February Visit (2/6/2020)

In February, I felt particularly lucky to be escorted the entirety of my hike by robins. They were busy stripping the stands of toyon of their berries, swooping here and there, calling to each other and scolding me. They would let me get close to them and stand under the bushes for a while, but then they would move away one by one down the trail to the next cluster of toyons.

StebbinsSketchbook1_2020Feb06

I was struck on this hike by how much white pitcher sage I saw in clearings, soaking up the sun. The abundance of white pitcher sage and also chaparral currant seem to me to be a sign of the growing dominance of sub-shrubs in the Stebbins habitats, as the annuals start to be shaded out and we follow the ecological stages of plant succession after the fire.

StebbinsSketchbook2_2020Feb06

I stopped for a captivating view with swaths of toyon, hairy-leaved ceanothus, and white pitcher sage. Below are some of the deposits left by mammals and a bird along that same stretch of trail.

StebbinsSketchbook3_2020Feb06

I believe the galls I spotted on the interior live oak are made by the gouty oak gall wasp (Callirhytis sp.).

StebbinsSketchbook4_2020Feb06

A clump of feathers in the grass at the side of the trail told the story of some kind of struggle, probably with a robin since they were so active and plentiful then. No sign of a body (or parts thereof), so either the bird escaped or the evidence was swallowed.

StebbinsSketchbook5_2020Feb06

As I neared the end of my hike, I noticed the unmistakable red of a robin’s chest in the brush down the hill along the side of the trail. The still form looked so peaceful – no sign of predation or struggle. It was a moving end to the drama that the robins had provided all along my journey.

StebbinsSketchbook6_2020Feb06

September Visit (9/29/2016) 2 of 3

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.

oakgalls_2016sep29_sm

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:

liveoakgrowth_2016sep29_sm

Blue oaks, which are deciduous, generally do not resprout from their bases, but show regrowth in their crowns:

blueoakgrowth_2016sep29_sm