If you have ever been to the desert Southwest (of the USA), you have probably noticed spider webs throughout the summer and even in early fall. And even if you have not noticed the webs, you’ll likely have seen leaves that look like they are floating in the air, which is really leaves stuck in a spider web. Sometimes, when you park your car for a few days, you’ll even get webs under your car, like this one.
This is a black widow spider web. It looks like there are a few widows that have taken up residence under the car. This is a common scene across Phoenix, AZ, where I took this picture. In fact, this might be how black widow spiders are moving from city to city. I previously wrote about my research in the movement of black widow spiders that you can check out.
Do you have a photo or video of an urban species doing something unusual? What about a rare plant or animal that you were surprised to find in a city? If so, let Lindsay know or Tweet at us and you could be featured as a future observation of the week!
I am interested in urban ecology and evolution. Urbanization can have drastic impacts on local ecosystems, both negative and positive, and creates a new environment for organisms to experience. To understand the impacts that urbanization plays on organisms, I look through the lense of population genetics and molecular evolution.
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Really interesting. Do you think there could be a behavioural advantage to building a web on a car? For example, Could they catch more food if near a reflective surface?
No. They are indiscriminately building webs on solid structures that have a crevasse for their hiding spot. It may be that since we tend to leave lights on the driveway, this attracts insects, which then attracts the spiders. These widow spiders don’t have very good eyesight and rely on chemical and vibration cues