In November, on a cool but not cold day, I hiked to the top of Blue Ridge. Looking out at Lake Berryessa, it was easy to see part of the area burned by the Cold Fire last summer.
On the way up the trail, I looked for mushrooms enjoying the damp left by rains earlier in the month, and observed regrowth of mountain mahogany (Cercocarpus betuloides), blue oaks (Quercus douglasii), and chamise (Adenostoma fasciculatum). The leaves of yerba santa (Eriodictyon californicum) along the trail were losing their waxy coating. The waxy coating, presumably beneficial in retaining water during dry months, is resinous and highly flammable. Yerba santa seeds may require fire to germinate and can also resprout from rhizomes following fire.
Hillsides stripped of their erosion-controlling vegetation by the fire have been shored up with erosion matting installed by Tuleyome and Friends of Stebbins Cold Canyon Reserve.
Looking across Cold Canyon I was struck by the “rivers” of dead tree branches running down the canyons of Pleasants Ridge. They made a ghostly grey against the greens of new growth and the hills still mostly yellow from the summer.
A few mid-action photos:
On a cool gray day, I thought that a scrub jay (Aphelocoma californica) in a gray pine (Pinus sabiniana) made a beautiful silhouette against the sky.
A number of spotted towhees (Pipilo maculatus) were foraging in the smaller trees along the trail. I caught one on a perch next to some stairs, and then drew a close-up from a photo.
All over the canyon, poison oak (Toxicodendron diversilobum) in its fall colors glowed vividly against the green and gray of the day.
Mountain mahogany (Cercocarpus betuloides) resprouting. I love the shape of their leaves.
Female coyotebrush (Baccharis pilularis) flowers, and a view of coyotebrush resprouting.
It’s oak gall season! I spotted the leaf below right in the middle of the trail, with galls from two different wasps. The urchin gall wasp (Antron quercusechinus) makes the spiny pink galls and the crystalline gall wasp (Andricus crystallinus) makes the furry pink galls. These wasps, in the family Cynipidae, lay their eggs in oak leaves (in this case a blue oak), and the eggs secrete plant hormone mimics which cause the leave to form the spectacular gall. The larvae grow and feed in the gall for weeks to years, depending on environmental conditions, and then pupate within the gall and emerge as adults.
Continuing the oak theme, I looked carefully at oak regrowth along Cold Creek. Interior live oak, an evergreen oak, is generally a more vigorous basal sprouter, as observed below:
Blue oaks, which are deciduous, generally do not resprout from their bases, but show regrowth in their crowns:
At the end of September, summer was officially over, but summer weather here lasts well into fall. Chamise regrowth was strong and healthy, and the buckeye leaves were brown and ready to fall, revealing the fruits:
The yellow hills allowed the new sprouts of the chaparral shrubs to stand out sharply:
Two wildflowers: western goldenrod (Euthamia occidentalis) along the trail, and annual willow-herb (Epilobium canum) in the dry creek bed. Three-leaf sumac (Rhus trilobata) was growing happily along the trail; it is a close relative of poison oak, and like that relative, grows back vigorously after fires.
Until this visit, I had only seen western fence lizards in the reserve, so I was excited to spot a speedy western skink:
I saw far more spider webs along the sides of the trail on this visit, especially funnel webs as below:
A hot and dry August day: first I noticed that heavy stillness particular to the very hot days of California summer, and then started paying attention to all of the active insects. Grasshoppers took off in all directions to escape as I walked along the trail and butterflies of all sizes were abundant.
One of the few flowers blooming, twiggy wreath plant (Stephanomeria virgata), attracted quite a few bees, both western honey bees (Apis mellifera) and a bumblebee, the black-tailed bumblebee (Bombus melanopygus edwardsii).
One grasshopper stayed still long enough for me to draw it. It slowly dawned on me that there was a reason it was less willing to fly away as I approached: it was missing its right hind leg. It was still able to fly, but taking off clearly took more effort.
A daytime moon over Blue Ridge:
I watched a Sonoma chipmunk (Tamias sonomae) working busily in the trees some distance away. The image below was drawn from a reference photo.
By June, Cold Creek was dry, at least in the lower part. It is possible that water remained in pools higher up in the canyon.
There were still a few wildflowers to find, and some Valley elderberry longhorn beetles (Desmocerus californicus dimorphus) on their favorite plant:
The leaves of yerba santa (Eriodictyon californicum) growing alongside the trail were strikingly shiny. The yerba santa often seemed to be growing in patches of weedy thistles (star thistle, milk thistle) and dandelions, which are much more abundant post-fire with much of the shade gone.
Brown summer hills and a vibrant cloud-free sky:
John De Benedictis, a Research Fellow at the Richard M. Bohart Museum of Entomology, has been collecting moths twice a month at dusk in Cold Canyon since 1989. I accompanied him for the first part of his visit on May 18. John sets up a sheet across the path at the entrance to the Reserve, and sometimes a second sheet parallel to the path (and perpendicular to the first sheet), when accompanied by Greg Kareofelas, a Research Affiliate at the Bohart Museum. John hangs a fluorescent light against the sheet, which transmits unfiltered UV light, a mixture of UV and white light.
John collects the moths that land on the sheet for later identification. John started his work in Cold Canyon three years after the last major wildfire and is watching closely to see how moth populations respond after the Wragg Fire. May is the month in which he has recorded the most moth species over the years; on a good night, he collects about a third of the species known to fly at that time of year. The numbers collected this May will be a good indication of how depleted the populations are after the fire.
When John first started collecting in 1989, not long after the previous fire at the Reserve, he observed that Sparganothis senecionana was numerous. S. senecionana is a tortricid that prefers to feed on low-growing plants. Over time, as fire recovery progressed, the numbers of S. senecionana decreased, while those of Archips argyrospila, the fruit tree leafroller (also Tortricidae), increased. A. argryrospila feeds on a number of plants including oaks, but seems more abundant in areas with oaks, and their numbers seem to have followed oak regrowth in the Reserve. This pattern now appears to be repeating after the Wragg Fire: John has observed that Archips numbers are considerable lower since the fire, along with the numbers of other oak-associated moths, indicating that they have been hard-hit by the fire and the loss of oaks.
In May, I enjoyed new blooms, still-green hills, and the cool shade along the Homestead Trail. Caterpillars were everywhere, a white-lined sphinx moth caterpillar (Hyles lineata) below, along with lupine seed pods and wild cucumber fruits:
Below, some pipevine swallowtail caterpillars (Battus philenor) on California pipevine leaves (Aristolochia californica). I also enjoyed seeing the cord moss (Funaria hygrometrica) with red seta (the seta were still yellow-green in March).
Many new wildflowers:
California buckeyes (Aesculus californica) were flowering:
Cold Creek still had clear water flowing: