A solitary animal, Javan rhinos don’t form social groups but live alone except when they mate or care for their young. Scientists think their lifespan may be around 30 to 40 years. We know they mate ...

Mating is a challenge for Sumatran rhinos. The critically endangered animals live in four isolated regions scattered across 10,000 square miles of steep, dense forest, and males rarely venture far.

Sudan, a northern white rhino and the last male of his subspecies, died Monday at the Ol Pejeta Conservancy in Kenya. The rhino — once called by the dating app Tinder as the “most eligible bac ...