The content you've requested is available without charge only to active Sigma Xi members and affiliates.
If you are an active member, affiliate or individual subscriber, please log in now in order to access this article. Be sure you've entered your member or subscriber number on your profile page.
If you are not a member, affiliate or individual subscriber, you can:
Although most jumping spiders prey on insects, those in the genus Portia prey primarily on other spiders. And they employ predatory tactics that are unusually complex and flexible for a creature with a pinhead-sized brain. For instance, Portia might stalk a spider on its own web and employ clever mimicry, vibrating the web in ways that resemble a small insect getting ensnared. When the resident spider comes to investigate, Portia attacks and kills it. The authors show several other tricks that these jumping spiders use, including moving across a web when the wind moves it, which makes it difficult for the resident spider to notice the movement of the attacker. These spiders even deceive and attack members of their own species. Most surprising, they fine-tune their predatory behavior to individual encounters.