Two rare North American right whales -- a mom and baby -- have been documented off the coast of Florida for the first time this calving season.
Aerial surveyors took photos of the roughly 31-year-old mom named Minus One and her fourth calf on Dec. 9 near Amelia Island in north Florida, the Florida Fish and Wildlife Conservation Commission's Research Institute said.
They're the second pair identified this calving season and the first off Florida for a species "approaching extinction," according to the National Oceanic and Atmospheric Administration. Experts estimate only 370 North American right whales remain in the wild, including fewer than 70 reproducing females.
The first mom and calf pair identified this season was another 31-year-old mom named Nauset with her baby, seen near Sapelo Island, Georgia, on Dec. 1, McClatchy News reported. One other pairing was reported about a week earlier off the coast of South Carolina, but marine researchers have yet to identify the mom.
Right whales migrate to the warmer waters near the Carolinas, Georgia and north Florida during calving season, which begins in mid-November and typically runs through mid-April, biologists say.
Right whale surveyors hope that other females recently spotted in Southeast waters may be mothers.
"Although there haven't been many sightings in Florida to date, we expect right whales are present or moving into the area," according to the FWC. "Right whales maintain a low profile and are often difficult to spot despite their enormous size."
The endangered species can grow to 52 feet long and weigh 140,000 pounds, with calves typically entering the world at a whopping 14 feet, NOAA says.
"These animals occur in coastal waters and are known to spend a lot of time resting and nursing near the surface of the water where vessel strikes can occur," according to the FWC.
Biologists suspect that stress from human-caused hazards such as strikes and entanglements have led to right whales giving birth less often. Addressing these threats is the key to helping the population rebound, researchers say, as right whales are dying faster than calves are being born.
Marine biologists encourage boaters to report right whale sightings to 877-942-5343 or to the U.S. Coast Guard on VHF Ch. 16.
Amelia Island is about a 30-mile drive northeast from downtown Jacksonville.