Mexican gray wolves have been born in the wild for the first time in decades, according to a report from the Mexican government.
The litter of wolves was born sometime in June. They were spotted by researchers, studying the western Sierra Madre mountains.
Parents of the young animals were released in December 2013, as part of a seven-year plan to reintroduce the animals to their native habitat. Wildlife conservationists were hoping the pair would reproduce, which they did.
The animals disappeared from the region 30 years ago. These are the first animals born in nature, bolstering the recovery plan. The National Commission for Natural Protected Areas in Mexico made the announcement of the discovery.
Thousands of Mexican gray wolves once lived in Mexico and southwestern areas of the United States. They were nearly wiped out by a combination of hunting, trapping and poisonings. Just five members of the species were still known to live in 1977.
Over the next three years, conservationists captured, and bred, these last survivors in a last-ditch effort to save the species. Starting in 1988, Mexican gray wolves were released into the wild in Arizona, Mexico and other areas in the desert southwest. Managed by the U.S. Fish and Wildlife Service, this first release consisted of just 11 animals. Re-introduction of the animals into Mexico started in 2011.
This sub-species of gray wolf is known as "El lobo," or simply, "The Wolf." Despite the name, the animals are not entirely gray - they possess distinct brown fur on their backs. They are speedy runners, with sleek bodies powered by long legs.
The exact location of the gray wolf pups was not revealed. This is standard practice, in order to protect the animals from tourists, or potential poachers. Mexican gray wolves typically have litters of between four and seven puppies. Packs care for newborns until they are about 10 months old.
The Fish and Wildlife Service released an annual survey of the endangered animals in the United States. They report at least 83 of the animals are living in New Mexico and Arizona. This is the fourth year in a row American populations of the animals has improved. The number of wild wolves living in Mexico is unknown.
"Although their numbers have grown slowly, and they remain the most endangered subspecies of wolf in the world," Defenders of Wildlife wrote on their website.
The wolf pups appear to be in good health, and are doing well, according to investigators.