Fauna of Bolsa Chica
The Birds & Animals of Bolsa Chica

Explore some of the variety of Fauna found at the Bolsa Chica Ecological Reserve and wetlands.
Chicks of Bolsa Chica
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Photograph courtesy of Jane Lazarz
These birds can be found year-round along the Pacific Coast in a variety of habitats. Their range is expanding as they adapt well to suburban landscapes where they can find flowers and feeders in our gardens. Males of this species have a very buzzy song, often sung while perched.
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Photograph courtesy of Steve Smith
Black Necked Stilt chicks leave the nest shortly after hatching. Both parents tend to their young, though the chicks feed themselves. They learn to fly at 4-5 weeks of age.
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Photograph courtesy of Steve Smith
Black Skimmers are more common on the east coast, though their range is expanding west. They prefer nesting on sandy beaches or islands where they are protected from open surf, making estuaries a perfect location.
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Photograph courtesy of Steve Smith
Caspian Terns are the largest of the terns. They can be found on the coast or inland near large bodies of water. Both parents will bring food to their young. Their diet consists mostly of abundant local fish. For example, along the California coast, they might concentrate on shiner perch.
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Photograph courtesy of Steve Smith
Elegant Terns migrate between Northern California in the late summer and early fall where they will breed and Peru and northern Chile in the winter. In California waters, they prey on northern anchovy. Elegant terns are very unlikely to stray inland.
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Photograph courtesy of Steve Smith
Least Tern chicks leave the nest a few days after hatching to look for hiding places. Both parents care for their young for about 2-3 months. They learn to fly after about 20 days.
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Photograph courtesy of Steve Smith
The Western Snowy Plover is a small shorebird, about 6 inches long. Though they are of an endangered species, these birds can be found nesting on coastal beaches as far north as Damon Point, Washington, and as far south as Baja California, Mexico.
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Photograph courtesy of Babs Levitan
Great Horned Owls are common across most of North America and much of South America. They hunt at night and prefer mice, rats, and rabbits. Young owls begin to leave the nest and venture out onto nearby branches after about 5 weeks, then begin to fly at 9-10 weeks.
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Photograph courtesy of Steve Smith
Plover young leave the nest after just 2 or 3 days. In some areas, both parents will feed the young. In other areas, the female may leave after a week, leaving the male to raise the chicks. In the latter case, both parents may find new mates and renest.
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Photograph courtesy of Steve Smith
Tern chicks leave the nest after just a few days in search of a hiding place. There, both parents will feed the chick. They will learn to fly when they are about 20 days old and may stay with their parents for 2-3 months.
Birds of Bolsa Chica
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Photograph courtesy of Larry Wan
Coots are adaptable birds usually found in flocks. They require marsh vegetation and shallow water for breeding, which is why they’re happy in the Bolsa Chica wetlands, golf courses, or park ponds. They are aggressive and noisy, making calls day and night.
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Photograph courtesy of Mark D. Bixby
The American Kestrel is the smallest, most widespread, and most familiar falcon in North America. They nest in tree cavities and search for prey from perches. They mostly eat large insects and favor grasshoppers.
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Photograph courtesy of Larry Wan
Avocets use their beaks to forage for small crustaceans and insects, sweeping their head side to side, keeping their upturned bill only just submerged in shallow waters. They find their food by touch and often feed in unison with their flock.
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Photograph courtesy of Larry Wan
The Black Bellied Plover breeds in high Arctic zones and spends winters on the coasts of six continents, including out Pacific Coast. Here, they feed mostly on polychaete worms, though they also eat mollusks, insects, and crustaceans. Bolsa Chica’s mudflats, open marshes, and beaches make a perfect winter home for these plovers.
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Photograph courtesy of Vince Thomas
This species is expanding its range across the U.S., and its numbers may be growing. Black necked stilts prefer marshy grasslands and shallow pools, though they are quick to make a home out of artificial habitats like sewage ponds. They feed mostly on insects and small crustaceans, finding their food visually then picking at it swiftly with their beak.
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Photograph courtesy of Mark D. BixbyCalifornia Gnatcatchers are an endangered species with a limited range in Southern California. They are more commonly found in Baja California. Their preferred habitat is coastal sage shrub where they can find small insects or even the occasional berry.
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Photograph courtesy of Larry Wan
Though California Gulls spend most of their time along the Pacific Coast, they can also be found well inland during the winter. They are mostly known as ground foragers, eating anything it can catch or scavenge. Young California Gulls learn to catch something in midair by dropping a stick and swooping down to catch it.
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Photograph courtesy of Larry Wan
Caspian Terns have a large coral bill, making it one of the most easily recognizable terns. They live along shorelines, using aerial dives to hunt for fish, and nesting on the ground.
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Photograph courtesy of Larry Wan
Eared Grebes breed inland, including the Midwest and parts of Canada, then migrate to the Gulf and Pacific Coasts for the winter. Each year, this bird is flightless for 9-10 months, the longest flightless period for any bird on the planet that is capable of flight.
