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Indigestion Can Protect Africa's Lions

The African Lion is of one of the worlds greatest predators and is now considered an endangered species

African lions are increasingly hunting domestic cattle. And many of them are being killed as humans retaliate. Now, in Botswana, a pilot project is underway to save the lion by making cattle taste bad.

The king of beasts is facing possible extinction. Its once proud numbers are dwindling fast.

Cascade of consequences

“Forty years ago, there were 450,000 across their former range on the African continent. Today that range has shrunk and there are less than 23,000 lions in the wild,” said Eli Weiss, founder of the Wildize Foundation. She said lions have fallen victim to a “cascade of consequences.”

“Climate change, which is changing migration routes of prey species. Water, as we all know. And then population increases, which is putting pressure on those habitats where those lions live, which [are] game-rich areas, which can also be agriculturally rich areas. So people are moving into areas formerly occupied by wildlife and lions and they’re bringing in their cattle. And as their cattle eat the grasses that the prey species would typically eat, it’s forcing the lions to find food elsewhere,” she said.

Kill and be killed

Lions are very territorial. So they stay within a specific area even if their typical prey has literally left for greener pastures.

“So the closest thing around is cattle. And that’s creating a huge economic loss to cattle ranchers and pastoralists. So in retaliation, when a lion kills a cow, that lion is then killed,” Weiss said.

The Wildize Foundation hopes to change the kill-and-be-killed cycle. That’s where Conditioned Taste Aversion, or CTA, comes in. Weiss says it’s aimed at the “hardwired” response in mammals to avoid eating what’s toxic.

Weiss said, “We’ve all had an experience where we’ve eaten something bad or drunk something bad and we got sick from it and, in future, can never eat it again.”

Conditioned Taste Aversion

So, for a lion, how do you make a seemingly delicious looking cow into something that turns its stomach?

“We do this by treating bait of the target prey species -- in this case it’s going to be a cow -- and get the lion to eat that. First we use untreated bait. Then we use a treated bait with a general pharmaceutical chemical called thiabendazole. It’s not a dangerous chemical. It doesn’t make them foaming-at-the-mouth sick. It just gives them an upset stomach,” she said.

Once the lion has had a good case of indigestion, untreated bait is then left. When the lion smells the cattle bait, the animal associates it with feeling sick and doesn’t eat it. Wildize then leaves bait of a prey species that the lion is free to eat.

“We want that lion to get the full olfactory experience of taste, smell and chewing through the hide and the meat to get that full effect of being averted,” said Weiss.

Wildize is using captive animals on a reserve in Botswana to test how well Conditioned Taste Aversion works. Even though the project may last several years, they’ll know by mid October if it’s a success. If it is, Kenya has agreed to use CTA to help protect its threatened lion population.

The method was first used successfully in the 1950s and 60s by CTA expert Dr. Lowell Nicolaus. His protégé, Denver Zoo research associate Bill Given, heads up efforts in Botswana. Over the years, it’s been used to save wolves, coyotes, raccoons, cougars, foxes and badgers in the U.S. and Mexico.