Flamingoes become an accidental source of pride in Mumbai

Flamingoes become an accidental source of pride in Mumbai

This article was originally featured on Hakai Magazine, an online publication about science and society in coastal ecosystems. Read more stories like this at hakaimagazine.com.

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, used as a reference point by scientists, flies in the mangroves that run along the shore. The trees are surrounded by tall buildings that shimmer in a cloud of pollution. In front of them, thousands upon thousands of flamingos gather from nearby roosting areas. As the sun rises, the creek’s lower reaches become tidal, exposing the mudflats, which are the flamingos’ preferred feeding ground. The army of pink advances.

Mrugank Prabhu takes out his camera and sets up his telescope in the boat. He then begins his count.

Prabhu is a scientist with the Bombay Natural History Society (BNHS), a 139-year-old organization involved in conservation and biodiversity research across India, 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 for wonder and mystery in Mumbai.

Flamingoes become an accidental source of pride in Mumbai
Mrugank Prabhu, a scientist with the Bombay Natural History Society, leads a study monitoring lesser and greater flamingos around the Thane Creek wetlands on the shoreline of Mumbai, India. Photo by Vaishnavi Chaudrashekhar

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 130,000 this year.

This phenomenon illustrates the complexity and wealth of urban coastal ecosystems across India, according to experts. Sunjoy Monga, a veteran local naturalist who is a member of BNHS and has also conducted a study on Mumbai’s wildlife, says that sometimes “human impact results” in conditions that appear terrible for nature but are actually a goldmine for some species. “There is so much organic riches in the gloom [of city ].

Now the flamingos have reshaped the ecological mindset of the city. They are showing that wildlife can be conserved even in the most difficult environments. Locals are proud to have flamingos as a source of pride. Citizens have been organizing annual flamingo themed festivals and runs over the past few years to raise awareness about local wetlands. In 2018, authorities designated almost 1,700 hectares of the creek and shore as a flamingo sanctuary.

But threats to these magnificent birds still exist, including a bridge being built across Thane Creek’s lower reaches where water flows into Mumbai Harbour. The BNHS study, which is the first of its kind in urban India and was funded by regional planning authorities, aims to monitor the ecology and biology of the flamingos as well as the biochemical characteristics of this creek. The study is now at the halfway point and has some surprises. Flamingos seem to be adapting to the bridge construction for the moment–they stay 500 meters or so from the construction 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.

Large flocks of greater and smaller flamingos are often found in the saline and acidic lakes of Kenya and Tanzania. Greater flamingos can live in both saltwater and freshwater habitats. However, smaller flamingos prefer to live in saline water and are considered “near endangered” by the International Union for Conservation of Nature. India is home to the largest number of lesser flamingos, mainly in the western states of Gujarat and the salt deserts. There are few historical records of flamingos in Mumbai; one from 1891 suggests they were an occasional bird of passage in the region.

Today’s flocks are thought to come largely from breeding grounds in Gujarat, some 600 kilometers away. Six birds that were tagged with satellite trackers in March this year moved to the region from Mumbai. Prabhu says that scientists at BNHS will soon tag more flamingos. This will reveal where they might go in the future.

Flamingoes become an accidental source of pride in Mumbai
The wetlands along the edge of Mumbai, including the 26-kilometer-long Thane Creek, provide prime feeding habitat for lesser and greater flamingos. Photo by Rakesh Dareshwar/Alamy Stock Photo.

Scientists now know, thanks to the leg-banding efforts of BNHS that many of the same birds return to Mumbai year after year. Many more flamingos began to flock to this fecally bolstered food ground after some of them discovered it. Prabhu says it’s like they have a memory.

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.

Prabhu and eight other members of his team sail out in their boats to count flamingos along one-kilometer transects marked with colored flags attached to mangroves. The creek’s mouth is where the water yawns to several kilometers wide. Each member of the team must row closer to shore as the water recedes and the birds arrive. They can then position themselves in the middle, where they can count the birds. They are left there for hours, waiting in the middle of the action, until the next tidal period.

