Listen to bear sound off in Yosemite tree: Groaning over a hard day?

A black bear was captured on video expressing himself from a tree in Yosemite National Park.

Bears can produce “a wide repertoire of sounds, typically when defensive, afraid, distressed or aggressive,” park officials said in a recent Twitter post.

But, they added, they’re “not sure what prompted this unscheduled a cappella concert.” In the video, the bear is heard moaning for nearly a minute.

The adult male is frequently seen in the park and appears to be healthy, officials said.

Lynn Rogers, who has been studying bears for more the 50 years, said it sounded like an anxiety call.

“It’s almost whining,” Rogers said. “Nothing in that is explosive.”

Bears frequently climb trees when they’re scared, according to Rogers. It’s how they evolved to escape Ice Age predators more than a millennia ago, he said.

“Bears developed the attitude,” Rogers said, “that if there’s danger, run first, ask questions later and stay near a tree.”