Tale of Two Squirrels

Take a look around your neighborhood these days and you'll probably see this squirrel busily collecting acorns and other nuts. It will bury them and dig them up in winter and spring.

I've watched some amusing yelling matches between squirrels and scrub jays. The squirrels swoosh their tails furiously and scream. (The more fluid, back-and-forth tail waving is an amorous gesture, according to Jim Dines, a mammalogist with the Natural History Museum of LA County.) Dines says, "Jays are particularly intelligent--they're related to crows--and will watch where the squirrels are burying their nuts so they can steal them later."

These are a few of the tidbits I learned reporting the following story on native and nonnative squirrels in the Los Angeles area.

NATIVE GRAY

Who hasn’t watched their backyard squirrels scurry along power lines, spiral up and down tree trunks, whip their tails and holler “chkk-chkk-chkk” at trespassing scrub jays?

Now that autumn trees are full of acorns, the antics are in overdrive.

Surprisingly, though, the squirrels leaping from bough to bough in urban Los Angeles aren’t native.

Before urbanization, trees were far less common in the Los Angeles basin. Ground squirrels burrowed into the earth, but the native arboreal squirrel lived in mountainous areas.

The story continues on Chance of Rain.

Lives in the Balance

An article in the prestigious science journal Nature this week includes a sobering graphic. In it, the earth is sliced into nine wedges representing planetary systems such as climate, fresh water, ocean chemistry, biodiversity, changes in land use, and the nitrogen cycle. Three of them are very red, indicating humans have already interfered with the climate, biodiversity, and nitrogen cycles sufficiently to potentially threaten our own survival on the planet. In terms of biodiversity, the graphic illustrates what conservation biologists have been saying for some time: Humans are causing other species to wink out at a rate 100 to 1,000 times higher than what the fossil record indicates as a natural baseline.

The authors note that Homo sapiens evolved and thrived during an unusually stable period in the earth's history, a 10,000 year increment called the Holocene. "Such stability may now be under threat," the scientists say. Human activities could "push the Earth system outside the stable environmental state of the Holocene, with consequences that are detrimental or even catastrophic for large parts of the world."

Click here for a summary of the paper. 

Note that "ocean acidification" refers to the absorption of carbon dioxide from the atmosphere by the oceans. The burning of fossil fuels is altering the chemistry of the seas, turning them more acid.

Bike and Play

Early Morning Ride Along the Arroyo Seco

I usually prefer a hike to a bike ride, but with a toddler in tow, biking has its advantages. It's generally easier to haul a 25-pound hunk of squirming flesh in a bike seat than in a backpack carrier. However, suitable routes are in short supply. If you're up early on a weekend, try this simple ride along the Arroyo Seco and around Pasadena's Rose Bowl.

This ride is not suitable for young children on their own bikes, unless you opt for a just a loop around the Rose Bowl.  

 

Start at the intersection of Arroyo and California Blvds. There's ample street parking. Head north on Arroyo, along the Arroyo Seco. The Arroyo is a major tributary of the Los Angeles River. At the rim here, it's lined with large oaks. If you've got a toddler aboard, he will appreciate the many spandex-clad bikers whizzing past. 

The Arroyo Seco Foundation has been working on and advocating for restoration of the area. One exciting development: the petite Arroyo Chub once again swims natural stretches of the stream. The chub is a small minnow native to slow-flowing, muddy or sandy stretches of Southern California streams. Urban development and introduced species have substantially reduced its populations. This information on their restoration to the Arroyo Seco comes straight from the Foundation's (ASF) website: 

The Arroyo Chub, a native species that once thrived in the Arroyo Seco, has returned. Last summer three hundred of the small fish were planted in the natural stream areas of Pasadena's Central Arroyo stream below Devil's Gate Dam and just above the Colorado Street Bridge, and recent sightings indicate the fish are doing well particularly in the lower stretch.

"This is a momentous development and a key milestone in our campaign to restore the natural attributes and functions of the Arroyo Seco," said Tim Brick, Managing Director of the Arroyo Seco Foundation. The fish restoration came as part of the Central Arroyo Stream Restoration Program completed by ASF and the City of Pasadena. The project included water quality islands in Brookside Park parking lot, trail improvements, and backwater pools and improved habitat for the fish.

On this ride, you will bike on the street, which is why I recommend starting out around 8:30 a.m. 

The route climbs steadily, but not too steeply, until it reaches the Colorado Street Bridge and 210 Freeway. This is where things get a tad dicey. As it ducks under the freeway, Arroyo Blvd becomes steep and narrow. I suggest you wait a minute for some other bikers to join you, then descend. This should help you be more visible to cars. You'll be through this bottleneck in a minute.

As you head towards the Rose Bowl, note the playground and Kidspace Children's Museum on your right. Bike traffic around the Bowl flows clockwise (reverse of the pedestrian route). 

My son and I topped our ride with a romp around the playground. We sent my husband back to get the car. He didn't complain, as he rode back unencumbered. 

Here's a link to another Arroyo Ride.

