A Species In the Pink

Despite pressure from development, flamingos are thriving on the shores of one of India’s most populous cities, with a little help from its locals

By Vaishnavi Chandrashekhar Updated: Mar 20, 2023 15:48:04 IST
A Species In the Pink photo: surabhi agarwal

It is not yet 8:00 a.m., and the sun is already fierce on a small rowboat anchored a kilometer from the eastern banks of Thane Creek, an inlet separating the island city of Mumbai from the Indian mainland.

A yellow cloth flutters in the line of mangroves along the shore. Behind the trees, tall buildings shimmer in a haze of pollution; in front of them, thousands of flamingos are gathering, flying in from nearby roosting sites. As the sun ascends, the tidal water ebbs, exposing the mudflats that are the flamingos’ feeding grounds. 

The army of pink advances.

In a boat, Mrugank Prabhu unpacks his camera, sets up his telescope, and begins his count. Prabhu is a scientist with the Bombay Natural History Society (BNHS), which is leading an ambitious 10-year-long study to monitor a unique phenomenon. Every winter, thousands of greater and lesser flamingos fly into Mumbai, forming a sea of pink against a backdrop of skyscrapers, bridges and oil refineries along the 26-kilometer-long Thane Creek. The seasonal gathering is a source of wonder in Mumbai, and also a bit of a mystery.

The flamingos only began visiting Mumbai in significant numbers in the 1990s. As the city grew in the 1970s and ’80s, so did the volume of untreated sewage flowing into Thane Creek, nurturing the algae that are the flamingos’ main food, and turning the area into a feeding ground for the birds. Their numbers have increased in the past two decades, from at least 10,000 in 2007 to an estimated 1,30,000 this year.

flamingo-view_032023034756.jpgFlamingo numbers in Thane Creek have gone from 10,000 in 2007 to an estimated 1,30,000 this year.

The phenomenon illustrates the complexity of urban coastal ecosystems in India, say experts. Sometimes, “human impact results in conditions that seem terrible for nature at a glance, but are actually a gold mine for some species,” says Sunjoy Monga, a veteran local naturalist, who has also led a study on Mumbai wildlife. Now, the flamingos are reshaping the ecological mindset of the city too, showing what wildlife can do for conservation even in the most pressured environments.

Flamingos have become a source of pride for locals. In the past few years, citizens have been holding annual flamingo-themed festivals and runs to raise awareness of local wetlands. In 2018, authorities designated almost 1,700 hectares of the creek as a flamingo sanctuary. Yet threats to these remarkable birds remain, including a bridge that is under construction across the lower reaches of Thane Creek where the water spills into Mumbai Harbour. The BNHS study—the first of its duration in urban India, paid for by regional planning authorities—aims to keep a check on the impacts of development by monitoring the abundance and biology of the flamingos and the biochemical characteristics of the creek. Now at the halfway mark, the study is unearthing some surprises. Flamingos seem to be adapting to the bridge construction for the moment—they stay 500 metres or so from the site—but the same environmental shifts that helped draw the birds here in the first place are changing the mudflats in ways that could jeopardize their future.

Massive flocks of greater and lesser flamingos are often associated with the saline and alkaline lakes of Kenya and Tanzania. India has the largest population of lesser flamingos outside the African continent, mostly in the salt deserts of the western state of Gujarat—the species is considered ‘near threatened’ by the International Union for Conservation of Nature. There are few historical records of flamingos in Mumbai; one from 1891 suggests they were an occasional bird of passage.

Today’s flocks are thought to come largely from Gujarat’s breeding grounds, some 600 kilometers away. Six birds tagged with satellite trackers in March of this year migrated to that region after leaving Mumbai. Where else the birds might go will be revealed in the coming years, says Prabhu. In the meantime, thanks to leg-banding efforts by BNHS, scientists do know that some of the same birds come back to Mumbai year after year. It’s as if they have place memory, says Prabhu.

The place, in this case, is bordered by a 400-square-kilometer port and nuclear facility to the west and high-rises and another port to the east. In between, some nature manages to thrive: an estimated 65 species of migratory birds are found in the Thane Creek mudflats, which stretch for seven square kilometers, and another 100 bird species live in the surrounding mangrove stands.

To estimate flamingo abundance, Prabhu and his team sail out in their boats, using binoculars and telescopes to count birds along one-kilometer transects. At the creek’s mouth, which yawns to over several kilometers wide, the team members must row, each in their own boat, closer to shore just as the water is receding and the birds are arriving. This way, they can position themselves in the middle of the action and get a reliable count.


img_7770_032023033108.jpgBNHS scientists Mrugank Prabhu studying the Mumbai flamingos and their Thane Creek habitat. Photo: Vaishnavi Chandrashekhar

The birds feed relentlessly, stalking across the mudflats, beaks sweeping the ground, taking in the muddy water that will be parsed for food through their unique filtration systems. Greater flamingos feed on a variety of food including mussels, shrimp and cyanobacteria—also known as blue-green algae—but lesser flamingos mainly eat cyanobacteria. Vast quantities of this algae covers the Thane Creek mudflats, more than in other creeks around the state, says Reshma Pitale, a marine biologist who leads the BNHS team responsible for monitoring the water and soil along the creek.

It’s not just sewage-driven growth in food that’s helped attract flamingos, however. Looking at satellite images of the creek, Prabhu found that mud deposition, which created the vast mudflats that host the flamingos, started increasing dramatically in the 1980s. The deposition was probably due to construction debris and sewage from expanding urban development washing into the creek during the monsoon, he says.

