The Honolulu Zoo welcomed three additions to its family with the birth of three Sumatran tiger cubs on Monday.

The three are the first tigers to be born at the Waikiki zoo since April 1981.

Sidney Quintal, director of the city's Department of Enterprise Services, said 9-year-old mother Chrissie and the three cubs appear to be healthy and doing fine.

While the cubs were born on Monday, zoo officials couldn't determine until yesterday that there were three babies. The sexes of the three are still not known.

Quintal said he could not say when the cubs would be available for public viewing.

"We want to make sure the cubs are healthy and that they open their eyes," he said. "Right now they're like any litter of kittens — they're born blind."

The plan is for the cubs to be named in the next few weeks.

It's not up to the city to determine whether any of the cubs will stay in Honolulu long term, Quintal said, but the Association of Zoos and Aquariums' Species Survival Plan for Sumatran Tigers.

It was the association's program that brought Chrissie and Berani, the cubs' 9-year-old father, to Honolulu in the first place, Quintal said.

The structured breeding program is designed to maximize genetic variability in the captive population. Chrissie and Berani previously produced a litter of two males and one female at the Fort Wayne (Ind.) Children's Zoo in April 2004.

The zoo likely will keep the cubs until they mature, Quintal said.

Chrissie was born at the National Zoo in Washington, D.C. She came to Honolulu in 2005 via the Fort Wayne Children's Zoo in Indiana. Berani was born in the Phoenix Zoo and came to Honolulu from Fort Wayne the same time as Chrissie.

There are 41 male and 27 female registered Sumatran tigers in captivity in 25 zoos within the United States and Canada, zoo officials said.

The gestation period for the Honolulu Zoo's three new cubs was 107 days, zoo officials said.

A second tiger habitat was built about a year and a half ago to accommodate the breeding pair, Quintal said. The facility was built for $200,000 with private help from the Honolulu Zoo Society.

Zoo officials want to ensure that a third adult tiger already at the zoo, an older female named Djelita, does not come in contact with the cubs or Chrissie, Quintal said.

Before yesterday, the last time tigers were born at the Honolulu Zoo was on April 27, 1981, to a pair of Bengal/Siberian hybrids, Tex and Marybell.

They produced a litter of five cubs, two of which were stillborn. Another cub died shortly thereafter, leaving one male and one female that were eventually sent to other zoos.

Meanwhile, there's a mini-baby boom going on at the zoo.

Two wrinkled hornbill birds were born about two months ago. About 45 days ago, a king vulture was born.

And zoo enthusiasts are getting ready for the arrival at the end of the month of two sun bears, Quintal said.

"They are a breeding pair, so we're ramping up to have (bear) cubs too," he said.