Scientists have discovered a previously unknown baby North Atlantic right whale off the coast of Canada, months after the calving season ended — a rare piece of good news for one of the world's rarest sea mammals.

Researchers with the Mingan Island Cetacean Study photographed the mother and calf near Anticosti Island, Quebec, on 25 September. After weeks of comparing the images with the North Atlantic Right Whale Catalog, scientists at the New England Aquarium in Boston determined the calf was born during the 2025–2026 calving season but had gone unseen in winter surveys.

A season total raised to 24

The discovery lifts the number of calves documented from the latest birthing season to 24, the most productive year for the species since 2009 and the fourth-highest count on record. Researchers had previously counted 23 mother-calf pairs.

The mother is a whale known to researchers as Silt, catalogued as number 1817. She is at least 38 years old, and the new calf is her sixth known offspring. Silt was briefly seen in the south-eastern US calving grounds in February 2026, so the calf may have been born there.

Why every calf matters

North Atlantic right whales number only about 380, and their population has fallen since 2010 after losing about a quarter of its size between 2010 and 2020. Only around 70 reproductive-age females remain.

The whales are threatened by collisions with large ships and entanglement in commercial fishing gear. Silt herself has survived at least five entanglement events, and her 2022 calf, Division, died earlier this year after a severe entanglement.

"It just goes to show you how big the ocean is, and how those animals can get lost out there," said Richard Sears, founder and director of the Mingan Island Cetacean Study.

**Sources:** [Associated Press](https://phys.org/news/2026-11-scientists-unknown-baby-whale-canada.html) | [New England Aquarium](https://www.neaq.org/about-us/press-room/press-releases/in-surprise-sighting-previously-unknown-north-atlantic-right-whale-calf-is-spotted-in-canadian-waters/)