Sunday, April 4, 2021

California's Rarest Ecosystems: The Prairies and Vernal Pools (Part One of a Two-part Miniseries)

The lower foothills of the Sierra Nevada are one of the most unique and almost universally ignored parts of California. Caught between the famous and heavily-visited forests and alpine regions of Yosemite's high country and the utilitarian agricultural fields of the Great Valley, the lower foothills are made of soils too poor to be developed, and too "plain" to be noticed by people rushing up the highways to the mountain resorts. For much of the year they seem barren and lifeless. But these prairies are one of the most precious of California's diverse ecosystems.
The prairies of California once extended the length of the Great Valley, a 400-mile-long grassland supporting millions of grazing animals, birds, and predators, including Tule Elk, Pronghorn, Deer, Grizzly Bear, Mountain Lions, Coyotes, Foxes, and numerous rodents, reptiles, amphibians, fish, and insects. In earlier times (more than 10,000 years ago) there were camels, horses, bison, giant ground sloths, Columbian Mammoths, Saber-tooth Cats, and Dire Wolves.

There were also modern-day wolves, and it is ironic and coincidental that a wolf returned this week to the Great Valley for the first time in a century. It is a young male from Oregon who made an epic journey through Modoc County into the Sierra Nevada near Yosemite Valley, and then into the Sierra foothills of Fresno County, and across the Great Valley (including two freeway crossings). At last report it's now in Monterey County (it's wearing a radio transmitter). 

The prairies were covered with native grasses that were quickly replaced by invasive species when European colonizers arrived and started herding sheep and cattle. Farms eventually replaced the ranches, and the remaining prairies, no more than 5% of the original land cover, were relegated to the fringes where the soils were poor and no water was available for irrigation. Those remaining prairies form a belt through the foothills of Sierra Nevada.  A narrow remnant can be found along the Coast Ranges and the Carrizo Plains west of Bakersfield.
The prairie soils in the Sierra Nevada foothills are notably poor in nutrients because they have not been part of an active floodplain in tens of thousands of years, and the fertile components have been leached away, leaving behind reddish iron oxides and thick clays. Differential settling and wind deflation has left small hollows and depressions that collect rainfall during the relatively rare winter storms. The clay prevents the water from seeping underground, so pools will persist for weeks or months at a time. These pools are the basis for one of California's rarest ecosystems, the vernal pools.
The vernal pools are islands of diverse life in the otherwise barren grasslands. Numerous species of plants and wildflowers, amphibians, and invertebrates have evolved to survive the weeks of water and the months of dryness. As the waters evaporate away, one species of plant after another germinates, grows, and goes to seed. The pools are often rimmed in colorful zones of different flowers.
I'm writing about the vernal pools today because the limitations of travel in the times of a pandemic have kept me pretty close to home. I live on the edge of the prairie between the Tuolumne and Stanislaus rivers and I was out there today. A few pools are left, and flowers are blooming across the region. The views are expansive, extending to the snow-capped peaks of the High Sierra.
The pools and plants provide food and cover for multitudes of bugs and other wiggly organisms, so the pools are trafficked by a large variety of birds, and dozens of species can be identified by discerning and observant individuals, and occasionally by me as well. 
I saw a half-dozen American Avocets in one pond a few weeks ago.
The prairies are one of the best places to see the rare and threatened Burrowing Owls. The area around Crabtree, Willms, and Cooperstown Roads are among the most dependable places to see them in our region.
Savannah Sparrows are a common species, and they'll occasionally cooperate with photographers.
The Western Kingbirds seemed to arrive from their winter homes in Mexico all at once last week. I saw none a week ago, and dozens today, including this one that hung about long enough for a picture.

I have no picture, but I came upon a Gopher Snake in the road that was in serious danger of being run over. I stopped, looked at it carefully to make sure it wasn't a rattlesnake, and then I picked it up to put it in a safer spot. I was suddenly reminded of how Gopher Snakes sometime pretend to be rattlers! They can flatten their normally narrow heads into the triangle shape of a rattler, and will strike in a similar manner. I didn't hold it for long...how do you explain to the EMTs that you picked up a rattlesnake that you thought was something else?

If you are lucky enough to live near a California prairie, this is a good time of year to explore them. If you tend to rush through this unique part of the Sierra Nevada and the Great Valley on your way to Yosemite or some other mountain destination, slow down and give these precious and unique lands a quick look. You won't be disappointed.
 

Sunday, March 28, 2021

A Worm Moon Rising, and a Very Far-away Plane

One of the really sad casualties of the pandemic was the ending of visiting our good friends on the night of the full moon rising. Their house has a fine view of the eastern horizon, and the rising moon is almost always a dramatic sight. After a hiatus of more than a year, we have had our vaccine shots and finally felt we could gather safely in a small group for the tradition tonight. And it was quite a sight.

