The yet-to-be-named male calf was born on October 25 to first-time mother Amala.

The zoo's unit supervisor Jennifer Conaghan said keepers were monitoring mother and calf, and both were doing well.

"Amala is being very protective of him," Ms Conaghan said.

"She is keeping her distance from us and keeping the calf close, which is what we expected to see.

"In the last couple of days Amala has brought the calf into a behind-the-scenes yard, and we've been able to monitor things more closely.

"We have seen the calf suckling and although it is still only days old, we are extremely happy with the situation so far and absolutely thrilled to have this new addition on the ground."

The zoo's greater one-horned rhino breeding program began in 2009 when Amala arrived from Los Angeles Zoo to join resident male Dora who came from Japan.

"This birth is a credit to years of work by the zoo's dedicated life sciences team to successfully introduce the two, an introduction which has produced a healthy calf following Amala's 15-month gestation," Taronga Western Plains Zoo director Matthew Fuller said.

"We're the only zoo in Australia to have three species of rhino, and three successful rhino breeding programs, so critical for these species that are all threatened in the wild."

The greater one-horned rhinoceros is classified as vulnerable on the International Union for Conservation of Nature Red List with as few as 2700 left in the wild.

Mr Fuller told the Daily Liberal that Amala and her calf would remain behind the scenes for the coming weeks to continue to bond.