Zookeeper, Zookeeper Make Me A Match: How The Denver Zoo Sets Up Animal Pairs

Feb 14, 2019

Love is in the air on Valentine's Day, even in the most unlikely of places.

At the Denver Zoo, Hollie Colahan helps make sure that nature takes its course. Colahan is the vice president of Animal Care at the Denver Zoo. She's also the Species Survival Plan coordinator for lions for the national Association of Zoos and Aquariums.

That means she decides which lions should go to which zoos.

The zoos detail each animal's life story and then use that information to find the best match in the best location, Colahan said. The overall goal is to ensure a healthy species population throughout U.S. zoos.

"It's like online dating for animals," she said. "But we look at different things, obviously, than people do."

But that can get a little... complicated, requiring looking at age, genetics, population diversity and sometimes even personalities. It isn't an exact science, Colahan said, and when animals don't "click," it can even be dangerous.

Interview Highlights

Denver Zoo's vice president of Animal Care Hollie Colahan stands in front of the zoo's lion exhibit, Predator Ridge. Colahan is the Species Survival Plan coordinator for lions for the national Association of Zoos and Aquariums.
Credit Stacy Nick / KUNC

On populating zoos:

Colahan: We want to have populations that are sustainable for the long term. We don't frequently pull animals out of the wild, anymore. A lot of people think that's where animals come from, but most of the animals you see in zoos were born in zoos.

So the genetics and the demographics of those populations become really important. We need to look at their pedigrees and make the best matches for breeding.

On handling bad lion first 'dates':

Colahan: Once you put a bunch of 300 to 400-pound lions together, there's not a lot you can do. They sort of run the show after that. But if things don't go well then we'll separate them and we might take a couple steps back and then try again. We might try some different techniques, sometimes waiting until the females are cycling, then they're a little more receptive to a new male so we might try that strategy. But it's usually just backing up and taking some baby steps forward again.

On why the Denver Zoo "split up" polar bears Lee and Cranbeary:

Colahan: So what we would see with Lee and Cranbeary — during that magical time of year when her hormones made her want to be with Lee, they got along fantastic, but that only lasted a few weeks and then she would be done with him and tell us that they didn't want to be together again.

I think that is a place where sometimes we do tend to anthropomorphize, because as humans we sort of project what we think of as long-term, monogamous relationships onto animals. And there are some animals that do that, but polar bears are one that — that's not part of their natural history to live like that.