This text was initially featured on Hakai Journal, a web-based publication about science and society in coastal ecosystems. Learn extra tales like this at hakaimagazine.com.
It isn’t but 8:00 a.m., and the solar is already fierce on a small rowboat anchored a kilometer from the jap banks of Thane Creek, an inlet separating the island metropolis of Mumbai from the Indian mainland. A yellow material used as a reference level for scientists flutters within the line of mangroves alongside the shore. Behind the bushes, tall buildings shimmer in a haze of air pollution; in entrance of them, 1000’s of flamingos are gathering, flying in from close by roosting websites. Because the solar ascends, the tidal water within the creek’s decrease reaches ebbs, exposing the mudflats which can be the flamingos’ feeding grounds. The military of pink advances.
Within the boat, Mrugank Prabhu unpacks his digicam, units up his telescope, and begins his depend.
Prabhu is a scientist with the Bombay Pure Historical past Society (BNHS), a 139-year-old group concerned in conservation and biodiversity analysis throughout India, which is main an bold 10-year-long research to watch a novel phenomenon. Each winter, 1000’s of higher and lesser flamingos fly into Mumbai, forming a sea of pink in opposition to a backdrop of skyscrapers, bridges, and oil refineries alongside the 26-kilometer-long Thane Creek. The seasonal gathering is a supply of marvel in Mumbai, and likewise a little bit of a thriller.

The flamingos solely started visiting Mumbai in vital numbers within the Nineties. As the town grew within the Nineteen Seventies and ’80s, so did the quantity of untreated sewage flowing into Thane Creek, nurturing the algae which can be the flamingos’ foremost meals and turning the world right into a feeding floor for the birds. Their numbers have elevated up to now 20 years, from a minimum of 10,000 in 2007 to an estimated 130,000 this 12 months.
The phenomenon illustrates the wealth and complexity of city coastal ecosystems in India, say specialists. Typically, “human impression ends in situations that appear horrible for nature at a look, however are literally a gold mine for some species,” says Sunjoy Monga, a veteran native naturalist and BNHS member who has additionally led a research on Mumbai wildlife. “There may be a lot natural richness amid the gloom [of the city].”
Now, the flamingos are reshaping the ecological mindset of the town, too, exhibiting what wildlife can do for conservation even in essentially the most pressured environments. Flamingos have grow to be a supply of delight for locals. Prior to now few years, residents have been holding annual flamingo-themed festivals and runs to lift consciousness of native wetlands. In 2018, authorities designated nearly 1,700 hectares of the creek and shore as a flamingo sanctuary.
But threats to those exceptional birds stay, together with a bridge that’s below building throughout the decrease reaches of Thane Creek the place the water spills into Mumbai Harbour. The BNHS research—the primary of its length in city India, paid for by regional planning authorities—goals to maintain a verify on the impacts of the bridge building and different developments by monitoring the abundance and biology of the flamingos and the biochemical traits of the creek. Now on the midway mark, the research is unearthing some surprises. Flamingos appear to be adapting to the bridge building for the second—they keep 500 meters or so from the development web site—however the identical environmental shifts that helped draw the birds right here within the first place are altering the mudflats in ways in which may jeopardize their future.
Huge flocks of higher and lesser flamingos are sometimes related to the saline and alkaline lakes of Kenya and Tanzania. Whereas higher flamingos can inhabit each saltwater and freshwater habitats, lesser flamingos are present in saline waters, and the species is taken into account “close to threatened” by the Worldwide Union for Conservation of Nature. India has the most important inhabitants of lesser flamingos exterior the African continent, principally within the salt deserts of the western state of Gujarat. There are few historic data of flamingos in Mumbai; one from 1891 suggests they have been an occasional chook of passage within the area.
Immediately’s flocks are thought to come back largely from breeding grounds in Gujarat, some 600 kilometers away. Six birds tagged with satellite tv for pc trackers in March of this 12 months migrated to that area after leaving Mumbai. The place else the birds may go will probably be revealed as BNHS scientists tag extra flamingos within the coming years, says Prabhu.

