Thiruvananthapuram: A group of researchers are running out of options to save around seven Oriental darters which have nested in a raintree on Trivandrum zoo premises. Darters commonly known as snake birds have got their beaks entangled in plastic and cloth debris. Unable to eat or feed their chicks, the birds are starving themselves to death. Darters with their pointed bills and shiny bodies had made Trivandrum zoo their favoured nesting sanctuary for years.
This year, a dedicated research team including Vijayalakshmi PV Natural History Museum ( NHM) Superintendent, Akhila C K Intern TNHM, Dr Sujith V Gopalan Wildlife consultant and TNHM Curator Deepthi P N started studying the nesting biology of these birds which uncovered a disturbing sight. Surveillance cameras have been installed to document the activities of the birds.
The visuals showed darters, currently nesting in a raintree on the zoo premises, struggling with plastic debris around their beaks. " What is distressing is that seven of them are parents. Some of them can't feed themselves and cannot bring food for their chicks. In some cases one of the partners have been bringing food for the darter with plasic entangled beaks and for the chicks. We have had six chicks which died after their parents were unable to feed them because of this issue," said Vijayalakshmi PV .
Despite Thiruvananthapuram Zoo being a plastic-free zone, it appears the birds encountered these hazards while foraging elsewhere and birds may have sourced nesting materials from polluted areas, researchers said.
"We cannot dart the birds to save them, when we try to catch them to undo the tangle, they get scared and fly away. We even sought the help of fire force and one of our zoo-keepers also tried but we couldn't do anything," said Vijayalekshmi.
Every year, these near-threatened birds nest in the zoo before the onset of the monsoon and complete raising their chicks as the monsoon recedes. The zoo’s freshwater lake, surrounded by lush riparian vegetation and teeming with fish, offers an ideal and safe habitat for the Oriental Darters.
At present there are 11 nests and nine have been identified as incubating nests. There are two nests with chicks and 17 fledglings have been spotted.
Oriental Darters typically use fresh leaves for bedding, but the presence of plastic and cloth debris in their nests poses a severe threat to their survival. The mature males and fecund females were observed struggling to remove the tangles, with a very low success rate, the researchers pointed out.