OMAHA, Neb. (AP) — Four endangered indigo snakes are the newest babies at Omaha’s Henry Doorly Zoo & Aquarium, marking a first-time birth of the species at the zoo.

The Omaha World-Herald reports that the snakes made their appearance Wednesday and Thursday.

Their births are the result of an Eastern Indigo Species Survival Plan recommendation. The zoo said in a news release that such plans manage threatened and endangered species to ensure that they are healthy, genetically diverse and demographically varied across institutions accredited by the Association of Zoos and Aquariums.

Eastern indigos are native to the southeastern U.S. and are considered the largest non-venomous snake in the country. Some reach up to 8½ feet in length.

Once they are able to feed on their own, the snakes will be moved to a habitat visible to the public.