A couple of weeks ago I blogged about the fact that 80 percent of the world’s wild cat species are at some level of risk of endangerment, including many species unknown to most people. But two species that are very well known, the African lion and the spotted leopard, are the subjects of a scientific paper just published in the journal Conservation Biology. The title of the paper is “Effects of Trophy Hunting on Lion and Leopard Populations in Tanzania.”
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The argument is often made — by hunters, of course — that neither species should be considered “endangered,” presumably because there are still more of them than of more critically and obviously endangered species. But endangerment is often a process whereby populations are nibbled away and fragmented, and already both species have suffered considerable losses, being reduced or totally eliminated from large portions of their former ranges. “Tanzania,” the report points out, “holds most of the remaining large populations of African lions (Panthera leo) and has extensive areas of leopard habitat (Panthera pardus).” Both are heavily hunted.
The hunting industry loves to promote the idea that trophy and big-game hunting promotes conservation by providing local communities with an economic incentive to protect the species hunted, and their habitat to the benefit of other species. But what the researchers discovered was that hunting did not prevent “some form of anthropogenic impact from local people.” They also found that “the intensity of trophy hunting was the only significant factor in a statistical analysis of lion harvest trends.” Those trends were downward. They also noted: “Although leopard harvests were more stable, regions outside the Selous Game Reserve with the highest initial leopard harvests again showed the steepest declines.”
Oops. Hunting seems not to be working, but don’t hold your breath for the big game industry to admit it.
Coincidentally on the same day I read that report I received a copy of a column by Canada’s best-known environmentalist, David Suzuki, titled, “Can’t Rely on Captive Breeding To Save the Species.” No news there for those of us who, from time to time, cross swords with the zoo industry. Captive breeding and release programs have made significant contributions to the protection of a tiny percentage of the wildlife species in severe decline, yes, but these tend to happen outside the zoo community or at least away from actual zoos.
But what pleased me was that Suzuki, who is a geneticist, was making the same argument, with far more authority than can be attributed to me, that I have often made about captive breeding. The more generations of animals bred in captivity, the further they “drift” from the genetic type of the wild form, potentially becoming ever more domesticated. “If,” writes Suzuki, “you take an animal (or any living organism, for that matter) out of its natural habitat and introduce it to someplace new, natural selection takes over and traits that are favorable to the new location — in this case captivity — become more and more common in subsequent generations.”
One caveat: I would not call what happens in zoos “natural” selection. It is imposed selection, with god-playing zookeepers deciding who breeds with whom. Their criteria are based on preventing inbreeding, not on the intricately complex suite of factors that contribute to the natural evolutionary trajectory of a species in the wild.
That brings us back to the big cats. There are plenty of African lions and spotted leopards in zoos. There are more tigers in zoos than in the wild. But these are animals moving, generation by generation, away from their wild, endangered kin. Survival of wild animals depends on the honing of instinctive and physiological characteristics that contribute to survival, and, in the larger species, social interactions within natural habitats vastly different from anything a zoo can provide.
But count on it: The myths will continue. The hunters will continue to call themselves conservationists and make fantastical claims that big game hunting equals conservation, and the zoos will continue to do the same, and science will continue to prove them wrong.
Blogging off,
Barry Kent MacKay