A 15-foot newborn gray whale calf and its mom are an unusual sight in San Francisco Bay, but some scientists say the recent visitors are yet another sign of a changing climate and shifting life patterns in the ocean.
Severely depleted by hunting before the practice was outlawed in 1940, the gray whale population usually mates in the tropical lagoons of Southern California during the winter, returning a year later to give birth. Researchers who study to the annual migration of the whales—which head north to feed in polar waters in the warmer months—suggest calves are being born earlier on the trip south.
This may suggest whales are staying in warmer polar waters for longer to feed on shrimp-like creatures, or that the northern feeding grounds themselves may be retreating northward along with ice sheets, making whale’s trip longer. San Francisco residents at least got a rare baby whale sighting and proof that short-term at least, their numbers are growing.