In 1991, a gorilla named Timmy moved from Cleveland to New York City.

At age 30, the Cameroon-born gorilla had never sired an offspring, and instead had formed a yearslong bond with an infertile female gorilla named Kate.

When zookeepers decided to transfer Timmy from Cleveland Metroparks Zoo to the Bronx Zoo — an effort to pass on his valuable genes — animal rights advocates fought back. They went to court to try and keep Timmy in Cleveland, arguing that a move would only hurt him. The suit was dismissed, and Timmy went on to become a father many times over.

The Timmy controversy unfolded around the beginning of Kevin Willis’ zookeeping career. Now the Minnesota Zoo’s vice president for biological programs, Willis points to cases like Timmy’s when he talks about how little the public understands zoos.

“If you look at the movie ‘Blackfish’ and Sea World’s response to it, and the public response to it, if you look at the public’s response to the shooting of the gorilla at the zoo in Ohio, there are a lot of people who I don’t think really thought very much about the role of zoos,” Willis said. “When those sorts of topics come up, I think people do start to question.”

These days, the questions spread a lot faster than they did in 1991. Type “Minnesota Zoo dolphins” into a Google search, and “Minnesota Zoo dolphins death” emerges among the top results. Do the same with bears, and “Minnesota Zoo bear breaks glass” pops up.

Last year’s story about a grizzly bear shoving a boulder into a pane of glass at the front of its enclosure drew 1.3 billion hits — the most ever for a story about the zoo.

In a talk Wednesday evening in St. Paul, Willis explained to a crowd of donors and members of the zoo’s young professionals group that the grizzly bear incident wasn’t as extreme as it appeared. The bears were digging in their enclosure, unearthed a boulder, and in the course of playing with it, broke one of the glass panes that divide them from visitors.

Even so, stories like that can raise questions about the role of zoos, and whether animals should live in captivity.

Willis, like most of those attending Wednesday’s event — “the choir,” as he describes them — would argue that there are plenty of reasons for zoos to exist, and for animals to live in them. Zoos offer an otherwise unlikely opportunity for people to see animals and learn about science, Willis said. He added that zoos can protect animals that in the wild might be lost to poachers or shrinking habitats.

U.S. zoos also do conservation work and strive to return animals to their natural habitats.

Conservation has been part of the Minnesota Zoo’s work since it opened in 1978, but it’s only recently been played up. A couple of years ago, the zoo lengthened its mission statement to include the idea of saving wildlife — underscoring that it’s not just a space for people to connect with animals, but rather a place that connects people with animals in order to preserve them.

At one point, Willis asked the crowd whether captivity is justified only because of conservation efforts. Some responded that the zoo helps animals survive that wouldn’t otherwise — orphans, for example, or animals that have lost their habitat.

That’s true, Willis said, but why does keeping animals in captivity need to be justified at all?

“I don’t think we need to justify [captivity],” he said. “I don’t think it’s wrong.”