Ironically, the mudflat habitat the flamingos depend on is now potentially threatened by excess mangrove growth, also fuelled by nutrients from the sewage. Because the mangroves cannot expand landward into the city, they are growing into the creek, says Prabhu. Satellite studies show mangroves are shrinking the width of the waterway and potentially encroaching into the mudflats. Mangroves are a vital shield against storm surge and also act as nurseries for fish; felling them was banned in the surrounding state of Maharashtra in 2018 after decades of legal battles to stem their destruction. The ban also means that authorities at the Thane Creek Flamingo Sanctuary must now get permission from the courts to remove new growth.

Coastal habitats are dynamic, influenced by both land and sea, says Pitale. Soils and biodiversity in Thane Creek change upstream to downstream, tide to tide, and season to season. And if pollution has been good for the flamingos, it has been lethal for fish. The diversity of fish in the creek has crashed since the 1980s, from 22 species recorded in the early 1990s to 12 species found in a 2000 survey. The decline is attributed to industrial pollution in earlier decades as well as the increased sewage and debris in more recent ones. Changes in the composition of mud may be changing the organisms on the mudflats, too. In the past two years, Pitale and her team have observed an explosion of alien bivalves on the mudflats. “Will this change the community? Will it outcompete other organisms?” says Pitale. “Anything can happen.”

On Earth Day, April 2022, a small group of upper–middle class residents meet on a trail along a dense patch of mangroves in Navi Mumbai, the town on the eastern banks at the mouth of Thane Creek. This and nearby mangroves and shallow ponds provide roosting sites for the flamingos when high tide covers the mudflats. The residents, members of Save Navi Mumbai Environment, a citizens’ network to protect local mangroves and wetlands, introduce themselves and describe their path to environmental activism. Many of them were first moved by the destruction of greenery in their own backyards; one professional, who brought his young son along, says he got involved after losing a local pond to a development project. Another man says he and his wife traveled to Lake Nakuru in Kenya to see flamingos some years ago, unaware of their presence in his own city. “What fools we were,” he says.


sunil-shruti-agarwal_032023033235.jpgSunil and Shruti Agarwal, co-founders of Save Navi Mumbai Environment. photos: courtesy of Sunil and Shruti Agarwal

After the meeting, Sunil and Shruti Agarwal, co-founders of Save Navi Mumbai Environment, take me up to their apartment, one of hundreds in the high-rises bordering the wetlands along the creek. From their 13th-floor balcony, you can see the mangroves that got them involved in environmental activism and, at high tide, the flamingos that brought others to their cause. Soon after the Agarwals moved here in 2013, they challenged the clearance of land for a new housing project and golf course on these wetlands. Neighbours told them they couldn’t win—the project was promoted by a subsidiary of the powerful Adani Group. But in 2018, the Bombay High Court stopped the development, giving the couple their first big victory. Since then, they’ve been fighting against other development projects in nearby wetlands and raising awareness about local biodiversity. They roped in their son and daughter and their friends to help organize neighbourhood festivals with games and activities for children, as well as an awareness-raising annual marathon called Run for Flamingos. At least 2,000 people participated in the event in 2020.

Authorities at the sanctuary, which is managed by the state forestry department, are also promoting tourism around the flamingos, hoping to educate the public about the birds and their habitat. Before the COVID-19 pandemic, a new marine education center and flamingo boat rides attracted some 17,000 visitors annually, including busloads of school students, says Virendra Tiwari, the senior forest officer who oversees the sanctuary. The ambitious management plan for the sanctuary includes increased security to prevent illegal construction, a big museum on the banks of the creek, and more boats for rides—but not so many that they would disturb the birds, says Tiwari. He is hoping that the sanctuary’s recent designation as a ‘wetland of importance’ under the international Ramsar Convention will also limit the destruction of ‘satellite wetlands’—the roosting sites that fall outside the 16.8-square-kilometer sanctuary but are identified in the Ramsar designation as part of a 48-square-kilometer buffer zone where ‘wise use’ is advised.


first-protest_032023033543.jpgChildren in Navi Mumbai participate in a rally for the local wetlands, 2017

The pandemic suspended many of the sanctuary’s activities, yet it increased flamingo fever. In the 2020 lockdown, residents of Navi Mumbai were stuck at home with nothing to do but look out their windows and see thousands of birds roosting at high tide. The flamingos made a particularly spectacular showing that year, arcing across suddenly clear skies, says Shruti. Photos and videos of the flamingos went viral, including on international media.

The flamingo is a useful totem for local ecology—but, as the Agarwals have found, it can also be reduced to an empty symbol. Late last year, the local municipality tagged Navi Mumbai as Flamingo City, putting up statues of the bird on streets and painting murals on walls. But local agencies haven’t put an end to development projects on wetlands. If the government saves the wetlands, says Shruti, “I’ll be the first to dress up as a flamingo and stand on the road.”

Out on the mudflats with Prabhu, the sun is overhead and the tide is rising. The flamingos are strutting back to the shoreline, slurping up food as they go. As the water streams in, so does the detritus of the city—packets of chips, beer bottles, medicine boxes, and the odd flip-flop. Prabhu packs up his scope and brings out the oar, ready to paddle against the strong pre-monsoon currents. His tally for the day: 15,000 flamingos in his transect alone. All around, flamingos are lifting off, stretching out like pink hockey sticks, to fly back to their roosts.

Mumbai’s flamingos are an accidental marvel, an inadvertent creation at the fragile intersection of the urban and natural worlds. Can the dynamic wetland habitat, with its competing human and ecological interests, sustain these birds in the years to come? The residents of this metropolis certainly hope so. For now, the flamingos offer a flash of unexpected beauty and hope amid grey skies.


First Published in Hakai magazine, 6 December 2022

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