos Elis Simpson. The other bird is a Semipalmated Sandpiper in breeding plumage and its wingtips are more or less in line with the tail tip. The bird on the right is a White-rumped Sandpiper in breeding plumage and you can see that its wing tips are noticeably beyond the tail tip.
But if you look at the back end of the bird and flick your eyes from one to the other you can detect that the bird on the right looks so much more pointed attenuated they call it in the books.
Look how horribly similar these two birds are! If you look at the colour and pattern of the upperparts they are almost identical, the brown mask and brown cap also very similar.