Within the meantime, due to leg-banding efforts by BNHS, scientists do know that a number of the identical birds come again to Mumbai 12 months after 12 months. After some flamingos found this fecally bolstered feeding floor, many extra started coming. It’s as if they’ve place reminiscence, says Prabhu.
The place, on this case, is bordered by a 400-square-kilometer port and nuclear facility to the west and high-rises and one other port to the east. In between, some nature manages to thrive: an estimated 65 species of migratory birds are discovered within the Thane Creek mudflats, which stretch for seven sq. kilometers, and one other 100 chook species stay within the surrounding mangrove stands.
To estimate flamingo abundance, Prabhu and his crew of eight sail out of their boats, utilizing binoculars and telescopes to depend birds alongside one-kilometer transects marked by coloured flags tied to the mangroves. On the creek’s mouth, the place it yawns to over a number of kilometers large, the crew members should row, every in their very own rowboat, nearer to shore simply because the water is receding and the birds are arriving. This fashion, they will place themselves in the midst of the motion, the place they will get a dependable depend. They wait there, marooned, for hours till the subsequent tidal cycle.
Up shut, the flamingos are not one mass of pink. It’s April and lots of the lesser flamingos are younger and nonetheless gray-white; they haven’t obtained their pink hue but. The higher flamingos tower over the lesser, and though extra plentiful globally, are clearly fewer in quantity. What gave the impression of a cacophony of horns from a distance distills into particular person calls that vary from farting sounds to porcine oinks.
The birds feed relentlessly, stalking throughout the mudflats, beaks sweeping the bottom, taking within the muddy water that will probably be parsed for meals via their distinctive filtration methods. Better flamingos feed on quite a lot of meals together with mussels, shrimp, and cyanobacteria—also called blue-green algae—however lesser flamingos primarily eat cyanobacteria. Huge portions of those cyanobacteria cowl the Thane Creek mudflats, greater than in different creeks across the state, says Reshma Pitale, a marine biologist who leads the BNHS crew liable for monitoring the water and soil alongside the creek. Cyanobacterial density additionally appears to extend after November, on the identical time the flamingos begin arriving.

The pattern is smart to Pawan Ok. Dadheech, a professor of microbiology on the Central College of Rajasthan and coauthor of a 2016 worldwide research on the meals of the lesser flamingo. Lesser flamingos want a selected sort of cyanobacteria referred to as Arthrospira, or spirulina, which requires alkaline water, he says. If Arthrospira is plentiful in Thane Creek, monsoon rains would dilute the creek water, lowering its alkalinity and thus the quantity of those cyanobacteria, he says. But, when the rains cease in September and the temperature rises, he says, “situations will probably be favorable for the manufacturing of [cyano]micro organism, and particularly Arthrospira.” The BNHS crew’s assessments ought to throw extra gentle on this principle within the coming 12 months.
It’s not simply sewage-driven progress in meals that’s helped appeal to flamingos to this space, nevertheless. satellite tv for pc pictures of the creek, Prabhu discovered that mud deposition, which created the huge mudflats that host the flamingos, began rising dramatically within the Nineteen Eighties. The change was corroborated by older fishermen, who recalled with the ability to stroll alongside a sandy shore for an important size of the creek within the Nineteen Seventies and ’80s. The sand is gone now, changed by mud. The mud deposition was most likely attributable to building particles and sewage from increasing city improvement on the jap banks washing into the creek in the course of the monsoon, says Prabhu.
