BOSTON -- There are two new adorable additions at the Franklin Park Zoo. A potto, a small primate, was born on Sept. 9, and a bongo, a type of antelope, on Sept. 28, zoo officials announced Tuesday.

The birth of the potto gave a boost to the tiny North American captive population, which only numbers 12 animals. Franklin Park Zoo is one of three zoos in the country to exhibit them, and one of the only zoos that has been consistently adding to the captive population.

This baby potto, not yet named, is the offspring of Tallensi (mother) and Rendille (father), and is being cared for by zoo staff off-exhibit, marking the third time a potto has been successfully hand-raised at Franklin Park Zoo. Zoo New England's animal care and veterinary staff prefer to have baby animals raised by their mothers, as they would be in the wild. However, Tallensi has never shown an interest in caring for her young so zoo staff had to step in to help ensure the baby potto’s survival.

Pottos are small primates native to the forests and wooded savannahs of West Africa and Central Africa. The nocturnal animals, which are covered with dark brownish fur, are slow-moving, well-camouflaged and are found in the forest canopy. Pottos, whose body-lengths measure between 12 to 15 inches long, give birth to one to two offspring. Full-grown pottos weigh just less than 3 pounds and have large, dark round eyes.

"We’re fighting to save the dwindling captive population of this fascinating denizen of the forest," said John Linehan, Zoo New England President and CEO. "Our staff is skillfully hand-raising the baby potto for about the first two and a half months of its life. The baby requires an extraordinary amount of time, care and attention and we are extremely proud of our success with this remarkable species."

Two weeks after the potto was born, Courtney, the zoo's 11-year-old female bongo, gave birth to a healthy calf. The baby, which the zookeepers named Isabel, weighed 42 pounds at birth and has delighted visitors with her bright eyes and big ears. The calf can be seen on exhibit with her mother and 4-year-old half-sister, Annakiya, who was also born at the zoo. The zoo has exhibited bongos since the late-1970s and the calf is the sixth born at Franklin Park Zoo.

Bongos are the largest, and often considered the most beautiful, forest-dwelling antelope found in the lowland rainforests of equatorial Africa. The animals have dramatic coats with 12 to 14 thin white stripes overlaying shades of bright chestnut. Bongos are fairly nocturnal and their large eyes and big ears enable them to see and hear better in poor light conditions.

"The potto and bongo are two exciting new additions to our animal family at Franklin Park Zoo," Linehan said. “We have had a long history of success with both animals and credit is due to our exceptional zookeepers and veterinary staff. These new babies will join the rest of our animals in delighting visitors and highlighting the importance of protecting natural habitats around the world.”

While many people associate animal births with the spring, it is important to note that pottos and bongos are native to tropical climates. Their reproductive cycles are not tied to our New England climate.