Redwood sorrel folds its leaves when exposed to direct sunlight.
When the leaves are in direct sunlight, they shrivel up and fold downwards within minutes. Sensitive cells in the plant detect the wavelength of light hitting it, causing the leaves to fold downwards when exposed to harsh light. This process is called nyctinasty.
Redwood sorrel’s folding is attributed to its sensitivity to bright sunlight. Because it is adapted to growing in low light conditions, intense light can damage the plant. Thus, folding its leaves is thought to protect it from harm.
To watch a time-lapse of this movement, check out this YouTube video. Please note that the plant shown is Oxalis triangularis, a different plant species in the same family as redwood sorrel.
Redwood sorrel is found on the West Coast of North America, from California to Canada.
It prefers understory habitats, often growing in coast redwood or Douglas fir forests beneath the shade of trees. It is one of the most common plants in the coast redwood understory.
Redwood sorrel leaves resemble clovers.
The leaves are 0.4 – 1.8 inches long. Redwood sorrel also has tiny (0.5 – 0.8 inch) flowers, which range from white to pink in color. Flowers can be seen in bloom from February to September.
Redwood sorrel is a good replacement for English ivy in a native plant garden.
Looking to make the conversion to native plants in your garden? Alternatively, are you looking for more native plants to introduce to your existing native garden? Consider the redwood sorrel. This plant grows well in shady conditions, forming a dense carpet beneath trees.
For more information on the planting and care of redwood sorrel in your garden, check out this article by S.F. Gate.
Cool facts about redwood sorrel:
Redwood sorrel is truly adapted to shady environments, as it is able to photosynthesize in levels of light that are 1/200th of full sunlight.
The family name of redwood sorrels, Oxalis, is derived from the Greek word “oxys”, meaning sour. This is because the leaves of plants in this family have a sour taste.
Beware of eating too much of any plant in this family, as they contain oxalic acid. Oxalic acid can be toxic when consumed in large quantities.
Scientists hypothesize that the columbine ancestor made its way from Central Asia to Alaska thousands of years ago by the the Bering land bridge that connected Asia to North America. Evidence of the columbine’s travels have been supported by DNA analyses of columbine species from around the world.
After its arrival in Alaska, the columbine ancestor begin to radiate out to other parts of North America. The evolution of North American species is hypothesized to be driven by pollinator specialization. For example, multiple species of red columbines have adapted red flowers (distinct from blue and yellow-flowered columbines found in other parts of the U.S.) and higher sugar contents in their nectar – an adaptation thought to meet the demands of their hummingbird pollinators.
The best time to see crimson columbine bloom is March – May.
The plant can be found in forest and meadow habitats where the soil is moist.
The outer, red parts of the flower are actually sepals. The “true” petals are the yellow parts on the inside of the flower. Overall, the entire flower is about 2 inches long.
Crimson columbine attracts pollinators, including hummingbirds.
These flowers are also relatively deer-proof, making them a great option to include in a California native plant garden. For more tips on how to cultivate crimson columbines in your garden, check out these tips from the Las Pilitas Nursery.
Cool facts about crimson columbine:
Its genus name, Aquilegia, is derived from the latin word aquila, meaning “eagle”. This name is thought to refer to its upright red sepals, which look like an eagle’s talons.
The flower’s common name, columbine, is derived from the latin word columba, meaning dove-like.
Anna’s hummingbirds are permanent residents in the Bay Area.
While some species of hummingbird migrate during the winter, the Anna’s hummingbird stays in the Bay Area year-round.
Their range has greatly expanded beyond its initial restriction to California and Baja California. Today, Anna’s hummingbirds can be found in parts of the southwestern United States, as well as up in British Columbia, Canada. Their expansion is thought to be related to their adaptability to feeding on exotic flowers and their use of artificial food sources (hummingbird feeders).
Anna’s hummingbirds are the most common hummingbirds on the west coast.
They can be found in a variety of habitats, ranging from urban gardens to open oak woodlands. Individuals can be located easily by listening for their buzzy song, which is often sung from atop a perch.
Anna’s hummingbirds eat nectar and insects.
Anna’s hummingbirds feed of nectar from native and non-native plant species, as well as artificial nectar provided at hummingbird feeders. It’s estimated that 90% of a hummingbird’s diet is composed of nectar, whereas the remaining 10% is composed of small insects.
Anna’s hummingbirds are a bright and feisty visitor at my own hummingbird feeders. They can be quite territorial, as exemplified by some individuals perching near the feeders and chasing away any unwelcome visitors that wander over in search of food.
Anna’s hummingbird males generate a non-vocal “squeak” during their breeding displays.
Females are responsible for all nesting responsibilities.
Anna’s hummingbirds have a breeding system in which females are solely responsible for parental care. Female Anna’s hummingbirds construct nests of soft plant fiber and spiderwebs that are 1.5 inches in diameter and 1 inch high. She lays 2 eggs, which take 16 days to hatch. Once hatched, the female will feed and care for the young until they are old enough to fly out of the nest at 23 days old.
