Spot-billed pelicans. Photo: Srikaanth Sekar/Flickr, CC BY-SA 2.0
Cyclones Nivar and Burevi brought relief to migratory birds after a two-year lull post-cyclone Gaja in the southern Indian state of Tamil Nadu, which was finally able to clock a good count of the winged visitors in the 15 wildlife and bird sanctuaries, even as avian experts warn that research, conservation and monitoring of bird habitats in the state leaves a lot to be desired.
Nivar made landfall on the night of November 25, 2020, bringing heavy rains in several coastal and northern districts of Tamil Nadu, southern Andhra Pradesh and Puducherry along India’s south-east coast.
Conversations on cyclone Nivar are incomplete without its predecessor Gaja, which had killed several thousand birds and animals in 2018. S. Ramasubramaniam, Conservator of Forests, Thanjavur said that apart from the 200 trees that were uprooted in Sirkazhi range, Nivar hadn’t affected wildlife across Tiruvarur and Thanjavur in the state. Further, these habitats desperately need rain-filled cyclones to enable microorganisms, phytoplanktons, zooplankton, and fish to thrive and in turn for birds to feed on them.
On the other hand, 2019 saw a sharp decline in migratory birds but following Nivar, they resumed their visits to the sanctuaries in Udayamarthandapuram and Vaduvoor. The annual visitors including flamingos, pelicans, sandpipers, bar-headed geese, garganey, pin-tailed ducks, black-winged stilt, Northern shoveler, and gull-billed tern have begun to flock to the Point Calimere Wildlife and Bird Sanctuary, Nagapattinam.
Pal Pandian, a birdwatcher at Koonthankulam bird sanctuary near Tirunelveli said that rainfall was meagre and the peregrine falcon and red-necked falcon have been spotted. Unlike 2019, when 172 Amur falcons were spotted during this season, not a single bird of the species that is known to take a marathon flight from China to South Africa through India has visited the sanctuary during the same time frame in 2020.
Emergency bird habitats, that included temporary man-made structures such as nesting sites, were arranged ahead of Nivar at the Oussudu lake bird sanctuary situated between Pulicat and Point Calimere wetlands, said Range Officer Dharmalingam. The sanctuary, home to 166 species and declared as one of the 93 significant wetlands in Asia by the Asian Wetland Bureau, had recorded a major drop in the most common bird species in January, this year.
S. Balachandran, the resident ornithologist at Point Calimere and Deputy Director, Bombay Natural History Society, explained that high-velocity winds that accompany cyclones are detrimental to bird congregation sites and rain-filled ones usher dramatic changes. While Cyclone Nivar ushered neither damage nor relief, cyclone Burevi ensured 40 cm rainfall in just two days. “Unlike 30 years ago, now only cyclonic depressions result in good rains in the state due to global climate changes exacerbated by local conditions which have turned disastrous for migratory birds,” Balachandran said.
S.M. Abbas, Tamil Nadu’s chief wildlife warden, said that no perceptible impact had been seen and statewide assessment of damages or losses would be carried only when there are any reports.
More migratory birds at Vedanthangal
According to range officer G. Subbiah, the last week of December saw around 100 painted storks showing up at the country’s oldest bird sanctuary, Vedanthangal in Chengalpattu, marking the completion of the arrival season of migratory birds.
Compared to December 2019, when 12,000 migratory birds showed up, this year saw the count increase to 15,000. Usually, by the last week of September to October, the sanctuary starts buzzing with winged visitors beginning with open-billed storks but it wasn’t the case this year due to insufficient rain from the southwest monsoon.
While in 2016-17, around 5,000 pelicans were spotted at the sanctuary during September-December, the year 2020 saw that count dwindle to 2,500. Migratory birds like pintails, grey pelicans among others had flown away due to water paucity from the sanctuary during October and didn’t return till December even as there was a sharp decline in black and white ibis visitors.
The usual count of 5,000 spot-billed pelicans had decreased to 2,000 at Vedanthangal. Minimal rainfall in the last two years had hit hard, both Vedanthangal and Karikili bird sanctuary. The much-needed rains poured only during cyclone Nivar in November but by that time, the birds had left. Before roosting, breeding, and settling at a place, migratory birds survey the habitat, and only if they find it conducive, do they stay else they disperse. With low water level at Vedanthangal in the initial months of the migratory season, many birds including the spot-billed pelicans had instead descended on the Melmaruvathur lake, the range officer noted.
Chennai’s struggle to protect its migratory bird habitat
Pallikaranai marshland is one of the eleven wetlands in Tamil Nadu that fall on the Central Asian Flyway, a key migratory flight path. Located in the heart of the city, the biodiversity hotspot has been reduced to one-tenth of its original size with the construction of IT corridor, government institutions, residential complexes, encroachments, and garbage dumping.
K.V.R.K. Thirunaranan, founder of The Nature Trust, said that in spite of the never-ending obstacles, the winged visitors haven’t missed their date with the wetland, which saw 40,000 visitors from 182 species in January 2020, the highest in a decade. “Around 25 long-toed stint birds were spotted in this season compared to the usual one or two apart from 800 rosy starlings. The initial week of October saw the grey-headed lapwing from South Korea turn up unfailingly and also marked the first sighting of Eurasian cuckoo,” he said.
The marshland was visited by 12 Asian pied starlings this season, first spotted in 2019.
