The birth of the pygmy slow loris is the Bronx Zoo’s first since re-opening its “World of Darkness” building last year.
Bronx Zoo
By Alexandria Brown
The Bronx Zoo announced Jan. 22 in a press release the birth of an endangered pygmy slow loris born on Dec. 13 last year. Native to Southeast Asia, it was the first primate born at the zoo since the reopening of the “World of Darkness” space in 2025, following major renovations.
The “World of Darkness” exhibit first opened in 1969, making it the first major zoo exhibit that let guests see nocturnal creatures like the slow loris during their active period. The historic building reopened last year with updated features, including programmable LED lights that simulate natural day-to-night transitions, showcasing the adaptations of 25 species that thrive in darkness.
The new inhabitant is a particularly significant addition, with the pygmy slow loris designated endangered by the environmental organization International Union for Conservation Nature’s Red List of Threatened Species. The group reports the species is vulnerable due to habitat loss from human settlements and agriculture, as well as hunting for the illegal pet trade.
The Bronx Zoo is part of the pygmy slow loris Species Survival Plan, is a breeding program managed by the nonprofit Association of Zoos and Aquariums that aims to help maintain a genetically diverse population of endangered species.
The small animals are born fully furred with their eyes open, and reach an adult weight of about one pound. They are carried on the mother’s stomach while infants, and intermittently are parked on branches while the mother forages for food.
Still growing, the baby will become more active and independent as it grows, and should be fully weaned by around 6 months old. Staff will determine the baby’s sex at its first veterinary exam.
The Bronx Zoo is open daily from 10 a.m. to 4:30 p.m. through April 1, and summer hours will begin the day after. Animal exhibits close 30 minutes prior to the park closing. Since the pygmy slow loris is sensitive to light, the zoo requests visitors not take flash photographs.