Saturday, April 29, 2017

Bell's Sparrows

Earlier in April, during our visit to Carrizo Plain, I was interested in more than just the beautiful wildflowers; I had my eye on a few bird species as well.  In addition to more flashy Horned Larks and Lark Sparrows, little Bell's Sparrows (Artemisiospiza belli) also caught my attention (and offered some good photo opportunities!)


Prior to 2013, the Bell's Sparrow and similar Sagebrush Sparrow (Artemisiospiza nevadensis) were considered a single species, the Sage Sparrow.  The two species are best distinguished by their range. Sage Sparrows have a larger range, which covers much of intermountain west; they can be found year round in the sagebrush lands of the Great Basin.  The range of the Bell's Sparrow overlaps with that of the Sagebrush Sparrow in eastern California, especially during the winter, and the two species can be very difficult to tell apart.  During the breeding season, Bell's Sparrows can safely be identified on their breeding grounds in coastal California and Mojave Desert.


Like many other sparrows, Bell's Sparrows can be quite inconspicuous as they spend much of their time foraging on the ground beneath shrubs for insects and seeds.  But during the breeding season, especially in the morning, males have a habit of perching on top of shrubs in the open to sing.  The male Bell's Sparrow's song was what initially attracted my attention to these lovey little birds.


Bell's Sparrows prefer shrubby habitat, such as sagebrush scrub and coastal chaparral.  Saltbushes (Atriplex sp.) and sagebrushes (Artemisia sp.) are two types of plants these birds are commonly associated with across their range.  In the Mojave, they also make use of abundant creosote bush scrub.

Tuesday, April 25, 2017

Wildflowers of the Sierra Nevada Foothills: Table Mountain Hike

The hunt for California's spring wildflowers continues, but the seasons are rapidly shifting!  Recently, we hiked to the top of Table Mountain in search of vernal pools and any other lovely springtime surprises this fascinating place in the Sierra Nevada foothills might have to offer.

Fields of lupine atop Table Mountain (Tuolumne County)

Though wildflowers abound during the spring, the year round draw of Table Mountain is its geology.  Located in Tuolumne county, Table Mountain can be viewed while driving along highway 108, between Knight's Ferry and Jamestown.  (Heading east on highway 108, you will begin to see Table Mountain shortly after passing the Red Hills area.)  The formation is obvious: a dark, flat-topped mountain with nearly vertical sides, rising above the surrounding foothill landscape.  The mountain that seems to wind sinuously through the foothills is a lava flow, the cast of an ancient riverbed. 

A portion of the "back" or northwest side of the mountain, as seen from along the hiking trail.

The basaltic lava erupted from the vicinity of the Sierra Nevada crest about 9 million years ago and flowed west along an old river channel, the Stanislaus riverbed.  The basalt displaced the water, cooled and solidified.  Over time, erosion stripped away the older, softer rock surrounding the riverbed.  Because basalt is more resistant to erosion than the surrounding rocks, the cast of the river was eventually left to stand above the landscape, an example of inverted topography.  Basalt from this eruption can also be found atop high ridges in other locations north and south of the river, from the Table Mountain area all the way to the river's headwaters in the Sierra.

Source: Google Earth

The image above is borrowed from Google Earth in order to lend a sense of perspective.  Seen from above, the outline of the ancient riverbed is clear.  Northwest of the highway, notice a portion of Table Mountain, seen as a brown ribbon.  This is the solidified river of lava, flowing south and west from its source in the Sierra along the course of the ancient river.

The flat, mesa-like top of Table Mountain

As one might expect, the top of Table Mountain is flat, like the mesas of the southwest (though geologically very different).  The width of the lava flow in the vicinity of Jamestown varies from 100 to 500 yards or more; in some places up and down "stream" remnants of the flow become patchy.  Portions of the lava flow can also be seen atop the bluffs upriver from Knight's Ferry.  A trailhead off of Rawhide Road in Jamestown gives hikers access to the top of Table Mountain.

