Wildlife experts have hit a dead end in their quest to determine how a gray wolf arrived in southern Michigan for the first time in more than 100 years.
The wolf was killed in January by a hunter who told investigators that he had mistaken it for a coyote. It was a shock: While gray wolves are common in Michigan's Upper Peninsula — the latest estimate is more than 700 — the state's southern Lower Peninsula doesn't offer the proper habitat.
''We just don't know how it got there,'' Brian Roell, wolf expert at the state Department of Natural Resources, said.
Separately, authorities who received a report about the DNR's investigation said Thursday that no charges would filed against the hunter or guide.
"The conduct here appears to be based on a reasonable and honest belief they were legally shooting a coyote,'' Calhoun County prosecutor David Gilbert told The Associated Press.
The 84-pound wolf was killed roughly 300 miles (482 kilometers) south of the Upper Peninsula. The DNR said it learned through social media about someone shooting a ''world record coyote.'' But this was no coyote.
Gray wolves are protected under the Endangered Species Act and can be killed only if they are a direct threat to human life, the DNR said.
Roell said he'd welcome tips if the public knows anything about the wolf's presence in southern Michigan.