Sunday, August 16, 2020

Exploring Sierra Valley

Sierra Valley - 8/10/20

One evening last week, my husband and I drove over to Sierra Valley.  My friend Mary, had told us about a few uncommon birds that she had seen earlier in the week, out in some shrinking wetlands in the valley.  So we took a picnic and went on a bird search!  To our delight, there were incredibly beautiful dark rain clouds over the valley!  The intermittent play of sunlight on the valley and its surrounding ridges was mesmerizing!  It was cool and hushed and peaceful!  The big sky and receding fields of tawny grasses felt so vast and unrestricted.  To me, it feels so full of life out there! 

Sierra Valley and Rubber rabbitbrush (Ericameria nauseosus) - 8/10/20

The play of light continued the whole time we were there!  
It was a heavenly evening out in nature!

Virginia Rail (juvenile) - Sora (juvenile)
Rallus limicola - Porzana carolina

Wetland Critters!

We lucked out and saw several uncommon birds, and one mammal that evening!  At the first small pond we stopped at, I saw a juvenile Virgina Rail right away!  In another two minutes a Sora appeared!  WOW!!!  I had never seen either one of these two birds before!  Both of them are classified as Rails, in the Rallidae family.  According to my field guides they are often seen in the company of each other!  They are both; secretive and more commonly heard than seen; live in shallow fresh water wetlands with emergent vegetation, such as cattails; feed on seeds and aquatic invertebrates; prefer to run rather than fly; and migrate at night!  The juveniles we saw, weren't actually very secretive and were easy to photograph!  If they got "spooked" by us, they ran into the thicket of stems that the surrounding cattails provided, but didn't stay long.  It was around 6:30 pm that we saw them.   Apparently they do most of their foraging for food in the evening and at night!  How lucky we were to have seen them!

Virginia Rail (juvenile) - Rallus limicola

In the summer, Virginia Rails eat more insects and fewer seeds than Soras.  They also feed on small fish, frogs, worms, slugs, and snakes!   In the winter, seeds make up most of their diet.  Most will migrate south to Mexico or west toward coastal regions for the winter.  These birds are fairly large, almost like a small chicken in size!

Sora (juvenile) - Porzana carolina

Rather than probe in the mud for invertebrates like Virginia Rails, Soras prefer to peck insects and seeds off the surface of the water.  In the winter, they primarily eat seedsThey migrate down to Mexico, or even as far as the north end of South America, for the winter.  They are slightly smaller than Virginia Rails in size.

Barn Swallow (juvenile?) - Wood Duck (male) - Savannah Sparrow 
Hirundo rustica - Aix sponsa - Passerculus sandwichensis

We also saw lots of swallows and sparrows in the vicinity of the wetlands, as well as an American Bittern that flew off before I got its picture.  Surprisingly, I spotted a male Wood Duck in its eclipse plumage!  Eclipse plumage is temporary plumage, that occurs in most ducks after the breeding period.  In the summer, ducks molt their flight feathers all at once, can't fly, and are vulnerable to predators for about a month.  In male ducks, the molt begins with the brightly-colored body feathers.  These are replaced with mottled brown feathers that provide better camouflage, and coincidentally make them resemble females!  Once the flight feathers have regrown, the birds molt again, and by October the full colors are back.  Even though the Wood Duck pictured above is in its eclipse plumage, I could tell it was a male because of its red eyes and the red markings on its bill.

American Kestrel (male)  - Red-tailed Hawk (adult)
Falco sparverius - Buteo jamaicensis

Several raptors flew overhead while we were out in the valley, but I only got a few photos.  Luckily this handsome American Kestrel posed for me!  We watched it fly over the grassy fields and "kite" in one spot as it searched for food, mainly other birds!

The Red-tailed Hawk perched on a power pole and scanned the grasslands for prey.  They mainly eat mammals, such as gophers and ground squirrels, but will also eat snakes and a few birds.
 
