California Black Oaks in the Rain - Quercus kelloggii
We received 1.58" of rain in the past ten days, along with some very blustery winds! Most of the fall leaves have been blown off the trees and now cover the ground in a beautiful golden-yellow, rusty-brown blanket. Our new Water Year total, that started on October 1st, is 4.48". The Water Year total for Oct. 1, 2022 to Sept. 30, 2023 was 86.55"! This total is quite a bit above the past three years of drought, with Water Year totals of 56.51" (2022), 34.18" (2021), and 39.62" (2020). We are so grateful for this past wet year, as well as the lack of forest fires! The forecast for the winter coming up is a wet one, which could mean lots of rain or snow in our area.
California Black Oaks in light Rain - Quercus kelloggii
Blue Oak - Quercus douglasii
Blue Oak Foothill Pine Woodlands
Since Fall has more or less disappeared from our neighborhood, we decided to drive down to the foothills for a hike or two. Luckily there was still a LOT of fall color in the South Yuba River State Park and the Daugherty Hill Wildlife Area.
Blue Oak Foothill Pine Woodlands
The terrain was rolling, grass-covered hills with gullies and creeks, and a river, vegetated by Blue Oaks, Live Oaks, Black Oaks, Gray Pines, Madrones, Coyote Brush, and many other shrubs. It is designated as a "Blue Oak Foothill Pine Woodlands" ecosystem. I was amazed at the multitude of different "greens" in the forest, including blue green, gray green, sage green, olive green, yellow green, and forest green.
One of the best books ever about the foothill oak ecosystem, but not a lot about the oak trees themselves, is "Secrets of the Oak Woodlands - Plants & Animals Among California's Oaks" by Kate Marianchild, published in 2014. It is a fascinating guide to little known wonders of several of the plants and animals found in that environment! I would highly recommend it to any curious naturalist! I found it fascinating!
Madrone berries -Toyon berries
Arbutus menziesii - Heteromeles arbutifolia
There were LOTS of Madrone berries hanging from the trees, as well as an abundance of Toyon berries in the nearby bushes. They were lovely! Apparently lost of critters eat these berries.
Concerning Madrone berries, Wikipedia states, "Native Americans ate the berries raw and cooked, but because the berries have a high tannin content and are thus astringent, they more often chewed them or made them into a cider. Overeating causes cramps. The Native Americans also used the berries to make necklaces and other decorations, and as bait for fishing. Bark and leaves were used to treat stomach aches, cramps, skin ailments, and sore throats. The bark was often made into a tea to be drunk for these medicinal purposes. Many mammal and bird species feed off the berries, including American Robins, Cedar Waxwings, Band-tailed Pigeons, Varied Thrushes, Quail, Mule Deer, Raccoons, Ring-tailed Cats, and Black Bears. Mule deer will also eat the young shoots when the trees are regenerating after fire."
Toyon berries form in June or July, but don't ripen until December! When they are green they contain cyano-glucosides in their pulp. When a bird tries to eat a green berry, cyanide gas is released and deters the bird! The un-ripened berries are also full of bitter tannins that discourage foragers! Over time the cyanide compounds gradually move into the seeds and the tannins diminish. In December, when the berries are bright red, they aren't bitter and the pulp no longer contains cyanide compounds! Approximately 20+ species of birds eat Toyon berries during winter!
Acorn Woodpeckers (male) - Western Bluebirds (male)
Melanerpes formicivorus - Sialia mexicana
We saw several Acorn Woodpeckers that day. They are one of the dominant species in the foothill oak woodlands. Acorns are the main food they depend upon in winter. They store acorns by drilling holes in dead tree trunks and putting an acorn in each hole! These acorn filled trunks are called "granaries". Granaries have been known to contain up to 50,000 acorns! Each granary is only used by one "family" of Acorn Woodpeckers.
We also saw LOTS of Western Bluebirds while we were there. In the summer Western Bluebirds are primarily insectivores. In winter they eat fruits and berries, such as juniper, poison oak, mistletoe, wild grapes, and elderberry. They like to live on the edge of open areas, such as meadows or burned areas. They are short-distance migrants, and generally move down slope in winter.
Osage Orange - Oak Mistletoe
Maclura pomifera - Phoradendron villosum
We also saw lots of mistletoe with berries in the oak trees. Over 28 species of birds in California eat the berries, as well as gray squirrels, raccoons, pine martens, chipmunks, porcupines, and ringtails! Mistletoe plants are dioecious, with the male and female species being separate plants. If you squish a mistletoe berry between your fingers, it will stick to your finger and you can't shake it off! They have a thick, viscous substance that makes them sticky. Being sticky, the seeds are easily transported to new areas by birds.