Alongside Thane Creek, different migratory wading birds can also have elevated, though a couple of extra years of knowledge is required to confirm the traits, says Prabhu. Small waders are attention-grabbing, he provides, as a result of their origin or vacation spot is commonly a thriller. It’s unknown, for instance, the place exactly within the Arctic the little stint—an annual customer on the creek—comes from. In June 2021, a curlew sandpiper, which breeds in Siberia, tagged right here was noticed 4,500 kilometers away in Tianjin, China. In April, a typical redshank that the BNHS crew had banded in 2018 was noticed in Russia. The Mumbai area seems to be an necessary cease on the Central Asian Flyway, a migratory avian route between the Arctic and Indian Oceans, says Prabhu. Though this has possible all the time been the case, the research’s banding efforts—greater than 15,000 birds have been tagged since 2018—ought to reveal extra particulars concerning the birds’ migratory pathways.
Prabhu and his crew may also be learning the flamingos’ breeding grounds in Gujarat within the coming 12 months to search out out if any components are pushing them to hunt meals elsewhere. If there’s a disturbance within the breeding habitat, is it attainable that flamingos compelled into Mumbai may finally grow to be year-round residents within the metropolis slightly than seasonal ones? That’s unlikely, suggests Prabhu, given the town’s intense monsoon and the pressures of a busy city setting. “Breeding is a special ball recreation [than feeding],” he says. “[Flamingos] want a safe and secluded space with low disturbance, and many mud to construct their mounds for nests.” With its low rainfall and distant location, the salt deserts of Gujarat present a safer house for nesting.
In Mumbai, satirically, the mudflat habitat the flamingos depend upon is now doubtlessly threatened by extra mangrove progress, additionally fueled by vitamins from the sewage. As a result of the mangroves can not broaden landward into the town, they’re rising into the creek, says Prabhu. Satellite tv for pc research present mangroves are shrinking the width of the waterway and doubtlessly encroaching into the mudflats. Mangroves are recognized to be a significant protect in opposition to storm surge and sea degree rise and likewise act as nurseries for fish; felling them was banned within the surrounding state of Maharashtra in 2018 after many years of authorized battles to stem their destruction. However the ban additionally signifies that authorities on the Thane Creek Flamingo Sanctuary should now get permission from the courts to take away new progress.
The complexity of coastal and concrete ecosystems challenges conventional understandings of conservation—together with the worth of sweeping guidelines—and highlights the significance of the BNHS research, says Ok. S. Gopi Sundar, a scientist with Seva Mandir, an NGO in Udaipur, India. “City ecosystems in India are … not nicely understood,” he says. Conservation approaches have typically been adopted from the West or from forest administration, the place situations are totally different, he provides. Chook range in Indian city areas is commonly a lot larger than that in temperate nations, as an example. “We are able to’t handle our wetlands with a textbook from Europe.”
Coastal habitats are dynamic, influenced by each land and sea, provides Pitale. Soils and biodiversity in Thane Creek change upstream to downstream, tide to tide, and season to season. And if air pollution has been good for the flamingos, it has been deadly for fish. The range of fish within the creek has crashed because the Nineteen Eighties, from 22 species recorded within the early Nineties to 12 species present in a 2000 survey. The decline has been attributed to industrial air pollution in earlier many years in addition to the elevated sewage and particles in newer ones. Modifications within the amount and composition of mud could also be altering the organisms on the mudflats, too.
Prior to now two years, Pitale and her crew have noticed a mysterious explosion of alien bivalves on the mudflats. “Will this transformation the group, will it outcompete different organisms?” says Pitale. “Something can occur.”
On Earth Day, April 22, a small group of higher–center class residents meet on a path alongside a dense patch of mangroves in Navi Mumbai, the city on the jap banks on the mouth of Thane Creek. This and close by mangroves and shallow ponds present roosting websites for the flamingos when excessive tide covers the mudflats. The residents, members of Save Navi Mumbai Surroundings, a residents’ community to guard native mangroves and wetlands, introduce themselves and describe their path to environmental activism. Lots of them have been first moved by the destruction of greenery in their very own backyards; one skilled, who introduced his younger son alongside, says he obtained concerned after shedding an area pond to a improvement challenge. One other man says he and his spouse traveled to Lake Nakuru in Kenya to see flamingos some years in the past, unaware of their presence in his personal metropolis. “What fools we have been,” he says.
