One animal you are almost guaranteed to see during a Hornblower Whale Watch Cruise is the California sea lion. These highly social and noisy marine mammals are usually spotted lounging on navigational buoys, or hanging around in groups by the bait docks. California sea lions are a type of pinniped; a group of marine mammals that includes all seals, sea lions, and walruses. Sea lions and fur seals are further grouped in the Otariidae family of “eared seals” which share the key characteristic of external ear flaps unlike “true seals” and walruses, which just have a tiny opening on each side of the head.
As you watch sea lions moving around on the bait docks, you’ll notice that they can tuck their hind flippers beneath their body and use all four flippers to “walk” around. Sea lions also have long, wing-like front flippers that they move up and down to fly through the water. Adult male California sea lions are easily distinguished from females by the raised bump on their forehead called a sagittal crest and are typically a darker brown. Males also grow much larger than females, reaching lengths of 6.5 to 8 feet (2–2.5 meters) and weighing 440 to over 880 pounds (200–400 kilograms). Adult females are about 5 to 6.5 feet (1.5–2 meters) and weigh 110 to 240 pounds (50–110 kilograms).
California sea lions range along the Pacific coast of North America and within the Gulf of California. Most of the rookeries (pupping grounds) are on islands in the southern part of their range. A female gives birth to a single pup every year, which she nurses for six to twelve months. California sea lions are active hunters, preying on a variety of fish, small stingrays, squid and octopus. While they have excellent eyesight both in and out of the water, they often rely on their sensitive vibrissae (whiskers) to detect and follow the movement of prey in dark or murky water conditions.
During a whale watch, you may see sea lions porpoising like dolphins while traveling to and from San Diego Bay. Less commonly, you may see them porpoising as part of a feeding aggregation with other wildlife such as terns, gulls, other seabirds, tuna, dolphins and occasionally even baleen whales, all feeding on bait balls of small fishes.