“Birds flocking to an area is a clear indication of it being biodiverse and secure. Conservation is to let nature be as human presence is the biggest disruption. Without Nivar, Chennai would have faced an immense water deficit. Let’s not blame cyclones for flooding when the root cause lies in a failure to restore lakes, unplanned homes, rising population along with an improper storm drainage system in the city,” he said.
The latest reports of dredging the marshland have left environmentalists worried. “There would have been no floods if Pallikaranai’s topography was retained. Dredging can have serious consequences on migratory birds,” said Balachandran.
“Since the city expanded, Pallikaranai has shrunk and numerous residential areas have sprung around it. The marshland proposal to develop infrastructure for flood mitigation in the southern parts of Chennai is not to dredge but only reduce the quantity of water that reaches the marshland from other areas through baby canals that will divert the water directly to the Buckingham Canal,” J. Meghanatha Reddy, Deputy Commissioner (Works), Chennai Corporation told Mongabay-India.
The Buckingham Canal runs through the core parts of the city and is the final outlet for many drains. Excess rainwater too flows from the roads to stormwater drains and into the canal, maintained by the Public Works Department. Though the canal, which connects three rivers (Kosasthalaiyar, Cooum, and Adyar) and flows the entire length of the city, was primarily constructed to be a freshwater navigation channel, it plays a crucial role in the flood mitigation scenario in the city.
More focus on building database on migratory birds
The Tamil Nadu Forest Department along with the Biodiversity Conservation Foundation conducted a synchronised bird census for the last three years, as part of which eight lakh birds from protected areas were assessed, the report of which will be released in December. Kumaraguru, conservation scientist and Honorary Wildlife Warden at Tiruvarur, Tamil Nadu Forest Department said that following every cyclone, the focus is solely on lack of electricity, waterlogging, and other utilitarian issues.
“The spotlight should as much be on our preparedness quotient, the impact on wildlife, natural ecosystem, and the overall role of human beings. Nagapattinam and Pattukottai districts had lost 50 percent of their green cover with Gaja and it would take a decade to make up for even half of it. In Vaduvoor bird sanctuary, the count had declined to 15,000 from 1.5 lakh right before Nivar. A day before the cyclone, more than 4000 birds of the painted stork, spoonbill, glossy ibis, and other species were spotted at a huge water tank in Viralimalai, Pudukottai district,” Kumaraguru said.
With the cyclone submerging the ground vegetation at the tank, the birds have again moved out. Inland wetland ecosystems like lakes and large public water tanks have turned temporary shelters and roosting sites, with the sudden surge in bird visitors from Vaduvoor like sanctuaries. “We lack records of birds that arrive before and after a cyclone at public tanks and pond ecosystems. We need to understand bird ecology, how and why they move for reasons apart from food or breeding, tolerance to environmental influences, tactics, breeding, and feeding ecology. There is a requirement for a strong database about local birds and their migration habits instead of reliance on sporadic eyewitness accounts,” he observed.
In-depth scientific application and management along with an effective tracking system of birds are missing. Regular, continuous monitoring, and study of cyclonic behaviour of birds must be undertaken. Above all, there is a severe crunch in funding for research, he said.
Disappearing species and ignored mudflats
Balachandran observed that several species from sand hoppers to vultures have disappeared over the years. “Point Calimere, a Ramsar site has extensive mudflats, yet many of them are not used by birds. Mudflats constitute an important ecosystem and attract shorebirds, among other species like crabs, which form the food base for these birds. Once degraded, mudflats are difficult to restore.”
An assured flow of funds to undertake multifaceted research on mudflats is lacking. There should be coordinated efforts at the global level as habitat degradation anywhere, affects birds everywhere.
“Deterioration in stopover zones, which are important for refueling, can limit the population of migratory birds on that flyway, similar to the decline in shorebirds which relied on the Yellow Sea. It was a surprise to learn that a cuckoo, which was monitored through satellite tagging by scientists could fly 7,500 miles from southern Africa to Mongolia. Unlike their counterparts abroad, Indian avian experts cannot track migratory birds across space by tagging them with transmitters as it is not allowed by the government citing national security. Only a few government organisations are allowed to do it but they lack the required expertise. Satellite mapping is crucial for bird conservation and identification of roadblocks in its migration route,” he said.
Puppet shows and vulture face masks: Coimbatore
Arulagam, a Coimbatore-based NGO has been holding puppet shows for villagers and art workshops on making vulture caps and face masks for school students in Nilgiris district and Sathyamangalam to discourage demonisation of the scavengers.
S.Bharathidasan, secretary of the NGO said that new concerns keep cropping up. Diclofenac, a drug which used to be prescribed for cattle diseases, was proven to affect the kidney of vultures and their population. “Drugs similar in composition to the banned diclofenac like Ketoprofen, Aceclofenac, Flunixin, and Nimesulide continue to be in use. Poisoning by cattle herders is another problem. The health department ensures that carcasses are buried without exception, leaving scavengers starved. With COVID-19, dead bodies are also sprayed with strong chemicals, the repercussions of which in vultures should be looked into,” he said.
KK Kaushal, Field Director, Mudumalai Tiger Reserve said that veterinarians are being educated about Diclofenac equivalent drugs and the plan for a captive breeding centre for vultures at the Sigur Reserve Forest Range has been approved.