So-called “infighting” — deadly competition between prides of lions for supremacy over an area — was always an unlikely explanation for the 11 lion deaths reported in Gir between September 10 and September 21.
Male lions do, indeed, kill each other in fights over territory. And while taking over a vanquished pride, males may also kill the cubs to establish their own bloodline. Precisely for that reason, females are rarely, if ever, harmed in a battle of prides. And that is why the fact that there were three lionesses among the 11 dead, seemed an odd case of “infighting”.
Another 10 lions have since died in Gir, and tissue samples tested at various labs have now triggered theories of “mystery diseases”. According to the Chief Conservator of Forests, Junagadh, the National Institute of Virology, Pune, has found evidence of a “viral infection” in some blood and tissue samples. Some reports have said canine distemper virus (CDV) has been found in four samples. The Forensic Science Laboratory, Junagadh, has found tick-borne protozoa infection in six samples. While both labs are carrying out further tests, an Indian Veterinary Research Institute (IVRI), Bareilly, team has reached Gujarat to collect samples.
As a precautionary measure, Gir authorities have captured and isolated 31 lions from areas adjacent to the one in which the deaths have occurred. They are apparently doing fine. Of the first lot that lost 21 lions, five still survive.
Gir has long lived in the shadow of potential epidemics. In 2012, studying frozen tissue samples taken from the carcass of a lion that died in 2007, IVRI researches flagged the presence of the Peste Des Petits Ruminants virus (PPRV). An alarmed Dr Richard Kock of the UK’s Royal Veterinary College warned that the disease could take an epidemic turn and wipe out 40% of Gir’s lion population.
The Gujarat State Bio-Technology Mission claimed to have studied 10% of Gir lions by 2013 to conclude there was no trace of CDV or PPRV in the wild population. In 2016, however, the deaths of four lions sent to Etawah’s lion safari park from Junagadh’s Sakkarbaug zoo were attributed to canine distemper.
PPRV or ‘Goat Plague’ is highly contagious, and can be deadlier than even CDV that wiped out a third of Africa’s lions in the mid-1990s. But it infects only domestic livestock — small ruminants like goats and sheep. It is part of a family of morbilliviruses that causes canine distemper in many carnivore species, measles in humans, and rinderpest in cattle. There is no record of PPRV making carnivores sick.
In fact, several viruses are passively present on carnivores, and this may at times even help build immunity. But there is always the possibility that PPRV may jump, mutate, and turn out to be catastrophic. Also, crammed for space, many Gujarat lions live in close proximity to feral or even domestic dogs, a species blamed for spreading CDV to African lions.