mumbai

Updated: Feb 01, 2018 10:17 IST

Degradation and loss of habitats to make way for construction in and around Mumbai has led to a significant decline in sightings of birds in the past 10 years, revealed an analysis of bird sightings logged during the Mumbai BirdRaces between 2008 and 2017.

A drastic decline in sightings was recorded at the Sanjay Gandhi National Park (SGNP) from 101 in 2008 to 52 in 2017. this was followed by Uran (179 to 79) and Phansad Wildlife Sanctuary (102 to 46). In the past two years, eight species have neither been sighted nor heard at the SGNP alone. While six species have not been recorded at any of the seven locations visited during the bird race.

“Birds are important for the ecology because they help in pollination and seed dispersion and maintain water table in forests,” said H N Kumara, senior scientist, conservation biology, Salim Ali Centre for Ornithology and Natural History, Tamil Nadu. “Bird races help in spreading awareness and can work as a stepping stone for citizen science movements, which can lead to large-scale scientific monitoring of birds across the country to help in their conservation.”

The 14th Mumbai BirdRace will be held on February 4 with 260 bird enthusiasts, including 20 children, participating in the event.

Naturalists estimate that 75% of grass-scrub-agriculture – or open lands – has either been lost or seriously impacted, which is evident with the decline in sightings in this habitat from 106 in 2008 to 60 in 2017.

“Many freshwater and coastal wetlands have disappeared or deteriorated alarmingly, including several freshwater bodies. Most are choked with refuse or suffer from serious pollution,” said Sunjoy Monga, naturalist who conceptualised the bird race.

He added that as a consequence of these two degraded habitats, ground-level birds or those found around wetlands such as larks, wagtails, partridges and quails have disappeared owing to declining in ground-based plant life and pollution.

Since the Mumbai BirdRace began in 2005, the total number of species spotted at freshwater wetlands dropped from 79 to 45 last year. In coastal wetlands, the number declined to 73 in 2017 from 91 in 2005.

Even though the Vasai-Virar corridor has not been part of the bird race since its inception, bird watchers in this belt have witnessed a steady rise in the number of species spotted. Sightings at these location during four of the seven years were the highest — 110 in 2017, 102 in 2015, 95 in 2014 and 79 in 2012. “The last reasonably good sites remain along Vasai– Virar, which is the new domain for large-scale developmental expansion as the city speeds northwards,” said Monga.

Overall, the number of species seen across all the locations has fluctuated since the Mumbai BirdRace began in 2005, which also recorded maximum sightings (277 bird species). The lowest number of sightings – 215 bird species – was logged in 2016.