A northern white rhinoceros that was only one of six left in the world has died at the San Diego Zoo Safari Park.
U-T San Diego reports Angalifu, who was about 44 years old, apparently died of old age on Sunday.
His death leaves only one northern white rhino at the zoo, one at a zoo in the Czech Republic and three in a preserve in Kenya.
Rhino horns are valued as dagger handles and are mistakenly seen as an aphrodisiac. As a result, poaching has pushed the critically endangered rhinos to the brink of extinction.
Attempts to mate Angalifu with the female northern white rhino at the San Diego Zoo Safari Park weren't successful.