‘Surprise’ calf adds to 2026 right whale calving season total

At the end of the North Atlantic right whale calving season last spring, researchers had tallied 23 pairs of right whale mothers and their babies, a hopeful showing for this highly endangered species. That total increased by one recently when a female named Silt showed up in Canada with a previously undetected calf.

“Sneaky Silt,” was the response from Jessica Thompson, senior wildlife biologist who leads the Georgia Department of Natural Resources’ marine mammal program.

“She was seen off the Carolinas, but she was never seen with a calf last season, and so she swam under the radar,” Thompson told The Current GA. “It’s good that these whales are avoiding vessels and avoiding detection, except for the fact that we really need to learn as much about them as possible. So I mean, part of me is like, ‘good job, mom. You stayed away from us. You did your thing.’ But the other part is like, ‘Okay, now come a little closer. We still need a biopsy of that calf. We want to confirm that that is your calf.’” 

The new total, 24 calves last season, has been bested only once over the last two decades when 39 calves were recorded in 2009. There are no known deaths or injuries among the newest calves.

Researchers from Mingan Island Cetacean Study captured images of a calf with its mother near Anticosti Island, Quebec, in late September. Scientists with the New England Aquarium who manage a photo-identification database called the North Atlantic Right Whale Catalog identified the mother as Silt and determined the calf was likely born during the 2025–2026 calving season. Silt (Catalog #1817) is at least 38 years old and has now given birth to six known calves in her life. She is a grandmother and a great-grandmother.

“This is an exciting discovery for us so late in the year,” Amy Warren, a scientist in the Aquarium’s Anderson Cabot Center, said in a press release.

Right whales, the official Georgia state marine mammal, were hunted to near extinction more than hundred years ago. They currently number about 380 individuals. While protected from hunting, many have been injured or killed by vessel strikes and by entanglement in fishing gear. 

At this time of year they are beginning their migration south from feeding grounds off New England and Canada to calving grounds centered off Georgia’s coast.

A female named Calvin has already been spotted on her way south, with confirmed sightings by research teams off New Jersey and Virginia beach, and a possible sighting off North Carolina by members of the public. 

“It’s possible that it is Calvin,” Thompson said of the public sighting.  “The swim speeds would make sense. It’s the same trajectory, the distance, but the photos weren’t good enough to confirm it yet.” 

Right whales typically give birth from mid-November through mid- April in the Southeast, where scientists theorize the water temperature strikes a balance of warm enough for newborn whales but not too warm for their blubber-coated mothers. It’s mainly expectant mothers that make the migration, but sometimes juveniles accompany them. Thompson is hoping the calf seen with Silt has already developed markings that will allow researchers to identify it in the future and eventually biopsy the calf and use DNA analysis to confirm its relationship to Silt.

Thompson was part of the team that struggled for two days in December to free Silt’s last calf, Division, from a serious entanglement in lobster fishing gear. While the effort was partially successful in removing gear, Division later died as a result of the entanglement. Silt herself has been entangled at least five times, leaving visible scarring on her head and tail. Another of her calves, #2617, died in 2005 after being struck by a vessel.  

Thompson’s team at DNR is set to begin its surveys for right whales Dec. 1. The DNR funds an aerial survey team from the Clearwater Marine Aquarium Research Institute and coordinates with that team to locate whales and photograph and biopsy them from boats. This year the DNR team will also be testing technology that aims to identify whales with infrared and thermal imaging to aid vessels in avoiding these animals, Thompson said.

“We’re really hoping this year is as joyous and as exciting as last,” she said.