THE LAST GLIMPSE of the first wolf translocated to Isle Royale National Park on Sept. 26 as she slips into the forests on the island. Researchers say this year’s annual wolf-moose study at Isle Royale National Park is in jeopardy due to the partial government shutdown. (National Park Service/John Pepin)

HOUGHTON — The partial shutdown of the federal government may imperil the latest iteration of the wolf-moose study on Isle Royale National Park.

Researchers are planning to head to the island for several weeks for the study, which tracks the relationship between wolves and moose on the island. Launched in 1958, it is the longest continuous predator-prey study in the world.

“I’m preparing as if we’re going next week, just because I have to be ready in case it does happen,” said Rolf Peterson, a Michigan Technological University professor who has worked with the study since the 1970s. “We’re held hostage to a larger issue.”

The shutdown began Dec. 22 over President Donald Trump’s request for $5 billion in funding for a wall on the U.S.-Mexico border. A number of government agencies and functions are included in the shutdown, including national parks.

There is no firm cutoff date for when the crew could do the study, but Peterson said they would cross a point of no return sometime in February. The study takes about seven weeks, Peterson said. To track the animals, there needs to be snow cover.

It takes about 25 hours of aerial work to estimate the wolf population, Peterson said. That usually requires more than 2 1/2 weeks.

“It’s starting to cost money next week, money that’s just wasted because we made commitments,” Peterson said. “There’s people traveling from distant places, and they’ve got nonrefundable tickets.”

If researchers cannot do the study this year, it would an unrecoverable opportunity, Peterson said,

“Once you lose the continuity, it starts to impact the integrity of the effort,” he said. “Science relies on integrity, and it’s critical.”

This year’s study would give researchers their first sense of the impact of three wolves brought to the island from Minnesota. The National Park Service is bringing 20 to 30 wolves to the island to rebuild the island’s wolf population — previously two — and provide a check on the booming moose population of around 1,500.

The NPS is scheduled to bring additional wolves to the island this winter from Ontario — which also could be jeopardized by the shutdown.

“The Ontario wolves represent a huge, good opportunity … it’s a one-time-only proposition,” Peterson said.