The grazing bison at the Minnesota Zoo may appear to be just another animal attraction. But the purebred herd — one of the last of its kind in the country — is key to keeping the species healthy for years to come.

The animals are part of the zoo's bison restoration project, a joint effort with the Minnesota Department of Natural Resources, which aims to breed bison to roam in state parks and further the zoo's conservation mission.

Saving wildlife has always been one of the Apple Valley zoo's goals — conservation, recreation and education — but officials say conservation is becoming a top priority, especially for animals native to Minnesota.

"Instead of it being a spoke in the wheel, it is the wheel," said zoo director and CEO Lee Ehmke.

Even amid a recent $1.5 million budget shortfall and dip in summer attendance, the zoo is not backing off. If anything, the state-owned zoo is pursuing its future plans with more urgency: a stream of capital projects, revitalization efforts and an uptick in conservation work.

All of the zoo's international conservation efforts are supported by private funding, while local projects are backed by a combination of donations and state dollars. The Minnesota Zoo Foundation, which acts as the institution's fundraising arm, is expected to pitch in more for conservation work — raising its contributions by 41 percent over the next five years.

"We can show people these incredible species they may have never heard of before," said Tara Harris, vice president of conservation at the zoo. "Hopefully, once we've gotten people to care about these animals, we can really show them how we're working to help save them in the wild."

Many of the zoo's most prestigious accomplishments have stemmed from efforts across the globe. Field workers in Namibia help save the critically endangered black rhinos. In Russia, zoologists study Amur tigers to replenish their dwindling numbers.

Private donors throughout the state have been generous with funding for international campaigns, Harris said, but many residents forget about the endangered animals in Minnesota. The zoo's work locally has included the bison herd, rare butterflies and studies of the state's declining moose population.

"It's important to not just save tigers in Asia but think about species in our own back yards," Harris said.

Behind the scenes at the zoo, Erik Runquist and Cale Nordmeyer are working to rebuild one of the zoo's smallest and most delicate native insects.

The Dakota skipper, a brown, quarter-sized butterfly, fluttered above 2 million acres of Minnesota prairie in the early 1900s. But now, less than 1 percent of that prairie remains and Dakota skippers have almost completely fallen off the map.

The zoo's native butterfly breeding program aims to produce a reserve population of Dakota skippers. About 150 tiny larvae are hibernating in Runquist's office freezer for the winter. In spring, they will be placed in pods of grass to grow. It's likely the first time anyone has been able to rear them all the way through their life cycle and breed them, he said.

"We are writing the manual on this as we go," said Runquist, the zoo's butterfly conservation director.

Wild support

Trumpeter swans may be the zoo's most successful reintroduction program.

By the mid-1980s, the swans had disappeared from the wild in Minnesota. Over three decades, the zoo was able to raise 182 swans in captivity.

By 2011, those birds and others helped restore the wild population to about 6,000 swans.

Ending conservation programs is actually the goal when they begin, officials said, because that means the animals are able to make it on their own.

"It's not just on the other side of the world," said Nordmeyer, the butterfly conservation specialist. "We have endangered ecosystems and endangered species here."

"And we can do something about it," Harris added.

Zoos across the nation have increased conservation efforts along with their entertainment-based exhibits because officials realized they couldn't sit back and watch as animals declined so rapidly in the wild, Harris said.

There is more of an imperative to save them, she said, which requires a willingness to put big bucks toward those efforts.

Minnesotans have done just that, donating $3.3 million last year specifically for the zoo's conservation work.

"We're working tirelessly on behalf of these species … so that many generations will be able to see a moose in Minnesota," Harris said.