Two common, stream-side spiders at Las Cruces. Trechalea extensa is large and hangs out on boulders, dangling it’s fore-legs in the water at night to potentially attract prey, such as small fish. Patricia Esquete’s student’s, Neola and now Macy, have been studying their ecology the past couple of years.
The other spider, probably a nursery web spider (Pisauridae) like this one from Palo Verde, creates a silken tether on a branch and dangles from it, skating on the moving stream surface and likely capturing floating prey as it moves downstream.
Macy, an REU student this summer (not pictured), discovered a large male Common Basilisk (Basiliscus basiliscus – aka Jesus Christ Lizard) under a rock while surveying for spiders. They get their name from “running” on water to escape, but this individual seemed to be too cold and wedged in hiding. I pulled it from the rock and we took some photos—only Juliet, my student, and another research mentor, Patricia, braved holding it.
Many Phrynosoma are capable of squirting blood from their eyes—a defensive mechanism that deters predators, such as small dogs and cats, from killing the lizards in a substantial percentage of encounters, according to a discussion with George Middendorf I had after meeting him in a diversity workshop at Las Cruces Biological Station. George has quantitatively characterized and reviewed the gruesome squirting!
While I didn’t get a chance to observe the squirting, and I didn’t provoke the animals with that purpose, they also flatten out quite a bit when handled!