'Incredibly Rare': Baird's Tapir Abby At Franklin Park Zoo Expecting Twins

BOSTON (CBS) – Staff members at Franklin Park Zoo are preparing for a rare birth sometime this summer.

Abby, a Baird's tapir, provided a big surprise when staff performed an ultrasound in December and discovered she is carrying twins. According to the zoo, twins are "incredibly rare" in all tapir species, and may be a first in Baird's tapirs since there are no records of previous occurrences.

The zoo said Abby's full-term due date would be mid-September. But her care team is preparing for an earlier delivery because that is often the case with twin births of many species.

"We have consulted with colleagues and experts around the world on this highly unusual pregnancy. While this is very exciting, it does come with some risk to survival of both calves," said Dr. Eric Baitchman, Zoo New England vice president of animal health and conservation.

Because tapirs are distantly related to horses where twin births are rare and risky, Baitchman said the care team can use that knowledge to prepare.

Abby is currently healthy and weighs 648 pounds. Baird's tapirs are an endangered species. They are the largest land mammal found in South America.