Muskrat - Ondatra zibethicus

On our way back home we lucked out again and happened across two Muskrats busily eating plants in the first pond we had visited!  Wow!  These aquatic mammals measure 12.5" in length, with a 9.5" tail, and a weight of 24-63 oz.!  They live in swamps, marshes, and wetlands in large family groups.  Marshes where the water level remains constant are their preference.  They are proficient swimmers, can stay underwater for 12-17 minutes, and have partially webbed hind feet!  Their fur is thick and traps air, which provides insulation and adds buoyancy!  The roots of aquatic plants, and other vegetation is their main diet.  They eat one third of their weight daily!  Burrows are dug in the banks of wetlands, to stay in during the heat of the day as well as at night.  Nests are built out of piles of vegetation on a base, such as a tree stump, typically surrounded by water.  What amazing little critters these are!
 
Muskrat - Ondatra zibethicus

Beckwourth Peak from Carmen Valley

Beckwourth Peak

From almost anywhere in Sierra Valley you can see Beckwourth Peak, at 7,252' in elevation.  You can also see it from several Lakes Basin trails!  For many years, we have wanted to go up to its top.  Last week my friend Mary drove me up there!  The dirt road is 4 miles long, and 4WD is essential for the last 2 miles (get directions online).  There is a gate at the 2 mile point that can be locked.  Luckily it was open, and we were able to drive to the top!  There were people working on the several microwave towers located near the peak, so we explored the area before the towers.  We found a few penstemons, as well as sagebrush, rabbitbrush, manzanita, Curl-leaf Mountain Mahogany, and Jeffrey Pine.  It was very dry from the hot summer sun and drying winds!  The view from the top was obscured by haze from wildfires but it was still impressive!

View north from Beckwourth Peak - 8/6/20

We passed several fascinating basalt-column formations on the way up.  I don't know much about the geology of this area, and I've been reading about it since we visited Beckwourth Peak.  I came across a brief explanation of the geology in  William Harnach's publication, "ANNOTATED CHECKLIST OF THE FLORA OF THE SIERRA VALLEY REGION OF SIERRA AND PLUMAS COUNTIES, CALIFORNIA", dated 2/17/16.
 
 "The geology of this region is complex but in simplistic form it is a down-faulted block basin (graben) that is filled with volcanic ash deposits and lake sediments and is similar to Lake Tahoe in geologic origin. The depth of these ash deposits and lake sediments in some areas is well over 1000 feet, as determined by geothermal drilling done in the 1970’s and 80’s. Within the region there are three main geologic features. The main one is the valley fill, consisting primarily of volcanic ash capped with recent erosional material that makes up approximately 60% of the Sierra Valley region. To the southwest, in the Calpine, Sattley, and Yuba Pass areas, and also in the northeast area of the valley in the Beckwourth Pass and Chilcoot areas are the granitic zones. Finally, the rest of the surrounding area is covered with pyroclastic flows and ash deposits. There are also several remnant volcanic plugs within the valley, with the most notable being Sugarloaf near Beckwourth." 

I also found the following brief geologic history of Sierra Valley on en.wikipedia.org. 
"An intermontaine valley at approximately 4,850 feet  elevation, Sierra Valley is surrounded by mountains ranging in elevation from 6,000 to 8,000 feet. The huge valley, 120,000 acres, is a down-faulted basin, formerly a lake of similar geologic origin to Lake Tahoe to the south, now filled with sediment up to two thousand feet thick. The former Lake has the suggested name of Lake Beckwourth and existed until approximately 10,000 years ago."

I need to do a LOT more research!  I'll keep you posted!

Basalt column formations on Beckwourth Peak

Frenchman's Canyon - 8/6/20

After we came down from Beckwourth Peak, Mary drove me to Frenchman's Canyon, about 18 miles east of the peak.  It was an amazing volcanic canyon, with dramatic formations and a lovely creek named Little Last Chance Creek!  I had never been there before!  We drove for a few miles through the canyon until we came to Frenchman's Lake, a favorite of local fishermen.  On the way back we pulled over and bird watched along the shaded creek.  To our delight we saw five juvenile Townsend's Solitaires feeding on the bugs flying above the creek!  I had read that they prefer to live on the east side, and there they were!  Wow!  The one pictured below is in the process of acquiring its adult feathers and losing it's juvenile, spotted appearance!

Left: Volcanic wall above Little Last Chance Creek 
Center: Townsend's Solitaire (juvenile) - Myadestes townsendi
Right: Fishermen on Little Last Chance Creek

What's happening in our garden?

Are the bears still around?

Check back next week for the answers to these questions and more!


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