Golden-headed lion tamarins are not very big. In fact, the Brazilian primates are tiny, weighing about two pounds and measuring only 13 inches. Their babies are even smaller, tipping the scales at around two ounces.
So when Lola and Coco became proud parents of twin tamarins on October 7, staff at the Smithsonian’s National Zoo were excited to see the newborns—except they couldn’t.
“They are well camouflaged hanging on to mom,” says Kenton Kerns, assistant curator at the Zoo’s Small Mammal House, where the family of four resides. “At first, we could barely see their heads as they clung to Lola. Now they stick their heads up and look around.”
This was the first time in 16 years that the species had given birth to twins at the National Zoo in Washington, D.C. Golden-headed lion tamarins, which have dark fur on their bodies and prehensile tails but display a golden lionlike mane on their heads, normally give birth to two babies at a time.
“It’s quite normal for them to have twins,” Kerns says. “The last time we had golden-headed lion tamarin babies, which was another set of twins, was from our previous family group. They had many litters of babies.”
All told, the Small Mammal House has celebrated 26 golden-headed lion tamarin births—a good thing since the species is threatened in the wild. Found only in the state of Bahia in Brazil, the primates are dwindling in numbers. Only 6,000 are believed to remain in the evergreen broadleaf tropical and semi-deciduous forests along the country’s Atlantic coast. They spend most of their lives frolicking high overhead in the forest canopy, foraging and feeding on the soft sweet fruits in the trees. New research shows that tamarins play a huge role in seed dispersal. But deforestation contributing to habitat loss threatens the animals and the International Union of Conservation of Nature lists the golden-headed lion tamarin as an endangered species.
The golden-headed lion tamarin is a similar but separate species to the golden lion tamarin, which is all gold in color. It also is threatened but an intensive breeding program through the Association of Zoos and Aquariums’ Species Survival Plan has raised its numbers from around 200 in the 1970s to about 3,000 in South America today.
“The National Zoo has been involved in lion tamarin conservation for the past several decades,” Kern says. “We’ve participated in the breeding efforts and held workshops and other programs dedicated to saving lion tamarins in the wild.”
Breeding Lola and Coco began with special steps to make sure the two were interested in each other. No, it didn’t involve flowers or wine. Instead, staff placed them in adjoining habitats with a screen between them so they could get familiar with one another.
“New animals can smell, hear and see each other this way, which we call a ‘howdy’ introduction,” Kern says. “Depending on the size of the mesh, they might even be able to touch a little. If the initial observations appear positive, we eventually remove the mesh screen and allow them to choose to share the same space. When we watched Coco and Lola, we were excited to observe they were very interested in each other immediately.”
Physical intimacy was a discreet affair, however. The keepers did not witness any serious canoodling, but did notice three-year-old Lola and seven-year-old Coco spending a lot of time together in a nesting box.
Staff had trained Lola to use a scale so they could monitor her weight. Soon, they noticed she was getting heavier and her belly bigger. At the end of four months—the normal gestation period for the species—Lola gave birth to the twin tamarins.
“The keepers have been able to interact with Coco and Lola up close, just like they did before the birth, so keepers have been able to get close-up views of the babies to assess their health,” Kern says.
The staff hasn’t given them names yet since the genders are still unknown. That will be determined in about six months, when the young ones get their first thorough health examination.
There is no live cam but visitors to the National Zoo can watch the young family doing their daily routines. The doting parents are focused on caring for the babies and really don’t mind if anyone is taking a peek at them.
“They seem to ignore crowds in the visitor space,” Kern says. “This makes for great viewing if you’re coming to visit them at the Small Mammal House.”
The Small Mammal House at the Smithsonian's National Zoo is open daily from 8 a.m. to 4 p.m. in Washington, D.C.