Harlequin Lupine (Lupinus stiversii)

Vernal pools and wildflowers grace the top of Table Mountain in the spring.  There was quite a bit of water present when we visited a week or two ago, with a few small waterfalls cascading over the steep sides of the lava flow.  White-throated Swifts (Aeronautes saxatalis), which nest on steep, rocky cliff faces, darted through the air above us, and lupines spread out in vast fields around us.

Sky Lupine (Lupinus nanus)


Harlequin Lupine, growing in a protected spot beside basalt boulders.


Lupine and Clarkia


Butter 'n' Eggs (Triphysaria eriantha formerly Orthocarpus erianthus)


 
Lupine

The hike to the top of Table Mountain is about 4 miles roundtrip, beginning at the end of Shell Road (off of Rawhide Road in Jamestown).  The first mile of the trail meanders through beautiful oak woodlands, verdant and flowery at this time of year.  Near the beginning of the second mile, the trail begins to ascend, gradually at first, through dense Chamise (Adenostoma fasciculatum) and a lovely, cool little stand of Western Spice Bush (Calycanthus occidentalis).  The path enters a heavily wooded area, and hikers welcome the shade of oaks as the trail becomes progressively steeper, ending in a final steep scramble over basalt boulders.  The view from the top is a pleasing reward.  Watch out for Poison Oak along the trail!


After wandering along the lava flow and enjoying the scenery as long as you wish, return via the same trail.  It's not a very long trail, so you should have plenty of time to stop and enjoy the beauty of California's oak woodlands!

Saturday, April 22, 2017

A Land That Time Forgot: San Bruno Mountain

Or, rather, a land that "progress" has mercifully not destroyed, an unlikely island of refuge in a sprawling sea of development. 


My relationship with (and, I admit, my knowledge of) San Bruno Mountain began one foggy March day a couple of years ago, when Eric and I went to visit a friend living in South San Francisco.  Our friend suggested that we go hiking at a place nearby, a mountain, he called it.  I was skeptical, and understandably so, situated as we were in a maze of suburbia on the San Francisco Peninsula.  My knowledge of the immediate area didn't extend much beyond the San Francisco airport, and I had heretofore failed to notice the 1,300 foot mountain rising above the city (probably because it is so often enshrouded by fog). 

Little did I know a glorious and unexpected wilderness awaited me atop that mountain.


Our ascent of San Bruno Mountain brought us through a thick grove of eucalyptus trees: non-native, rather weedy, entirely to be expected (unfortunately).  Before long, we broke through the trees, climbing steeply through a lovely grassland.  Were those native grasses I spied, tucked into the typical exotic mix?  There certainly was a beautiful patch of Blue-eyed Grass (Sisyrinchium bellum) along the trail! 

Blue-eyed Grass (Sisyrinchium bellum)

As we climbed, I became more intrigued, and a sort of slow dawning came over me: this was a special place, a remnant of what used to be.  Being the lone naturalist in our hiking party, the significance of the mountain was mostly lost to the others at the time.  As we reached the top of the mountain, the wind blew and the fog surrounded us, enveloping us in our own private world.  We could see neither sea nor city; not another human being, not a sign of buildings or roads (except for the trail we were on), not a blight on the natural landscape.  For all we could tell, we were on a high mountain peak in a remote wilderness, forgotten by humanity and left to progress as nature intended.


Once upon a time, all of the San Francisco Peninsula looked like San Bruno Mountain.  That is, the Peninsula once supported the vast assemblage of plant communities and wildlife that are now holding out as remnant populations on 3,600 acres of the mountain's slopes.  The mountain is home to 13 rare and endangered plant species, and three federally listed endangered butterflies: Mission Blue (Icaricia icarioides missionensis), Callippe Silverspot (Speyeria callippe callippe), and San Bruno Elfin (Callophrys mossii bayensis).

