Wednesday, October 28, 2015

25-Oct-2015 Nooksack Cemetery, Everson, Washington

Sample site. Click to enlarge.
Wanting to get in at least one more field day before the rain switch gets flipped and Washington's wet season begins in earnest, Rod Crawford and I headed up to Everson in Whatcom County.  We spent most of the day collecting spiders in and around the Nooksack Cemetery and neighboring Nooksack Elementary School before tapping a round of pine cones in Everson on our way home (interesting area history here).

Nooksack Cemetery
Juvenile Xysticus sp. on a headstone
The cemetery and school sit atop the end of a tongue of elevated land bordered by a wooded Breckenridge Creek and the highly cultivated Sumas River floodplain.  While Rod dove headlong into his search for productive leaf litter at the foot of the bluff, I began searching the headstones and grave markers for eight-legged life.

Zygiella atrica in a retreat
on a headstone
Araniella displicata on headstone
Orb-weavers, crab spiders, linyphiids and the jumping spider Salticus scenicus (Salticidae) made up the bulk of my "rock collection".  Rod pointed out that most were common forest spiders, which led him to suspect that they had ballooned their way into the cemetery. 

Philodromus spectabilis on a headstone
Zygiella atrica on school window sill
Ready for new frontiers and, frankly, a bathroom, I eventually ambled next door to the Nooksack Elementary School's row of playing field Honey Buckets and then collected spiders from the exterior of the school building.  Luckily it was Sunday, so nobody was present to be concerned about the middle-aged woman with the "butterfly net" staring at brick walls, downspouts and door frames.  Where introduced Araneus diadematus (Araneidae) reigned supreme on the cemetery shrubbery and buildings, introduced Zygiella atrica and Z. x-notata (Araneidae) were the most common orb-weavers I found on the school building.

Zygiella x-notata removed from
retreat on school building
Ponderosa cone site in Everson
Since the cemetery had no pines, on our return trip through Everson we knocked on a few doors of homes where pines had been planted in the yard.  A pair of mature ponderosa pines (Pinus ponderosa) in one kind woman's side yard supplied me with a fallen cone sample of 43 cones.

The tapped cones yielded 11 spiders and 4 species, plus 7 adult harvestmen.  As I've found in other cone samples in western Washington, many of the spiders present and all of the harvestmen were introduced species.  However, Ozyptila praticola (Thomisidae), which we have found in great abundance in the Seattle area, was not among them.  Further, we didn't find it in any of the other microhabitats we sampled in the area, and Rod hasn't collected any from other sites he's sampled in Whatcom County.  If the species has spread south from the Vancouver area, its presumed point of introduction in British Columbia, we have yet to detect it in northern Washington state.

Read Rod's account of the day here.

Philodromus spectabilis on a headstone in Nooksack Cemetery

No comments:

Post a Comment