The Burgers’ Zoo in Arnhem, the Netherlands, got a surprise last Saturday as a white rhino named Kwanzaa gave birth to a male calf, Vince, a month before zookeepers were expecting him. Births in captivity are considered extremely rare, with only 10 white rhinos being born in European zoos in 2011, according to the Burgers’ Zoo.

Vince is said to be healthy and doing well, although he won’t venture outside or meet his father until zookeepers are sure he is strong enough, a spokesperson told BBC News. Of the premature birth, the spokesperson didn’t seem too overly concerned with it: “That’s not terrible because he’s very healthy, as you can see. Rhinos have a pregnancy for about 17 months and a month earlier or a month later–that’s also normal,” he said.

The healthy baby is Kwanzaa’s second with her mate, Gilou. They had their first calf, named Dozer, in 2010.

White rhinoceros, also known as square-lipped rhinoceros, are the biggest of the five rhino species that are still in existence today.

The term “white rhino” is actually a misnomer, thought to have resulted from English-speaking settlers of South Africa mistaking the Dutch word “wijd,” which means “wide,” for “white.” The white rhino was called the wijd rhino because its mouth is wide.

The International Union for Conservation of Nature lists the white rhino as “near threatened,” meaning it could someday be extinct, and the animal continues to be threatened by poaching and habitat loss, according to the World Wildlife Fund.

Photo courtesy Burgers’ Zoo