Many may feel threatened by rising water level in Hirakud Reservoir, but for birds, it is their shield. Hundreds of birds use islands surrounded by water inside Hirakud Reservoir in Odisha’s Sambalpur district for congenial ground nesting away from predators.
Tweets of winged species and their mass nesting liven up unmanned and picturesque islands in Hirakud Reservoir every year before they go under vast swathes of water during monsoon.
Seven to eight islands in Hirakud Reservoir hosts annual nesting of birds between March and June, unafraid of predators those cannot access the islands.
Birds usually scrape ground to create nests where they can easily lay eggs and stand guard before chicks emerge from eggshells.
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 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 those are observed to participate in ground nesting inside Hirakud 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, (DFO - Hirakud wildlife division), said.
It is not always easy to spot eggs. The eggs look similar to surface that help camouflage and reduce chances of predation. “The biggest threat to eggs is scorching heat during the month of 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 a keen bird watcher.
Mr. Patra said, “to evade attention of predators from eggs, birds quiver their wings to appear as an easy target. Often they perform injury-feigning act. Such anti-predator behaviors in birds seek attention of enemy away from the nests, being protected by a parent.”
“The newborns of birds with ground nests are born with functional body parts and tiny wings. Even though they are quite adapted to the habitat by birth, yet the parents continue to protect and comfort the babies with moisture and also to un-hatched eggs,” he said.
The DFO Ms. Das said, “on our parts, we have ensured that these islands remain inviolate. Fishermen and boaters are sensitised regularly. Neither they go near the islands nor do they take others to there.”