Explained: How Gujarat estimated its lion population without holding a census
Conducted once every five years, the Lion Census was due on June 5-6 this year, but was postponed after the lockdown was announced on March 24.
On Wednesday, the Gujarat Forest Department announced the population of Asiatic lions in the state — 674, up from 523 in a Lion Census five years ago. Unlike in previous years, this count was estimated not from a Census, but from a population “observation” exercise called Poonam Avlokan.
Why was the Lion Census not conducted this year?
Conducted once every five years, the Lion Census was due on June 5-6 this year, but was postponed after the lockdown was announced on March 24. Over 1,500 forest guards, foresters and range forest officers were deputed on policing duty to enforce the lockdown.
The Forest Department invites NGOs, experts and wildlife enthusiasts to join the Census for transparency and augmenting manpower, but this time, Forest Minister Ganpat Vasava said on June 3, it was not advisable to send so many people inside the forest as the Bronx Zoo in New York had reported a case of transmission of novel coronavirus from a human to a tigress.
So, how were the numbers estimated?
Through Poonam Avlokan, which is a monthly in-house exercise carried out every full moon. Field staff and officers spend 24 hours assessing the number of lions and their locations in their respective jurisdictions. It was a mechanism developed by the Forest Department in 2014 as part of preparations for the 2015 Lion Census.
This time, the exercise was undertaken from 2 pm Friday to 2 pm Saturday. It covered 10 districts where lion movements have been recorded in recent years, and 13 forest divisions. All these divisions, save Surendranagar and Morbi, were part of the 2015 Lion Census too.
How is this ‘observation’ different from a regular census?
The Lion Census involves larger participation. Around 2,000 officers, experts and volunteers were involved in the 2015 Census. That makes the Census more transparent. The lion ‘observation’ this month was conducted by around 1,400 forest staff and a few experts.
The Lion Census usually runs for more than two days, including a preliminary census and a final census. It is done using the block counting method — in which census enumerators remain stationed at water points in a given block and estimate abundance of lions in that block, based on direct sighting of lions who need to drink water at least once in 24 hours during the summer.
A ‘lion observation’ is an in-house exercise, conducted only by forest staff. The methodology too is different as, instead of remaining stationary at water points, teams keep moving in their respective territories and make their estimates based on inputs provided by lion trackers and on chance sightings.
Has the Lion Census ever been postponed before?
The first Lion Census was conducted by the Nawab of Junagadh in 1936; since 1965, the Forest Department has been regularly conducting the Lion Census every five years. The 6th, 8th and 11th Censuses were each delayed by a year, for various reasons.
The 2020 count is particularly important. The 2015 Census had counted 523 lions, up from 411 in 2010. But 12 lions were killed in a flash flood in Amreli just a month after the 2015 cenus, followed by deaths of more than two dozen lions in an outbreak of canine distemper virus (CDV) and babesiosis in 2018. A babesiosis outbreak was reported in Gir (east) this summer too, and around two dozen lions are reported killed.