The baby François' langur (Trachypithecus francoisi) was born on Dec. 13, the first birth of the species at the facility, Philadelphia Zoo wrote on its Facebook fanpage.
"We've named her Quý Báu (pronounced "Qwee-bow"), which means "precious" in Vietnamese," it said, adding François' langurs are native to southern China and northern Vietnam and classified as endangered by the International Union for Conservation of Nature (IUCN).
A video of Quy Bau posted on the zoo’s Facebook account on Jan. 16 received around six million views, over 142,000 reactions and 16,000 comments. Many expressed their congratulations and adoration toward the baby langur.
The population of François' langur has been declining for several decades. They are threatened mainly by habitat loss and hunting, with some people believing their bones have medicinal value.
While there is no reliable population estimate, there are likely no more than 200 individuals left in Vietnam, according to IUCN.