PROVINCETOWN (CBS) — Good news for an endangered species: researchers say they’ve documented North Atlantic right whale mother and calf pairs in Cape Cod Bay. The Center For Coastal Studies says three calves have now been seen in the Bay this spring.

Local naturalist Peter Flood photographed the first pair on Sunday off Race Pain – a mother named Calvin who had been seen with her new calf in February off the Georgia coast.

A CCS aerial team spotted a mother named Palmetto and her new calf on Tuesday off Mayflower Beach in Dennis. And later in the day the team photographed Harmonia and her new calf east of Manomet.

“To our knowledge, this is the first time that either of these two new moms have brought their calves into Cape Cod Bay,” noted Dr. Charles “Stormy” Mayo, director of the Right Whale Ecology Program, in a statement. “At this point in time we don’t know what specifically drew them here this year, although good feeding conditions is likely part of the story and the results of our right whale habitat monitoring work may offer up some clues.”

The Center said only 10 known North Atlantic right whale calves were born this season. One likely suffered deadly wounds when it was hit by a boat and hasn’t been seen since January.

“It’s a long and perilous journey from the right whale calving grounds off Florida and Georgia to Cape Cod Bay, so it’s always a relief to see the mothers and their offspring arrive unscathed,” Dr. Mayo said. “With only 400 of these animals left in the world, it’s up to us to do everything we can to protect them while they’re in our waters, even during these incredibly difficult times.”

The New England Aquarium said earlier this month that sightings of the endangered whales are increasing off the coast of Massachusetts.