A wizened-old, wise-looking bird wearing a monocle on its bill retrieves a dog-eared book from her study, flips through it, and consults a page that has a world map with coloured markings. Turning to an expectant flock from her species, she then tells them where to winter and where not to, with the exactitude of an algebraic equation.
When we go by dated field guides or any old information (there is a lot of it stubbornly floating around cyberspace) left untouched by fresh observations from the field, we believe in a scenario as absurd as the afore-illustrated.
Birds don't read field guides and they may extend their range disregarding printed information.
Here is an example relevant to our parts. For at least 15 years now, we know the Grey-headed lapwing has extended its wintering range, working Tamil Nadu, especially its coastal section, into its itinerary. The fact was brought to light by the journal Indian Birds as early as 12 years ago, in its November-December 2006 issue, based on field observations by ornithological heavyweights like V Shantaram.
Despite this, don't be surprised to see information that excludes Tamil Nadu from the Grey-headed lapwing's wintering range, come your way. Dated information has it that as far as India goes, grey-headed lapwings winter only in its northeastern section.
Incidentally, nearly 20 days ago, in December 2018, The Hindu reported photographic documentation by L Premjit, a member of Deccan Birders, on the sighting of a Grey-headed lapwing at the Kolleru lake, believed to be a first there.
This season, almost all the birders I have made small-bird talk with, have sighted the bird in different parts of Chennai, without any difficulty. Speaking for myself, besides the Perumbakkam wetland, I have sighted this winter visitor at a grassy bog in Akkarai, Sholinganallur.
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The “winter wardrobe” of certain species can be so similar to those of certain others, causing birdwatchers to peer harder into the field glasses, their brows wrinkled in concentration. Besides almost-similar winter plumage, there could be extraneous factors making identification a slightly longer process.
To illustrate, here’s an example from a section of the Pallikaranai Marsh found on Velachery Main Road, where I recently saw a Marsh sandpiper parked on what looked like an earthern-stony outgrowth in a small waterbody organically connected with the wetland.
In their winter finery, the Marsh sandpiper and the Common greenshank can look strikingly similar. One of the distinguishing factors is the supercilium, which is extended in the Marsh sandpiper, and is somewhat similar to that of the Wood sandpiper. Identification by supercilium can be tricky when the bird has wet it, while foraging for food in the waters. The Marsh sandpiper in question had a wet supercilium, but not so wet as to create any doubt.
Now, a cardinal fact about birdwatching — If one door to identification is closed, there will always be a couple of others that don't required to be knocked on. So, there were two other giveaways: The darker, thinner and finer bill and pale lores, features of the Marsh sandpiper distinguishing it from the Common greenshank (which has a thicker, lighter bill that is noticeably upturned, largely due to the curvature of the lower mandible).
Field Notes is a weekly column about the resident and winter-visiting birds of Chennai
