It takes a lot to preserve rare and endangered animals. The Miller Park Zoo in Bloomington is part of several Saving Animals From Extinction (SAFE) programs, what used to be called species survival efforts.
“The snow leopards, the red pandas, some of our birds. I don't know the exact number of species, because we also have Puerto Rican crested toads and a lot of fish and wildlife managed reintroduction program species as well,” said zoo director Jay Pratte.
Pratte said a recent success story for SAFE efforts at the zoo is babies born to a pair of Cottontop Tamarins, a young male last year and a female this year.
“These are critically endangered South American rainforest species. This is a really big deal for the population. As we move forward, these animals will then have recommendations for where they could go to participate in breeding programs,” sid Pratte.
He’s also excited about the zoo’s giant anteaters. An exhibit opened in a new habitat last year with a female named Chili.
“In the last few months, we received and were able to introduce a young male Arnaud. We've seen some reproductive behaviors. We're going to be keeping an eye on them pretty closely,” said Pratte.
Recent archeology involving remains of a small population of wooly mammoths that had survived their mainland relatives for thousands of years on a Siberian island showed they had a number of genetic diseases from inbreeding forced by isolation and a small population. Pratte said the scenario applies to many rare animals today. And it’s not just inherited diseases, but genetically generated poor resistance to disease.
“Cheetahs were historically thought to have experienced a genetic bottleneck 10,000 to 12,000 years ago. As a result of that inbreeding of the small population, there is a genetic locus, called the major histocompatibility MHC complex,” said Pratte.
As a species, they don't have genetic resistance to diseases such as FIP, or feline infectious peritonitis.
“That has heavily impacted cheetah populations over time,” said Pratte.
Tasmanian devils are a current example, he said. There's a facial cancerous disease affecting both wild and captive populations that conservationists are trying to manage.
“There's such low variation in their genetic responses to disease that this one particular pathogen is coming in, and it's taking a very heavy toll, and could actually wipe out the population,” said Pratte.
This forces SAFE program managers to look carefully at animal lineages.
“If you're looking at any population, your F1s are your founders. We’re always looking at whether we have founder animals? For example, one that was not born in another American Zookeepers Association accredited institution. Were they from the wild? Was it one that we know has genetics that are new to the population? Those are not common anymore,” said Pratte.
Once you go down the branches of the family trees, program managers track F2 and F3, the subsequent generations.
"There are numbers and coefficients for relatedness that help us determine what are going to be good matches. Some of it may be how prolific and well an individual has bred," said Pratte.
Finding mating matches
Pratte said sometimes a pair of animals have had so many offspring among north American zoos that the program managers have to look to Europe for potential mating matches.
Sometimes an animal in the next generation has to exit the breeding pool. Sri and Sage, the snow leopards who came to the Miller Park Zoo as cubs, were both born with “Swimmers Legs Syndrome,” a condition that causes an animal’s legs to splay to the sides. It affects walking. It can also happen in domesticated dogs and cats.
“This showed up in both cubs. We know this is genetic,” said Pratte. “That was one of the determining factors that lead to Sri being sterilized. They were going to be non-breeding,” said Pratte.
Pratte said it is possible to introduce new genes to the animals, but it isn’t easy, because rarely are there remaining populations of wild animals. Another option is hybridization, or the introduction of breeding animals from a species found at different points on the globe.
“Let's say there's one of the giraffe species that is struggling. Do we then take and introduce potential reproduction from other giraffes to help and create a hybridized subspecies that's got a better chance? Or do we just watch it happen?"
Pratte said the philosophy of creating hybrids is a heavily discussed topic in the zookeeping world.
And, as with that ancient remnant mammoth group, sometimes there is no option left.
“Giant pandas, are only found one place in the world. You can't reintroduce genetics from anywhere else in the world for giant pandas, because there aren't anymore,” said Pratte.
A stretch is cloning animals, using preserved tissue to reintroduce genetic diversity. Pratte said it is a speculative and tricky topic whose costs are not fully known.
“There’s not enough evidence right now for us to know if that’s successful. Everything has been focused on have these animals survived, do they have the ability to be viable, and less like, are their genetics intact?” said Pratte.
SAFE plans have a lot of moving parts. Pratte said animal care factors matter as well as genetics.
"Are they well enough to survive that level of stress for a transfer to a new facility and introduction? Does the receiving facility have experience introducing them. You don't introduce Sumatran Tigers if you don't have some experience or great advice," said Pratte.
Pratte said SAFE plans in which the Miller Park Zoo takes part are an effort to redress the ‘pretty terrible job’ humans have done in managing wildlife diversity, which has led to extinctions.
“My personal belief is we're stewards as human beings. We evolved to be the dominant life form on the planet. It is our obligation, in my perception, for us to care for the rest of the species,” said Pratte.
To improve that stewardship, Pratte said the zoo is embarking on a yearlong strategic planning process that will assess exhibits, space, the potential for new animal displays, and how to update existing ones to current standards.