A Northern Checkerspot (Chlosyne palla): not one of the endangered butterflies, but the only one I photographed!

In 1999, famed ecologist E.O. Wilson called San Bruno Mountain one of the most important and threatened biodiversity sites in the world.  Located in San Mateo County, San Bruno Mountain is now a state park, more or less protected from development, with miles of trails open to outdoor recreationists.

San Bruno Mountain Watch is the organization largely responsible for saving the mountain.  Born in 1970, the mission of the mountain watch group is to “preserve and protect the native ecosystems of San Bruno Mountain, in perpetuity.”  This group has taken on the responsibilities of environmental stewardship, in addition to creating outreach programs that aim to engage the public in protecting the mountain for its value as public open space as well as for its native ecosystems.  And the work is not finished.  Tracts of land adjacent to the mountain, including dune habitat and pockets of native grasslands, are on private property and at risk for development.  Even the 140 acre quarry on the east side of the mountain holds the potential for restoration, as stonecrop (Sedum spathulifolium), the host plant for the endangered San Bruno Elfin Butterfly, is found growing on the rocky outcroppings of the quarry walls.

Stonecrop (Sedum sp), a host plant for the endangered San Bruno Elfin Butterfly

Much of the mountain is composed of the sedimentary rock greywacke, part of the Franciscan complex, which geologists estimate formed about 130 millions years ago during the Mesozoic era.  At that time, the present coastline was underwater, and the sedimentary rock formed as layers of sediment were deposited in oceanic trenches.  The mountain itself is a fault block that began to rise about one million years ago.  The Franciscan greywacke has formed relatively thin, rocky soils on the steep mountain slopes, with pockets of clay soils found where the slopes are more gradual.  According to the website of San Bruno Mountain Watch, there is an inland sand dune on the western slope of the mountain, a remnant from a time long ago when the coastline was farther inland.  (I haven't visited the dune area myself.)

Coast Iris (Iris longipetala) is a rare, California endemic with limited distribution; it is associated with the diminishing
coastal prairie plant community.

Microclimates on the mountain, created by varying combinations of fog, high winds and sun exposure, create the opportunity for a diverse assemblage of plant communities to share a relatively small area.  In all, ten distinct plant communities can be found on the mountain.

The most common plant community is Northern (or Franciscan) Coastal Scrub, comprised largely of coyote bush (Baccharis sp.), sagebrush (Artemisia sp.), lizard tail (Eriophyllum staechadifolium), bush monkey flower (Mimulus aurantiacus), and coffee berry (Frangula californica, formerly Rhamnus californica).  San Bruno Mountain boasts the largest remaining example of this plant community, which once covered the peninsula along with coastal grassland.

Coast Rock Cress (Arabis blepharophylla), a rare, endemic plant found on San Bruno Mountain, in association with
coastal prairie and northern coastal scrub communities.

Two types of grasslands or coastal prairies can be found on San Bruno Mountain; these plant communities contain the greatest diversity of plants, have the highest productivity, and provide habitat for all three endangered butterflies.  San Bruno Mountain preserves possibly the largest, most diverse and intact area of coastal grassland prairie left in California.

Valley Needlegrass Grassland graces the southern slopes of the mountain, a mix of purple needle grass, California melic, June grass, blue wild rye and San Francisco blue grass.  Wildflowers also abound in season, on these warmer, drier slopes.

Coastal Terrace Prairie is found on northern exposures, able to withstand a greater amount of fog and wind.  Grasses found in the Coastal Terrace Prairie community include Pacific reed grass, California oat and hair grass, and three types of fescue: California, Idaho and red.

Ceanothus, or Blue Blossom, in full bloom on the mountain - an important butterfly host plant!

Central Coast Riparian Scrub, comprised of willows, elderberry and ferns, can be found at sites of seeps and springs.  Less conspicuous communities include Blue Blossom (Ceanothus) Chaparral, the rare Valley Wild Rye Grassland, Freshwater Marsh (near Colma Creek) and Freshwater Seep, as well as Coast Live Oak Woodland in a few sheltered canyons.  A small remnant of Central Dune Scrub, a community that is rapidly disappearing in California, is tucked away on the west side of the mountain.

