A rare Blainville’s beaked whale rescued on Maui earlier this month is progressing in its recovery, officials said Thursday.

Volunteers from the University of Hawaii at Hilo continue to tend to the 11½-foot-long, 1,800-pound whale at the school’s Hawaii Cetacean Rehabilitation Facility on the Big Island.

The whale was rescued in shallow waters Aug. 16 from South Maui and flown to the marine mammal hospital that opened in December.

Beaked whales are deep-water swimmers that are rarely seen, and less than 20 have been held in captivity. None have survived long enough to be returned to their natural habitat, the university said.

“We’re fully aware of the challenge we face, but are encouraged by how well she is doing,” said Jason Turner, director of the facility and UH-Hilo marine science professor. “While the animal’s condition has periodically slipped, it has generally remained in stable condition.”

Turner said the whale is able to swim on her own and is being tube-fed, but has not yet accepted solid food.

The group of 15 to 20 volunteers have been working around the clock to help save the whale, said David Schofield, National Oceanic and Atmospheric Administration’s marine mammal response coordinator.

They are still trying to pinpoint the exact nature of the animal’s ailment. The results of initial blood tests pointed to a kidney problem, but her signs appear to have improved.

The whale also has elevated glucose levels, which could be a sign of diabetes. However, experts are working with very limited information since the species is so understudied and they have no baseline health data for comparison, officials said.

Full rehabilitation could take months and will require expansion into a nearby larger and deeper facility that will allow the whale to swim at greater depths before returning it to the ocean.

Researchers are looking to the patient to learn what they can about the deep-diving whales that spend little time at the surface.

Robin Baird, who has filmed groups of Blainville’s beaked whales off the Big Island, hopes regular high-frequency acoustic recordings can be made because very few sounds have been made from the species.

According to NOAA, the estimated number of animals in the Hawaiian stock is 1,200 to 2,200, the Northern Gulf of Mexico is about 100 animals and there is no current estimate for the Western North Atlantic Stock. The species is protected under the Marine Mammal Protection Act.