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Photo courtesy of Jane LazarzAs their name suggests, Burrowing Owls live underground in burrows. They are also long-legged owls that hunt on the ground during the day and often stow away extra food.
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Photograph courtesy of Norman Chu
Forster’s Tern looks very similar to the Common Tern. However, Forster’s have proven to be more of a marsh-dwelling bird, especially in summer, and unlike the Common Tern, they regularly winter along southern U.S. coasts.
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Photograph courtesy of Larry Wan
Most Marbled Godwits breed in the Northern Great Plains region, then winter on the coast in marshy habitats. Unlike most other shorebirds, these birds forage almost entirely on plant tubers during migration, using their upturned bill to clip tubers.
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Photograph courtesy of Jane Lazarz
Despite their size, Great Blue Herons actually only weigh 5 or 6 lbs., in part due to their hollow bones. These birds have specialized feathers on their chests that continuously grow and fray. They comb these feathers with their middle toe claws and use the down to remove oils from the rest of their feathers.
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Photograph courtesy of Mark D. BixbyThese birds are slightly smaller than Great Blue Herons, though still large with massive wingspans. They were nearly hunted to extinction in the late 19th century, but conservation movements replenished their populations and lead to some of the first laws protecting birds.
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Photograph courtesy of Babs Levitan
Great Horned Owls have long, ear-like tufts atop their heads, yellow eyes, and a deep hooting voice. These birds are commonly depicted in story books, but don’t be fooled – these are powerful birds. When clenched, their talons require 28 lbs. of force to be opened, and this power allows them to pursue prey larger than themselves.
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Photograph courtesy of Mark Bixby
Killdeer are plovers found at the beach, grasslands, parking lots, and golf courses. They run around in spurts, occasionally stopping with a jolt to see if they’ve startled up any insect prey and get their name from the shrill kill-deer they call out so often.
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Photograph courtesy of Larry Wan
The Least Tern is among the smaller terns, with wing spans of about 20 inches. They are migratory, and can be found coastally, in South America and southern North America. Least Terns nest in colonies, though they are endangered by beach goers, urbanization, and spring heat waves brought on by climate change.
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Photo courtesy of Steve Eric SmithRidgway’s Rails are on the Conservation Red Watch list, largely due to wetland loss and degradation. They are listed in the US as federally endangered. These birds have special glands that allow them to drink saltwater.
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Photograph courtesy of Jane Lazarz
The Red Tail Hawk is the most common and familiar in North America. In some areas, they’re even adapting to cities. They’re recognizable by their trademark reddish-brown tail, but the rest of their plumage varies from black to brown to white in the Western U.S.
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Photograph courtesy of Kurt Bayless
Lesser Scaups have tiny peaked hats on the back of their heads, which differentiates them from the Greater scaup, which has a more rounded head. Lesser scaups can dive for 25 seconds, reaching a depth of 60 feet.
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Photo courtesy of Cindy TiehenMale and female Long Billed Curlews look very similar, but the females have a longer bill with a more pronounced curve. Both males and females incubate the eggs, but the female will typically abandon the brood 2-3 weeks after hatching, leaving her mate to care for the young. The pair will mate again the following year.
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Photograph courtesy of Larry Wan
Mallard Ducks are the ancestors to most domestic duck breeds. Domestic ducks like this one are commonly found in lakes and ponds, all over the US and Canada (where they breed). Migrating flocks of mallards travel at about 55 MPH.
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Photograph courtesy of Norman Chu
The California Coast is one of only a few places where Savannah Sparrows can be found year round. Otherwise, they breed in Canada and the northern US, and migrate to the southern US and Mexico.
Mammals
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Photograph courtesy of Mark D. Bixby
Coyotes are able to adapt to environments modified by humans and is a prominent figure in North American folklore, often depicted as crafty and clever. They may walk 3-10 miles each day and are more active during evening and night times.
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Photograph courtesy of Jane Lazarz
Beechey Ground Squirrels, also known as California Ground Squirrels, are social creatures who live in burrows. They rarely venture more than 160 ft from their homes, only foraging for food nearby. They communicate with one another with different scents, tail signals, and sounds.
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Photograph courtesy of Mark D. Bixby
Cottontail Rabbits play a key role in their ecosystem’s food chain. They eat plants and are hunted by larger predators. If their population is abundant, predators will take advantage of them rather than hunting farm animals. This keeps the cottontail population in check, which prevents damage to farm crops.
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Black-tailed Jack Rabbits are the third largest hares found in North America. Adults measure 2 feet long and weigh between 3-6 lbs. They can be found throughout the southwestern US and Mexico, though their habitat is being fragmented by residential and commercial development.
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Photo courtesy of E. Chin
California Sea Lions are “eared seals”. These sea lions are native to the North American West Coast, preferring shallow waters for swimming and rocks or docks for resting in the sun. CA Sea Lions are very playful, intelligent, and vocal.
