Over a 12-hour period on May 10 and 11, American Red Wolf mother Charlotte whelped a litter of eight healthy, squirming pups in a secluded den at Point Defiance Zoo & Aquarium.

This is the second litter of the Critically Endangered species to be born at the zoo in seven years.

Photo Credit: Point Defiance Zoo & Aquarium

Zoo keepers monitored the young family over the weekend via cameras placed in their behind-the-scenes den. The pups are not viewable by zoo guests.

On May 13, staff biologists checked on and weighed the precious pups and discovered a ninth pup that did not survive, an occurrence that’s not unusual in large litters, according to zoo staff.

The pups are part of a Species Survival Plan© (SSP) that includes more than 40 zoos and wildlife centers across the country and has helped bring this iconic animal back from the brink of extinction.

These eight pups represent another big step in saving the American Red Wolf. On May 15, the staff gave the tiny pups a hands-on exam. The pups, which include three males and five females, weigh 11 ounces to 13 ounces each – roughly the weight of a can of soda.

The pups’ father hasn’t been introduced to his offspring yet. If he tries to come into the den, Charlotte warns him off with a low growl. Eventually she will allow him to meet the pups. Zoo staff members plan to propose prospective names for the pups and allow fans to cast votes for their favorites.

By the 1970s, only 14 red wolves were all that remained of this species that ranged across the Southeastern United States, from Pennsylvania to Texas. In 1980, the U.S. Fish and Wildlife Service declared the Red Wolf biologically extinct in the wild.

Today, some 40 roam the Red Wolf Recovery Area operated by the U.S. Fish & Wildlife Service in northeastern North Carolina where they were reintroduced to the wild three decades ago. Red Wolves remain one of the most endangered Wolf species on Earth.

See more photos of the pups below.