16-Mar-2018 Stanwood, Washington

Site location map. Click to enlarge.

I'd had my eye on Stanwood for some time as a place to search for the introduced crab spider Ozyptila praticola. This is because Stanwood was the only remaining urban area between Seattle and Bellingham that I hadn't yet sampled. This sunny, warmish day turned out to be the day! In all, I tapped fallen conifer cones at four Stanwood sites.

Scots pine cone and owl
pellet full of rodent bones

Rodent skull in owl pellet

For my first sample I tapped 100 fallen Scots pine (Pinus sylvestris) cones near Heritage Park and collected 20 spiders. The sample contained at least 6 species, but only one was mature and identifiable: a female Tachygyna vancouverana (Linyphiidae). The most common spider in the sample, however, was Enoplognatha probably-ovata (Theridiidae), of which there were 13 juveniles present. If this spider sample was a bit ho-hum, the sampling location was not. This was on account of the ground beneath the trees being littered with owl pellets! At least one pellet contained a visible rodent skull.

Lonely parking lot pine

Lots of cones, few spiders

I found my next cone source in the parking lot of a restaurant on Route 532, the city's main thoroughfare. A lone black pine (P. nigra) was growing in a small patch of soil surrounded by blacktop and concrete -- not a particularly promising site. However, fallen cones and needle litter had been allowed to accumulate, so I decided to go ahead and sample. Fifty tapped cones produced only 2 spiders: another female T. vancouverana and another juvenile E. probably-ovata.

This row of Douglas-firs...

...provided lots of open cones

If that last sample was disappointing, the next one, taken at the Stanwood Cemetery, was the most diverse of the day. A row of Douglas-firs (Pseudotsuga menziesii) planted along a section of the back fence provided a multitude of open cones. I tapped 50 cones and collected 24 spiders and at least 7 species, six of which were immediately identifiable. These included the linyphiids Erigone aletris, Grammonota kincaidi, Neriene digna, and yet more T. vancouverana. Also present were several juvenile Platnickina tincta (Theridiidae) and a penultimate male Philodromus dispar (Philodromidae). All in all, a typical urban sample for this part of the state.

Church Creek Park

My final sampling location was the wooded Church Creek Park, where I tapped more Douglas-fir cones and also sifted a batch of moss collected from bigleaf maple (Acer macrophyllum) trunks and logs. The cones produced only 7 spiders from 3 species already collected this day, including the two present at each of the four sampling sites: T. vancouverana and E. probably-ovata.

Ozyptila praticola was absent from all four of the cone samples. And while I haven't yet ID'd the moss spiders, there were no crab spiders in that sample, either. If O. praticola is present in Stanwood, it is too localized or at too low a density to be detected by my sampling methods.

Female Neriene digna tapped from fallen Douglas-fir
cones in Stanwood Cemetery