Sunday, July 10, 2011

Payette river rafting trip

My friends and I went to Idaho for a few days of great rafting on the Payette river. We stayed at a nice campsite not far from Crouch, a small town that had the craziest 4th of July fireworks I had ever seen. Our campsite was located by the river and had enough trees to provide shade...and interesting spider habitat. I searched for spiders a couple of times between our rafting adventures.


 View of the river from our campsite

My first find was this dictynid spider, which did not look like the dictynid species at my field sites in Logan Canyon (Utah). I had to gently poke her out of her tangle web to get a better look.


Close to the river, I noticed a male linyphiid spider in a sagebrush shrub. This spider was hanging upside down in its sheet-like web. When prey get caught in the web, linyphiid spiders bite them through the web while remaining upside down.



Anneli and Andy found this spider on the ground by our kitchen area. I have not seen this very cryptic looking species before, but I would guess that it is a philodromid spider, as it looks like a darker version of Philodromus histrio, a species common on sagebrush in Northern Utah. Philodromids are wandering spiders that do not rely on webs to catch prey. This family resembles the true crab spiders (Thomisidae) but philodromids have legs that are subequal in size whereas thomisids have third and fourth legs that are shorter than the first two pairs of legs.




One night, as we were chatting by the campfire, we noticed a small arthropod running around by our feet. Upon closer inspection, it turned out to be a solpugid!! Solpugids are also known as camel spiders but they are not spiders- they are a closely related order of arachnids. I was very surprised and excited to see one here, because I thought they were only found in desert areas. I guess that's not the case! Solpugids are typically nocturnal predators that use their impressive chelicerae to macerate their arthropod prey. I have heard that very little is known about solpugids because they are not easy find and difficult to keep in captivity. Perhaps this individual was hunting for arthopods that had been attracted to our campfire.


Solpugid hunting next to our campfire


That night I went to bed a little after midnight. As I was starting to fall asleep in my tent, I felt something walking on my arm. I turned on my headlamp and saw something hop straight onto the light! It turned out be a Phidippus jumping spider. I took a quick picture of it, let it out of the tent and went back to sleep. Jumping spiders are diurnal predators, but it has been shown that they sometimes use artificial light to hunt at night. This paper by Frank (2009) has some information on the subject:

Frank KD (2009) Exploitation of artificial light at night by a diurnal jumping spider. Peckhamia 78.1:1-3
http://peckhamia.com/peckhamia/PECKHAMIA%2078.1.pdf



Phidippus attracted to my headlamp. Picture taken after midnight.

2 comments:

  1. For me, this is no other outdoor adventure that can match river rafting. When I get through the turbulent waters, I feel great inside me - the pure adrenaline rush. I'm relieved from my stress.

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  2. This is a great post ! it was very informative.

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