Year-round, the Central Coast is rich in biodiversity – from the shrublands, the coastal shorelines, the steep hilltops, and the abundance of native plants – a wide variety of wildlife hangs out or migrates for food, shelter, and of course, to pay us a visit.
Some of the most iconic wildlife here on the Central Coast includes the monarchs of Pismo Beach, the sea otters of Morro Bay, and the elephant seals of Piedras Blancas. Below is some insight for when and where to see each of these species, along with more fun facts.
The Monarch Butterfly (Danaus plexippus)
Throughout coastal San Luis Obispo County, monarchs can be found hidden in the tops of eucalyptus trees, cypress trees, or even in your backyard milkweed. Monarchs are not currently on the endangered species list, but still scientists worry for their survival. Fortunately, the Pismo State Beach Monarch Butterfly Grove – one of the largest in the United States – is publicly owned, which allows for better protection of the insect.
The butterflies that migrate to our coast are part of an ongoing tagging study to help researchers discover more about their life patterns. There are two populations of Monarchs that call the U.S. home: the eastern population living east of the Rocky Mountains, which migrate south to spend winter in Mexico, and the western population, living west of the Rocky Mountains, which migrate to the coast of central and southern California.
The western Monarchs’ summer range extends to the Pacific Ocean and up as far as southern Canada. In October, to escape the freezing temperatures, the butterflies instinctively know to fly south, some over 1,000 miles – a risky journey that many do not survive. By November, most monarchs are overwintering in treetops ranging from the San Francisco Bay Area down to San Diego.
Pismo State Beach is home to one of the largest over-wintering congregations, with a count of 3926 butterflies in December 2019, according to the Oceano Dunes State Park. When the sun is out, they are usually more active, flying around and sunning with their wings open in the treetops. They sometimes leave their canopies, in search of water and nourishment from flower nectar, though they do not need much. Unless they use a lot of energy while overwintering, they mostly store up reserves on their journey south. Then in late February, as the air grows warmer and the females are done mating, their northern migration begins, in search of milkweed plants to lay their eggs. Soon after, they die, lasting about six to eight months in total.
Once the eggs hatch (after just a few days of arrival), they transform into tiny larvae that begin obsessively eating milkweed leaves day and night – it is the only food they can eat but it will increase their weight 2,700 times within just two weeks (equivalent to a human baby growing to the size of a gray whale in just two weeks). Once it has reached full size, the full-grown caterpillar will attach itself to an object, shed its skin, and form a chrysalis (a hard, green and gold colored outer skin). For the next two weeks inside the chrysalis, the caterpillar rearranges its body’s molecules – a process called metamorphosis – and then it emerges into the beautiful orange and black Monarch butterfly we know.
Then the new summer Monarchs continue flying farther north, mating, laying their eggs on milkweed, and dying. The “super generation” that survives the migration south lives six to eight weeks, while other generations only live about four to six weeks. Each new generation flies farther and farther north, following the milkweed – it takes about five generations to make it back north for the milkweed. Scientists are uncertain how successive monarch generations know to return to the overwintering sites, though they suspect it is linked to sensors in their antennae. And with the shortening days of Fall, this generation of monarchs will begin the migration south.
Different organizations and agencies are working across the U.S. to protect and restore habitat for monarch butterflies through research, educational workshops, and resources for conservation.
The California Sea Otter (Enhydra lutris)
Almost anywhere in the Morro Bay estuary, a sea otter can be seen twirling in the water or cracking open clams. The sandspit barrier that surrounds the inlet of the bay creates a break and keeps the water calm and protected – the perfect habitat for a furry creature who lays on its back all day. Though the otters hangout year-round, they are especially playful and abundant when the sun is out and the weather conditions are calm. Spectators can walk along the boardwalk that wraps around the estuary (right behind The Great American Fishing Company) for the best on land, up-close view.
Though sea otters seem to be widespread nowadays, it was not always that way. Back during the maritime fur trade of the 1700 and 1800s, sea otters were hunted to near extinction and their population greatly decreased. They used to extend continuously along the North Pacific Rim but became restricted to just a few small remnant colonies. In the 1970s, a scientist named Dr. James Estes discovered the important presence of sea otters and their dramatic effect on coastal habitats, which eventually lead to their classification as a “keystone species” – meaning they are largely depended on by other species in an ecosystem and if removed, the ecosystem will drastically change.
Sea otters live in a cold ocean environment, so in order to keep warm they rely on two traits: a very high metabolism (to generate body heat) and a dense fur coat (for insulation). In order to maintain a high metabolism, sea otters consume up to 25% of their body weight each day – for warmth and survival. Their carnivorous diet consists of an array of (mostly invertebrate) marine species: crabs, clams, sea urchins, snails and worms. Sea otters have the densest fur in the animal kingdom, every square inch of their body consists of 1 million hairs! Their dense fur allows for a pocket of trapped air to serve as insulation in the cold ocean water. Sea otters spend anywhere from 2 to 4 hours everyday grooming themselves, in order to maintain that pocket of insulation.
The Northern Elephant Seal (Mirounga Angustirostris)
In peak times, up to 24,000 elephant seals can be seen lounging along our shoreline throughout the year, doing what looks like a variety of yoga poses. They visit our beaches in age driven beach coverage twice a year : December to March is the birthing a breeding season for adults,, May to October you can find much of the seal population shedding massive layers of skin and fur for their catastrophic molt, and finally,during the fall juvenile haul-ou you can see yearlings taking a break after their first migration at sea. The best time to view battling bulls on the beach is the end of November when the first mature males arrive to shore to claim their territory.
The northern elephant seal is the largest seal in the northern hemisphere and is the second largest seal in the world (after the southern elephant seal). Adult males can stretch up to 16 feet in length and 4,000 to 5,000 pounds in weight. The females are much smaller in size, at about 9 to 12 feet in length and 900 to 1,800 pounds, and pups are 3 to 4 feet long at birth and weigh about 70 pounds.
And where to see these large creatures? Located just seven miles north of San Simeon on Highway 1 is the Piedras Blancas Rookery – a large accessible viewpoint, free and open to the public daily.
From December through March, pregnant female elephant seals arrive to shore for birthing season, with the majority of expecting mothers arriving in January. Births typically occur just a few days after the mother’s arrival. Elephant seals pups are typically born during nighttime, weighing about 70 pounds at birth and up to 300 pounds at weaning. During the last week of nursing (about 24 days), a female mates with the alpha bull then takes off to sea without her pup. The pups typically get left alone to learn to swim and find food on their own. By March and April, most pups are ready to depart for the sea.
Beginning in April, females and juvenile elephant seals return to the shore to molt – a process in which elephant seals shed the outer layer of their hair and skin. They lay around for about four to six weeks during this time, without consuming any food. Most females and juveniles return to the ocean by the end of May. And from June through August, subadult and adult males arrive at the shore to begin their molt separately. By then, the beaches are mostly cleared out, besides the large adult males who sometimes remain to the end of summer.
From September through October, females and sub-adults arrive on the shore to prepare for the fall haul-out, in which they return to the beach to rest up. The purpose of this is unclear, however, it allows the seals time to strengthen their muscles and bones. And for adult males, it is a time for sparring with each other and winning over female attention – as well as giving us human spectators quite a show.