A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times

A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times

A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times

A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times

A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times

A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times

A female bison calf born May 16, scampers with its mom Leotie and the other bison at Brookfield Zoo's Great Bear Wilderness Exhibit Wednesday morning. The female calf marks the first birth of this species at the zoo since the early 1970's. | Rich Hein~Sun-Times