Tuesday, November 24, 2015

21-Nov-2015 Fidalgo Head, Washington

Site location. Click to enlarge.
The same sunny dry spell that made it possible for me to tap pine cones in Federal Way the day before gave Rod Crawford and me an opportunity to collect another full fall sample at one of Rod's unsampled gridspaces.  Our original plan had been to head south and collect near Matlock on the Olympic peninsula, but predicted temperatures were slightly higher for Anacortes on Fidalgo Island, so we headed north instead.

Douglas-fir & juniper on Fidalgo Head
Looking across Burrows Bay towards
Sugarloaf (left) and Mt Erie (right)
Our sampling site was a rocky prominence called Fidalgo Head, located on the northwestern point of the island.  The trail was slippery with moist red clay and caused us each to "sit unexpectedly", as Rod put it, but otherwise little effort was required to access this lovely spot.  Near to the precipitous face of the head, the dense inland forest opened to a few small grassy meadows growing on a very thin veneer of soil over bedrock.  The meadows were punctuated by Douglas-fir (Psuedotsuga menziesii), Pacific madrone (Arbutus menziesii) and tree-sized coastal junipers (Juniperus scopulorum), and featured large pockets of reindeer lichen.

Future fallen cone microhabitat:
Douglas-fir cones still on tree
Fallen Douglas-fir cones were often
near deer scat at this site.
Although I swept the meadow grass (2 species) and searched for ground-active spiders (to no avail) and spiders in webs (nothing not found elsewhere), I spent much of my time tapping Douglas-fir cones.  Since the scales on most cones were only partially opened, I adopted the method I've used with mountain hemlock cones (described here).  It is a more time-consuming procedure than conventional pine cone tapping, but worth the effort.  Tapping 50 cones got me only 7 spiders (all linyphiids) but 4 species not collected by other means, plus 20 pseudoscorpions from the family Chthoniidae.  In all, about 1 in 6 species we collected at Fidalgo Head came from my tapped cones.

As dusk loomed, I searched webs on a boulder while Rod finished sifting moss.  A couple hiking past asked if I was collecting moths, and was I a biologist.  They were interested to learn that I was looking for spiders, asked to see some, and said they were excited to get back to camp and tell their kids that they'd met a real biologist on the trail.  Now that made my day!

Read Rod's trip narrative here and view his photo album here.

Spider collectors cast long shadows!
Sunset over the San Juan Islands

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