Adorable but Deadly Fluff Balls, Better Known as Pygmy Slow Lorises, Born at the Smithsonian’s National Zoo

Small mammal caretakers at the Smithsonian’s National Zoo and Conservation Biology Institute (NZCBI) were in for a surprise late last month when they arrived at work. Naga, a 3-year-old pygmy slow loris, had two newborn babies holding on to her. They’re the first of their endangered species born at the zoo, according to an announcement.

Zookeepers had suspected that Naga was pregnant—she’d started gaining weight after being introduced to a 2-year-old male named Pabu in September—but they didn’t know for sure because her thick fur made it difficult to obtain an ultrasound image. So on March 21, when Kara Ingraham spotted Naga hanging out on a high branch at a time of day when she’s normally sleeping, she knew she needed to take a closer look.

“I went to go check and she had the babies clinging to her,” Ingraham, an animal keeper in the zoo’s small mammal house, tells Smithsonian magazine in an email. “They were probably born right before we came in.”

The two babies are healthy and happy, though keepers are keeping a close eye on them because one of the babies was smaller than the other at birth. Veterinarians will determine their sex in a few months.

“They have been doing really well,” says Ingraham. “We have been able to get almost daily weights on both babies and they are both consistently gaining and look very strong.”

Pygmy slow lorises are listed as “endangered” by the International Union for Conservation of Nature. They live natively in the mixed deciduous and evergreen forests of Cambodia, Laos and Vietnam, where they face threats from habitat loss for logging and use in traditional medicine.

These docile, nocturnal animals have large eyes and round faces, which also makes them a “big target” for wildlife trafficking and the pet trade, according to Ingraham.

“They really do look like little teddy bears,” she adds.

But they’re hard to keep as pets: Pygmy slow lorises are the only primates known to produce venom—which can incapacitate large predators, including humans—and they primarily feast on tree sap. They’re also sensitive.

“Their social, medical and nutritional needs are really difficult to meet for pet owners and the pressure that the illegal pet trade puts on their wild populations has driven the decline in their population,” Ingraham says. “We hope that guests understand what animals do and do not make good pets and when they see videos of exotic animals in pet homes that they remember the loris and don’t engage with or support that content.”

The National Zoo is doing its part to help boost the species’ numbers in partnership with the Association of Zoos and Aquariums. As part of its Species Survival Plan, the association played matchmaker and sent Naga and Pabu to live at the National Zoo in August 2022 in hopes that they might someday reproduce. (Naga had been living at the Brookfield Zoo in Illinois, while Pabu was at Little Rock Zoo in Arkansas.)

The association selects animals for breeding based on their genetics, as well as their health and temperament.

About a year after Naga and Pabu arrived, animal keepers slowly introduced the two—and, apparently, they hit it off right away. The species’ gestation period is about six months so, while keepers didn’t observe them mating, the birth timeline suggests they bred not long after meeting.

“Every birth helps to keep a sustainable and healthy population of lorises under human care to serve as ambassadors for their species,” says Ingraham. “When guests come to the Small Mammal House and see the lorises, they have the opportunity to learn about this unique and venomous primate and also to understand the threats they face in the wild and what they can do to help.”

With pygmy slow lorises—as with humans—opposites seem to attract. Naga is calm and sweet, and she tends to get spooked easily. She can often be seen resting in the exhibit or exploring slowly. Pabu, meanwhile, is inquisitive and energetic. He fearlessly approaches keepers at feeding time and eagerly participates in training sessions.

Females tend to be the primary caregivers in growing pygmy slow loris families, though males sometimes interact with their babies. At NZCBI, keepers have mostly seen Naga grooming, nursing and carrying the infants—but they’ve also watched Pabu take over parenting duties when Naga heads out in search of food.

“Pabu has proved to be an attentive and patient father,” according to the zoo.

Much of the time, the babies hold onto Naga as she wanders around. But, in the mornings, she will often “park” them on a branch or in their nest while she ventures off, which is a common pygmy slow loris behavior, says Ingraham.

“Keepers have a really good relationship with both Pabu and Naga, and they have been very accepting of us entering the exhibit and picking up both babies from the nest,” she adds. “We bring them out for a quick weight behind the scenes and then return them to the nest. Usually Naga is still eating breakfast and watches as we put them back while she continues eating.”

Right now, the babies rely on their mother’s milk for nutrition. But, within the next few weeks, they may start nibbling on insects or tree sap. They’re already starting to show signs of curiosity about their surroundings.

“The babies make a very cool clicking vocalization and like to stick their heads out of the nest and check out everything around them,” says Ingraham.

Sarah Kuta | READ MORE

Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.