After the assembly, Sunil and Shruti Agarwal, cofounders of Save Navi Mumbai Surroundings, take me as much as their house, certainly one of a whole lot within the high-rises bordering the wetlands alongside the creek. From their Thirteenth-floor balcony, you may see the mangroves that obtained them concerned in environmental activism and, at excessive tide, the flamingos that introduced others to their trigger.
Quickly after the Agarwals moved right here in 2013, they challenged the clearance of land for a brand new housing challenge and golf course on these wetlands. Neighbors advised them they couldn’t win—the challenge was promoted by a subsidiary of the highly effective Adani Group. However in 2018, the Bombay Excessive Courtroom stopped the event, giving the couple their first huge victory. Since then, they’ve been preventing in opposition to different improvement tasks in close by wetlands and elevating consciousness about native biodiversity. They roped of their son and daughter and their associates to assist manage neighborhood festivals with video games and actions for kids, in addition to an awareness-raising annual marathon referred to as Run for Flamingos. At the very least 2,000 folks participated within the occasion in 2020. “No one’s going to run for wetlands,” says the Agarwals’ daughter, Surabhi.

Authorities on the sanctuary, which is managed by the state forestry division, are additionally selling restricted tourism across the flamingos, hoping to coach the general public concerning the birds and their habitat. Earlier than the COVID-19 pandemic, a brand new marine schooling heart and flamingo boat rides attracted some 17,000 guests yearly, together with busloads of college college students, says Virendra Tiwari, the senior forest officer who oversees the sanctuary. The unit has an bold administration plan for the sanctuary that features elevated safety to stop unlawful building, a giant museum on the banks of the creek, and extra boats for rides—however not so many who they might disturb the birds, says Tiwari. He’s hoping that the sanctuary’s latest designation as a “wetland of significance” below the worldwide Ramsar Conference may also restrict the destruction of “satellite tv for pc wetlands”—the roosting websites that fall exterior the 16.8-square-kilometer sanctuary however are recognized within the Ramsar designation as a part of a a lot bigger 48-square-kilometer buffer zone the place solely “smart use” is suggested.
The pandemic suspended lots of the sanctuary’s actions, but it elevated flamingo fever. Within the 2020 lockdown, residents of Navi Mumbai have been caught at residence with nothing to do however look out their home windows and see 1000’s of birds roosting at excessive tide. The flamingos made a very spectacular exhibiting that 12 months, arcing throughout all of a sudden clear skies, says Shruti. Photographs and movies of the flamingos went viral, together with on worldwide media.
The flamingo is a helpful totem for native ecology—however, because the Agarwals have discovered, it can be lowered to an empty image. Late final 12 months, the native municipality tagged Navi Mumbai as Flamingo Metropolis, placing up statues of the chook on streets and portray murals on partitions. However native businesses haven’t put an finish to improvement tasks on wetlands. If the federal government saves the wetlands, says Shruti, “I’ll be the primary to decorate up as a flamingo and stand on the street.”
Out on the mudflats with Prabhu, the solar is overhead and the tide is rising. The flamingos are strutting again to the shoreline, slurping up meals as they go. Because the water streams in, so does the detritus of the town—packets of chips, beer bottles, drugs containers, and the odd flip-flop. Prabhu makes his final notes, packs up his scope, and brings out the oar, able to paddle in opposition to the sturdy pre-monsoon currents. His tally for the day: 15,000 flamingos in his transect alone. Throughout, flamingos are lifting off, stretching out like pink hockey sticks, to fly again to their roosts. Their vivid flight is sort of fantastical in opposition to the haze and high-rises. Mumbai’s flamingos are an unintentional marvel, an inadvertent creation on the fragile intersection of the city and pure worlds. Can the dynamic wetland habitat, with its competing human and ecological pursuits, maintain these birds within the years to come back? The residents of this metropolis actually hope so. For now, the flamingos provide a flash of sudden magnificence and hope amid grey skies.