Our eastern horizon is the composed of the alpine peaks that surround Yosemite Valley, and in the twilight picture above, one can see the snowy peaks of the high country. The snow is a welcome sight, but it is still too little to put a dent in the second year of drought conditions.

I was kind of amazed that I could just make out some trees on the ridges below the peak. The camera (which I just love) is an appropriate point-and-shoot for fools like me who need a 60x zoom for capturing birds and moonrises.
As the moon lifted above the horizon, I thought it was passing a power line when I realized the line was moving. It was a jet plane with a contrail following! I can't even begin to estimate how far away the plane was...

The Worm Moon refers to the thawing of the soil, allowing worms to start doing what worms do. We don't see much of a difference here in the warm climes of California, but the worms are certainly active in the garden right now.

This moon is also a "super-moon", meaning the moon is relatively closer to the Earth in this part of its orbit, so it appears a bit larger and brighter than "normal". There will be four "super-moons" this year.


 

Saturday, March 20, 2021

The Vernal Equinox: Equality in Unequal Times

The sun set today on an unequal and unbalanced world. But for a day, the whole world shared a moment of equality, the day and night being more or less equal at all latitudes. Supposedly the day and night are both 12 hours long no matter where you are. There is a bit of squishiness in that statement, given that the refraction of the image of the sun makes the day last a few minutes longer, six minutes or so.
The sun sets due west on the equinox, which allows for interesting pictures in an otherwise mundane location like an absolutely flat valley with lots of east-west roads and irrigation canals. Some years I try to be out running errands, but today I was at home, so I went a few blocks west to where one of the canals has just been filled for the irrigation season.

 

Friday, March 19, 2021

Doo, doo, doo, Lookin' Out My Backdoor: What to do when you're stuck on the couch on rainy day


I have had few chances to write about my geological journeys for the last year, because there have been precious few geological journeys. Well, literally none. I'm blessed by having the Tuolumne River flowing by a half-mile from my house, and I'll spend a bit of time there almost every day exercising and searching out birds and other life forms. But rain turns the trail to mud, so I was pretty much stuck on the couch for the afternoon.

The rain has been rare this year, and the air outside smelled delicious (that's also truly rare in this valley). So the back door stood wide open during the afternoon while I sort of napped on the couch. But I kept the camera at my side. Who knows what could happen?

The main goal of the day was to catch a few pictures of our truly rare birds for this time of year: a pair of Hooded Orioles. They are tropical migrants, and so far this year only five have been reported on eBird in the entire San Joaquin Valley (there are more in Southern California and the central coast, as they are starting their northward migration). Our area used to be the northern boundary of their range, but with a warming climate and the planting of ornamental palms, they are found as far north as Arcata. They like the palms to construct their unique hanging nests, and as I've found, they love the sugar water in Hummingbird feeders. They've been coming by a dozen or more times a day, a male and a female, for a drink. Normally I can only take pictures through a window and blinds, but with the open door, I got some sharper images. The male is the brighter one with the black face and throat (below).
While waiting for another appearance of the Orioles through the narrow doorway, I saw fluttering in the far distance, about three backyards away. Zooming in I saw a flock of Cedar Waxwings. They fly through the neighborhood every so often looking for fruits, berries, and insects. I haven't seen any for a month. I must not have been looking...
The Orioles aren't the only birds that like coming to a Hummingbird feeder. We have a pair of Anna's Hummingbirds that visited today as well. They are the only Hummingbirds who stay in our region through the winter. Black-chinned and Rufous Hummingbirds will be arriving as spring progresses.
One kind of bird has been a constant visitor in our yard all winter: the White-crowned Sparrow. Most of them will leave the region in a few weeks on their way to breeding grounds as far north as the Arctic Circle. They do a great job of picking up the sunflower seeds that get scattered on the ground by the other birds.
The House Sparrow is a Eurasian native that was introduced to North America in the 1850s, and they quickly spread across the continent and are among the most common birds around. We see them so often that we become inured to their presence. I suppose we should admire species so adaptable as to be able to live successfully wherever humans do.
We have House Finches and Purple Finches that spend time at our feeders, but I was not successful at getting decent pictures today. Later on we had one more visitor, another bird seen so often in our region that one can sometimes take it for granted. But familiarity can't take away the stunning beauty of the California Scrub Jay (until somewhat recently called the Western Scrub Jay). They are found along the Coast Ranges from the Puget Sound to the southern tip of Baja California. There are dozens of them along the Tuolumne River this year, perhaps because of a huge acorn crop this year. But they also like the seeds available in my yard.
And that was the nature I experienced today through a narrow sliver of the landscape visible while looking out my back door.


Wednesday, February 17, 2021

Mars Landing! And a Speculative Question: What Spot Would You Pick on Earth?

