Saturday, February 27, 2016

25-Feb-2016 Square Lake, Washington

Site location. Click to enlarge.
Considering that February is the heart of western Washington's rainy season, I have been pleasantly surprised at how much spidering I've been able to do this month.  And since this past week was essentially rain-free, Rod Crawford and I were able to squeeze in one additional field trip before the month draws to a close.

This white pine was conveniently located
in the middle of the trail!
The day's destination was the northeastern corner of Square Lake, which is located a few miles south of Port Orchard on the Kitsap Peninsula.  Note the ridges trending NNE-SSW on the site location map above.  They're relics of the Fraser glaciation. A very interesting topography!

When Rod sampled a nearby gridspace last year, he noted that western white pines (Pinus monticola) were present there.  Always a good enticement for me, even better that it turned out to be true for this site as well!  I was delighted to spot numerous pines next to the trail during the short hike to the lake, not to mention one growing smack dab in middle of the trail itself.  And fallen cones were plentiful.

Mossy pine cone
Despite no rain reported in the area several days prior to our visit, the cones were heavy with absorbed moisture and full of lots of organic debris.  As if to emphasize the moist fertility of the area, many cones even had moss growing on them.

I tapped my usual sample of 50 cones and collected 10 spiders and 57 (!) pseudoscorpions.  All but one of the spiders were from the family Linyphiidae (the other was an agelenid), while all but one of the pseudoscorpions were from the family Neobisiidae (the other was from Chthoniidae).  I later tapped an additional 10 cones which produced 2 more linyphiids and even more pseudoscorpions, the latter which I didn't have the heart to collect.

Female Wubana pacifica
A bit blurry, but this photo shows
Wubana's white "butt spot" (not
the technical term :)
Three spider species were identifiable in my cones sample: Frederickus coylei, Wubana pacifica and Lepthyphantes zelatus.  Although all three species are common in western Washington leaf litter, we didn't collect the first two in any other microhabitat at this site.  Once again, cone tapping saves the day!  Or at least, helps fill out the site species list.

Just a few of the dozens of pseudo-
scorpions I tapped from pine cones
Rod noted how rotund many of the pseudoscorpions were and wondered whether they were perhaps full of eggs.  Whatever the explanation, they sure seemed to be flourishing in these pine cones.  At an average of 1.14 pseudoscorpions per cone, this was by far the highest density I've tapped from fallen cones.  The next highest density was 0.56 that I tapped in October 2011 from ponderosa pine cones in Brooks Memorial State Park (Klickitat County).

Since western white pines are not the dominant forest tree species anywhere in Washington state, I've had to hone my pine-spotting skills in order to find them.  When I have a good line of sight into the forest canopy, I usually find them by spotting the tree's feathery foliage and large, pendant cones.  But when I'm inside a dense forest where the canopy is just a distant, indistinguishable mass of green, I simply search for fallen cones along the trail and look for the western white pine's unique bark pattern on nearby tree trunks.

Looking up the unusual pine
with the alder-appearing trunk
Mature western white pines have fairly smooth grey bark broken into flat rectangular scales.  It's often described as "checkered".  The pattern is always visible because pine bark is never obscured by epiphytes...or so I thought until we visited Square Lake!  Almost immediately upon hitting the trail I spotted the foliage and pendant cones of a nearby mature white pine.  But as my gaze slid down the trunk of the tree, I was surprised to see that it was entirely covered in epiphytes.  Had I not seen its crown, I would have been certain I was looking at an alder!  Alder (Alnus) bark is typically "painted" with accumulations of mosses, liverworts, lichens, and algae.  As the saying goes, to every rule there is an exception.

Tree trunk comparison. A. typical white pine, B. unusual alder-appearing white pine, C. typical alder

Read Rod's trip description here.

Monday, February 22, 2016

21-Feb-2016 Bellevue Highlands, Washington

Site location map. Click to enlarge.
Another sampling event in the catch-as-catch-can category, this time in the Highlands area of Bellevue.  Although I usually keep my nose to the grindstone on spider collecting ventures, especially short ones like this (I had only 2 hours, less if it started raining), I couldn't resist taking the time to stop at one of the area's numerous Indian grocery stores first to stock up on snacks.  What a treat!

Cone source: Pinus nigra trees
Cone microhabitat, scales hardly open
Not far from the grocery I found my cone source: eight black pines (Pinus nigra) planted along 140th Ave NE.  These trees had been heavy cone producers, but few of the cones had more than a few scales even partially open.  I see this repeatedly in P. nigra in western Washington, where this exotic tree species is widely planted.

Tenuiphantes tenuis in my net
Preserved Erigone male
With some diligent searching, however, I managed to scrounge up 50 of these barely-opened cones, and tapped 9 spiders from them.  Immediately identifiable were female Tenuiphantes tenuis and Tachygyna vancouverana, both from the family Linyphiidae and both species I tap frequently from cones in the greater Seattle area.  The other identifiable species was another linyphiid, an Erigone male.  I'll have to wait for the specimen to cure before I can identify it to species.  I've tapped an Erigone from cones only once before: a male E. aletris last October in Lynnwood.


