Surprise! It's a baby elk.

About five weeks ago, the New York State Zoo at Thompson Park had an unexpected delivery when 16-year-old Rosie the elk gave birth to Mystic.

"Once some large animals have given birth, it can be difficult to tell they're pregnant," zoo director John S. Foster said. "We didn't have a clue she was even pregnant."

Mr. Foster said that Rosie is also near the end of life expectancy for elk and zoo staff didn't think she could bear another baby.

The gestation period for elk is 250 days.

Since her birth, Mystic has been hidden in one corner of the elk exhibit by Rosie. Mr. Foster said this behavior is similar to that of deer. The mother will go about her business during the day, checking on the young occasionally.

Then, as the young deer or elk becomes more steady on its feet, it wanders around with more freedom. Mystic is now at that age and will be seen by more visitors, along with her mother and the two male elks in the exhibit.

"She's just darn cute right now," Mr. Foster said. "She's now running around in the group. They're a protective family, very alert to anything that's going on around them."

Mystic will nurse until she's about six months old. The zoo will decide whether to keep her in the exhibit or place her at another zoo after a year.

The zoo also faces a decision about its wolves. After the recent death of Gandalf, one of the zoo's two gray wolves, the zoo is considering several options.

The best, Mr. Foster said, "would be to be able to find funding to allow us to obtain socialized wolves."

Socialized wolves are raised around people, so they would be seen more by visitors and would allow keepers to go into an exhibit.

In other zoo news:

■ The wolverines, Valentine and Stinky, are waiting on fence repair to move into the wolverine exhibit. The two have been introduced slowly after Stinky, a 9-year-old male, contributed to the death of his previous mate in July 2007. Valentine is a 2-year-old female.

■ The otter exhibit design is almost complete. The site for the 1,800-square-foot site was cleared in May. The exhibit will hold four river otters. One otter, Louie, is staying at the Wild Center in Tupper Lake while the exhibit is completed.

■ The zoo is still waiting for the stainless steel mesh for the new bald eagle and turkey vulture/raven exhibits. "It has to be cut to fit," Mr. Foster said. "We've been pestering them."

■ The zoo is looking for a new home for the two alligators that were confiscated by the Department of Environmental Conservation in Lowville in May.