This is final installment of a three-part series about the idiosyncrasies of the cheetah–and the myriad struggles zoos face when attempting to mate these majestic felines in captivity. Part 2 can be read here; Part 1 is here.
Compared to other big cats, cheetahs are high maintenance. Captive cheetahs are prone to stress. They need space to run around and prefer privacy. Males need opportunities to live with other males; females need space to live alone. Attentive animal keepers need to correctly identify when a female is heat and then walk through male introductions. If a given male does not work out, ideally other eligible bachelors will be on hand.
It can be taxing for zoos to juggle specific cheetah mating demands along with those of other animals. But large, private off-site facilities, or “breeding centers,” offer a solution.
“You can look at the numbers over the last 25-30 years and the facilities that have by far had the best success are the ones that are keeping the larger numbers of cheetahs,” says Steve Bircher.
A handful of centers were initially built in the 1980s. Only in the last ten years have new centers cropped up, including the Smithsonian-run one in Virginia. The centers are spread out across the United States, from Florida to California. They range in size from 1,800 acres to 10,000 acres, and house between 12 to 30 cats.
One lingering issue is money. “When half of the [cheetah] population are in eight facilities, those eight facilities are really absorbing the cost,” says Smithsonian’s Adrienne Crosier. On average, it takes $9,000 to maintain one cheetah per year. This means centers with 15 plus cheetahs like Front Royal are spending upwards of $135,000 annually on cheetahs. Crosier is currently working on a proposal to share these costs across all AZA affiliated institutions.
Despite being one of the most studied animals, and the community commitment to these facilities, it is still a struggle to breed captive cheetahs. According to the AZA, at least 25 cubs a year are needed to maintain the current captive population and even more births are needed to increase it. Thus far in 2012 there have only been 14 cubs born, including the 2 cubs from the Smithsonian. Last year, only 12 cubs were born; in 2010, there were around 20 cubs.
Part of this difficulty stems not from getting cheetahs to mate generally, but getting the right cheetahs to mate. The heyday of captive cheetah breeding was in the 1990s. Since then, managers have been “more selective” with cat mating recommendations. And today many genetically valuable cheetahs are nearing or already past their breeding prime.
The goal is to breed cheetahs naturally, but especially with the other populations, assisted reproductive strategies could help. According to the AZA, artificial insemination “is the most practical” method. In the 1990s, female cheetahs were one of the first big cats to be successfully inseminated with male sperm outside of intercourse. But cheetah artificial insemination trials have not worked in the past 10 to 12 years, says Crosier. Even though “we changed virtually nothing.”
Another option is in vitro fertilization, where an egg and sperm are removed from a female and male cheetah, respectively. The fertilization, or combination of the egg and sperm, is done in the lab rather than in the cat. Then the fertilized egg is reinserted into a cheetah. This process oftentimes requires two females: one who donates the egg, and the other who brings the baby to term.
Crosier and colleagues have studied cheetahs beyond their breeding prime, ages nine and over. They discovered that the uteruses of older felines are prone to disease, likely a result of stress and genetic legacy issues, but their eggs are healthy. These findings were published in the journal Biology of Reproduction in 2011.
Although still in research phase, the eventual goal is to use the older females eggs for in vitro fertilization. The fertilized eggs will then be inserted into younger, healthy females. This method would preserve the genetic diversity of the older captive cheetahs, says Crosier.
Another option is ditching the genetic restrictions all together. If managers “pay less attention to higher levels of inbreeding,” Mother Nature may take care of the rest, suggests Bircher, who readily admits he is not a geneticist. History has shown that cheetahs are very resilient, he adds.
But the Smithsonian Institution, for one, has no intentions of ignoring genetics, says Crosier. For cheetahs, and many other captive endangered animals, preserving genetic diversity is just as important as making new babies.
Today, Ally’s two young carefree cubs can be seen zooming around their pen in Washington D.C. Despite their rocky entrance into this world, they are healthy and playful. But in the not-so-distant future, the cubs will start their own breeding journeys.
“If you have one animal breed and its offspring never breeds, we are losing that genetic line,” says Laurie Marker. The importance of these cubs mating cannot be overstated.
Hand-raised cubs are often handicapped by a lack of exposure to other cheetahs. Aware of this, keepers at the Smithsonian have been arranging regular play dates with the other zoo cheetahs and strict about not excessively handling the cubs. Whether the young cats successfully receive enough social skills for mating, only time will tell.
But let’s say they do – then what? “Can we still save the species?” asks Marker, who more than Crosier and Bircher is focused on wild populations.
The distant end goal is to eliminate the human stresses on wild cheetahs and rebuild their population, potentially using captive born cheetahs for this mission. But until captive breeding success rates skyrocket, the struggle of the wild cheetahs is largely being put on hold.
However, cheetahs on exhibit like Carmelita and Justin are helping to make this point. As “great little ambassadors for their species,” said Crosier, the two fluff balls are promoting awareness about cheetah conservation in their own adorable way.