 

Courtesy of NASA

The landing is almost here (or by the time you read this, it's happened already, for better or worse)! I hope, hope, hope that all goes well. Mars is a tough target, and I've seen to many failures and disasters. But...if they are able to stick the landing, we'll have an incredible adventure ahead of us, exploring the Jezero Crater, the site of an ancient sea and river delta complex. It's thought to be one of the most likely places to find evidence of any life that might have evolved on Mars.

Jezero Crater delta complex, landing site of the Perseverance Mission

Lots of good resources and landing schedules can be found here: Landing Toolkit: Perseverance Rover - NASA Mars. I've checked out things ahead of the landing, as you can see below, and the rock samples look intriguing.

(You can do your own pic with the mission toolkit)

I'm curious. The Mars landing site was carefully chosen as to glean the most information possible in a small area. If you had a single chance to land a rover on Earth for an only exploration, what place on Earth would you pick for the landing? And why? Answer in comments!


Saturday, January 30, 2021

You Can See Yosemite Valley from the Tuolumne River! In a Manner of Speaking...

Those of you who know the layout of Yosemite National Park will also know that the title of today's post must come with some kind of caveat because any hiker or cartographer knows that the Tuolumne River in Yosemite National Park flows through a vast gorge the depth of the Grand Canyon (it's even called the Grand Canyon of the Tuolumne River). You just can't see the one valley from the other.

But...the Tuolumne River also flows across the flat plains of the Great Valley of California, and if we count "Yosemite Valley" as being also some of the significant peaks and cliffs that ring Yosemite Valley like Half Dome, El Capitan, and Sentinel Dome, you can in fact see the valley from the Tuolumne River.

This is not one of my occasional posts about the better-known spot for viewing Half Dome from Hall and Keyes Roads near Turlock. I get in enough internet trouble over that one, but it is indeed possible to see the very top of Half Dome and El Capitan from my daily walking trail along the Tuolumne River in Waterford. But the additional caveat is that it has to be a really clear day, and we have precious few of those over the course of year. Sometimes weeks can pass between sightings of any mountains at all. But following our huge storm this week, the air was crystal clear today.

The additional caveat is that you need binoculars or a good zoom lens to see the domes and cliffs. With the naked eye, the mountains are difficult to distinguish from one another. But on those rare clear days, and with the right equipment, and knowing where to look, you can indeed see some of Yosemite Valley's most famous landmarks. In a way of course it is frustrating. I'd rather be there than here, but chances will start increasing as the pandemic finally begins to subside.

If you are wondering about the cranes in the foreground, our 1964 vintage bridge is being replaced by a safer, wider bridge. The anchoring columns of the present bridge are unstable during floods; all bridges are perfectly safe, the engineers say, right up until they are not.

In any case, if you couldn't make out the various domes and cliffs and peaks in the opening picture, they are labeled below. 

If you live in the Central Valley (we call it the Great Valley) and wonder if you can see any particular Sierra peaks, check out caltopo.com and find the dropdown command for "simulated view". You can adjust the map for a view from anywhere covered by the program. Below is an example of the view I used to label the peaks shown in this post.




Wednesday, January 6, 2021

A Beautiful Scene for a Horrific Day

There aren't many days like this. That can be both a good thing and a bad thing. My country was rocked by a coup attempt and the Capitol Building was invaded and vandalized for the first time in centuries. It dominated my day and little else was accomplished, other than to stare unbelievingly at the screen where the events unfolded in Washington D.C. and various state capitols. When things settled somewhat, we had to get outside, away from the media. And we discovered it was one of the clearest days of the year.
We headed a few miles east to the single best viewpoint I know of in the western foothills of the Sierra Nevada: Turlock Lake State Recreation Area. The lake mainly serves as a fishing and boating site (as well as being a principle irrigation reservoir), but there is some interesting geology, and a wonderful view.

The dam is constructed on the sediments of the Turlock Lake and Mehrten formations, and a number of interesting fossils have been found in the area: mastodons, camels, horses, huge tortoises, and gigantic 9-foot-long tusked (really!) salmon.

East of the main picnic area there is a paved road that climbs to the top of the highest local hill, and on a clear day like this one was, the view extends from the high peaks of Yosemite National Park across the Central Valley to the mountains of the Diablo Range, and the rest of the Coast Ranges. Today was one of the clearest days I've seen in a long time.
Some lenticular clouds were building over the Sierra Crest, making me wish I was I could be up there and a little closer, but that wasn't to be this time. Maybe soon...
Postscript (1/30/21): Anonymous asked what peaks were visible in these pictures. I checked on caltopo.com and found that we were looking at the heart of the Yosemite high country. Here are the caltopo.com images for the last two views above. The first shows from left to right Mt. Simmons, MaClure, Lyell, and Clark.
The second shot shows Mt. Clark, Gray Peak, and Red Peak.