The gender of the babies, which were born March 10 to 33-year-old Julia and April 17 to 19-year-old Tuti, is not yet known. Ernie, 31, is the father of both and both Julia and Tuti are experienced mothers, having reared three healthy gorillas between them, the zoo says.
The infants and their parents live with the rest of their troop in the Bronx Zoo's Congo Gorilla Forest, a 6.5-acre footprint in the southwest corner of the zoo that opened in 1999.
Newborn gorillas weigh about 4 to 5 pounds, but they grow to formidable sizes. The world's largest primate, the adult male gorilla weighs between 350 and 450 pounds and when standing upright, can be up to 6 feet tall. Adult females weigh between 150 to 250 pounds and are up to 4 feet tall, the zoo says.
Western lowland gorillas are designated as critically endangered by the International Union for Conservation of Nature. Their natural range spans tropical and subtropical forests in equatorial Africa. They are primarily vegetarian, mainly consuming fruits, plants, and some insects. They spend much of their time on the ground, but are excellent climbers.
For more information about the gorillas and the zoo's other exhibits, click here.