9-Oct-2017 South Fork Beaver Creek, Washington

Site location map. Click to enlarge.

Last year about this time, Rod Crawford and I sampled spiders in the gridspace covering the town of Plain and part of Little Chumstick Creek valley, both located in Chelan County. This day, since Stevens Pass was still free of snow, we decided to make what would likely be our last trip of the year over the pass, and sample an adjacent gridspace.

View down the "road".

As so often happens in field work, conditions on the ground were different than expected. Namely, the forest road paralleling South Fork Beaver Creek, which we had planned to take to our preferred sampling location, no longer existed! In fact, it hadn't existed for decades, judging from the volume of vegetation growing on its former bed. Luckily the main forest road was also in the gridspace, so Rod quickly returned to it to begin his sampling there.

One of several generations of markers
on the witness tree.

I didn't start sampling quite yet, since I was curious to follow a very narrow, almost hidden path along the former road that someone had pruned vegetation here and there to mark. And so I slogged on through the wet and slippery tangle, expecting to find a hunting blind. What I found was flagging hanging over the trail, which led me to notice a witness tree on the hillside directly above.

Male Spirembolus mundus

Female Pityohyphantes sp. #5

Curiosity satisfied, I beat conifer foliage as I worked my way slowly back to the main forest road. Interestingly, although the deciduous understory was quite wet, most of the conifer foliage was dry. Thanks to quite cool temperatures along the creek, many spiders were moving slowly enough to photograph, even in the dim light of the understory.

My main cone source

By the time I returned to the forest road, Rod had scouted the area and located a small grove of ponderosa pines (Pinus ponderosa) for me. Yay, cones to tap! Unfortunately the grove was fairly young and so I was only able to find 17 cones. However, after searching farther down the road, I found a pair of mature trees that had dropped hundreds of cones. It took a scramble up the steep roadside embankment to access them (going up is never the problem. It's getting down again...), but I was happy to get a good sample.

Lots of cones up the embankment!

From 100 cones I tapped 12 spiders from six families. Four species were identifiable, including typical denizens of eastside cones like Meioneta fillmorana (Linyphiidae) and Cryphoeca exlineae (Hahniidae). The surprise of the sample was an atypical female Pityohyphantes tacoma. Rod also found them in conifer foliage. They were atypical in the shape of their genitalia, but also in the sense that this was the first Pityohyphantes I'd tapped from a fallen cone.

You can read Rod's trip report here.

Fireweed (Chamaenerion angustifolium) and ocean-spray (Holodiscus discolor)