Thursday, February 18, 2016

18-Feb-2016 Mill Creek, Washington

Sample site location (red arrow) in
relation to nearby Ozyptila praticola
collection sites
There's nothing that beckons like a sun break in winter, especially when the thermometer hits 50 F!  And since business took me to Mill Creek, a town I hadn't collected spiders in previously, I made sure to find an hour to tap some pine cones while there.

The tree, the ivy
My cone source was a white pine tree.  Whether eastern white pine (Pinus strobus) or western (P. monticola) I couldn't be sure because the bark wasn't well enough developed to tell.  I've found both species planted in the urban landscapes of Pugetopolis.  Whichever species it was, it was growing in a typical urban setting: surrounded by pavement and with an understory of pure English ivy (Hedera helix).

A cone suspended in the ivy matrix
I usually curse English ivy because, like the exotic invasive it is, it entirely snuffs out native plant species.  But I must admit that it did serve several useful functions in this case.  First, the dozens of cones that had fallen onto/into it escaped removal by groundskeepers.  And second, the cones suspended in the ivy matrix, which was up to 2 feet thick in some places (!) were fairly dry even though it had rained the night before.  Not so the cones I found on the ground, which tended to be muddy.  So I can hardly complain about the presence of the ivy, at least under this particular tree.

The haul
I tapped 50 fallen cones and collected 4 spiders, all juveniles.  Two were likely Ozyptila praticola (Thomisidae), the introduced crab spider that I'm working to determine the local distribution of.  The others were a theridiid and a Philodromus sp. (Philodromidae).  Not an exciting catch, but it does serve as another point on the O. praticola map.  Or at least, a fuzzy point.

Beautiful pine foliage blowing in the wind

Saturday, February 6, 2016

2-Feb-2016 Bay View, Washington

Sample sites. Click to enlarge.
Back in the field with Rod Crawford and Ben Diehl!  The focus of our spidering activities this day was the "census-designated area" of Bay View.  Bay View is situated on the southeastern shore of lovely Padilla Bay in Skagit County.  Our first stop in Bay View was the dike-top trail Padilla Bay Shore Trail. We then drove a mile or so north to the Bay View Cemetery.

Neriene digna penultimate
male in web on metal
garage wall
This south-facing corrugated
metal wall was loaded with
overwintering spiders.
We began our day's collecting in the trail's parking lot, which is surrounded by large maintenance or storage buildings and a scattering of old rusty equipment.  Collecting linyphiids from their webs on the building with corrugated metal sides was straight-forward, but it took me some time to find the orb weavers that had built webs on the old wooden structure.  I did finally find one by following its trip line to its hiding place - under a big curl of peeling paint!

Spider-hiding paint peel
Translocated spider microhabitat
(cones and pine needles)
Rod had spotted a few shore pines (Pinus contorta subsp. contorta) in photos of the trail head itself, so I had some small hope that I might find a few cones there to tap.  Unfortunately a groundskeeper had removed the cones and pine needles from beneath the pines.  I later found these materials dumped at the edge of the marsh.  Why do groundskeepers insist on doing this?  Cones and needles are not just spider habitat, they're ornamental!  Leave them be!

Tiny male Tachygyna ursina approaching
a sizable juvenile Philodromus rufus
Juvenile Philodromus rufus in "tiptoe"
pre-ballooning posture
After our productive day of spidering at the Nooksack Cemetery last October, I was looking forward to collecting at Bay View Cemetery.  But February isn't October, and in the end I found only two spiders on headstones in the entire cemetery.  Humorously enough, I didn't even see the tiny male Tachygyna ursina (Linyphiidae) until it approached the juvenile Philodromus rufus (Philodromidae) that I was busy photographing.  Apparently the ursina startled the rufus when the former tried to walk over the latter, because the rufus jerked the ursina off its leg and send him dangling by his drag line.  The thrills, the spills!

Douglas-fir trees and fallen cones
A fallen Douglas-fir cone = great
spider habitat!
I didn't spot any pine trees at the cemetery, but a stand of Douglas-firs (Pseudotsuga menziesii) next to the utility shed had a nice accumulation of open cones lying beneath it on needle littler. I tapped 50 of those cones and collected 11 spiders.  Most were juveniles of the introduced species Enoplognatha probably-ovata (Linyphiidae), but two native linyphiids were present as well: Tachygyna vancouverana and T. ursina.

Caterpillars were more common than
spiders on the grave monuments
Moss 'highlighted' monument messages
One of the delights of frequent spider collecting is that, in addition to gaining spider knowledge, I am able to observe the seasonal changes in weather, flora and fauna.  Something I noticed this week were pairs of birds in synchronous flight.  A pair of bald eagles (Haliaeetus leucocephalus) near the head of the Padilla Bay Shore Trail alternated short flights together with sitting in close proximity on treetop branches and chatter-calling.  [A pet peeve of mine is that movie makers always substitute the scream of the red-tailed hawk (Buteo jamaicensis) for the eagle's chatter call, probably because eagles sound like whiny seagulls.].  At Bay View Cemetery, I also saw a pair of ravens (Corvus corax) flying synchronously from tree to tree.  Looks like spring courtship has begun for these species.  Maybe this is why Valentine's Day is in February?

Read Rod's trip narrative here.

Sunset over Padilla Bay during low tide