February, 2008

Jumping Spider

One of many spiders without a common name, this jumping spider (Anasaitis canosa) is, nonetheless, a very common resident in our yard. They're tiny, quick on their feet, and tend to hide a lot, so jumping spiders are rarely as evident as their numbers would suggest. When a creature is less than 1/4 inch in length, and it doesn't bother us, we usually don't pay much attention to it.

This jumper, though, is quite a character. Not only is it probably the most numerous species of jumping spider in our yard, but it has a complex set of behaviors that warrant spending a little time spider watching. Easily distinguished from other jumping spiders by the body markings and the white pedipalps (appendages on the front of the face), A. canosa individuals can be observed as they hunt, protect their territories, and court. Females and males have similar markings, but males are smaller and their abdomens are usually thinner. Behaviors range from the usual hunting tactics employed by any predator to lots of leg waving and dancing about when a male spies a female. These spiders are rather shy and will hide if threatened, but if a person just sits still and watches them for awhile, they quickly start to ignore observers and go about their typical arachnid business.