Published Jun 1, 2017 at 12:39 PM | Updated at 9:16 AM EDT on Jun 2, 2017
A brave mother bison stood her ground and protected her newborn from a coyote at Yellowstone National Park.
The park service tweeted on Tuesday pictures taken by ranger Joy Guffy.
The mother was "successful" at defending her calf from the "very determined" coyote, the park tweeted. She had just given birth.
Check out photos of the confrontation below.