The Big Blue

I've launched a new column for this blog's sister site, Chance of Rain. Edited by Emily Green, the weekly rambles explore nature in and around urban Southern California. Here's a taste with a link to the full story:

THE DINOSAURS are gone. So too the mammoths, saber-toothed cats and short-faced bears. Even California’s mascot, the grizzly, no longer roams the state. Megalopolis has replaced megafauna. Yet the largest animal ever still graces the California coast. This summer, I went looking for it.

The story continues on Chance of Rain.

Trills and Thrills in the Garden

I'm so excited that I'm hopping up and down. Hopping like a California Towhee in the underbrush of my yard! California Towhees look a like big, plain brown sparrow, but with a longer tail.

Its presence is evidence that my humble habitat is doing its job.

I immediately emailed conservation biologist Dan Cooper of Cooper Ecological to ask if this meant I could claim my native plants are providing good habitat, superior to your average garden. "Yes," he answered. "That's awesome. They are a major indicator of native habitat, in my opinion."

I've had my yard "certified" by the National Wildlife Federation's Garden for Wildlife program. If you've got native plants, consider applying. After you fill out some forms and pay a small fee, they'll send you a sign that helps raise awareness of the role yards can play in sheltering and feeding wildlife.

Another thrill in the garden this week: My barely five-month-old California fuchsia is blooming. This native is a welcome addition to a native/Mediterranean-climate garden because it blooms when most of the other plants don't. Nevin Smith, author of Native Treasures, says its long, red tubular flowers are "a classic example of flowers evolved for pollination by hummingbirds." The hummers can thank dry garden queen Emily Green, who gave me two of the plants.

Lean and Green

Some folks know I'm a frequent contributor to Arroyo Monthly. I love this publication for Irene Lacher's excellent editing, and her willingness to run longer stories. Only some of the pieces I've written fit the focus of this blog, but my September story on a new green development in Eagle Rock isn't too much of a stretch. Here's an excerpt and a link to the full story.

Earlier this year, retired teacher Karen McKay and her husband John were searching the online real estate service Redfin for a home in the Pasadena area. Nothing stood out. “A lot of the places were 1920s bungalows,” says McKay. “They were cute but required someone younger and more energetic to keep them up.” Plenty of condominiums were listed, but the McKays didn’t want to deal with a homeowners’ association.

Then they read about Rock Row — 15 new homes squeezed together on half an acre on Yosemite Drive in Eagle Rock. The individual parcels were tiny — only five inches separate the residences — but buyers would own their lots. There were no shared walls and no potentially contentious homeowners’association. Plus, the project was in the vanguard of environmentally friendly construction. “We didn’t know that people were building like this,” McKay says of the dual-flush toilets, double-pane windows, low-water landscaping and more.

The McKays consider themselves lucky to have found Rock Row in time. Priced around $500,000, the homes sold out within a month. If the project holds up to rigorous third-party inspections, it could become the first multi-home development in Los Angeles to earn a Leadership in Energy and Environmental Design (LEED) rating, the gold standard for green buildings.

Click here for the the full story.

Chaparral

As the station fire continues to rage in the Angeles National Forest, I can't help mourning some of my favorite hiking and camping spots. Indeed, some of the family-friendly places mentioned on this blog have either burned or are likely to burn. 

But fire is a natural part of the forest's dominant ecosystem, chaparral. Chaparral consists of large evergreen shrubs such as ceanothus (above), chamise, manzanita, mountain mahogany, and laurel sumac. It often intergrades with sage scrub habitat, characterized by summer deciduous plants such as sages.  

Chaparral shrubs can regenerate after fires. Some resprout from burls or root crowns under the soil, others have seeds that are capable of lying dormant for a century until fire stimulates them to germinate. It's remarkable considering chaparral fires frequently reach temperatures of more than a thousand degrees. "Making them among the hottest fires in any natural environment in the world today," according to Philip Rundel and Robert Gustafson, authors of Introduction to the Plant Life of Southern California.  

"This system is a fire-prone ecosystem," Rick Halsey told KPCC listeners this week on a segment of "AirTalk" I produced.  "Its natural fire return interval is every 50-50 years, so these big fires are natural to the landscape. Not the frequency, because most of these fires are caused by humans. But the size and intensity are perfectly normal. So instead of looking at this thing as a tragedy that could have been prevented, and trying to manipulate the landscape, what we need to do is create communities that are adapted to the landscape rather than forcing the landscape to adapt to us.”  

Halsey leads California Chaparral Institute. The problem, according to Halsey and other fire ecologists, will come if people ignite another fire in the area before the native plants have time to recover. "The trick now is to keep fire out of this fire scar for at least 30 years or so," he said. "At that point the plants and the system are capable of recovering properly. The scary part of this now is often a few years after a fire, weeds get into the area, especially in wind-driven events and you can re-burn areas that already burned only 4 years before. For example the Witch fire in '07 in San Diego County burned 70,000 acres that burned 3 years before." The end result of frequent fires is a diverse landscape native shrubs are replaced by a sea of a few invasive plants, such as non-native annual grasses. 

To learn more about the problem of frequent fires, read my magazine story from last fall called Sparking the Fires.