As rapid urbanisation has led to rampant destruction of wetland ecosystem in and around Mumbai, thousands of flamingos did not fly back to their nesting sites along the Gujarat coast this year. Instead, the pink-winged visitors stayed put by braving the summer and monsoon seasons, experts said.
Local fishermen said more than 7,000 flamingos didn’t leave the 10-kilometre wetland stretch from Airoli to Vashi along the Thane creek this year. Generally, the birds arrive in Mumbai by early November and take off by June-end for finding suitable nesting sites in Gujarat.
Scientists from the Bombay Natural History Society (BNHS) identified two reasons for this change in the migratory pattern of flamingos. “This year, weather conditions have been conducive for a large population to stay back. After El Nino — warming of the Pacific Ocean — moved away, there have been heavy rains that led to abundance in food,” said Deepak Apte, director, BNHS. “This time, the entire juvenile flamingo population stayed back along with a significant number of adults.”
Apte added that other flamingo habitats in Uran, Vasai, Sewri-Mahul, Mulund, Bhandup and even as far as Rann of Kutch, Gujarat (their nesting site during summers) have fallen prey to developmental activities, and hence these birds are congregating in small areas.
“The impact of untreated sewage, garbage stuck in mangrove areas and development in other wetland habitats has pushed these birds to hold on to the Airoli-Vashi belt since it is relatively better protected,” said Nandkumar Pawar, member, fisherman community.
Experts pointed out that flamingos were sighted in newer areas such as Manori creek and Malshej, Pune district, during the monsoon. “These areas do not usually harbour a large congregation of flamingos. An almost 50% decline of the wetland ecosystem at Uran has led to this scattered phenomenon,” said Sunjoy Monga, naturalist.
Monga added that flamingos accidentally arrived along the Mumbai coast during the early 90s in search of a suitable habitat. “Much more than other waders, these birds change their migratory pattern faster in search for their rich diet of algae and planktons. However, human intervention is now speeding up the migratory process, and altering their natural pattern,” said Monga.
State mangrove cell officials said they were notified about the presence of more than 15,000 flamingos along the Thane creek, which was declared a flamingo sanctuary last year, and about 10,000 at Airoli-Vashi by the second week of October. “Compared to last year, the increase in population this time is unusual as these numbers are recorded in December,” said N Vasudevan, chief conservator of forest, state mangrove cell. “One of the reasons could be shortage of food at other nesting areas.”