The number of tiger attacks on people is growing in India's Sundarban islands as habitat loss and dwindling prey caused by climate change drives them to prowl into villages for food, experts said.
Wildlife experts say endangered tigers in the world's largest reserve are turning on humans because rising sea levels and coastal erosion are steadily shrinking the tigers' natural habitat.
The Sundarbans, a 26,000 sqkm area of low-lying swamps on India's border with Bangladesh, is dotted with hundreds of small islands criss-crossed by water channels.
"In the past six months, seven fishermen were killed in an area called Netidhopani," Pranabes Sanyal of the World Conservation Union said.
"Owing to global warming, the fragile Sundarbans lost 28 per cent of its habitat in the last 40 years. A part of it is the core tiger reserve area from where their prey migrated."
But as sea levels rise, two islands have already disappeared and others are vulnerable. Wildlife experts say the destruction of the mangroves means the tigers' most common prey, such as crocodiles, fish and big crabs, is dwindling.
Sundarban villagers pass through tiger territory on boats to fish in the sea, or to collect honey in forest areas.
"Villagers are not supposed to enter a number of islands earmarked as tiger territories, but they seldom follow the rules, get attacked and claim compensation," Pradip Shukla, a senior forest department official, said. Villager Ashutosh Dhali became a local celebrity after television cameras captured him being attacked in February.
"We were trying to catch the tiger perched on a tree of our village with tranquiliser shots," said the 47-year-old villager.
"But it flung on me after falling on a net and bit my loins."
Once home to 500 tigers in the late 1960s, the Sundarbans may only shelter between 250 and 270 tigers now, wildlife officials say. The Indian Statistical Institute said the number is as low as 75.
Most tigers have been wiped out due to poaching and habitat loss. Authorities said a tiger was killed by poachers in the Sundarbans earlier this month, the latest such killing in India.
The area is the world's largest mangrove reserve and one of the most unique ecosystems in South Asia, recognised as a UNESCO World Heritage Site.
Ullas Karanth, of the Wildlife Conservation Society India, says that the Sundarbans are a poor quality tiger habitat because of low prey densities.
"The tendency to seek alternate prey in the form of livestock – and sometimes humans – might be higher in these tigers," Karanth said.
As sea levels rise, mangroves have been overexposed to salt water. Many plants have lost their red and green colours and are more like bare twigs, exposing tigers to poachers who hunt them for their skin and bones.
There were about 40,000 tigers in India a century ago. A government census report published this year says the tiger population has fallen to 1,411, down from 3,642 in 2002, largely due to dwindling habitat and poaching.