During monsoon season, these critically endangered birds move into fields

The critically endangered Bengal florican – a grassland bird more threatened than the tiger – use not just protected grasslands but agricultural fields, too, find scientists. This suggests that conserving these cultivated areas could be as important as protecting the grasslands where these birds breed.

Fewer than 1,000 adult Bengal floricans remain in the world in two, very fragmented populations. One of them is in the grasslands of the terai, the fertile foothills of the Himalayas, which spans across Nepal and Indian states such as Uttar Pradesh. But how do these grassland dwellers deal with the monsoon, when the grasslands they dwell in gets flooded?

Researcher Rohit Jha of Dehradun’s Wildlife Institute of India and a team from other organisations in India and Nepal came together to study the distribution, movements and survival of this poorly-understood population in the Indian subcontinent. They conducted 934 field surveys to spot floricans between 2013 and 2016 and studied the movement of eleven birds fitted with small satellite tags.

Their results show that during the monsoon (the non-breeding season), the birds had far larger home ranges. They moved out of protected grasslands and into low-intensity agricultural fields along large rivers – which were interspersed with grasslands, had no roads and very few people – to escape the floods common during this time. Floricans need alternating patches of short and tall grass to thrive, and till several decades ago, the large herbivores of the terai – such as rhinoceroses and swamp deer – would do this job of creating these perfect habitats, says Jha.

“But now there are fewer mega-herbivores left, so only dense, tall grasslands remain in protected areas,” he says. “So this could be triggering this movement of floricans into fields.”

Some of the tagged birds spent more than half a year in such fields, adds Jha. Hence, conserving these fields – by ensuring safe agricultural practices – could be as important as protecting the birds' grassland habitats.

Taking into account the floricans' preferences for grassland habitats, and with location data from their primary surveys, the team also tried to predict potential undiscovered populations of the birds in the area. Their analyses show that though the birds' habitats get severely fragmented towards the western parts of the Indian subcontinent, there could be some unrecorded populations of floricans in the states of Assam and Arunachal Pradesh which have not yet been surveyed. Jha hopes to go in search of these floricans in the immediate future.