Saturday, December 12, 2015

9-Dec-2015 Fircrest, Washington

Site location. Click to enlarge.
This time of year, field trips don't always turn out as planned.  With the Puget Sound region in the midst of a multi-day series of rainstorms, I knew that it was a big gamble to attempt any field work.  But I was antsy to get back outside, so I decided to see what I could accomplish in an afternoon with less than 50% chance of rain predicted. Greater Tacoma was my destination because it is the next metropolitan area south of Federal Way, the southern-most place I've found the introduced crab spider Ozyptila praticola (Thomisidae).

"It might be raining where you are."
A southbound lane on Interstate 5 was closed due to flooding right before my exit in Fife.  This was pretty emblematic of the day: local flooding.  And intermittent downpours.  The ground was so saturated from days of rain that water was pooling and even fallen cones protected by tree foliage above were sopping wet.  Really wet cones are difficult to tap because they quickly saturate my net, which becomes muddy.  This makes it hard to see expelled spiders, especially spiderlings.  Next time I venture out on a wet day, I'll come prepared to collect cones into containers so that I can process them later, after they've dried a bit.

Sample site
Fallen cones
Anyhow, given the conditions I was finding, I decided to forego collecting and just reconnoiter the area for cone deposits that I could return to to sample some other, drier day.  Driving the 10 miles between Fife on the east side to University Place on the west side, I found several accumulations of cones.  Most of them were dropped by the exotic black pine (Piuns nigra), so when I spotted a huge native western white pine (Pinus monticola) in Fircrest, I couldn't resist tapping as many cones as my net would allow.

Female Lepthyphantes leprosus
Lepthyphantes leprosus epigynum
I was only able to find 10 cones in the public right of way, but my net quickly became too much of a mess to handle more anyways.  From them I tapped 3 spiders and 3 species, the only identifiable one being a female Lepthyphantes leprosus (Linyphiidae).  When I return in drier weather I hope I can get permission from the landowner to tap the dozens of additional cones lying on private property, because this appears to be a promising trove.

Besides coming away with a list of promising cone sampling locations for my next foray, the trip turned out to be useful in improving my knowledge of local geography.  Until now I didn't realize how big the Puyallup River is because it's scarcely visible from I-5, and I'd always flown across it without even realizing it!  Seeing it in flood stage from a local bridge caused me to add it to my mental list of potential natural barriers to the southward spread of O. praticola.
View of Puyallup River from Eells St. bridge on July, 2015. Screen grab from Google.

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