We took these photos about 10 km off Loreto between Isla Coronado and Isla del Carmen. We saw first humpback whales with one breaching, then some fin whales, and finally 7 blue whales. Intermixed were hundreds of common dolphins and miscellaneous sea birds.
How does one tell a blue whale from a fin whale? First, a blue whale is larger, reaching up to 30 meters, whereas a fin whale’s length never exceeds 22 meters. Lengths of dorsal fins are different, too, with the blue whale’s 1/3 m. and positioned very far to the back, and the fin whale’s 2/3 m.. The most important diagnostic, however, is coloration. The blue whale is a mottled blue/grey color, and the fin whale is darker and a solid dark gray to brownish-black color. Finally, the blue whale’s very wide tail fluke (sometimes 1/4 of the length of its body) is often raised before a deep dive, while the fin whale rarely shows its tail fluke before diving deeply. Blue whales feed on krill by opening their mouths, taking in volumes of water with krill and then expelling the water through pleats in their throats and using their baleen to strain out the shrimp-like krill.
(End of Large Cetacean Identification 101 😉
