CURWOOD: Wolves are fully protected and very vocal in Yellowstone National Park. Reporter Jennifer Jerrett went out to listen with a wolf expert.

MCINTYRE: I’m Rick McIntyre. I work for the park service in Yellowstone National Park, and my title is Biological Technician.

MCINTYRE: One of things that I often think about when we hear wolves howling is...I’m sure you know the story...that it was the last of the original Yellowstone wolves that were killed in 1926 about a half a mile from where we’re standing. And so for any visitor that had come to Yellowstone from 1926 to 1995 when wolves were brought back and re-introduced and re-established...I’m sure they had a great experience visiting the world’s first national park and would have seen a lot of great stuff, but there’s one thing they missed out on. There would have been an unnatural silence here. But luckily we realized what a big mistake that was and figured out how to rectify it. So we’re experiencing that right now. That silence is over.

CURWOOD: That's biologist Rick McIntyre...and friends. Reporter Jennifer Jerrett brought us that audio postcard from Yellowstone National Park.