Bison calves born this spring are growing quickly, building relationships and learning survival skills. Sometimes called “red dogs” because of their orange coats, bison calves are slowly becoming dark brown like their parents. Neal Smith National Wildlife Refuge in Iowa has a small herd of bison in a 700-acre enclosure and visitors can safely observe them from the visitor center or the auto route tour. Photo by Joanna Gilkeson, U.S. Fish and Wildlife Service.