Friday, July 29, 2016

23-July-2016 Union Creek, Washington

Site location map. Click to enlarge
Last summer Rod Crawford and I collected spiders at Sand Ridge Trailhead, located southeast of Mt. Rainier in Yakima County.  Today we decided to check out Union Creek Falls, located northeast of Mount Rainier about 20 miles due north of Sand Ridge Trailhead.  Since the elevation of the two sites is about the same, I figured I'd find ponderosa pine (Pinus ponderosa) cones to tap just as easily this time as last time.  That is always an attractive prospect to me.  But Union Creek was a doubly enticing destination since to reach it we would drive through the little enclave of Greenwater.  Greenwater is the next town "up-canyon" from Enumclaw, which is the most southeastern place in western Washington where I've found the introduced thomisid Ozyptila praticola.  I was eager to make a brief cone-tapping stop in Greenwater to see if I could find O. praticola there.


Rod sorting a sweep sample in front of
my cone source
The fallen cone microhabitat
I decided to stop at the long-closed Buzzy's Greenwater Cafe.  Being closed, it offered plenty of parking, and the grounds were unlikely to be fastidiously manicured.  A towering Sitka spruce (Picea sitchensis) growing near the restaurant's main entrance had dropped numerous cones on tree litter and sparse herbs.

Enoplognatha thoracica
I tapped 50 cones and collected a juvenile harvestman and 2 juvenile spiders, a Xysticus and an erigonine.  I also turned over a few rocks and found a female Enoplognatha thoracica (Theridiidae), who immediately set to work rolling her egg sac, presumably in preparation for repairing the damage I had caused to her nest.  This introduced species is fairly common in western Washington; I have tapped if from cones at a dozen sites, and Rod and others have collected it from a variety of other microhabitats.  In the brief time I was tapping cones, Rod collected numerous additional species from herbs and conifer foliage.  Since Greenwater is in an unsampled gridspace, we have a good head start on a dedicated field day there.

Union Creek

Rod crossing log
bridge over Union Creek
A boulder-eye view of Union Creek
Falls and gorge
I noted a spindly western white pine (P. monticola) growing in the picnic area next to the trailhead.  I thought it might come in handy if I didn't find any ponderosas on the trail.  Our first destination was Union Creek Falls, but first we had to cross Union Creek.  The creek was running just high enough that rock-hopping wasn't possible.  Then Rod spotted the makeshift bridge: a log over the creek.  Someone had thoughtfully tied a rope above it to steady the wobbly.  Just a few minutes scramble from there and we were in the small but attractive Union Creek Falls gorge enjoying a cool, fine mist from the waterfall.  There were no good cone sources here, so after collecting spiders from the creek boulders and gorge wall, I continued up the trail in search of pines.

A ponderosa (l) and white pine
(r) flank the trail but neither
provided accessible cones
Perhaps this lizard and I were doing
the same thing in this bark pile:
hunting spiders
Several times along the trail I glimpsed tantalizing pines, but all were either out of reach on the other side of boulder talus, had dropped their cones over cliffs, or were too small to produce cones.  I finally gave up and tapped 50 Douglas-fir (Pseudotsuga menziesii) cones.  The resulting 3 spiders weren't terribly exciting, but at least one was mature, a female Lepthyphantes mercedes (Linyphiidae).

White pine cone source
near trailhead
Fallen white pine cones
Upon return to the trailhead I found that the pine I'd noted earlier had only a few fallen cones beneath it.  This was a disappointment.  But as I crossed the footbridge over Union Creek on my way to find Rod and let him know I was ready to leave, I found what I was looking for.  A towering western white pine was growing on the opposite bank of Union Creek, and it had dropped dozens upon dozens of cones!  I tapped 50 cones and collected only 5 spiders but 4 species.  That's a high maturity rate for a cone sample!  Besides another L. mercedes this sample contained a Micaria pulicaria, which we didn't find in any other microhabitat this trip.

Read Rod's trip narrative here.

The rock walls of Union Creek gorge were a good place to find Callobius
My camera barely captured the subtle lilac sheen on the abdomen of
this female Callobius.

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