Stalking decisions of web‐invading araneophagic jumping spiders from Australia, Azerbaijan, Israel, Kenya, Portugal, and Sri Lanka: The opportunistic smokescreen tactics of Brettus, Cocalus, Cyrba, and Portia

Abstract

In laboratory experiments using lures (dead spiders in lifelike posture), six salticid species from four genera (Brettus, Cocalus, Cyrba, and Portia) are shown to use an opportunistic smokescreen tactic, comparable to a tactic previously demonstrated in Portia, in experiments using living prey instead of lures. After invading webs of other spiders, each of these species exploits situations in which the resident spider's ability to detect the predator's approach is impaired: periods when the web was being blown by a fan (simulating wind) or shaken by a moving magnet attached to a cork (simulating struggles of an insect ensnared in the web). When stalking a spider, each species moved significantly farther during intervals when disturbances (i.e., simulated wind or simulated insect struggles) were present than during intervals when no disturbances were present. However, when oriented toward an ensnared insect in the web, when already feeding on a spider, or when in a vacant web with no prey spider in view, there was no evidence that the salticid timed locomotion to correspond with the presence of disturbances, suggesting that the behavioural reaction recorded is reserved specifically for occasions when the salticid is oriented toward prey spiders in webs.