On the ground near the parking lot, we found several grapefruit-sized fruits of the Osage Orange trees. They are such strange fruits! We opened one up and it looked like a pineapple inside, and smelled like a pine tree! The plant contains latex, which causes the fruits to be bitter and unpalatable to humans and wildlife. This latex can also cause dermatitis in humans. The plants are dioecious, with the female producing the large fruits.
Osage Orange trees are not native to California. They are indigenous to the Red River drainage of Oklahoma, Texas, and Arkansas, as well as the Blackland Praries and post oak savannahs. They were planted across the US by settlers, mainly for hedgerows. . The name is derived from The Osage Nation, a Midwestern Native American tribe of the Great Plains, who prized the plant for its wood, to make their bows. The wood is heavy, hard, strong, and flexible, capable of receiving a fine polish. Today, the heavy, close-grained yellow-orange wood is dense and prized for tool handles, fence posts, and other applications requiring a strong wood that withstands rot.
Gall made by a Crystalline Gall Wasp - Andricus crystallinus
I found this cool tiny structure growing on a Black Oak Leaf. It looked like a tiny hairy tree! My guess is that it is a gall, formed possibly by a Gall Wasp. I know that galls don't harm their host plant, and that there are over 1,500 types of galls, but I don't know much more about them. The following information on galls is from http://www.bio.brandeis.edu/fieldbio/galls/galls.html.
"Galls are abnormal growths that can arise in all parts of a plant resulting from the work of usually immature insects and other organisms. In a way, they are basically "plant tumors." Unlike human tumors, galls usually do not injure their hosts to the point where the entire plant is debilitated. The few injurious galls appear only to attack pears, wheat, grapes, and roses.
There are over 1500 species of gall producers. However, most galls are produced by plant mites, gall midges, and gall wasps. These creatures produce galls to provide food and shelter for themselves. Galls can be simple deformities consisting of a rolled leaf edge or a pouch-like growth on the plant, or complicated structures made out of seemingly unrelated plant tissue that are highly organized.
The principal gall producers include:
1. Plant mites - microscopic, pale yellow or translucent organism (not an insect) with a slender, pear-shaped body and transverse ridges or lines. The gall producers are in their larval stage and have 4 legs, while adult mites have 8. Mites produce simple galls ranging from leaf deformities such as pouches or pockets with erineum [an abnormal felty growth of hairs from a leaf epidermis] that it winters under.
2. Aphids and plant lice - soft-bodied insects with sucking mouth parts. These insects produce complicated galls, wintering on the bark, then hatching out in the spring and attacking a bud to form their galls.
3. Gall midges - small delicate flies that are about 1/4 inches long, and have antennae. The maggot larvae are what produce the galls. Gall midges winter in galls and emerge in the spring.
4. Gall wasps (also known as Cynipids) - Wasp larvae that are formed usually on oaks.
Although the number of gall producing organisms are numerous, there are only a few host plants available for them to inhabit. This severely limits the types of trees these insects can inhabit. As a result, gall producers are very plant specific, and most of them reside among willows, oaks, goldenrod, and asters. Galls vary in shape, size, and complexity. "
California Black Oaks, Blue Oaks, and Gray Pines
Quercus kelloggii - Quercus douglasii - Pinus sabiniana
Blue Oaks are found only in California. They are named for the bluish-green cast of their deciduous leaves, which are currently a lovely, rich, brownish-yellow. They are the most drought tolerant oak, of California's deciduous oaks, and have deep extensive root systems. They usually grow between 3,000'-4,000' or lower, on dry hilly terrain where a water table is unavailable. They can live to be 400 years old!
They are usually 20'-60' tall, with a diameter of 1'-3', and a broad, rounded crown of branches. The leaves are simple or slightly lobed. They live where the winters are mild and wet, and the summers are hot and dry. The trees are monoecious (both sexes on the same tree) and are wind pollinated. The acorns are eaten by a wide variety of wildlife, including squirrels, birds, bears, and deer. We didn't see very many acorns on the ground. Oaks don't produce lots of acorns every year. They can have "bumper crop" years and low-yield years.
I hope to go back down to the foothills again soon. It was such a beautiful change from where we live!
What's happening on the North Yuba River?
Are there any new birds arriving for the winter?
Check back next week for the answers to these questions and more.
Your questions and comments are always appreciated! Please email me at northyubanaturalist@gmail.com. Thanks!
