Mammals Among Us: California's Coast

As a group, mammals are surprisingly diverse.  While all mammals breathe air, have fur or hair, and give birth to live young, they vary significantly in their habitats and modes of transportation.  While most walk or hop while moving about on land, some fly and others swim, some spending most or all of their lives in water!  While some of these aquatic mammals spend a good deal of time on land at the water's edge, like seals and sea lions, other mammals, such as whales and dolphins, never leave the marine environment they were exquisitely designed to inhabit.

With 840 miles of coastline (ranking third in the nation behind Alaska and Florida), it is perhaps not surprising that marine mammals make up a significant portion of California's wildlife.

Let's explore the variety of mammals that may be seen along California's beautiful coast and within its offshore waters.

Sea Otter, Elkhorn Slough

Sea Otters, the most aquatic members of the weasel family, only rarely come ashore.  Nearly their entire lives are spent in the ocean, where females even give birth!  In California, Sea Otters are uniquely associated with kelp forests, where they spend much of their time feeding, floating and sleeping, often wrapped in the kelp itself.  One of the very few mammals to use tools, Sea Otters use rocks from the sea floor to crack open the shellfish they feed on.  Typically, an otter holds the rock on its chest or stomach while floating on its back, and repeatedly bashes the shellfish on the rock until it cracks.  (Where Sea Otters are close enough to shore, this behavior can be witnessed from land, and observers can even hear the sound of the rock and shellfish cracking together!  While the otter is breaking open the shell in this way, it usually turns its face carefully away in order to avoid being splashed.  It's really quite fun to watch!)

Sea Otter in kelp, Santa Cruz

Sea Otters are the only sea mammal without blubber.  Instead of relying on an insulating layer of fat to keep warm in frigid oceans waters, Sea Otters are protected by incredibly thick fur.  With up to one million hairs per square inch, Sea Otters have the densest fur of any animal.  And they are very particular about keeping their fur well-groomed (which is another fun behavior to observe in the wild!)  

Sea Otter, Moss Landing

That luxurious fur was nearly their undoing, and Sea Otters were almost lost to us forever due to overhunting.  And with them, we nearly destroyed the kelp forests as well.  

Read more about the conservation of Sea Otters - and why it matters - in this article.  

Sea Otter, Moss Landing

Harbor Seals are another one of our cutest marine mammals, often found lounging about (somewhat slug-like) on rocky shorelines, breakwaters and wharves.  They are fairly small seals, males reaching a little over five feet in length.  Harbor Seals are highly variable in color, ranging from extremely pale tan to almost black, though most are shades of brown or gray, and dappled or spotted. 

Harbor Seals, Monterey

Seals and sea lions are members of the group of mammals known as pinnipeds, a word meaning "fin-footed."  The fin-feet of seals and sea lions do in fact do double duty as flippers, for fast propulsion and agile maneuverability in the water, as well as feet, for shuffling somewhat clumsily on land.  Seals and sea lions are carnivores, feeding on a wide range of fish, octopus, squid, crab and bivalves which they hunt in the water.  They come ashore to defend breeding territories, mate and give birth, as well as to loaf about on the sand or rocks.  

Harbor Seal, Monterey

California's only other true seal species is the Northern Elephant Seal which, as its name suggests, is a truly immense creature.  Females reach nearly 10 feet in length, and males may exceed 16 feet, from tail to snout, and weigh over 7,000 pounds.  Like many marine mammals, elephant seals were long viewed as valuable commodities, largely for the amount of oil they produced, and as a result were nearly hunted to extinction.  120 years ago, there may have been as few as 100 individuals left in existence; today, thanks to conservation efforts, populations have recovered to somewhere around 150,000.

Elephant Seals, Point Reyes

There are a few key differences between seals and sea lions.  The first is the placement of the front flippers.  The front flippers of seals are close to the head, making them unable to raise their heads very far above their bodies.  This also makes them fairly awkward on land.  The front flippers of sea lions are placed farther back on the body, allowing sea lions to raise their heads up, as pictured below, and "walk" fairly well on land.

The second difference to look for is the presence of external ear flaps.  These "ears" are absent in true seals and present in sea lions.

California Sea Lions are the most common species of sea lion on the coast of California, and the one most likely to be encountered along wharves, marinas and breakwaters.  Often, their noisy "barking" is heard long before they are seen, as gregarious groups of these pinnipeds lounge about together at favored haul-out sites.

California Sea Lions (and cormorants), San Diego

Three additional species of sea lion may be found off California's coast, but they are far less common or likely to be encountered than the California Sea Lion.  All six of our pinnipeds (California Sea Lions, Harbor Seals, Northern Elephant Seals, Northern Fur Seals, Guadalupe Fur Seals and Steller Sea Lions) may be seen on and around San Miguel Island, the northwestern-most of the Channel Islands, though Guadalupe Fur Seals and Steller Sea Lions are both quite rare there.

Guadalupe Fur Seals (really sea lions) breed on Guadalupe Island, off the coast of Baja California, and may rarely be encountered off the Channel Islands, where they formerly bred.  

Northern Fur Seals (also sea lions) breed mainly in the Gulf of Alaska, though females and their young migrate and may be seen in Californian waters.  A small breeding colony has recently been established on San Miguel Island.

Steller Sea Lions are also a predominately northern breeder, but a small breeding population exists on Ano Nuevo Island.  Significantly larger and paler than California Sea Lion, they are by far the less likely to be seen of the two species. 

The most strictly marine of all of our mammals, whales and dolphins are member of the order Cetacea.  Within this order exist two distinct suborders: the toothed whales and the baleen whales.  Dolphins are placed in their own family within the group known as the toothed whales, and the most common species encountered is, appropriately, the Common Dolphin.  

These intelligent and inquisitive mammals often follow in the wake of whale watching boats and they are such a delight to watch!

Other dolphins of Californian waters include Risso's Dolphin, White-sided Dolphin, Northern Right Whale Dolphin, Bottlenose Dolphin, Pilot Whale and Killer Whale. 

Common Dolphin, off the Channel Islands

Baleen whales are best represented in California by Humpback and Gray Whales, which are often seen on dedicated whale watching boat trips.  Blue Whales and Minke Whales and Fin Whales are present as well.

Humpback Whale tail fluke, Monterey Bay

If boats aren't your thing, you still have a chance to catch some exciting glimpses of these magnificent marine creatures from shore.  While whale spouts, the plumes of vapor that spout into the air as a whale surfaces to breathe, are often spotted with the naked eye, having binoculars or even a spotting scope will help immensely.  Whale spouts and flukes (whale tales that rise in the air as a whale dives) may be observed from land, especially from elevated headlands like Point Lobos in Carmel, Point Pinos in Pacific Grove and Point Reyes in Marin County.  Dolphins may occasionally be seen gamboling in the surf not far off shore.

Some of the best places that I know of to find sea otters and pinnipeds in Central California include Moss Landing Harbor (for Sea Otters and Harbor Seals), Monterey Bay from Fisherman's Wharf to Point Pinos (for Harbor Seals and California Sea Lions), and Ano Nuevo State Park and Point Reyes National Seashore (for Northern Elephant Seals.)  

Monterey Bay is also an excellent location to embark on a whale watching trip to see whales, dolphins and more!

And, you might also enjoy a visit to the Marine Mammal Center in Sausalito, where visitors can view marine mammals that are being rehabilitated before their return to the wild, and learn about ways to help with marine mammal conservation.