We crept up to the small pond which you can see behind the trees in the photo above. There were about twenty birds in the water, a mixture of species. I took a few photos while we were still far away, just in case the birds noticed us and flew away. But the trees shielded us from view, so we could get in reasonably close and get a good view.
One of the common water birds which I would have liked to see is the common Greenshank (Tringa nebularia). It winters in India, China, and southwards, all the way to Australia as well as South Africa. In summer it moves far north, to Scotland, Norway and Siberia to breed. It used to be common in the waters around Mumbai, 
but I’ve not seen it for some time. The pond had something like it, but our guide peremptorily said "Marsh sandpiper". I’d not seen this closely related bird, Tringa stagnatilis, before. The Family had no opinion. I took a record shot (alongside) and moved on.
The fun started after we opened our field guides much later. It turned out that the two birds can be easily confused. Grimmett, Inskipp and Inskipp told us that the Marsh Sandpiper is "smaller and daintier" with "proportionately longer legs". The bit about the legs is repeated in the Wikipedia article. Since the bird had not moved at all while we watched, we had no idea about the length of its legs. What about the range? The greenshank is definitely found in Bhitarkanika National Park, whereas the Marsh Sandpiper is "known to be occasional, scarce or erratic". Could we decide by the fact that it was the middle of March? No, since the northward migration does begin in March (at least in Africa) but apparently continues up till the middle of May.
The only possible resolution came from The Family, who noticed that the greenshank has a slightly upturned beak, whereas this one seems to have a completely straight one (hard to see in the photo). We found a good online field guide, which made us look harder at the photo: the pale streak along the eye and the bright white underparts, both of which are characteristic of the Marsh Sandpiper. So perhaps it is that after all, and we have just added some weight to its "scarce" sighting in this region.
What do you think?
