Fall Willows on the North Yuba River - 10/31/24
The recent rainfall coupled with cooler temperatures, and less hours of daylight , have caused the North Yuba River Canyon to show its Fall colors! Without the rainfall, a lot of the leaves would have just dried up and turned brown. Luckily they didn't, and the canyon is alive with the yellows and oranges of autumn leaves!
During the growing season, chlorophyll is continually being produced and broken down and leaves appear green. In early autumn, in response to the shortening days and declining intensity of sunlight, chlorophyll production slows down, stops, and eventually all chlorophyll is destroyed. The colorful yellow (xanthophylls) and orange (carotenoids) pigments that are present in the leaf, are then unmasked and show their colors. The red and purple pigments (anthocyanins) are manufactured from the sugars that are trapped in the leaf. These pigments are what cause the vivid color changes in leaves!
Willows on the North Yuba River - Salix sp.
Willows grow along a lot of the shoreline of the North Yuba River.
At this time of the year, they are one of the main plants that are vibrant yellow in color. I just love their silken reflections!
The beautifully colored Fall leaves don't last forever. As the days shorten and temperatures drop, not only do the leaves change color, but a process called "abscission" begins. The leaves don't just fall off the tree, they are actually being pushed off the tree by the tree itself! As Fall progresses a layer of cells, known as the abscission layer, starts to grow between the end of the leaf stalk and the twig supporting it. These cells slowly grow and cut the leaf off from the tree without leaving an open wound.
Indian Rhubarb on the North Yuba River - Darmera peltata
Indian Rhubarb grows along rocky streams and river beds throughout the Sierra, up to 6,600' in elevation. The leaves are huge, up to 2' wide, and the leaf stalks can be 1-3' tall! They grow from rhizomes that hug the underwater rocks. In fall, the leaves turn yellow-orange and sometimes a lovely salmon pink in color! They are one of my absolute favorite river plants!
American Dipper with Indian Rhubarb in the background
Cinclus mexicanus - Darmera peltata
American Dippers live year-round on the North Yuba River. I wonder if they enjoy the fall colors like I do! I know they can see the fall color changes. In fact, birds see many more colors than humans! Humans can see red, blue, and green, and colors and shades made from combinations of these. Birds, however, are able to perceive the familiar rainbow of colors we know and parts of the ultraviolet(UV) spectrum that we can’t see. The following information is from the website at https://northamericannature.com/can-birds-see-color/.
"Bird vision is also sharper than humans. Birds can distinguish small differences between similar shades, so they can see colors that we can’t. Birds generally have four types of cones in their eyes instead of three like humans, and they perceive color differently. Not all birds have four cones, but birds normally have more cones in their retinas than humans and other mammals.
Each cone in the retina has a drop of oil in it. This oil filters out different colors, allowing the birds to see different shades, much like a camera filter. The oil is either transparent, pale, or red, or yellow and gives them greater contrast between colors. This helps birds filter out leaves, bushes, and trees to find their prey, and can even help them find fish in deep water. Mammals, including ourselves, do not have this oil in their eyes.
Humans can see one non-spectral color, purple. We can see purple when our blue and red cones are stimulated. Scientists believe that birds can see up to five: purple, ultraviolet and purple ultraviolet and green, ultraviolet and red, and ultraviolet and yellow."
American Mink - Neovision vision
To our TOTAL surprise, we spotted an American Mink in the North Yuba last week! I hadn't seen a Mink in the river for five years!!! It was initially standing on a rock in the middle of the river, then it dove in and resurfaced several times! WOW!!! It looked to be good-sized, maybe over 2 feet in length! We got to watch it for about a minute before it disappeared!!! How exciting! What a thrill! Fingers crossed that we see it again in the near future!
