India is home to many unique ecosystems with varying climates. Cold regions, like those to the north, near the mighty Himalayas, and warm to hot regions in the west, centre, and southeast. Owing to lower temperatures and a paucity of food, the winter months see birds migrating in large numbers to the warmer regions of the subcontinent.
Wetland Migratory Birds
Pondicherry is not a place one would tend to associate with wetland birds. However unknown, the union territory that lies along the Bay of Bengal and bounded by the state of Tamil Nadu hosts some of the most beautiful migratory birds in the country. Every year, during December, local birders eagerly anticipate the arrival of these winter migrants. Ducks, waders, gulls, terns and harriers are plentiful, and for the following three months, these species call the wetlands of Pondicherry their home.
A great example of the incredible migrants that visit Pondicherry was the sighting of Eurasian Oystercatchers in 2022. With their bold pied plumage and long red bills, they spend their time scouting for oysters in the tidal zone. Commonly seen at Pulicat Lake, a wetland around 300km from Pondicherry, their presence in the region was a pleasant surprise. We found a small flock consisting of eight individuals. This was the very first record of the species for us, although there have been two or three different unofficial sightings.
While there is joy in sighting rare guests, there is equal happiness when coming across some of our repeat winter visitors. Brown-headed Gulls flock in thousands, as they fly down from their breeding ground in the trans-Himalayas and beyond. Mildly different from the Brown-headed Gulls, we also find Black-headed Gulls, but not of the same strength. Both species arrive in their non-breeding plumage, and the only distinction between these near-identical species is a white patch on their wingtip.
Wood Sandpipers and Common Sandpipers occupy the edges of every patch of water. One can often find Temminck's and Little Stints hiding amongst these commoners. The smaller shorebirds are often overshadowed by the larger godwits, redshanks, greenshanks, and Black-winged Stilts. The wintering stars, Greater Flamingos, flaunt their slender legs and pink outfits. This is also the time for resident species of Pondicherry’s wetlands to build nests. Cormorants, storks, and ibis decorate Prosopis trees as they prepare to raise their new generation.
While we watch these birds in the distance, the blaring sun creates a mirage, distorting the landscape. Meanwhile, a special wintering shorebird—the Ruff, roughs it out under the unforgiving heat, foraging at the perimeter of shrinking water bodies. Like the gulls, the visiting Ruffs are only seen in their non-breeding plumage. Two of the largest members of the shorebird family seen on the banks of wetlands here are the Whimbrel and Curlew, with the former outnumbering the latter. The largest flocks belong to the medium-sized Pacific Golden Plovers that sometimes reach a strength of several thousand.
Wetland migrants are fascinating for they fly in large numbers across borders. Instinct drives them from colder to warmer regions. Looking further out, one has a good chance of finding Bar-headed Geese, Knob-billed Ducks and Green-winged Teals. The rarity of the aforementioned birds in these parts lies in the brevity of their sightings. Contrastingly, ducks like Eurasian Widgeons, Northern Pintails, and shovelers gather in tens of thousands every year.
Forest Migratory Birds
We, nature lovers, when talking about migration, tend to think of only shorebirds, ducks and other waterfowl. We often forget that migration occurs in the forests as well. For the very same reasons, forest-dwelling species also travel to warmer climates. Migration can be vertical, where birds descend from higher altitudes to the foothills. It can also take birds across latitudes, bringing them to warmer areas near the equator.
We have been observing the migratory species that visit our coastal hometown of Pondicherry for nearly a decade. Earlier, limited to the Indian Pitta and Orange-headed Thrush and the occasional vagrant, the list has since grown substantially.
It is surprising how migratory species seamlessly blend into their new environments despite being absent most of the year. It is a phenomenon to ponder upon, where a stable ecosystem can accommodate a growing number of species in one particular niche. Most migratory birds that visit the Tropical Dry Evergreen Forests of Pondicherry are primarily insectivorous.
The pitta calls during the crepuscular hours of November signal the onset of migration. Indian Pitta is probably the first to occupy the undergrowth, followed closely by the Orange-headed Thrush. Their soft calls ring out from the canopy of emergent trees in these Tropical Dry Evergreen Forests. Next arrivals include the Indian Blue Robin and Blue-throated Flycatcher. Territorial and elusive, their melodies entrap each and every birder in the vicinity. While our eyes roam to spot the blue of the flycatcher and robin, a Slaty-legged Crake cautiously moves around in the leaf litter. Black Drongos occupy perches in and around open grassland or forest edges. Meanwhile, the visiting Ashy Drongos flit in the dense forest canopy, occasionally joined by a pair of Black-naped Monarchs.
There are two subspecies of the Orange-headed Thrush—Geokichla citrina citrina and Geokichla citrina cyanota. The former breeds in the Himalayan foothills and the latter in the Western Ghats. Surprisingly, it is G.c.citrina that is more numerous around Pondicherry, while the G.c.cyanota is rarely seen, despite being found closer to us. This may be because the climate near the Ghats stays warmer during winter than in the Himalayas, allowing the G.c.cyanota to stay put. The two subspecies are very distinct in appearance. G.c.citrina has a uniform orange head, and G.c.cyanota, sometimes referred to as the white-throated, has a white patch on the cheek and throat with two vertical black stripes running across the white of the cheek. Along with the regular visitors, there have been a few astonishing vagrants like the Tickell’s Thrush, Plum-headed Parakeet, Stork-billed Kingfisher and Green-Pigeons.
Not unlike in the forests, the variety of migrants in the wetlands have also increased at a steady pace. Although we dearly miss the migrants that don’t visit our shores and woods anymore, we eagerly look forward to new visitors in our little corner of the world.