In the past four years, around 100 spot-billed pelicans have died in the Kokkarebellur Community Reserve, famous for bird sightings.
Spot-beaked pelicans will arrive to nest in the Kokkarebellur Community Reserve in Mandya’s Taluk Maddur in early October, but forest officials and birders are on edge due to the reported deaths of around 100 pelicans in the past four years . Although the root cause of pelicans’ death is yet to be determined, laboratory tests and studies are underway to find the source.
A few years ago, these birds arrived in December. Over the past couple of years, spot-beaked pelicans have started arriving in Kokkarebellur, famous for bird sightings, in late October. These birds typically start breeding from December and stay in the region until June / July with their offspring. However, the period from December to February / March is vulnerable for these birds as most of the deaths have been reported in these months. 59 died in the 2017-2018 season, 17 in the 2018-2019 season and 12 in the 2019-2020 season.
Aksheeta Mahapatra, a wildlife researcher at the Wildlife Institute of India, Dehradun, is working with the Karnataka Forest Department to investigate the cause of these deaths. He noted that lab tests and autopsy revealed that a roundworm infestation may have led to the death of the spot-billed pelicans. However, although these worms are commonly found in living things, they are usually not lethal.
Worm-infested spot-billed pelicans treated at Kokkarebellur
To this end, Aksheeta notes that nematode infestation is likely the secondary cause of deaths, while the primary cause of deaths is not yet known. “There is something else that is activating their immune system and making it weak and, as a result, the nematodes are multiplying. Infested birds are unable to eat and drink anything and die after falling from trees, “he said.
What has baffled forest officials and researchers is that spot beaked pelicans also nest in other parts of Karnataka, Andhra Pradesh, and Tamil Nadu, but the deaths have been centered in Kokkarebellur. Some deaths have also been reported in Kukkarahalli and Lingambudhi lakes in the city of Mysuru. At Kokkarebellur, herons, egrets, and painted storks are among other birds that share space with spot-billed pelicans, but deaths have only been reported in pelicans.
Contaminated water bodies in the vicinity of Kokkarebellur, particularly in the Shimsha River, a tributary of the Cauvery, which flows half a kilometer from the community reserve, are one of the causes of the pelicans’ death. Villagers claim that untreated wastewater from Maddur and Shivapura, as well as from nearby sugar factories, is also discharged into water bodies.
Untreated wastewater and industrial effluents have contaminated the Shimsa River
A forestry staff member explained that spot beaked pelicans swallow a certain amount of water while catching fish in water bodies. When contaminated water gets into their stomachs, they could get worm infestations. However, another staff member said that pelicans leave Kokkarebellur after July and only return in October, leading to the theory that the birds could contract the infestation elsewhere before coming to Kokkarebellur and succumb to the disease.
Ardent bird lover Linge Gowda, a familiar face in Kokkarebellur, has rescued hundreds of chicks that fall from nests due to sibling competition, strong winds, or other reasons. The chicks have been raised at the rescue center since 1994.
But Linge Gowda is now concerned about mass deaths around adult birds, something he hasn’t witnessed in his life. He is also concerned that the deaths have all occurred in the past four years.
The number of billed pelicans visiting Kokkarebellur has also decreased. A source that monitors bird numbers said previously around 500-600 bird pairs came to nest, but in the past two years only about 250 pairs have arrived for nesting. However, the number of painted storks has remained the same, with the reserve reporting around 1,000 pairs each year.
Linge Gowda pointed out that the number of trees that pelicans can nest has also decreased in recent years. It was one of the main reasons pelicans didn’t arrive in the number of years ago, he said.
Forest officials, however, remain confident and say the death toll from wildfire pelicans has dropped significantly over the past two years. They have also started planting saplings on the reserve.
Lokesh, a forest department staff member posted to Kokkarebellur, said two pelicans were rescued this year during the early stages of the infestation. After the treatment, they both recovered, one in January and the other in September. If the infection is detected early, it improves the chances of recovery, he said. Often this has not been the case because they only learn of a bird’s disease when it falls from trees, and by then it’s too late.
A spot beaked pelican rescued in Kokkarebellur after falling from a tree
Satish, a veterinarian who conducted the autopsy on pelican carcasses, said it is impossible to disinfect the water bodies in the surrounding villages as some of them are huge. He hoped that pelicans would naturally develop resistance to worm infestation.
Deputy Forest Conservator Mysuru Wildlife Division Alexander said, although preventative measures are low, the forest department is working to minimize deaths. Among the steps taken, Alexander explained, fish were added to nearby tanks so that pelicans can feed in the immediate vicinity and avoid contaminated water bodies.
Girisha is a freelancer who writes about wildlife and the environment.