The doings of one mammal namely humans is killing all others. This has been the finding of a recent study published in the Philosophical Transactions of the Royal Society B. The study authors say that at least twenty percent of all known mammals are nearing extinction and the major threat is to the larger species.
“The example I often tend to bring up is Tasmanian Devil, familiar to many from the Looney Tunes cartoons, because it’s an example of how a species that is common, or at least not uncommon, can suddenly, through the emergence of a novel threat, be plunged into a steep decline,” lead author Michael Hoffmann said.
He explained how a relatively new cancer, Devil Facial Tumor Disease, is causing the downfall of this particular mammal.
The team led by Hoffman analysed the data gathered for International Union for Conservation of Nature’s Red List. They covered the period from 1196 when all the species had been assessed for the first time, till 2008 the last assessment done.
They documented those species that are rapidly declining in population and their changing extinction risk. The researchers found many large animals facing the most threat like rhinos, tapirs, elephants dugongs and manatees. They also found two species of antelope, Dama Gazelle and the Addax found in North Africa having very little chance of survival due to non-stop hunting.
The team explained that large size mammals had in general a lower population which added to their peril of getting extinct.
“Large size has often been linked to elevated risk of extinction in mammals because, among other reasons, large mammals tend to occur at lower densities, have a slower reproductive rate, and are more likely to be vulnerable to hunting, by-catch and other forms of exploitation,” Hoffmann explained.
The location also played a key role in determining the probability of extinction of a species in that region.
Southeast Asia was said to be a location where over exploitation was rampant.
The study team also feared that the rate of extinction is so rapid that by 2008 some mammals have already become extinct, like the Christmas Island Pipistrelle.
“As recently as January 2009, there were thought to be as few as 20 remaining individuals,” Hoffmann said. “In August 2009, authorities returned to the island to capture some of the remaining individuals for captive breeding, but only a single individual was detected and it evaded capture before disappearing entirely.”
Bats were also found to be threatened in some places because of the deadly White-Nose Syndrome first noticed in 2008. It killed thousands of hibernating bats in US earlier this year.
The good news coming from the study was the increase in population of 24 species of mammals.
“The two major success stories to my mind are the Black-Footed Ferret (U.S. and Canada) and Przewalski’s Horse (Mongolia), which both were considered “extinct in the wild” until just a few decades ago,” Hoffmann said. “Now, largely through captive breeding and reintroduction efforts, they have seen dramatic recoveries in their populations.”
Brett Scheffers, a researcher with the Department of Biological Sciences at the National University of Singapore conducted another study on mammals, birds and amphibians. He found that in the past 122 years, at least 351 species thought to have gone extinct have been rediscovered.
“Rediscoveries, without aggressive conservation, likely represent the delayed extinction of doomed species and not the return of viable populations,” Scheffers said. “In short, there is hope, but we must step up rapid conservation efforts.”
Hoffman also feels the same.”What we need is to rapidly ramp up efforts, and to work in a more strategic, coordinated and smarter way than we have up until now,” he says.
Mammals have a safe future only if humans give them that chance.