Are Pine Cone Spiders Just Litter Spiders?

Many of the spider species I've found in fallen pine cones have also been found in forest litter*.  This raises the question, do spiders randomly wander into fallen cones because cones are simply a constituent of the litter, or do spiders gravitate to cones because cones are a separate microhabitat that provides something that litter doesn't?

*Forest litter consists of tree needles/leaves and other plant debris (including cones) that accumulates on the forest floor.

I began pursuing this question in 2012 by sampling eastern white pine (Pinus strobus) cones and associated litter in Massachusetts.  I'll blog about that soon, but since I'm presenting my past spider collecting trips in reverse chronological order, I'm first going to recount a 7-day collecting trip that Rod Crawford and I took in Washington's Chelan and Spokane counties in October, 2013.  During The Great Spokane County Expedition, as Rod playfully dubbed it, I was able to compare the spider catch from fallen ponderosa pine (Pinus ponderosa) cones and associated pine forest litter.

Below are maps showing the locations of our sampling sites.  Map 1 shows the relative location of the Chelan Co. (map-center) and Spokane Co. sites (map-right) within Washington state.  Map 2 zooms in on the Chelan County sites.  Map 3 zooms in on the Spokane County sites.  Maps were made with GPSVisualizer.

Map 1. Location of 2013 Pinus ponderosa fallen cone and litter sampling sites in Washington

Map 2. Location of sampling sites in Chelan Co.

Map 3. Location of sampling sites in Spokane Co.

Stay tuned for my first field report from this 7-day excursion: Bear Mountain, Chelan County, Washington.

9-Dec-2014 Randall Morgan Sandhills Preserve, Felton, California

View into the preserve from the gate.

Today Clothilde and I had permission to collect cones in the Randall Morgan Sandhills Preserve thanks to folks at the Sandhills Alliance for Natural Diversity who put me in touch with folks at the Land Trust of Santa Cruz County.  The preserve encompasses an old open pit sand mine, so what was once a hill of forested sand is now a sandy hole with encroaching sandhills vegetation.

Collecting site with commanding
view of Mt. Hermon Rd.

We found a nice accumulation of cones amid pine needles and oak leaves on the forested quarry rim overlooking Mt. Hermon Road.  These cones, as we so frequently found elsewhere in the preserve and sandhills region, had scales only partway open.

Metacyrba sp. epigynum

From 23 cones we extracted two spiders by the beat method (nothing by the peel method): a juvenile salticid and a female salticid.  We also collected several pseudoscorpions, an arachnid not uncommonly found in fallen pine cones.

Clothilde with our bag o' cones

Thanks to an assist from Rod Crawford and The Peckham Society's extensive online resources, we've tentatively ID'd the female salticid as Metacyrba taeniola similis.

This was my final pine cone spider collecting trip for 2014 in California.  The next set of blog posts will describe the 7-day spidering expedition to Washington state's Chelan and Spokane counties that Rod Crawford and I took in October, 2013.  Stay tuned!

1-Dec-2014 Quarry Road West Spur, Felton, California

Wet cones and needles indicated recent rain

The suburban area west of the Graniterock's Quail Hollow Quarry looked full of possibilities in the satellite photos, but Clothilde and I found few cones and even fewer open cones during our thorough search of the neighborhood’s accessible ponderosa pines (Pinus ponderosa), which weren’t many to begin with.  Having had success finding cones on the east spur of Quarry Road last week, we decided to go back and explore its west spur.  The manzanita shrubs along the trail were still in bloom and absolutely mobbed with hummingbirds.

Poison oak in fall raiment

Cone scales only partly open

Clothilde discovered poison oak.  I won’t say how.

Passing a leaky wooden water tank, several friendly water district workers and a monumental cross apparently erected when industrialist Henry J. Kaiser owned the land (a survey marker was stamped “HJ Kaiser”), we found an extensive patch of cones on a needle-strewn sandy slope below some mature ponderosas.  As has frequently been the case in the sandhills, the scales on the cones were hardly halfway open, but as I keep saying, the microhabitat is what it is.

View across closed quarry to Skypark

View across Skypark to quarry wall.

We collected 20 cones and retreated to Skypark to process them, once again taking in the reciprocal views from quarry rim to Skypark and back again.

Today's compliment of Homo sapiens in the park included a group of painfully insecure teens, a group of groundskeepers listening to songs with misogynistic lyrics during their lunch break, and an adorably nerdy chemistry student who asked some really good questions.

The front end of a dictynid.

The front end of a Xysticus crab spider.

The cones may have been soggy and poorly opened, but they still had a few spiders in them: two dictynids and a male Xysticus (Thomisidae).  Another day, another data point on the Chart of Spider Knowledge.

25-Nov-2014 Quarry Road East Spur, Felton, California

The cone-producing tree.

Today Clothilde and I headed directly for Michael Gray Field, the Santa Cruz County baseball diamond I’d spotted on my previous trip.  Disappointingly but not too surprisingly, every last cone had been removed from beneath the magnificent ponderosa pines (Pinus ponderosa) behind the field.  It would have been a unique collecting spot, to be sure, given that the only plant in the understory was ice plant (Carpobrotus edulis), the South African invasive that has been so successful at colonizing California’s coastal cliffs…and apparently also the dust mote region of at least one inland baseball diamond.

Leaving our car parked at Gray Field, we walked to the nearby Quarry Road gate and were delighted to see at least half a dozen linked locks on its chain.  This usually spells “public” rather than “private”, and seeing no signs warning away trespassers, we headed into a lovely ponderosa forest with a manzanita shrub understory in full bloom.  We would learn soon enough by the San Lorenzo Valley Water District truck passing us that a) this was indeed public land, and b) by the driver’s friendly wave that nobody minded that we were there.  We didn’t have to travel far along the eastern spur of the road to find our cones.

