CHICAGO (AP) — Four pups of a critically endangered species of wolf have been born at Lincoln Park Zoo in Chicago.

The zoo says in a news release that the two male and two female red wolf pups were born April 13 — the first new litter of red wolf pups at the zoo in nearly a decade.

Curator Dan Boehm says the arrival of the pups comes at a time when scientists estimate there are fewer than 30 red wolves left in their native habitat of North Carolina.

The wolves — named for their red-tinged fur —have over the years been driven to the brink of extinction by hunting. The zoo is taking part with other zoos in a Red Wolf Species Survival plan to increase the red wolf population.