A variety of lupine species on the mountain are host plants for
the endangered Mission Blue Butterfly.

The small creeks, seeps and wetlands of San Bruno Mountain support Pacific Tree Frogs (Pseudacris regilla) and the rare San Francisco Forktail Damselfly (Ischnura gemina).  Historically, these wetlands have been home to endangered San Francisco Garter Snakes (Thamnophis sirtalis tetrataenia) and threatened California Red-legged Frogs (Rana draytonii).  Hopefully, with continued conservation and restoration efforts, one day the mountain will again support populations of these unique species.

According to San Bruno Mountain Watch's website, the biodiversity counts for the mountain are:
662 plant species, 42 butterflies, 195 birds, 5 bumblebees, 30 ant species, 24 mammals, 13 reptiles, and 6 amphibians.  Quite impressive for one mountain island, isolated as it has become in a sea of civilization.

Mammal inhabitants include brush rabbits and jack rabbits, rodents such as gophers, ground squirrels, mice and voles, Gray Foxes, Long-tailed Weasels, raccoons, skunks, opossums, shrews, and of course, the ever-present feral cat.  Sightings of mountain lion, red fox, badger, bobcat and coyote have also been confirmed.  A coyote population on the mountain would be an exciting thing indeed, as the presence of coyotes leads to greater biodiversity, especially in bird species, as coyotes prey on feral cats, opossums and skunks, which are leading predators of birds, fledglings and bird eggs.  One interesting paper I read suggested that the abundance of cemeteries in the nearby town of Colma has inadvertently created enough of a wildlife corridor to allow coyotes and other wildlife to reach the mountain's isolated island of habitat.


Since my first visit to San Bruno Mountain, I have returned to this island a few more times, and each experience has been different.  I have witnessed the mountain in its many moods: Damp, close fog one day, keeping the mountain's secrets; billowing, rolling fog another day, tumbling over the mountain on biting winds.  Refreshing summer breezes and wisps of cloud have met me on the mountain; dazzling sunshine and crystal skies have revealed views extending across the San Francisco Bay and out to the Pacific, the Farallon Islands on the horizon.

But the mountain I like the best is the brooding mountain: thick, moody fog cloaking its slopes, swirling on the wind and blotting out the surrounding cityscape; dense, sheltering fog protecting this secret, forgotten place from the busy world.  Because it is only after a climb up the mountain and into the fog that one feels as if it is truly possible to visit the California of days gone by, to return to a land that time forgot.


More information on this remarkable mountain island can be found at San Bruno Mountain Watch's very informative website, which I read thoroughly after my initial, surprising visit to the mountain: http://www.mountainwatch.org/

Wednesday, April 19, 2017

Wildflowers of the Sierra Nevada Foothills: Red Hills Area of Critical Environmental Concern

Red Hills Area of Critical Environmental Concern: a big name for a special place in the Sierra Nevada Foothills.  Markedly different from surrounding areas and supporting a unique assemblage of species, this area is considered a biological or ecological island.

Bitter root (Lewisia rediviva)

Driving past the Red Hills area on highway 108/120 west of the junction with highway 49, observant motorists will notice a striking difference between the grassy, oak-dotted hills that provide rangeland for grazing cattle, and the sparsely vegetated rocky terrain of the Red Hills. 

Buckbrush and Gray Pine cover Red Hills

The inhospitable soil of Red Hills excludes the annual (and exotic) grasses of surrounding areas and instead supports an assemblage of scraggly-looking gray plants, including Gray Pine (Pinus sabiniana) and Buck Brush (Ceanothus cuneatus), with an understory of herbaceous plants which put on a striking and unexpected wildflower show in the spring. 

In the spring, Goldfields (Lasthenia californica) carpet the ground at Red Hills.