American Mink - Neovision vision
Minks aren't seen that often because they are mainly nocturnal, and are especially active at dawn and dusk. They are called "aquatic weasels" because they can pursue prey underwater. They eat muskrats, crayfish, frogs, ducks, waterfowl, and fish, in rivers, streams, ponds, and lakes. They can swim a distance of 100' underwater, and can dive to a depth of 15'!!! They also hunt on land and eat shrews, mice, and rabbits. They are mainly solitary, except briefly during mating. Both males and females are polygynandrous, and have multiple mates. Mating takes place in the winter. The female makes the nesting burrow in the bank of a stream, river, or lake and lines it with grasses and the fur from prey. 1-8 young are born sometime between April and May. The female solely feeds and cares for the young. American Minks are native to North America. They live in every state in the U.S. except for Arizona!
Coastal Rainbow Trout - Onchorhynchus mykiss irideus
Right now the river water clarity is extreme! I was able to catch this photo of a Coastal Rainbow Trout from our bridge! Adult trout can be 18-20" in length. The one pictured above was probably around 15" long! Right now the river is a chilly 42 degrees! Being coldblooded, trout become less active when the the water temperature drops below 40 degrees. Their metabolism and respiratory rates slow down. Adult trout usually stay in deep pools during fall and winter.
View through the Cottonwoods of the Sierra Buttes
from Salmon Creek Campground
Autumn in the Lakes Basin
The Aspen leaves have finally changed color in the Lakes Basin! A week ago they were still mainly green! My friend Nancy and I decided to take a hike in the Lakes Basin to check out some of our favorite areas for Fall color.
The Salmon Creek Campground borders an incredibly beautiful, dryish, tangled wetland. It has small creeks and meadows, as well as Dogwoods, Cottonwoods, Aspens, Junipers and Pines. The grasses are long and thick, currently blanketed in Cottonwood leaves, and lying on the ground. So of course we had to lie down on the grasses, and watch the overhead cottonwood trees drop their leaves one by one! Such beauty!
Gray's Lovage seedhead - Ligusticum grayi
In the summer, thousands of wildflowers bloom there. Now, in the fall, the wildflower seedheads bring a new delicate beauty to the area!
Quaking Aspens & American Dogwood
Populus tremuloides - Cornus sericea
The Lakes Basin Campground has a short trail through a beautiful, small Aspen Grove that is glorious at this time of year! In addition to the incredible fall colors, the sound of the aspen leaves in the wind is music to our ears!
Quaking Aspens & American Dogwood
Populus tremuloides - Cornus sericea
The contrast of yellow Aspens and red Dogwoods is a familiar beauty here in the Fall!
A distant view of the Aspen Grove from the campground bridge
Aspens, grasses, willows, dogwoods, and currants are just a few of the plants that have "blossomed" with color this fall!
Dwarf Bilberry in Bilberry Basin - Vaccinium cespitosum
On the Round Lake Loop Trail, there is a basin between Silver and Round Lakes that is filled with water in the spring. In the fall it is bone dry and showcases brilliantly colored Dwarf Bilberry plants! We hike there every year just to see the bright-red Dwarf Bilberry. The color is amazingly beautiful! The photo above is of front-lit Dwarf Bilberry.
Dwarf Bilberry in Bilberry Basin - Vaccinium cespitosum
The photo above is of back-lit Dwarf Bilberry plants! The leaves are brilliant fire-engine-red in the sun! It's astonishing every time I see it! We were so lucky to see them at their peak color! Such Beauty!
Just past Bilberry Basin is Round Lake. We decided to have lunch on the sunny shore in the wind and it was fabulous! Surrounded by beauty, with a fall chill in the air, and in the company of a dear friend...who could ask for more?
Have the Black Oaks turned fall colors yet?
Check back in two weeks to find the answers to these questions and more!
After 8 years of posting my blog, I've decided that I'm only going to post my blog twice monthly from now on. My next post will be on the weekend of November 16th. See you then!
Also, check out my latest post on my newly re-opened Damp Earth Blog at dampearthart.blogspot.com
Your questions and comments are always appreciated. Please email me at northyubanaturalist@gmail.com. Thanks!