Amphibians and Reptiles
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Photo courtesy of E. ChinGopher Snakes may appear intimidating, as they are long and muscular, but they are actually nonvenomous. They range from 3 to 8 feet long and have larger eyes than most snakes of that size. Gopher snakes are often mistaken as rattlesnakes, but gopher snakes are typically longer and slimmer, have rounded pupils, and do not have rattles at the end of their tails.
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Photograph courtesy of Mark D. Bixby
Southern Pacific Rattlesnakes are one of the largest rattlesnakes and is one of several dangerous, venomous rattlesnake species native to California. Their venom is highly toxic to humans, but they only strike humans if they feel threatened or cornered. These snakes’ venom changes as they age, becoming stronger as they age.
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Photograph courtesy of Jane Lazarz
Western Fence Lizards can be up to 8.4 inches long. Most live in California, but they are also found as far north as Washington and as far south as Baja California. They tend to eat beetles, ants, flies, caterpillars, and spiders.
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Photo courtesy of E. ChinMale Side-Blotched Lizards have different color morphs: they can have yellow, orange, or blue throats, and each color indicates a unique mating strategy. Males also use a push-up display to defend their territory.
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Photo courtesy of Beverley HansenLegless Lizards have evolved to the point where their limbs have been reduced so that they can’t be used for locomotion. Still, they have remnant hip and hind leg bones. They may be distinguished from snakes due to eyelids, external ear openings, or having a notched rather than forked tongue.
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Photo courtesy of Beverley Hansen
Southern Alligator Lizards are native to the North American Pacific Coast. They can drop their tail if attacked and usually have 9 to 13 dark crossbands on the back, sides, and tail, with adjacent white spots.
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Photo courtesy of Stephanie WhiteThe Green Sea Turtle is an endangered species. It is also one of the largest sea turtles and the only herbivore among the species. They are mainly found in tropical and subtropical waters, and they travel long distances between feeding grounds and the beaches from where they were hatched and return to nest.
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Western Toads are considered friends to gardeners because they eat common garden pests like insects and bugs. They will also eat ants, beetles, sowbugs, spiders, centipedes, slugs, and earthworms. Western Toads live for 8 to 12 years in the wild.
Marine life and Invertebrates
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Photograph courtesy of Mark D. Bixby
The Common Hairstreak is also known as the Gray Hairstreak, so named for the thin, hairlike extensions located behind the wings. There are over 70 different hairstreak species found throughout North America. The common hairstreak caterpillar is green but forms a brownish-black chrysalis when it is fully developed. It remains in the pupal stage in the winter, then emerges in the spring as a butterfly.
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Photograph courtesy of Mark D. Bixby
Fiery Skipper Butterflies are small, only measuring about an inch long in total body length. While sitting, these butterflies can hold their wings in a triangle shape, which is unique to their species. They are thought to do this as an adaptive way to better absorb the sun’s rays.
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Photograph courtesy of Mark D. Bixby
Monarch Butterflies are known for its large size (they average a 4-inch wingspan), their coloration (which warns predators of their unpalatable taste), and their migratory patterns (they migrate about 1,800 miles on the California coast).
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Photograph courtesy of Mark D. Bixby
Skipper Butterflies are so named for their powerful flight. While they are faster than butterflies, they don’t travel far, and few species migrate. Wandering skippers are one of five subspecies, and can be differentiated by noting its browner, and less intensely orange color, with thicker black coloring.
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Photograph courtesy of Mark D. Bixby
Flame Skimmer Dragonflies may be seen from May through the fall and are among the more common dragonflies in Southern California. While males have a bright orange color, females are paler or tan, with a white stripe down their thorax region.
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Photograph courtesy of Mark D. Bixby
Dragonflies can reach speeds of up to 35 MPH. They also predate dinosaurs, having ruled the skies over 300 million years ago. Dragonflies also have two large compound eyes with nearly 360* vision. They can see a wider range of colors than humans can, and each eye has about 28,000 lenses. All told, dragonflies use about 80% of their brains to process all the visual information they receive.
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Photo courtesy of Carl JacksonRound Rays are found in the muddy, shallow waters off the coast of California, and are those most likely to be involved in stingray injuries to humans. A common way for waders and swimmers to avoid such an incident is to perform “the stingray shuffle”: keep your feet flat and shuffle along. Seal Beach, California, has the most concentrated population of round rays on the Pacific Ocean’s east coast and also has the most stingray incidents of any one place in the world.
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Photo courtesy of John HannanAdult crabs forage on any number of fish and invertebrate species. They can be found in shallow, muddy areas in lower estuaries all the way to depths of 2,000 feet.
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Photo courtesy of Alan WendellCaterpillars have one job: to eat! During the larval stage, a caterpillar has to eat enough and store enough energy to sustain itself through its pupal stage and into adulthood. Caterpillars’ first meals are often their eggshell and they may increase their body mass by 1,000 times or more, all to sustain metamorphosis.