The difference between the grassy oak savannahs and scrubby Red Hills, one might guess immediately, is a product of geology.

Five Spot (Nemophila maculata)

Most people probably immediately link that precious mineral gold to the Sierra Nevada foothill region, otherwise known as the Mother Lode.  But what many don't realize, is that tucked along the base of the Sierra Nevada mountains is a belt of metamorphic rock - slate, marble and the like - which includes a fair amount of California's state rock, serpentine.  Serpentine rocks and the soils derived from them underlie the unique landscape of Red Hills.

Bird's Eye Gilia (Gilia tricolor) - one of my favorite!  Notice the blue pollen on the anthers - a unique feature of gilias.

To understand the origin of these metamorphic rocks, one must travel back through millions of years of geologic history.  Between 544 and 65 million years ago (during the Paleozoic and Mesozoic eras), subduction was occurring along the western edge of the North American continent as plates converged.  As material from the seafloor, limestone reefs and even parts of oceanic crust was scraped up and "smashed" against the edge of the continent, intense heat and pressure metamorphosed or transformed this material into metamorphic rocks.  Differing occurrences of various minerals account for different types of rock.  For example, rocks from the earth's mantel, which have large amounts of the mineral olivine, form the rock serpentine. 

Bolander's Linanthus (Leptosiphon bolanderi) characteristically shows a slight affinity for serpentine soils.

The Red Hills area includes a large portion of the Tuolumne complex of ultramafic rocks, metamorphic rocks that are unusually high in magnesium and iron, as well as nickel, chromium and cobalt.  These minerals are not conducive to the growth of vegetation (magnesium, for one, causes calcium deficiency in plants); in high enough doses, they are toxic to plants.  Coupled with low amounts of the basic nutrients plants require (nitrogen, phosphorus, potassium), these serpentine soils create inhospitable growing conditions. 

Ithuriel's Spear (Triteleia laxa) is endemic (limited) to California.

 Yet, remarkably, life will always find a way, and a small handful of plants, often referred to as serpentine endemics, have adapted to grow and even thrive in these impoverished soils.  Gray Pine and Buck Brush, while present in other areas, seem oblivious to the unfavorable conditions of serpentine soils, and flourish where other foothill species cannot.  Several plants occur only in the Red Hills area and surrounding Tuolumne County, such as California Verbena (Verbena californica) and Rawhide Hill Onion (Allium tuolumnense).

Blue-eyed Grass (Sisyrinchium bellum)

The first time I visited Red Hills ACEC was on a field trip for a botany class I took at CSU Stanislaus; the second and third visit were also for field trips in other botany classes!  But there is clearly a reason this place holds such appeal for botanists, with its unique assemblage of species found nowhere else sprinkled amongst more widespread species that have managed to eke out existences in an otherwise unfriendly landscape. 

Shooting Star (Primula sp.)

Much like our desert regions, the Red Hills area has been neglected over the years: it was "unproductive" from an agricultural as well as mining standpoint, useful for little else besides a dumping ground and place to recklessly drive off-highway vehicles.  Thankfully, since the early 1990's it has been protected by the federal government and this valuable ecological island will be preserved.

Showy Red Sierra Onion (Allium obtusum)

Spring is undoubtedly the time to visit Red Hills: the creeks are running (in wet years), the wildflowers are blooming.  Goldfields color the otherwise gray hillsides, and it seems everywhere one looks, delicate blooms can be found hiding among rocky outcroppings.

Cream Cups (Platystemon californicus)

About 17 miles of looping trails wind throughout the area, providing ample opportunities for the hiker and the equestrian... during the winter and spring months.  (Conditions become quite desert-like during the long, hot, dry stretch of summer and fall.)  I highly recommend bringing a trail map with you, as trail markers are not always dependable.  A map can be accessed through the Bureau of Land Management's website:

https://www.blm.gov/sites/blm.gov/files/documents/files/media-center-public-room-california-red-hills-acec.pdf


Purple Mouse Ears or Douglas' Monkey Flower (Mimulus douglasii) is a miniscule flower
(the whole plants stands a proud 2 - 3 inches tall) with an affinity for serpentine soils.