Cool facts about Anna’s hummingbirds:
In the Bay Area, an Anna’s hummingbird nest once delayed construction at the Richmond-San Rafael bridge. The nest, protected under the Migratory Bird Treaty Act, was discovered in a grove of trees designated to be cut down for the expansion. The crew halted removing the trees until after the nest and birds were gone.
Anna’s hummingbirds are capable of torpor. When temperatures drop outside at night, Anna’s hummingbirds will also drop their own body temperatures. They simultaneously slow their heart rates and breathing to enter a hibernation-like state. Once temperatures rise again, they resume normal bodily functions.
All hummingbirds are only found in North and South America.
Brown pelicans have made a dramatic return from their critically low numbers in the 1970’s due to the effects of DDT. However, the fight for the brown pelican is far from over: today, they face threats from food scarcity as Pacific sardine and anchovy numbers have shown declines.
California brown pelicans faced critically low numbers in the 1970’s from the effects of DDT and endrin.
From the 1950’s to 1970’s, the brown pelican almost disappeared from North America due to the effects of pesticides, namely endrin and DDT. DDT weakened the strength of breeding birds’ eggshells, resulting in failed breeding attempts as parents crushed eggs while trying to incubate.
The plummeting populations resulted in the species being federally listed as endangered. The ban of DDT in 1972, as well as the decrease in use of endrin, allowed pelican numbers to recuperate. By 2009, the species had recovered enough for its endangered listing to be lifted.
On the west coast, pelican populations face declines from lack of food availability.
Today, all brown pelicans still face threats from oil spills, entanglement in fishing gear, and disruption during their breeding season.
On the west coast in particular, however, pelican populations face starvation due to a decrease in the availability of Pacific sardines and anchovies. Overfishing and unusually warm waters have caused declines in the two fish populations, which has in turn negatively impacted brown pelican populations. In 2010, emaciated pelicans were reported at California wildlife centers. Younger pelican individuals were even recorded going after murre colonies in Oregon, grabbing chicks and shaking them until they regurgitated fish for the pelicans to eat.
Juvenile California brown pelicans appear brown overall, whereas adults sport more rich coloration.
Non-breeding adult pelicans have yellowish faces and white necks. The rest of their bodies are brownish gray.
During the breeding season, the necks of adult brown pelicans turn reddish-brown in color. On the west coast, breeding adults also develop a red throat. Birds in breeding plumage can be seen from December through August.
Juvenile brown pelicans are brown above and whitish below, with grayish bills.
California brown pelicans can be found resting along California’s coast.
Brown pelicans can be found foraging in shallow waters. When they’re not searching for food or breeding, they can be found resting in areas near the coast.
While in flight, birds will typically form lines. Their flight is extremely graceful, as they glide and flap in unison.
California brown pelicans feed by diving in the water.
They feed primarily on fish, diving head-first into the water from 20 – 40 feet in the air to capture their prey. Before swallowing the captured fish, pelicans empty their pouches of water. The California brown pelican and the Peruvian pelican are the only two pelican species that plunge dives for food.
Gulls, particularly Heermann’s gulls, are known to steal fish from the pouches of brown pelicans that have just returned from a dive.
California brown pelicans nest colonially on the ground.
To breed, brown pelicans form colonies, meaning that they nest in large groups with members of the same species. Their nests are usually constructed of sticks.
They lay 3 eggs on average, which hatch after 4 weeks of incubation. Once the eggs hatch, the young are cared for by both parents.
Cool facts about California brown pelicans:
The largest roosting site for brown pelicans in the Bay Area is in Alameda on Breakwater Island. Breakwater Island is an L-shaped island in Alameda, built from rocks to help reduce wave action in the area.
Brown pelican pouches can hold up to 2.6 gallons of water.
Brown pelicans can live to be up to 30 years old.
Brown pelicans are incredibly large, with wingspans of 6.5 to 7.5 feet.
There are very few hobbies that I can say have changed my life for the better, and birding is at the top of that list. Here are just a few ways that birding has influenced me.
I have many hobbies that have enriched my life: reading, cooking, and dancing hula all come to mind as interests that make me feel happy and fulfilled. That said, there are very few hobbies that I can say have changed my life for the better. Here are just a few ways birding has influenced me.
1. Birdwatching taught me how to pay attention.
Birding has completely transformed my day-to-day activities by teaching me how to pay attention. While birding has allowed me to further develop my attention span, it has also taught me how to integrate nature into my day-to-day activities by simply paying attention.
Take walking from your parked car to a building as an example. Before I learned the sights and sounds of individual bird species, a walk from my car was just another task. Learning how to watch birds has flipped an irreversible switch in my mind, turning every moment outside into an opportunity to see or hear new things.
Today, even when doing something as simple as watering my plants outdoors, I passively pay attention to who’s around. Dark-eyed junco hopping underneath my gardening shelves, looking for spilled seed. House finch singing from a perch on the ornamental tree across the street. It’s an incredible gift that I’m grateful to have learned.
