The world population of the endangered black rhinoceros has been expanded by one with the birth of a 50-pound female on a South Texas ranch.

Fewer than 1,200 black rhinos are believed to remain in all of Africa.Calvin R. Bentsen said the black rhino calf was born Tuesday at his family's ranch north of McAllen in the Lower Rio Grande Valley.

Bentsen said both the baby and her 1-ton mother were doing well in a 1-acre pen protected from the potentially dangerous 2,800-pound father.