According to the norms, buildings have to seek permission of the BMC to trim trees, which officials said had not been sought by the society. “The contractor trimmed a few branches of four tamarind trees. We are sending them a show cause notice to ascertain whether they had the necessary permission from the Tree Authority. We are also going through our records to verify if they had applied for permission. Generally, we avoid cutting branches that have bird nests, but there are no specific rules regarding this,” said YR Valunj, junior tree officer, H-West ward.

On Monday, around 80 hatchlings had died when the branches on which their nests lie were trimmed and several hundred eggs were seen lying on the ground, said Pooja Sakpal, co-founder of Youth Organization in Defense of Animals (YODA), who rescued the remaining hatchlings.

Residents of Nectar CHS at Bandra had hired a private contractor to trim several tree branches jutting into their compound from the adjacent Avabai Petit School at Pali Hil. Members of YODA were able to save 51 hatchlings and one egg, added Sakpal. The weak hatchlings, which include 49 Egrets, 2 herons and one egg currently under the care of Sakpal, need to be rehabilitated.

“We have informed the Thane forest division who said they would check for availability of cages for the hatchlings in Karnala. Another option is to keep these hatchlings with private fosters, after taking necessary permission from the Thane forest division. We have not received any confirmation from the forest department yet,” said Shakuntala Majumdar, president of Society for the Prevention of Cruelty to Animal, (SPCA), Thane unit.

“We are doing minor repair work on cages at Karnala and should be able to take the hatchlings within three to four days,” said VP Patil, Divisional Forest Officer (anti-poaching), Thane.