My wife and I were in Yellowstone, the first week of June, 1984. About 75yds off the road, laying in a small river, hoofs on the bank, body in the water, was a calf elk, with the cow going into and out of the water. I pulled over and ran back (without the camera due to the rain/snow) to watch, and the cow is frantic, and BUGLING like crazy. The calf eventually lost his hold on the bank and was swept downriver, the cow following, and still bugling.
I had no idea cows could bugle.