SEWARD, Alaska — Marine mammal specialists from across the country have descended on an Alaska aquarium to help care for a baby beluga whale that became separated from its mother shortly after its birth.

The male calf is under 24-hour care at the Alaska SeaLife Center in Seward, being fed by a stomach tube while learning how to suckle from a bottle.

‘‘He’s currently doing very well, swimming on his own and he has been from the first time he got here, learning to take food from a bottle, which has been challenging,’’ said Tara Riemer Jones, the center’s president and chief executive.

It is believed to be the first baby beluga rescue in the United States, at least since federal record-keeping began in 1972, she said. Other attempts at rescue resulted in calf deaths or in one case, the calf being returned to its pod.

It is such a rare event that specialists have been helping with the animal’s care, including staff members from the Georgia Aquarium in Atlanta, Shedd Aquarium in Chicago, and SeaWorld in San Diego.

The whale was estimated to be 2 days old when it was found near South Naknek, in Alaska’s Bristol Bay, on June 18. Officials believe a storm probably separated the calf from its mother.

Tim Lebling, the Alaska SeaLife Center’s stranding coordinator, flew to South Naknek that afternoon to retrieve the calf.

It was flown 90 minutes back to Seward in dry transport. Lebling said the calf was placed on an air mattress in the plane, positioned so its weight wouldn’t put pressure on vital organs, and then constantly covered with wet towels.

ASSOCIATED PRESS