For more information on the geology of the Mother Lode region (much, much more information) a geologic guide book titled "Roadside Geology and Mining History of the Mother Lode" is available in PDF form through the Bureau of Land Management, and can be accessed through their website.

 https://www.blm.gov/ca/pdfs/bakersfield_pdfs/field_trips/mother_lode_south/pdfs/2006_part_1_maricopa-jackson.pdf



Tuesday, April 18, 2017

Wildflowers of the Sierra Nevada Foothills: Hite Cove Hike

'Tis the season for wildflowers!  If you live in any of California's lower elevation locations (as most of us do), now is the time to get outside and see the blooms!

White Fairy Lantern (or Globe Lily) (Calochortus albus), bedecked with raindrops

Valleys and hills are springing to life, but the window of opportunity is small; by about mid-May, most of the blooms will be gone from low elevations and we'll have to hike higher up in the mountains in search of wildflowers (not that that is a bad thing, of course!) 

Lupine (Lupinus sp.)

Hite Cove Trail, located off of highway 140 near El Portal on the road to Yosemite National Park, is one of the best places in the central Sierra Nevada foothills to see an array of spring wildflowers.

Twining Snakelily (Dichelostemma volubile)

The trail follows the south fork of the Merced river, wending along the river canyon cliffs for the first 1.5 miles before dropping down to follow the river.

River canyon, south fork of the Merced River

The roundtrip hike out and back to Hite Cove, an abandoned mining settlement, is 9 miles.  But since the trail meanders up the river canyon with no real destination (no lake, waterfall or mountain peak), hikers can turn around at any point.  The goal of this hike is to see wildflowers!

Purple Owl's Clover (Castilleja exserta)

A nice option for a shorter trip is to hike two miles out to a point where the trail drops down beside the river.  Jutting out into the river are some really neat metamorphic rock formations, with distinct fold patterns.  Turning back at this point provides a nice, flowery four mile roundtrip hike.

Folds of metamorphic rock along the south fork of the Merced River

The trail starts at just under 2,000 feet in elevation, with no major elevation gain along the trail.  The trail does have some steep, undulating hills, and the going was a little slow when we hiked it in the rain.

Golden Brodiaea (Triteleia ixioides)

However, spring rains in California's oak woodlands coax otherwise secretive amphibians out of hiding, and we saw several Sierra Newts (Taricha sierrae) along the path.  They are quick to get out of the way and hide themselves in tall vegetation or under rocks and logs, so it was tricky to get a decent photo!

Sierra Newt (Taricha sierrae) hiding in poison oak

Since the goal of this hike is to see a profusion of wildflowers, Hite Cove trail is best hiked from March to mid-May.  By the end of May, the flowers and grasses are drying out and the trail, with its southwestern exposure, gets pretty hot for most hikers.  As the trail crosses private property, it is closed during the fire season (summer and fall).

Clematis (or Pipestem) (Clematis lasiantha)

The trailhead is 10.5 miles west of Yosemite's Arch Rock entrance, and 21 miles east of Mariposa, at the site of Savage's Trading Post.  Park off of the highway, on the north side of the road; there is a portable bathroom located here. 

Purple Chinese Houses (Collinsia heterophylla)

This is a dog-friendly hike, but beware of ticks!  It's a good idea to keep dogs leashed here, as the trail is very narrow and hugs the cliff, dropping off steeply to the river in many places.

Mountain Jewelflower (Streptanthus tortuosus)

Happy hiking and wildflower hunting!  Remember to "leave no trace" when you visit these special places.  Stay on the trail to avoid trampling vegetation; leave nothing but footprints, take nothing but photographs!

California Indian Pink (Silene laciniata ssp. californica)