Cones on needles and oak leaves.

Empty spider egg sac on cone scale.

We processed our cones again in Felton’s Skypark, where, looking west from our picnic table, we could see the inner western wall of a closed quarry.  Today’s collection site had been just over that rim.

Together we collected seven spiders from our 20-cone sample, five by the tapping method and two by the peel method.

18-Nov-2014 Quail Hollow Ranch, Felton, California

"The office"

Collecting solo today with an eye towards Zayante Road, I headed up to Quail Hollow Ranch County Park and quickly found plenty of fallen ponderosa pine (Pinus ponderosa) cones on a trail along the forest edge, just south of the horse stables.  The nearby picnic table that I processed the cones on was situated next to a tiny, coot-inhabited pond.  And it didn’t rain more than a few drops.  Can't get any better than that!

Cone processing went smoothly, the only interruptions being a park official who fired up a front-end loader just to drive 20 yards over to me to tell me to move my car; a friendly couple with a tiny threadbare dog; and a jogger who was enthused to meet another arachnophile and recommended I check out the woodpile behind the outhouse if I wanted to find some “Zayante tarantulas” or black widows.  He also kindly alerted me to the presence of a doe and two yearlings nearby.

...some cones on grass.

Some cones on sand...

It wasn’t until I was leaving with my haul of 12 pine cone spiders
(a whopping four of which I collected using the peel method) that I learned that I should have had a permit to collect in this park.  Oops.  Well, at least I had been careful to stay out of the designated sensitive area.

The day's catch was mostly comprised of juvenile salticids and gnaphosids, including several Micaria sp. ant mimics.  But unlike my other Santa Cruz Co. sites to date, which had been teeming with Oecobius sp., I only collected one here.

...had fuzzy palps.

This red and black juvenile salticid...

On the way home I decided to make use of the remaining daylight to cruise the area for potential future collecting sites.  A ponderosa pine-rimmed public baseball diamond snuggled up against a pine woods along Graham Hill Road seemed like the most promising next spot.  Next to that was a gated Quarry Road, which seemed to have potential.  I also followed Whispering Pines Drive through suburban Felton and was pleasantly surprised to find that there were indeed ponderosa pines on that street.  People of the pine-free Pine Flat Road in Bonny Doon, take note!  Sadly, as is the rule in human-dominated landscapes, local landowners had removed virtually every fallen cone, even from the roadway.

An actual pine at the intersection of Whispering Pines and Pinecone streets.

11-Nov-2014 Martin Road, Bonny Doon, California

View across the preserve to a rare unmined sand hill

Far from being put off by our previous long drive and chilly half sample, Clothilde was eager to join in the actual cone processing fun, and I was happy for the help and good company.  By now I’d learned how to better identify ponderosa pine areas in Santa Cruz County from Google Map’s aerial photos, so this time we were able to home in on trees without delay.

Although today’s trees turned out to be in the Bonny Doon Ecological Reserve, which is closed to collectors, again we were able to collect all the cones we needed from the public side of the fence.  Roadside margins aren’t the most pristine of habitats, but here in the early 21st century they are ubiquitous and so, in my opinion, are not to be sniffed at.  They are an environmental reality of our day.

Road margins, an ecological reality

The deciding fence line.

It was chilly and foggy back at Felton Covered Bridge County Park, where we processed the cones, but this time we’d come prepared (hoodies!).  And the afternoon proved fruitful; together we collected 12 spiders from our sample of 20 cones, all but one spider via the tapping method.  And with the two of us working in tandem, we completed the task in about half the time it would have taken me to do it solo.  This is no small matter, since cone peeling is a very time-consuming method of sampling.

Ebo evansae with her long, striped legs.

Silver 'n brown Euryopis

Today juvenile Oecobius sp. made up 2/3 of our catch, but we also collected two spiders from my personal "genus of interest", Euryopis (Theridiidae), as well as a female Ebo evansae crab spider (Philodromidae) and a male Hololena funnel-weaver (Agelenidae).

Clothilde Labrousse, pine cone spider collector.

3-Nov-2014 East Whitlock Road, Mariposa, California

Today's cone source

I now have a field buddy!  Niece Clothilde Labrousse took an interest in my pine cone spiders project and was excited to get a toe into the Sierras, so we set off together to collect a sample in Mariposa.

Our first stop was in the town's eponymous park, Mariposa Park.  There we were happy to scope out some covered picnic tables and basic facilities, but found no open cones under the park’s ponderosas, even those in the untended woods above the park.  Just a few miles further into the Sierras, however, we found a serviceable clump of trees in a privately-owned field that had conveniently dropped cones on the public side of the fence.

The scales of many of the cones were rather poorly opened, and the cones were damp due to recent rain, but the microhabitat is what it is.

Cones on dried grass, pine needles and oak leaves

Back at Mariposa Park, we could hear truants riding skateboards in the nearby skatepark as we set to work processing the cones.  The day turned out to be colder and breezier than predicted, and I hadn’t dressed warmly enough, so rather pathetically we called it a day after processing only 10 cones.  Spider haul for the day: one juvenile gnaphosid, from a peeled cone.

We sprinkled the remainder of the cones at the base of a nearby ponderosa (groundskeepers had been overenthusiastic here, too), and headed home.  We’d only completed a half sample, but the company, the conversation and the scenery made for an enjoyable day.