Miami (AP) – A rare greater one-horned rhinoceros has been born at Zoo Miami through artificial insemination. Zoo officials say it’s only the second time in the zoo’s history.

The unnamed baby rhino was born Tuesday and it’s not clear whether it’s a boy or a girl. Greater one-horned rhinos usually weigh between 4,000 to 6,000 pounds.

Natural breeding wasn’t successful so a special team of reproductive specialists for endangered species came from the South East Zoo Alliance for Reproduction and Conservation.

The Miami Herald reports the crew artificially collected semen from the father in January. They artificially inseminated the mother the next day.

The expectant mother had been under 24-hour observation leading up to the birth.

Zoo officials said there are less than 3,000 Indian rhinos left in the wild.