Up close, you can see that the flamingos don’t just look like one mass of pink. It’s April, and many of the smaller flamingos still have their gray-white coloring. Although the greater flamingos are more numerous worldwide, they are still smaller in number. It was a sound that sounded like a cacophony from afar, but it becomes individual calls that range between farting sounds and porcine oinks.

The birds feed relentlessly, following the mudflats with their beaks, sweeping the ground and taking in the muddy water. Greater flamingos consume a variety food, including shrimp, mussels, and cyanobacteria, also known as blue-green alga. However, smaller flamingos prefer cyanobacteria. Reshma Pitale (marine biologist) is responsible for monitoring the soil and water quality along Thane Creek mudflats. The flamingos arrive in November and the cyanobacterial density seems to increase.

Flamingoes become an accidental source of pride in Mumbai
A flock of lesser flamingos flies over the mudflats and mangroves on the Mumbai shoreline. An estimated 165 species use these habitats. Photo by Dinodia Photos/Alamy Stock Photo.

The trend makes sense to Pawan K. Dadheech, a professor of microbiology at the Central University of Rajasthan and coauthor of a 2016 international study on the food of the lesser flamingo. Lesser flamingos prefer a particular type of cyanobacteria called Arthrospira, or spirulina, which requires alkaline water, he says. If Arthrospira is abundant in Thane Creek, monsoon rains would dilute the creek water, reducing its alkalinity and thus the amount of these cyanobacteria, he says. Yet, when the rains stop in September and the temperature rises, he says, “conditions will be favorable for the production of [cyano]bacteria, and especially Arthrospira.” The BNHS team’s tests should throw more light on this theory in the coming year.

It’s not just sewage-driven food growth that has attracted flamingos. 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 change was corroborated by older fishermen, who recalled being able to walk along a sandy shore for a great length of the creek in the 1970s and ’80s. The sand is gone now, replaced by mud. Prabhu says that the mud deposition was likely due to construction debris and sewage from the monsoon.

Along Thane Creek other migratory wading bird may have increased, although a few years of data are needed to confirm the trends, says Prabhu. He says that small waders are fascinating because of their mystery origins and destinations. It is not known, for instance, where exactly the Arctic little stint–an annual visitor to the creek–came from. In June 2021, a curlew sandpiper, which breeds in Siberia, tagged here was spotted 4,500 kilometers away in Tianjin, China. In April, a common redshank that the BNHS team had banded in 2018 was spotted in Russia. Prabhu says that the Mumbai region is an important stop on Central Asian Flyway, which is a migratory route for avians between the Arctic Ocean and the Indian Oceans. Although this has likely always been the case, the study’s banding efforts–more than 15,000 birds have been tagged since 2018–should reveal more details about the birds’ migratory pathways.

Prabhu’s team will also be looking at the flamingos’ breeding grounds in Gujarat over the next year to determine if there are any factors that might be causing them to move to other areas. Is it possible that flamingos could be forced into Mumbai if their breeding habitat is disturbed? Prabhu believes that this is unlikely given Mumbai’s intense monsoon and urban pressures. He says that breeding is a different game than feeding. “Flamingos need a safe and quiet area with low disturbance and lots of mud to build their nests.” The salt deserts of Gujarat, due to its low rainfall and remote location, are a safer place for nesting.

In Mumbai, ironically, the mudflat habitat that flamingos rely on is now at risk from excessive mangrove growth, which is also fuelled by nutrients from the sewer. Prabhu says that mangroves are not able to expand into the city and are instead growing into the creek. Satellite studies have shown that mangroves are shrinking in width and could be encroaching on the mudflats. Mangroves are known to be a vital shield against storm surge and sea level rise 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 the Thane Creek Flamingo Sanctuary authorities must get permission from the courts in order to remove any new growth.

The complexity of coastal and urban ecosystems challenges traditional understandings of conservation–including the value of sweeping rules–and highlights the importance of the BNHS study, says K. S. Gopi Sundar, a scientist with Seva Mandir, an NGO in Udaipur, India. He says, “Urban ecosystems are not well understood in India.” He adds that conservation approaches have been often adopted from the West or from forest managers, which are not suitable for Indian conditions. For example, bird diversity in Indian urban areas is much higher than in temperate countries. “We cannot manage our wetlands using a textbook from Europe .”

