Treetops to the Ocean: Marbled Murrelets

Cover photo: © Aaron Maizlish, 2017, some rights reserved.

Marbled murrelets are full of surprises – defying all expectations of a seabird, they nest high up in redwood trees. Learn about their nest discovery in 1974 and their close ties with coast redwoods.

Cover photo: © Aaron Maizlish, 2017, Flickr Photo Album, some rights reserved.

Places to See Marbled Murrelets

Marbled murrelets are seabirds.

By nature of being seabirds, murrelets spend the majority of their lives out at sea in search of food. They eat mostly fish and crustaceans.

Marbled murrelets are very unique amongst seabirds in that they nest high up in redwood trees.

Most other seabirds, including their close cousins puffins and murres, nest on rocky cliffs along the shore. The marbled murrelet defies all expectations of a seabird by nesting high up in redwood trees. They will sometimes travel 30 miles inland to nest.

Their solitary nests up in old-growth trees makes them very difficult to find – a tactic that’s thought to help discourage predation. Parents will also only fly to the nest to switch who’s incubating or to feed young very early in the morning or late at night to avoid detection by predators.

Marbled murrelets are different colors in the breeding and non-breeding season to camouflage with their different habitats.

Marbled murrelets are small, robin-sized birds. They are black on top and white on bottom during the non-breeding season (any time when they’re not attracting mates or nesting).

Marbled murrelets adopt mottled brown plumage during the breeding season – a unique transition that’s not found among their close relatives. This brownish color is thought to help them camouflage with the redwood trees that they nest in.

Marbled murrelets live along the northwest coast of the United States.

Their range extends from southeastern Alaska to northern California.

The marbled murrelet is listed by the state of California as endangered.

In Oregon and Washington, the species is listed as threatened. Factors such as habitat loss, predation by other birds (namely Steller’s jays), and low food availability have affected their population.

Image result for crumb-free sign marbled murrelet stellers jay sign
A common sign at campgrounds, featuring a Steller’s jay and a warning to clean up all traces of food. Source: Save the Redwoods League.

In many California state and national parks, you’ll notice a campaign urging visitors to keep their space “crumb clean”. This movement is to discourage the number of Steller’s jays and other scavenging birds that are attracted to food that people leave behind.

Why be worried about attracting Steller’s jays, when it’s a charismatic and attractive bird? Well, in addition to eating human leftovers, Steller’s jays will also eat the eggs and young of other birds. One such species is the marbled murrelet, whose numbers are negatively affected by Steller’s jay predation.

Cool facts about marbled murrelets:

  • The marbled murrelet’s nest was discovered in 1974 by accident, when a tree climber in Santa Cruz stumbled upon its nest.
  • Marbled murrelets are the most recent species to have their nest discovered in North America.
  • Marbled murrelets are also known as “fog larks”, since their keer-keer call was heard early in the morning high up in redwood forests. It wasn’t until their nest was discovered in the 1970’s that people put together who was vocalizing.

Resources to learn more:

Daytime Owls: Western Burrowing Owls

Cover photo: © Julio Mulero, 2017, some rights reserved.

Did you know that not all owls are active at night? Meet the burrowing owl – a small, charismatic species of owl that is out during the day.

Cover photo: © Julio Mulero, 2017, Flickr Photo Album, some rights reserved.

Places to See Western Burrowing Owls

Shoreline Park Circle

Shoreline Regional Park

Western burrowing owls are small, standing at about 10 inches.

Western burrowing owls have a mottled pattern of brown and white across their body. They have bright, yellow eyes and long legs. They are small owls, averaging 8 to 10 inches in height.

Burrowing owls are facing steep population declines in the Bay Area.

Habitat loss and fragmentation have led to steep declines in the Bay Area’s burrowing owl population. In the mid-1980’s, it was estimated that there were 640 individuals, with three-quarters in the South Bay alone. In 2017, a survey in the South Bay reported just 64 individuals during the breeding season.

Projects for owl habitat restoration and public education programs are being implemented now. For more information on how you can get involved, visit the Santa Clara Audubon Society’s volunteer page and the Golden Gate Audubon Society’s docent page.

Burrowing owls are found in two areas in the United States: the west and Florida.

Burrowing Owls are separated into two subspecies: one species found in the western United States (western burrowing owl) and one species found in Florida (Florida burrowing owl). In the San Francisco Bay Area, they are found in isolated areas in the East Bay and South Bay.

In the northern part of their range, western burrowing owls will migrate south for the winter, arriving at their wintering site in October and departing from it in March.

Western burrowing owls live in flat grasslands, occupying abandoned burrows dug by mammals.

Burrowing owls are found in grassland areas, often in close association with California ground squirrels. They prefer areas with very short vegetation so that they are able to easily detect predators.

Burrowing owls are known to reside in close proximity to humans. One example of this is a population of burrowing owls that lives at the Mountain View Shoreline Park golf course. Here, the small population is adored by the regulars – some golfers have even named individual birds.

Western burrowing owls are opportunistic eaters.

Western burrowing owls are raptors, meaning that they capture and kill their prey with their feet. To forage, burrowing owls will hover, fly, and run to chase their prey. Burrowing owls are opportunistic eaters, meaning that they will feed on a variety of sources depending on its availability. They are known to eat insects, small mammals, reptiles, amphibians, and small birds.

Burrowing owls will imitate rattlesnakes to scare off predators.

