Ideal ground:A river tern stands guard over its newly-hatched younglings.Special ArrangementSpecial Arrangement

Many may feel threatened by the rising water level in Hirakud Reservoir, but for birds, it is their shield. Hundreds of birds use the islands within the waterbody in Odisha’s Sambalpur district as a congenial nesting ground away from predators.

Tweets of winged species and their mass nesting liven up the unmanned and picturesque islands in the reservoir every year before they go under vast swathes of water during the monsoon.

Seven or eight islands in the reservoir host annual nesting of birds between March and June.

Birds usually scrape a hole in the ground to create nests where they can easily lay eggs and stand guard.

According to experts, eggs get sufficient heat if laid on ground and birds opt places near waterbodies for temperature regulation.

This has been observed in more than 13 species of birds in the Hirakud Wildlife Division.

River tern, little tern, little ringed plover, black winged stilt, oriental pratincoles, small pratincoles and red-wattled lapwing are the bird species that are observed to participate in ground nesting inside the Reservoir every year.

“These islands are safe for birds to nest. Predators such as dogs and other wild animals from nearby Debrigarh Sanctuary cannot go near islands due to vast water surface that surround the submerged hilltops. Only natural predation takes place. Sometime raptors pick up eggs,” said Anshu Pragyan Das, Divisional Forest Officer, Hirakud Wildlife Division, said.

An adaptation

It is not always easy to spot these eggs, as they look similar to the surface and remain camouflaged. “The biggest threat to eggs is the scorching heat during May and June. However, birds are smart enough to find shadow amidst grass vegetation and behind boulders to escape from searing heat,” said Bhubaneswar Patra, a Forest Ranger in Debrigarh Sanctuary and keen birdwatcher.

To divert the attention of predators from the eggs, birds quiver their wings to appear as an easy target; often, they perform injury-feigning acts, explained Mr. Patra, adding that these anti-predator behaviours keep the nests safe.

Ms. Das said, “On our parts, we have ensured that these islands remain inviolate. Fishermen and boaters are sensitised regularly.”

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