2. Watching birds got me to spend more time outside.
I’ve always loved the outdoors, but birding has presented me with the incentive to explore as many new habitats as possible, in hopes of observing more bird diversity.
Since I’ve begun birding, I’ve travelled to habitats ranging from rocky seashores to the edges of lush agricultural fields in search of a particular species. I’ve gotten to know a diversity of places, thanks to the journeys that birdwatching has brought me on.
3. Birds were a gateway to learning about other incredible wildlife.
Birds, like all other life, interact with a myriad of other species in their day-to-day activities.
As an avid birdwatcher, you sometimes can’t help but wonder who else is in the picture as you’re watching a particular bird. What kind of shrub is that California towhee scuttling under? What kind of plant is that song sparrow using as its singing perch? What kind of mammal did that red-tailed hawk just snatch up?
These are common questions running through my mind as I watch birds, and are all musings that prompt me to jump on my computer once I’m back home to do some research. This cycle has led me to discover the names and life histories of many non-bird species, thus allowing me to become a more well-rounded nature lover.
4. Birdwatching has brought me to an amazing, tight-knit birding community.
Joy loves company, as proven time and time again in the friends that I’ve made through birding. Whether I’m living in the San Francisco Bay Area, upstate New York, or in the suburbs of Australia, there isn’t a single place that I haven’t found a tight-knit and supportive group of birdwatchers and nature enthusiasts. By joining local birding email listservs, local Audubon chapters, or even visiting a local nature center, I’ve met many new, welcoming faces.
5. Watching birds has allowed me to deepen my knowledge and involvement in local conservation issues.
Being a part of the birding community also meant joining forces with incredible advocates and leaders in environmental grassroots movements. Because of my involvement in the birding community, I’ve been able to learn more about important local conservation issues and projects that impact the habitats of native species.
In the Bay Area alone, I’ve been exposed to the wonders of wetlands restoration for native species, the declines of raptors such as American kestrels and burrowing owls, and the impacts that even a single crumb left behind at a campsite can have on the dynamic between Steller’s jays and marbled murrelets. While I would have likely read about these issues before becoming a birder, being an avid birdwatcher brings you that much closer to the battlefront of local conservation concerns.
(Bonus) 6. The excitement doesn’t stop at watching birds.
Birding has brought me happiness beyond just watching birds – it has allowed me to find other outlets for my passions, whether it be science education and outreach, science writing, photography, or travel.
Letting birds into my life has given me an incredible sense of purpose and belonging, and I can only hope that it will do the same in yours. Cheers to your next (or first!) birding adventure.
For more information on local bird species in the Bay Area, check out our wildlife resources on birds.
Pacifica, Ca – Once a troublesome segment of highway, Devil’s Slide Trail was converted into a recreational trail in 2014. Visit the area to see awesome seabirds and raptors, and to learn more about the Common Murre Restoration Project that’s active in the area.
Science Spotlight: Common Murre Restoration at Egg Rock
Common murres are gorgeous and vaguely penguin-looking seabirds. Common murres actively breed in colonies at Egg Rock, which is visible from Devil’s Slide Trail.
The Egg Rock colony was estimated to have 3,000 birds in the early 1980’s; however, disaster struck with the 1986 Apex Houston oil spill. The oil spill delivered a fatal blow to the common murre population, eliminating the birds at Egg Rock. Scientists, determined not to let the population of common murres vanish, formed the Common Murre Restoration Project. The project, run by the U.S. Fish and Wildlife Service, set out to restore the Egg Rock population that was wiped out during the oil spill. It also sought to increase the numbers of common murres and other seabirds across Central California.
To restore murres, the project employed social attraction techniques. Social attraction, first developed by Project Puffin to restore breeding Atlantic puffin populations, works by tricking birds into thinking that other individuals of the same species are already present at a specific location. This incentivizes breeding birds to set up their nests at that location.
To trick the common murres at Egg Rock, scientists placed common murre decoys on the island, played common murre sounds from speakers, and placed mirrors at the site to create the illusion of movement to birds flying overhead. And the result? The murre breeding colony on Egg Rock has been restored, and has increased every year since the project’s implementation in 1996.
Devil’s Slide Trail is a segment that was formerly part of scenic Highway 1. Frequent landslides and closures made this a particularly troublesome segment of highway, prompting talk of opening an alternative route over Montara Mountain. Local public outcry strongly opposed the conversion of the mountain into a highway, and grassroots efforts worked to advocate for the opening of a tunnel instead. In a sweeping success, Tom Lantos Tunnels opened in 2013, protecting the mountain and allowing the scenic views of our coast to be preserved.
In 2014, the Devil’s Slide segment of Highway 1 was converted into a recreational trail for joggers, bikers, and hikers. The trail is also a part of the California Coastal Trail, which will extend 1,200 miles along the coast from Mexico to Oregon once completed.
Visit the Park
Please note that there is no entrance fee to enter the park. Dogs are allowed on leashes.
Here are some helpful resources to plan your visit: