Spot an Owl at Shoreline Regional Park

Mountain View, Ca – Right in the heart of the Silicon Valley, Shoreline Regional Park is a gem where you can see wildlife from burrowing owls to pelicans.

Species to Look Out For

Western Burrowing Owl

About the Park

Mountain View, Ca – Regional Park

Science Spotlight: Burrowing Owls at Shoreline Park

The western burrowing owl is a small species of diurnal owl, meaning that it’s active primarily during the day. True to their name, western burrowing owls nest and reside in burrows in the ground – relying on sites that have already been excavated by burrowing mammals such as the California ground squirrel.

The burrowing owl has been experiencing steep population declines over the past 30 years due to habitat loss. Their population was estimated at 640 birds in the 1980’s, with three-quarters of the population residing in the South Bay alone. In 2017, the South Bay reported just 64 adults at 5 breeding sites.

The City of Mountain View employs a part-time specialist in charge of monitoring the burrowing owls, restoring their habitat, and ensuring park plans are in line with federal and state regulations protecting the owls. Local organizations, such as the Santa Clara Valley Audubon Society, are also involved in initiatives to help protect the burrowing owls.

For more information on western burrowing owls in the Bay Area, check out the Bay Area Naturalist article The Bay Area’s Fight for the Western Burrowing Owl.

Park History

The area around Mountain View and Sunnyvale was once inhabited by the Ohlone Native Americans. Spanish settlers arrived in the 1700’s, and established the first missions in the area in 1777.

The area that is now Shoreline Park was formerly a dump/junk site, a hog farm, and a sewage treatment plant. In 1968, Mountain View decided to renovate the park to make the space available to the public for enjoyment of the outdoors. The park was completed in 1983, relying on garbage from San Francisco and neighboring cities to provide fill for the area.

The park is near the Rengstorff House, a historical mansion built in the 1860’s. You can also see the Shoreline Amphitheater, a popular concert venue in the Bay Area.

Visit the Park

Please note that there is no entrance fee to enter the park. Dogs are not allowed.

We recommend taking the trail from the Shoreline Boathouse parking lot towards the kite-flying area. Be sure to scan California ground squirrel burrows for burrowing owls!

Here are some helpful resources to plan your visit:

City of Mountain View – Shoreline Park

Gallery

The Bay Area’s Fight for the Western Burrowing Owl

Cover photo: © Nathan Rupert, 2010, some rights reserved.

Learn about the burrowing owl’s current conservation status in the Bay Area and the current initiatives to protect them.

Cover photo: © Nathan Rupert, 2010, Flickr Photo Album, some rights reserved.

Quick Facts

The western burrowing owl is a small species of diurnal owl, meaning that it’s active primarily during the day.
The burrowing owl used to be common in the Bay Area, but habitat loss has caused a steep decline in their populations over the last 30 years.
Local conservation groups are working to improve habitats to make them more attractive to owls, and are working on monitoring sites known to have owls.

Nestled on the edge of a corporate development next to the entrance to a local wildlife preserve lies a small, fenced-off lot of short grass. Here, after minutes of scanning small mounds of dirt, Dan and I encountered our first burrowing owls. An adult sat hunkered down, directly next to a young owl that was curiously peering back at me with large, yellow eyes. With this developed backdrop, it is difficult not to question the fate of this charismatic species.

A Bay Area Species in Peril

The western burrowing owl is a diurnal owl, meaning that it’s active during the day. It’s fairly small, standing at about 10 inches high. True to their name, they nest and reside in burrows in the ground – relying on sites that have already been excavated by burrowing mammals such as the California ground squirrel. They can often be found standing vigilant outside of their burrows during the day.

This endearing bird was once a common bird in the South San Francisco Bay Area. In the mid-1980’s their population was estimated to be about 640 individual birds – with three-quarters of the population residing in the South Bay alone. Today, their population has been reduced to isolated breeding and overwintering populations (overwintering populations migrate to the Bay Area during the winter to escape cold temperatures in their other homes). In 2017, the South Bay reported just 64 adults at 5 breeding sites.

An adult and juvenile western burrowing owl in the South Bay.

Habitat Loss and Evictions

Habitat loss is the main threat that these owls face. The South Bay was once host to native grassland habitats; however, housing and other commercial developments to address a booming human population have outcompeted the owls for space. The East Bay is facing similar problems – areas that overwintering owls need to be successful have rapidly disappeared, putting stress on their populations.

Even at sites where the owls reside, the active removal of burrowing owls takes place. Developers that are initiating projects at known burrowing owl sites will hire contractors to install one-way doors at burrowing owl sites – allowing the owls to leave their burrow, but not to re-enter.

These “evictions” are rendered legal because individuals or nests are not harmed. However, many groups criticize the practice since there is no monitoring of the evicted birds after the traps are installed. Burrowing owls have high nest site fidelity, meaning that they have high rates of returning to the same breeding site, and even specific burrow, year after year. With the evictions taking place without long-term monitoring of the displaced owls, the effects of practices such as these are unknown and the evictors are not held accountable.

Bay Area Organizations Band Together for Owls

Efforts to increase the population of breeding burrowing owls in the South Bay are currently being implemented. A number of South Bay organizations have banded together to increase the population of breeding owls at Warm Springs in Fremont. Based on the outcome of their efforts, they will apply what they’ve learned at this site to the management of other sites in the South Bay. Similarly, the Santa Clara Valley Audubon Society is working in Alviso, a neighborhood in San Jose, to provide suitable habitats for the owls. The group works to install artificial burrows and mow the area to keep vegetation short.

In the East Bay, the Golden Gate Audubon Society, the City of Berkeley Marina and the Shorebird Nature Center have joined forces to create the Golden Gate Audubon Burrowing Owl Docent Program. The program focuses on raising public awareness about keeping dogs on-leash to help protect the overwintering owls that use the areas in the East Bay. Docents also keep track of the burrowing owl numbers in their area – allowing for long-term population data.

Efforts such as these provide hope for burrowing owl populations, yet their fate is still undecided in the face of the rapidly expanding Silicon Valley.

For more information on how to volunteer for the Golden Gate Audubon Society’s Owl Docent Program, please visit this page and scroll to “Train to Become a Docent” towards the bottom of the page. For more information on volunteering with the Santa Clara Valley Audubon Society doing habitat restoration at Alviso, please visit this page.

Resources

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 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.

Tag: owls