With a cluster of endangered false killer whales making a rare appearance off Kona, scientists were able to tag members of the elusive group for the first time ever.

“It was an amazing encounter,” said Robin Baird, a research biologist with Cascadia Research Collective. “It was the highlight of our trip, and really, it was the highlight of our year.”

Little is known about the movement and whereabouts of this particular group of whales, which hasn’t been seen in nearly four years.

But that should change as researchers Saturday were able to attach satellite tags to the dorsal fins of three of the whales. Each tag — attached remotely with a titanium dart — will provide location updates 10 to 12 times a day over the next couple of months.

Only 150 to 200 false killer whales are found in the waters of the main Hawaiian Islands, making it Hawaii’s rarest cetacean, a classification that includes whales, dolphins and porpoises.

Even though false killer whales are widespread in warm oceans throughout the world, Hawaii’s population — divided into three individual clusters — is unique because it generally remains within 70 miles of shore, according to Cascadia. The species was listed as endangered in 2012.

Light winds Saturday allowed the research vessel based at Kawaihae, Hawaii island, to venture farther north than usual, Baird said, and that’s where they encountered the 50 or so members of Cluster 2 spread over five or six miles in deep water.

“It was so exciting,” he said. “They are so rare.”

False killer whales live into their 60s and tend to remain in social clusters in the way killer whales stay in pods.

Of the three Hawaii clusters, Cluster 1 is usually seen five to 10 times each year, while Cluster 3 is seen once or twice a year, Baird said. By contrast, Cluster 2 has been seen only 20 times since individual false killer whales were first documented in 1986.

On Saturday, the last day of a weeklong project, researchers were able to photograph about 20 different individuals to compare them with an existing photo catalog.

Each adult in the population is distinctive, Baird explained, and researchers compare notches, nicks and other markings on dorsal fins to identify individuals.

Of the 20 whales photographed Saturday, researchers have identified 15 individuals, including one that was first documented in 1986 and was only the 15th false killer whale identified in Hawaii waters.

So far, the satellite data show that since Saturday the tagged whales have remained off the north end of Hawaii island in the Alenuihaha Channel. On Thursday afternoon the tagged whales were about halfway between Maui and Hawaii island.

Baird, who has been studying the false killer whale in Hawaii since 1999, said it will be interesting to see where Cluster 2 goes in the next few weeks to months.

One of the fascinating behaviors exhibited by this particular species, he said, is the passing around of food from one animal to another without devouring it.

“It is the only species that has this kind of symbolic prey sharing,” he said. “It reflects the trust of a long-term hunting companion and the social bonds that exist between them.”

The team of researchers included Daniel Webster, Annie Douglas and Baird from Cascadia Research Collective, the nonprofit organization that is leading the research. Other researchers were Carmen DeFazio from the Hawaiian Islands Humpback Whale National Marine Sanctuary and Kona residents Deron Verbeck, Julie Steelman and Colin Cornforth.

The project was funded by grants from the federal Pacific Islands Fisheries Science Center and the Hawaii Ocean Project, and was undertaken in collaboration with the national marine sanctuary.