The Indian skimmer is an odd bird with a strong underbite. The longer lower mandible is perfectly adapted to its style of fishing. It flies low over the water surface with its bright orange beak agape, the knife-like lower bill slicing the liquid. Any fish or shrimp too slow to dodge is snapped up. About 20% of the total population of fewer than 2,500 birds nest along river Chambal. Villagers here call it pancheraa, that which tears water.
When conservation biologist Parveen Shaikh arrived at the Chambal to study the species, villagers couldn’t believe she came all the way from Mumbai to observe these koel-sized black and white birds. They were even more astonished to learn she was being paid. They grumbled they had been watching these fowl all their lives with no such remuneration.
Nesting together
Studying the Indian skimmers’ nesting behaviour is no easy task. In late winter, they leave the coastal tidal flats of Gujarat and Sunderbans for the Chambal. In summer, the dropping river level exposes stretches of sand, where they prefer raising their offspring. The parents don’t go to any great trouble in making a nest to cushion their progeny. They scrape a shallow depression in the soft sand and lay three or four speckled eggs. Several birds nest together, creating nurseries. By then the air temperature often hits 45ºC. The adult pair feeds in the early mornings and late evenings and takes turns incubating the clutch. But in the afternoon, the ground is hot enough at 50-55ºC to bake the eggs. The embryos need cooling rather than more warmth.
An Indian skimmer at home on the waterbed. | Photo Credit: Dhairya Jhaveri
The proximity of the river comes in handy as the parents wet their bellies before squatting on their nests. Since evaporation rates are high, the birds hurry to the water’s edge every three to five minutes. For 25 days, they frantically continue to keep eggs, and then chicks, warm at night and cool during the day.
If Shaikh had to cope with the broiling heat as her subjects did, she would remain in the water. With no trees to provide shade from the sun and mugger crocodiles lurking in the river, she adjusted her timings. She ventured out, like the parent birds, at sunrise and late afternoon to scout for nesting sites, monitor the fate of the nests, count the number of incubation days, and tally how many chicks hatched and how many fledged.
Working in heat at full blast may sound gruelling, but she says raising funds for this work was even more difficult. The species’ lack of charisma and the region’s historical lawless reputation initially left donors unconvinced.
Canine threat
Being surrounded by water offers some security for the nests. But when the river level falls further, the islets become conjoined with the banks, creating bridges for dogs and cattle. Skimmers are not militantly protective of their offspring. They scramble to the air while screaming in alarm. This parental strategy does nothing to deter the canines from polishing off all the eggs and fluff-ball chicks on a sandbar within 10 to 15 minutes. The herbivorous livestock cause as much damage by trampling on the exposed nests.
The occasional black-bellied terns that nest along with the skimmers become missiles, swooping and striking any prowler. They didn’t spare the researcher, who waved a stick but wasn’t fast enough to fend off one attack that left her with a bruise on her scalp. This avian feistiness, however, cannot ward off determined animals.
During the first two years of her study, only 15% of skimmer eggs hatched. The riverine islands needed better protection. Shaikh experimented with fences and recruited villagers as guardians, increasing the hatching success to over 85%. The men chase any animals that blundered onto the sand spits. She plans to fence more colonies and employ more people. At least some residents are now paid to watch the birds.
Janaki Lenin is not a conservationista but many creatures share her home for reasons she is yet to discover.
Published - September 23, 2022 06:34 pm IST
