A rare Channel Island fox pup is the latest addition to the Santa Barbara Zoo. The baby, a male, was born April 12 and is being hand-raised because its mother isn't able to nurse. It opened its eyes last weekend and is "doing really well," said the zoo's director of animal medicine, Dr. Karl Hill.

This rare Channel Island fox pup was born at Santa Barbara Zoo on April 12. Anna Davison/SBN

"We were feeding around the clock for the first week," Hill said. The mother was unable to nurse because of damage to her teats. Hill said she came to the zoo in that condition and its not known if she had been injured or was born with a defect.

Her pup now weighs about seven ounces — triple its birth weight. Fully grown Channel Island foxes are only about the size of a domestic cat; they're the smallest canines in North America.

The zoo has five adult Channel Island foxes — two breeding pairs and another adult. The last time they bred successfully was 2002. Those foxes were sent to Los Angeles Zoo and the Charles Paddock Zoo in Atascadero. Hill said the latest pup would probably go to another zoo.

Channel Island foxes are found on six of the eight Channel Islands; each island is home to a unique subspecies. The pup, its parents and the zoo's other breeding pair of foxes are the San Clemente Island subspecies. The zoo also has a Santa Rosa Island fox.

The San Clemente Island fox is classified by the state as a threatened species; the foxes on Santa Cruz, Santa Rosa, San Miguel and Santa Catalina islands are listed as endangered by the federal government.

To try to bolster fox populations, captive breeding programs have been established on several of the Channel Islands, and Santa Barbara Zoo staff has helped the effort.