All right, I’ll admit it; the first California Sea Lion I ever saw was at the famed Sea Lion and Otter Show at Sea World. But, the image of that tongue-wielding mongrel has stuck with me ever since, even if the antics of its wild counterparts are not quite as unreserved. Well, sometimes.
Gregarious and rambunctious are only some of the words used to describe California Sea Lions. If you were to ask a fisherman, the words might not be so kind as these clever animals are quick to snatch a free meal from the end of a fishing line. However, their streamlined bodies and characteristic elongated front flippers make them agile in the water and a pleasure to swim with for any SCUBA or free diver.
California Sea Lions, Zalophus californianus, are probably the most commonly seen pinniped along the Pacific coast of California, often overtaking buoy markers or even the swim step of unused yachts as their sunbathing posts. Populations of California Sea Lions on the West Coast are at historically high levels. Since the mid-1970s, they have increased at a rate of six to eight percent a year, tripling in population. The current population of these animals is believed to be about 145,000. Most of this increase in numbers is attributed to the regulations imposed by the 1972 Marine Mammal Protection Act, and California Sea Lions are no longer considered endangered. But I say the population surge is from the free meals these slippery creatures acquire from unsuspecting divers and fishermen.
Their distinctive earflaps and elongated front flippers make California Sea Lions unmistakable, or maybe it’s just their obnoxious bark that can be heard reverberating from almost any dock or pier off the Pacific coast that will leave you certain. Consider this little morsel of information; ball-balancing circus seals that have entertained us from early childhood are actually Sea Lions. In fact, due to their intelligence and enthusiasm, the majority of trained "seals" in circuses and amusement parks are actually California Sea Lions. While the sausage-shaped bodies and stumpy front flippers leave most seals somewhat restricted while on land (other than doing the break dance move known as the "worm" to get around), the long front flippers of Sea Lions help them to move about quite easily on land as well as in the water. Other than that, seals lack external ears and rather than the dog-like face of Sea Lions, seals look like they have had a close encounter with an 18-wheeler. I just want to know what the seals did to Mother Nature to be so deserving!
As we have just learned, there are some differences between Sea Lions and seals, but there are also differences between male and female California Sea Lions. For example, males are typically much larger than females, reaching a typical length of 2.4 meters and weight of 200 to 400 kg while females normally only reach 1.8 meters in length and weigh up to 100 kg. While the fur of males is usually a dark brown, the fur of females is often much lighter or even tan. All males have thick necks, while a protruding forehead, known as a sagital crest, characterizes only mature males. Think of it like this; the older a guy gets, the thicker his head.
As their common name suggests, California Sea Lions occur primarily off the coast of California, but they also occur around the Galapagos Islands as well as Japan. On the Pacific coast their range spans from British Columbia to the Sea of Cortez in Mexico.
The breeding season of California Sea Lions occurs between May and July. At the onset of the mating season, mature bulls or males, are the first to inhabit the rookeries. Prior to the arrival of the females, the males scuffle and fight in order to stake claim on the premiere territories of the rookery. Better territories ensure larger harems of females with which the males will pass on their dominant genes. Year-long gestation periods yield a single pup. Therefore while some females are without pups, others have just given birth.
It is easy to see that life at a rookery is anything but melancholy. Though adult males and females are often observed resting on rocks or taking care of the very young, juvenile Sea Lions are in the water frolicking every chance they get. The best time to visit a California Sea Lion rookery is mid-summer to fall, when pups have become energetic adolescents. This is also when most bulls have left for their winter homes, an important detail to note for all of you black neoprene-laden divers that bear some resemblance to an enticing female Sea Lion.
As one diver after another steps over the side of the boat, Sea Lions often launch themselves in a huge commotion towards the boat to investigate. Often chasing one another through the seagrass and kelp, California Sea Lions occasionally involve a diver in the play. Never will you feel so clumsy or encumbered by neoprene and hoses as when these daredevils soar through the water in a beeline for you, yank on a strap and then promptly disappear before you realize which end is up. This is often the time when divers opt for the more minimalist approach of freediving. Included in this notion is the fact that Sea Lions take blowing bubbles underwater as a sign of aggression.
California Sea Lions have bodies that are specially equipped for swimming. When they dive, their inner ears and nostrils close, the oxygen in their system concentrates in the heart and central nervous system as opposed to organs that are non-vital to the dive. This is a response known as the Marine Mammal Reflex. Sea Lions have the ability to remain underwater for an average of 8 to 20 minutes, something free divers can only dream of. In fact, California Sea Lions have been recorded diving as deep as 900 feet, wooooo-weeee. These animals can dive to these depths because of their high tolerance for carbon dioxide.
One of the more common behaviors boaters typically observe California Sea Lions engaged in is known as jug-handling. Unfortunately this is not in any way related to a trip to Hooters, but rather has a much more scientific explanation behind it, i.e., thermoregulation. California Sea Lions that are seen resting at the surface with one flipper out of the water are actually regulating their temperature. The capillaries of Sea Lions are close to the surface of the skin and therefore catch the warmth of the sun to heat their bodies. In contrast, if a California Sea Lion is too hot, they may dip their flipper in the water and raise it back into the air, which will then cool their body temperature due to the evaporation process. Because of the arc formed by the flippers, sealers named this stance the "jughandle" position. Today sea lions resting in this fashion are said to be "jugging."