Tuesday, November 10, 2015

27-28 Oct 2015 Southeast Of Lake Sammamish, Washington

Sample site locations. Click to enlarge.
My family and I have been systematically hiking our way through the entire regional trail system in King County, Washington.  Since this activity has coincided with my effort to discover the local distribution of the introduced crab spider Ozyptila praticola (Thomisidae), I had my net and vials with me on 27 October when we hiked the lower end of the East Lake Sammamish Trail and happened to find pine trees that had dropped open cones in an accessible spot.  Finding accessible pine cones had been difficult along this particular trail, since virtually every parcel along it is privately owned and most trailside pines had dropped their cones on the private side of the ubiquitous fences.

27 Oct: Southeast Lake Sammamish

SE Lake Sammamish sampling site
Fallen P. monticola cone in
salal (Gaultheria shallon)
Two huge old western white pines (Pinus monticola) growing close to the trail had dropped numerous cones, many of which had been pressed into the mud by vehicles.  But I was able to find 15 intact cones to tap, and those cones produced 21 spiders and 2 identifiable species as well as some harvestmen.

Microneta viaria epigynum
The introduced linyphiids Tenuiphantes tenuis, Microneta viaria and Enoplognatha sp. (probably ovata) accounted for half of the spiders present.  As for Ozyptila, I collected one juvenile specimen.  It had praticola coloration and patterning, so I'm pretty sure that the species exists east of Lake Sammamish.  However, I cannot prove it with this specimen.

28 Oct: Issaquah

Issaquah sampling site
Fallen P. nigra cones under
juniper shrubs
The following day, I decided to return to the same general area and see if I could find any adult O. praticola specimens.  If the adult season for the local population is the same as it is for its British population, then the odds were quickly decreasing that I'd find many more adult specimens before spring.  However, with the rainy season already having begun, I couldn't pass up the opportunity that this not-entirely-soggy day presented to make one last effort.

Black pine (P. nigra) trees planted in front of a local business provided me with 45 tappable cones and 14 spiders.  Half of them were Ozyptila, but they were all juveniles, and all praticola in appearance.  The day before, I had thought that there was nothing more annoying than finding one juvenile Ozyptila probably-praticola, but I was wrong.  It was much more annoying to find seven of them!
A flock of cackling geese (Branta hutchinsii) in flight over Lake Sammamish

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