I just handed in a near-final draft of my predation paper, so I took a stress relief break to photograph some spiders. The philodromid (Running Crab Spider) is a male Philodromus dispar that we found on the way into the lab this morning, but the other one I do not know. Any ideas? UPDATE: this may be Neriene digna, a Linyphiid.
On this Weekend Expedition, Catherine and I found out what just a tiny bit of Pacific Spirit Park has to offer. It is really large, and we did not cover very much ground!
Since this was a joint effort, we decided to concentrate on forest invertebrates, which worked well during our last field season in French Guiana. Catherine is really good at spotting things!
The first of her great finds was this lovely Dance Fly (Empididae). They look a bit like Robberflies, and in fact are somewhat related (both are Orthorrhapha). The Empidids are a really diverse group, so if anyone has ID suggestions, I would love to hear them!
The second major find is what looks like a gravid Wolf Spider. This big girl was sheltering in a rotted log, and impressed us with its lovely large abdomen.
And check out these Net-winged Beetles (Dictyoptera simplicipes). There were a whole bunch in a seeming mating aggregation on a rotting log in one dark little section of the forest. So colourful!
Those have to be one of the most impressively bright insects of early spring that we have!
The second bright spot in these dark woods was this gorgeous male Amaurobiid, sheltering in a knot hole in a snake fence. You can see his modest hacklemesh web and his dark retreat. These spiders are fascinating and beautiful, and I would like to learn more about them…
A fern frond for colour and contrast in a small patch of sun.
The author in situ. Photo by Catherine!
As we left the park, this Equisetum emerging from the moist soil near Camosun Bog was a beautiful sign of spring.
But wait! There’s more! On our way out to a bus stop, we were immediately impressed by a large gathering of bees in Chaldecott Park. These were Andrenids (update: they may have been Colletes) busy mating, digging nests and provisioning them. There were hundreds if not thousands in this small 20 m sq. patch of grass. I did not get a good chance to shoot them really well, because a big rainstorm was coming, but I think I will head back out there this afternoon with Mike to examine some of the bees for parasites. This patch might also be a good spot to put in a temporary fence to keep folks from damaging the nest site. With all the concern for native pollinators, it seems like a good place to try to protect.
Colours boosted to emphasize bees.
The same as above, with yellow and green pushed to white and desaturated. Look at all those bees!
at the burrow
excavation
Sometimes the easiest way to shoot a macro subject is indoors, under carefully controlled conditions. Because the forecast this weekend called for rain, and I had a lot of writing to get done, I spent the weekend at school without any real outdoor adventure. I took a few hours to shoot some captive arthropods and a salmonberry flower from outside the school. I took some time to illustrate the effect of different background lighting on some of the subjects. Besides the photos you see below, the other results of the Weekend Expedition were mixed: my paper needs major surgery*, and the sac spider you see above escaped during a photo shoot. Good for the spider, not so good for me! Anyway, enjoy, and let me know what you think!
*the good news is Catherine is helping with the “paper surgery”…I think I was just stuck and in need of an outside perspective.
Our gorgeous spring weather has turned back to rainy Vancouver miserableness, so instead of an expedition outdoors, I will do some studio shooting indoors at school (as a short break while writing the last paper of my thesis on caracara predation behaviour). The target of the weekend’s shooting will be captive and indoor spiders such as this male and female western Black Widow (Latrodectus hesperus).
During the last field season, Catherine and I went to the Nouragues reserve in French Guiana to do some work on army ants, as well as to tie up some loose ends of the caracara study. Because we wanted to determine the population density of these ants, we needed to walk several trail transects over the course of a few weeks. There are not many loop trails available near the Pararé camp, so we had to walk out to the start of our transect before we could begin. We aimed for a start time of 1:30 – 2 pm, so we often hiked out early so we could have a lunch at the transect start before beginning the return walk.
Our westernmost transect.
Eciton burchellii, one of the ant species we were studying.
On our first day walking the western transect, we were a bit early, so I decided to do some photography. I asked Catherine to look around for cool things to shoot, so we started off by examining the leaf litter. The Neotropical rainforest is absolutely loaded with spiders, many of them in the Ctenidae, or Wandering Spider family, which make great subjects.
After shooting a couple spiders on the ground, I suggested Catherine have a look on the tree trunks, as I am familiar with the cryptic ways of some forest creatures (e.g. 1, 2). She quickly found a couple resting moths that she at first took for bracket fungi.
The moths were great, but the encounter that was to be one of the highlights of our trip was when Catherine found this gorgeous and cryptic spider brooding her egg sac on a small trunk near the trail.
My first instinct when shooting macro is to use a flash, but the falloff can be severe and ugly. The flash shows the detail quite well, but the character of the animal and the scene is altered entirely. Luckily we had a tripod, which is perfect for a still subject such as this, and allows natural lighting to convey the mood of the early afternoon forest.
Here is the spider as seen on the trunk with a wide lens and natural light.
At first we thought it was a Ctenid or Pisaurid because of the eye arrangement. Note the impressive camouflage of the egg sac. The female spider has obviously woven in bits of lichen and plant material to help the vulnerable egg sac blend in.
Check out these ridiculously long spinnerets! This is definitely not a Ctenid or Pisaurid!. This is a Hersilliid, A.K.A. “Treetrunk Spider” or “Longtailed Spider”. They use these huge spinnerets in prey capture.
This was our first meeting with a Hersiliid spider, and what a gorgeous specimen, and what luck to find her brooding! We returned several more times to this end of the transect, and always kept an eye out for her. She remained in the same place, patiently guarding her young until the end of our transect study. We were not there to see if the eggs hatched out or not, but we hope they did. Unfortunately, there are no Hersiliids in Canada, and only one in the US, so until we return to South America, our treetrunk spider lifetime count will remain low. This fortunate encounter with the Hersiliid taught us several things:
1) Neotropical spiders are abundant and diverse. Simple eye arrangement charts for North America may not work in South America!
2) Use the tripod wherever possible! The natural light is often beautiful, and much better than what a flash can provide.
3) Hersiliid spiders are awesome. In the future, we will make sure to try to observe them laying silk or capturing prey.
UPDATE: Catherine has her own blog post about these awesome spiders here.
Advanced composition tip: weevils add cuteness.
This is one of my favourite images of this spider.
Now the treetrunk spider printed at 16″ X 20″ has pride of place over Catherine’s yarn collection.