Burrowing owl calls sound like a two-part coo-coo. Just like parrots are known to mimic humans, the burrowing owl is known to mimic the rattling sound of a rattlesnake. This vocalization is thought to be a means to deter predators, since an angry rattlesnake is a threatening sound to many animals.

For more burrowing owl sounds, check out their sound page by the Cornell Lab of Ornithology. For more information on the hissing mimicry, check out this page by the Audubon Society.

Burrowing owls nest in burrows, using the poop of other animals to deter predators.

Breeding burrowing owls nest inside of their burrows. They will line the inside and entrance of their burrows with other animals’ dung, which is hypothesized to mask the smell of their young from predators.

They will form loose groups when nesting, perhaps to help owls better detect predators since more individuals are present to be vigilant. Young burrowing owls rely on their parents for food until they are about 4 weeks of age. By 6 weeks of age, young burrowing owls are capable of flight.

Cool facts about western burrowing owls:

  • Western burrowing owls are one of two subspecies of burrowing owl – the western burrowing owl, which lives on the west coast of the U.S., and the Florida burrowing owl, which only lives in Florida.
  • Burrowing owls don’t actually excavate their own burrows! They rely on mammals like the California Ground Squirrel to dig the burrows for them.
  • A young adult novel, Hoot, was written about Florida burrowing owls. In the novel, a group of young kids bands together to help save local owls from losing their habitat to development.

Resources to learn more:

In Need of Protection: Western Snowy Plovers

Cover photo: © Pacific Southwest Region USFWS, 2009, some rights reserved.

Learn about a small species of threatened shorebird that can be found on the beaches along California’s coast.

Cover photo: © Pacific Southwest Region USFWS, 2009, Flickr Photo Album, some rights reserved.

Places to See Western Snowy Plovers

Wilder Ranch Circle

Wilder Ranch State Park

Western snowy plovers are disappearing in California due to disturbance and habitat loss.

The listing of the western snowy plover as federally Threatened in 1993 has led to very important conservation initiatives. Western snowy plovers are easily disturbed while breeding, so human activity and introduced predators (such as cats and foxes) disrupt their breeding seasons. This, along with the loss of healthy beach habitats, has resulted in the decline in western snowy plover populations. While it is estimated that their populations once numbered in the thousands, approximately 2,000 individuals are estimated to remain on our coasts today.

Today, several initiatives on California’s beaches are actively working to restore their populations. Groups of citizen scientists and biologists actively monitor snowy plover populations.

The restriction of dogs on beaches is another important initiative. Dogs disturb snowy plovers on nests, causing them to expend energy to flee. Even when on leashes, dogs have the capacity to do harm by disturbing the plovers. Because of this, actions are being taken at state beaches to enforce no-dog policies, and areas are being roped off from human activity so as to not disturb the breeding plovers.

Western snowy plovers are white and beige – perfect for blending in with sand on beaches.

Western snowy plovers are small shorebirds, reaching lengths of about 6 inches. They have thin, black bills and dark gray to black legs.

The bird’s upperparts, the area between the base of the bird’s neck to just above the tail, are pale gray to beige. They have white foreheads and a white stripe along the eyebrow line. The bird’s underparts, the area under the bird’s head to beneath its tail, are white. During the breeding season, adult birds will have dark patches on their shoulders.

Western snowy plovers live along the Pacific coast.

Western snowy plovers are found along the Pacific coast from Washington all the way down to Baja California. The birds that live along the coast generally stay there year round; however, some populations that live inland will migrate short distances to the coast for the winter.

Western snowy plovers prefer sandy beaches – a habitat also loved by humans.

Snowy plovers are prefer sandy beaches above the high tide line – an area that’s also commonly used by humans. They also can be found in salt flats. Snowy plovers prefer areas with little or low vegetation so that they are able to survey the area for predators.

Western snowy plovers like to snack on small invertebrates.

Western snowy plovers will eat small invertebrates such as sand fleas. They will often forage by running forward a few steps, stopping and picking up something that’s edible, then running forward again in search of more food.

Western snowy plovers have a variety of calls, often sounding like trilling or a whistle.

For the western snowy plover’s sounds, check out this page from the Cornell Lab of Ornithology.

Male western snowy plovers are in charge of taking care of young.

Snowy plovers breed from early March to the end of September. Their “nests” are not the typical nests that people are used to seeing. Rather, they are made in shallow depressions of sand. Their clutch size, or number of eggs that they lay in a single nest, is 3 on average.

Western snowy plovers are polyandrous, meaning that a female will breed with more than one male at a time. The males and females will share the task of incubating the eggs before they hatch; however, soon after hatching has occurred, some females will ditch the males and leave the responsibility of taking care of the chicks to him.

Snowy plover chicks are precocial, meaning that they are able to move around and forage very quickly after hatching. When looking after the young, adults will not feed them. Instead, they guide them to suitable feeding areas. Adults will look after the young until they fledge, or when their feathers and wing muscles are fully developed for flight. This takes about one month for snowy plovers.

Western snowy plovers act like they’re injured to protect their young.

When a predator is approaching a nest, adult snowy plovers will do a broken wing display, meaning that the adult will pretend to have a broken wing and move in a direction away from the nest. This is intended to lure the predator away from the nest,  to decrease the chance that the predator will find the nest and eat it.

Resources to learn more: