Partner Series
Rare Baby Black Rhino Born at St. Louis Zoo
Credit: Saint Louis Zoo.

A black rhinoceros calf was born at the St. Louis Zoo on Jan. 14. The newborn is the first of its kind born in the United States in 20 years.

The baby boy weighed in at a whopping 120.5 pounds (55 kilograms). He is nursing well with his mother. The pair are enjoying some quality time together behind the scenes, according to zoo staff. When the weather turns warmer, they will move outdoors. [See other zoo babies .]

First-time parents Kati Rain, the mother, and Ajabu (pronounced ah-JAH-boo), the father, arrived at the zoo in 2007. Kati Rain is from Sedgwick County Zoo in Kansas, and Ajabu from the San Diego Zoo Safari Park. Both are six years old.

The new black rhino is the eighth calf born at the St. Louis Zoo. The zoo's black rhinos are part of a program to build a genetically healthy population of the critically endangered rhinos in North American zoos. Today there are 60 black rhinos living in 38 institutions.

The black rhino's numbers have declined more dramatically than any rhino species. The rhinos are heavily poached for their horns . According to the International Union for Conservation of Nature (IUCN), only about 4,200 black rhinos are still alive on the planet.