Flamingos come to Mumbai for a few months per year but there are more than normal.

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The birds traditionally migrate to the area for feeding from September to the end of May, according to Rahul Khot, assistant director at the Bombay Natural History Society (BNHS), which monitors the flamingos.

Last year a record 134,000 flamingos were counted in the area, but Khot believes a new record will be set this year.

BNHS had already counted 125,000 flamingos before its work was disrupted by India's coronavirus lockdown measures, introduced on March 25, said Khot, who expects the population to surpass the previous record by the end of May.

The birds are benefiting from a lack of human activity due to coronavirus lockdown measures.

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It's not just the huge number of birds that's attracting attention -- they have also spread to wetlands where they were previously a rarity, added Khot.

"They are being reported from places where they have earlier been reported less in number because there is no human activity there now," he said.

Removing human pressure on the environment allows us to appreciate the importance of the wetlands in Mumbai, he added.

Tales of curious animals exploring towns and cities empty of humans have emerged around the world, but the phenomenon has been especially noticeable in India due to the country's normally crowded urban areas and high levels of pollution.

The birds come to the Mumbai area to feed and breed.

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India has been in lockdown to prevent the spread of coronavirus for over a month. Trains, flights and buses are not running and only essential services are operational.

In March, Mumbai experienced its best air quality on record, according to a recent analysis by IQAir -- a global air quality information and tech company.

Other animals that have benefited from humans' absence include monkeys, which have descended on Delhi in great numbers, and dolphins, which have been spotted in the Ganges river for the first time in years.

The lockdown was set to end on April 14, but was subsequently extended until May 3. Since April 22, some states with fewer cases have had some lockdown measures relaxed but transportation remains suspended.

An earlier version of this story misstated why the flamingos migrate to Mumbai. This has been corrected.