TAMPA, Fla. (WFLA) – Four critically endangered red wolf puppies were born at ZooTampa in April, the zoo announced Monday.

The three female and one male pup were born to 3-year-old mom, Nymeria, on April 28.

The pups had a 2-week checkup on Friday and are doing well. The zoo said in a Facebook post their eyes are open and they are gaining weight.

The zoo is hopeful the pups will emerge from their den later this summer.

In March, a mating pair of red wolves began to call the zoo home and staff said they were hopeful there may be pups.

ZooTampa participates in The Association of Zoos and Aquariums’ Red Wolf Species Survival Plan, as well as the U.S. Fish and Wildlife Service’s Red Wolf Recovery Program.

According to National Geographic, there are only an estimated 35 or fewer red wolves left in the wild.

The zoo says although extremely unlikely, all red wolf sightings should be reported to redwolf@fws.gov.