Dreaming about Colombia, part 1: El Paujil reserve

In 2008 I went to Colombia to visit my family in Bogota and to spend some time in a couple of reserves that belong to the Fundacion ProAves, an NGO dedicated to the conservation of birds and their habitats. I had such an amazing time there that lately I have been longing to go back. While I wait for my next colombian adventure, I decided to post some spider pictures from that trip. The amount and diversity of spiders in these reserves was staggering, making these places a dreamland for arachnologists. There were spiders and spider webs everywhere!

El Paujil is a  reserve dominated by rainforest, located in the departments of Santander and Boyaca. I spent a few days there, dedicating all my time to observing all the plants and animals I could find. I found it exciting to think that there are probably many undescribed species in this part of the world. We spent nights in a nice wooden cabin in the reserve. One of the first spiders I found was the one below, behind the cabin:

 

At lunch time, I noticed this small Argiope (family Araneidae) near the base of a tree. In North America, these spiders are known as Garden Spiders. Argiopes build orbwebs with a special silk structure in the middle called a stabilimentum (see picture below). The pattern of the stabilimentum varies across species, and the role of this structure is subject to debate.

Argiope sitting on the stabilimentum of it web

I also noticed this pretty jumping spider, which was wandering on a wooden post close to our lunch area:

 

My last find at lunch time was this araneid spider, which I found hidden in a rolled-up leaf. The silk structure at the tip of the leaf had called my attention. This spider had a roughly triangular shape, with several humps on the posterior part of her abdomen.

 

Along one of the trails in the reserve, I found my first Micrathena spider. I was so excited to find it but a little frustrated because I felt a little rushed as the rest of the group kept on walking. In addition, my camera lens had gathered condensation due to high humidity levels. I was able to take one acceptable picture. Micrathena spiders are araneids (they build orbwebs) that have a typical arrow shape due to the spiny projections on their abdomen.

On the side of a more open trail, I noticed many spiders like the ones below. Their translucent legs were hard to notice against the background vegetation. I think these were oxyopids, a family also known as the Lynx Spiders, due to their hunting strategy which consists in jumping and running after their prey, and their relatively good eyesight. I was able to take pictures of some spiders that had caught a prey item, including a fat caterpillar. Oxyopids have spiny legs, as seen in these pictures.

A red jumping spider caught my attention along another trail. It was very active and curious, and jumped on my camera a couple of times to investigate it. I had to place him back on the plant to take more pictures.

I found this other jumping spider in a very shaded area, where the canopy was dense:

One orbweb along the trail had a pretty spiral shaped stabilimentum. In an attempt to find out who had built this web without scaring the spider away, I carefully placed my camera behind the web and took a picture at random, hoping that it would be in focus. My strategy worked and revealed that there indeed was a spider hiding under the stabilimentum, but I can't tell what spider this was.

One section of the trail was in close proximity to a river. Upon inspection of a big log, I noticed this beautiful orbweb spider. I had never seen this species before, but I think it may be a tetragnath spider of the genus Leucauge. Members of this genus have a cluster of long trichobothria (these are hair-like structures that detect vibrations) prolaterally at the base of their femurs on their fourth legs. These trichobothria are noticeable in the picture below. The second picture shows the orbweb, with relatively few radii and a "hole" in the center, which are typical tetragnath web characteristics.

Also by the river, we found this Pisaurid spider (also known as Fishing Spider) resting on a small tree trunk. These spiders are able to stay underwater for a few moments. They feed mainly on aquatic invertebrates and sometimes on small fish.

At night time, my cousin Esteban, Ryan and I went out exploring not too far from our cabin. We were rewarded with a small tarantula, which was wandering about right next to the steps that led to our cabin.  Tarantulas have fangs that point straight down, whereas other spiders have fangs that cross each other.