Wolves and moose fight for survival on Michigan's Isle Royale National Park. For more than 50 years, researchers have been closely watching them in the world’s longest-running study of predators and prey.
The number of predators on the island has been sinking fast.
The Park is a dedicated wilderness area, so managers do their best to keep it as untouched by humans as possible. But people might need to step in.
Phyllis Green is the park's superintendent. “At this point we’re concerned about the low levels of wolves on the island, but we’re also concerned about making sure the next steps we take are well-thought-out,” she says.
There are just eight wolves left on Isle Royale. This is the first year that Michigan Technological University researchers were unable to document any pups born to the wolves.