Coastal habitats can be dynamic and are influenced by both land- and sea-based factors, says Pitale. Thane Creek’s soils and biodiversity change from upstream to downstream, tides to tides, and season to season. Pollution has been good for flamingos but deadly 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. Industrial pollution in the earlier decades and increased sewage and debris in recent years have both contributed to the decline. The organisms living on the mudflats may also be affected by changes in the composition and quantity of mud.

In the past two years, Pitale’s team has observed a mysterious explosion in the number of alien bivalves living on the mudflats. Pitale says, “Will it change the community? Will it outcompete other organisms?” “Anything could happen

On Earth Day, April 22, 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. These mangroves, as well as shallow ponds nearby, provide flamingo roosting areas when the mudflats are covered by high tide. Residents from Save Navi Mumbai Environment, a citizen network to protect local mangroves, and wetlands, introduce themselves, and then describe their journey to environmental activism. Many of them were moved by the destruction and destruction of greenery in their backyards. One professional brought along his young son to help after losing a local lake to a development project. Another man claims that he and his wife went to Lake Nakuru, Kenya, to see flamingos years ago. They were unaware of their presence in their own city. He said, “What fools were we,”

After the meeting, Sunil Agarwal and Shruti, cofounders Save Navi Mumbai Environment, took me up to their apartment. It is one of many high-rises that border the wetlands. 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. Neighbors said they couldn’t win because the project was being promoted by an Adani Group subsidiary. But in 2018, the Bombay High Court stopped the development, giving the couple their first big victory. They have been fighting against other developments in nearby wetlands and raising awareness of local biodiversity ever since. Their son and daughter recruited their friends to organize neighborhood festivals with activities and games for children and an annual marathon called Run for Flamingos. At least 2,000 people participated in the event in 2020. Surabhi, the daughter of the Agarwals, says that “nobody’s going running for wetlands.”

Flamingoes become an accidental source of pride in Mumbai
Shruti, left, and Sunil Agarwal, cofounders of Save Navi Mumbai Environment. Their apartment overlooks the mangroves, which are a magnet for migrating flamingos. Photo courtesy of Sunil and Shruti Agarwal

The state forestry department manages the sanctuary and promotes restricted tourism around flamingos. This is in an effort to educate the public about the birds’ 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. Tiwari says that the unit has an ambitious management plan that includes increased security to stop illegal construction, a large museum on the creek banks, and more boats for rides, but not too many that they disturb the birds. 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 much larger 48-square-kilometer buffer zone where only “wise use” is advised.

The pandemic caused many activities to be suspended at the sanctuary, but it also 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. Shruti says that the flamingos displayed a spectacular display in 2009, as they soared across suddenly clear skies. Photos and videos of the Flamingos were viral, even on international media.

The flamingo is an important symbol for local ecology, but, as the Agarwals discovered, it can also be used as a symbolic representation of insignificance. The local municipality designated Navi Mumbai Flamingo City late last year. They put up statues of Flamingo City on the streets and painted murals on the walls. However, local agencies have not stopped development of wetlands. Shruti says that if the government saves the wetlands, “I’ll be dressed up as a Flamingo and stand on road .”


Prabhu is out on the mudflats, the sun is shining and the tide is rising. The flamingos are returning to the shoreline and slurping food as they go. The city’s trash is also rushing in as the water flows in: packets of chips and beer bottles, medicine boxes, and even a flip-flop. Prabhu packs up his notes and gets out his oar ready to paddle against strong pre-monsoon currents. His tally for the day: 15,000 flamingos in his transect alone. Flamingos can be seen flying around the area, reaching out like pink hockey sticks to return to their nests. Their vibrant flight is almost unbelievable against the high-rises and haze. Mumbai’s flamingos, an accidental wonder at the fragile intersection between the natural and urban worlds, are a marvel. These birds will be able to survive in the future if the wetland habitat with its competing ecological and human interests can continue to support them. It is a hope that the residents of this metropolis have. The flamingos are a beacon of hope and beauty amid the gray skies.

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