Repopulation research continues at Linwood’s Wildlife Science Center

The Wildlife Science Center has dedicated a lot of its time assisting the repopulation of Mexican gray wolves. And continued research is one way the center is helping.

“We’re always doing the best we can to save Mexican wolves, which descend from seven individuals,” said Karen Bauman, manager of reproductive sciences at St. Louis Zoo. “Every sperm is sacred.”

During the month of February, scientists visited the Wildlife Science Center in Linwood to collect semen samples from gray wolves. There are only two weeks out of the year that wolves mate, making for a short window for collection.

Grey wolves are the main species of wolves that live in Minnesota and are also throughout Yellowstone National Park. Mexican gray wolves are a subspecies and have a lot of similarities to the gray wolves.

Cheryl Asa, retired director of research at the St. Louis Zoo, explained the reason behind studying gray wolves.

“We use the gray wolf as a model for the Mexican gray wolf,” Asa said. “Because Mexican wolves are officially in a U.S. Fish and Wildlife Service recovery program, there are a lot of restrictions on handling them and how you can handle them, and there aren’t a lot of them. So it’s difficult to run a research trial with them.”

Asa said the recovery program is working with farmers and ranchers to help keep the wolf population steady, but there are predators that are still being killed if coming after animals on farms.

“The threat to Mexican wolves in the wild is still conflict with humans,” she said.

There is progress being made, however. A group has been started called “range riders” — people on horseback who watch for the Mexican gray wolves.

Asa explained college universities are now helping improve the conservation field by having programs on “human wildlife conflict.”

When Asa was working at the St. Louis Zoo in 1990, she was approached by the head of Fish and Wildlife Services Mexican Wolf Recovery Program and asked to start a gene bank for the subspecies.

“The zoo has been housing that and paying for that and financially supporting it, all those years,” she said.

Now that they are collecting genes or wolf semen, there is a process that goes along with it. And Asa wants to explain that it’s not harmful.

This process is being used on the wolves to add to the gene bank for research. No harm comes to the wolves as they are given a mild sedative, which they will wake up from within two hours of being given, therefore there will be a quick recovery.

Bauman walked through how the collections work and benefits of the research.

“It’s really great for us to use a very similar species to do scientific studies to see what might work best with Mexican wolves,” she said.

Bauman said the way they freeze and thaw sperm affects the quality of it, so they test different media solutions to see what will provide and preserve the semen best.

“Today one of the experiments we’re running is we’re testing a new media for our solution that we put the sperm in once we collect it, and it has a salt and sugar solution and a cryoprotectant, which protects the outside membrane of the cell,” she said.

In 2016 Bauman said through studying different solutions they were able to successfully find one that can be used with Mexican gray wolves.

“These (gray) wolves are amazing scientific ambassadors,” she said.

Throughout their studies at the science center, Bauman said they were able to verify that the technique for artificial insemination used for domestic dogs worked in wolves and was able to be used on Mexican wolves for safe repopulation.

Bauman said it’s really important for samples to remain frozen in the zoo over time.

“After I’m retired or maybe after my children are retired or whatever, there might be a need for that specific genetic combination,” Bauman said. “To have that in the zoo and have it frozen is a really amazing resource for the genetic management of the Mexican wolves.”

In the past, Bauman said there has been one frozen sample that produced one litter but with only one puppy coming from it, while fresh semen that’s been inseminated was almost 100% successful in Mexican wolves. But they will continue to research and repopulate.

“We’re inseminating some Mexican wolves in different places across the country this year, so stay tuned,” Bauman said.

She explained some believe the myth that the Mexican wolves simply didn’t breed enough, causing their endangerment. However, she said, it was caused by people killing the wolves.

“Mexican wolves do breed (naturally) really well in zoo population and in professional care, so that’s not the reason we do the research or the banking,” Bauman said.“We do the research and the banking because we’re interested in harnessing the genetics. So every time we bank a sample and leave it, that contribution in the liquid nitrogen can live well beyond the animal’s lifetime and its children’s lifetime, and its grandchildren’s lifetime.