Two endangered sea creatures the size of 4-story buildings spotted off Florida coast

A pair of highly endangered North Atlantic right whales traveling together made “rare” appearances off Florida’s Gulf Coast.

The nearly 40-foot female whales appear to be moving south after they were spotted in February near the Alabama-Florida border, McClatchy News previously reported.

Koala and Curlew were documented near Fort Myers on March 19, then again a couple miles off Marco Island the next day, the Florida Fish and Wildlife Conservation Commission said.

During calving season, the whales migrate south to give birth in the warmer waters off the Carolinas, Georgia and Florida, according to the National Oceanic and Atmospheric Administration. Fewer than 400 whales are left in the population, including about 70 reproducing females, as biologists fear the species is “headed toward extinction.”

Experts said it’s “rare but not unexpected” for North Atlantic right whales to make their way around the Florida peninsula to the Gulf.

It’s not surprising the pair would venture as far north as they did in February, but it is “unusual” for them to do so in the Gulf of Mexico rather than the Atlantic, marine biologists in Texas said. The whales been spotted off the coast of Amelia Island near Jacksonville at the same latitude — but that’s about 370 miles east.

“Very little is known about how right whales transition from the Atlantic Ocean to the Gulf and vice versa,” biologists with the FWC said in a Feb. 3 Facebook post. “The most recent sightings in the Gulf include a mother-calf pair in 2020 and a juvenile in 2018.”

For years, researchers have been hoping Curlew and Koala will calve, but neither 14-year-old Curlew nor 16-year-old Koala have ever calved, according to the New England Aquarium’s North Atlantic right whale catalog.

Female North Atlantic right whales reach sexual maturity at age 10, but some whales have recently been giving birth for the first time later in life, and with longer time between calves, experts say.

One of the 10 calves documented so far during the 2025 calving season was born to an 18-year-old first-time mom, and another was born to a 20-year-old first-time mom, records show.

Authorities are urging boaters to operate with caution, as the whales move slowly and may not be easily spotted from the surface. Koala and Curlew may be heading toward the Florida Keys.