George Sanker / Black bear (Ursus americanus) female and cubs on rocky slope. Yellowstone National Park, Wyoming, USA. May.

Jenny E. Ross / A female polar bear (Ursus maritimus), and her 23-month-old triplets, hunting on the sea ice. Hudson Bay, Manitoba, Canada. November

Shattil & Rozinski / Pronghorn antelope with three young {Antilocapra americana} Red Desert NP, Wyoming, USA

Matthias Breiter / Grizzly Bear (Ursus arctos horribilis) mother with triplets, crossing sedge flat, Katmai National Park, Alaska

Jenny E. Ross / Polar bear cubs (Ursus maritimus) triplets age 2-3 months next to their mother. Wapusk National Park, Manitoba, Canada. February

Jenny E. Ross / Adult female polar bear (second from left) and her 24-month-old triplets (very unusual for all three to survive), hunting on the sea ice.

Jenny E. Ross / Polar bear (right, foreground) female and her triplets age 23-months triplets, Hudson Bay, Manitoba, Canada. November.