As we move further into the new year, here’s an overview of the season so far:

The Totals

We know of 38 North Atlantic right whales wintering in the southeastern U.S. Thirty are females and all are 6 years or older. That means all could be potential mothers this season.  Nine have already been seen with calves. We’re hoping for more. (Update: One of the calves was seen Jan. 3 with severe wounds consistent with being hit by a boat propeller. Boaters are urged to report if they see this calf.)

Why Biopsy Calves? 

Four calves have been biopsied to confirm genetics. Why is this important?

Distinguishing physical characteristics sometimes don’t develop on right whales until later in life. Genetic analysis is often the only way to identify a calf or juvenile, including who its mama is.

Through this work, researchers have recorded “calf swapping.” That’s where a calf is seen with what’s thought to be its birth mom but is actually another adult female that has adopted it.

Also, tracing the survival of calves to adulthood and knowing the age of adults are metrics that help power statistical models estimating population numbers and survival rates. These metrics are essential to understanding the future of North Atlantic right whales – which number only about 350 and are the most critically endangered large whale on Earth. Every whale that survives each year can mean the difference in this species’ survival.

North Atlantic right whale Horton (#3360) and calf about 6 miles east of Cumberland Island on Jan. 3 2024 (Clearwater Marine Aquarium Research Institute/NOAA permit 26919)

Horton and calf about 6 nautical miles east of Cumberland Island (CMARI/NOAA permit 26919)

The Scoop on Swerve and Horton

Swerve (right whale catalog no. 1810) was the first whale spotted by our crew. It was Nov. 29, the day before the official start of the calving season.

Swerve was being evasive, so we didn’t try to get close enough to collect data other than photos confirming her ID. We joked on the boat that, considering her size and behavior, she was hopefully very pregnant and ready to give birth — alone.

When we saw Swerve on Jan. 3, about five weeks later, she had a calf. A calf that looked more than a month. We were able to take quality photos of both, even though Swerve was being a good mom and kept the calf away from our research vessel. That meant we couldn’t get a biopsy sample for genetic and health analyses.

Later that day, we spotted Horton (whale no. 3360) and her calf, a pair we hadn’t seen since Dec. 7. Unlike with Swerve, we were able to biopsy both the mother and calf.

And now you know why those samples are essential.

Top: Closeup of Swerve off Georgia’s coast (DNR/NOAA permit 26919)