Zebra Jumper

• Its two huge front eyes have a movable retina that it shifts behind the lens to scan the scene, rather like moving one's eyes without moving one's head.
• Its visual acuity is the best known in an animal of its size and rivals that of some mammals.
• Before it jumps it fixes a safety line to the substrate: if the leap fails, it hangs there and climbs back up.
• It is Europe's most familiar jumping spider: the one seen on any sunny wall, striped black and white like a zebra.
• Its eyesight is among the best in the invertebrate world. The two large front eyes have a movable retina that scans the scene, and they let it see in detail from several centimetres away and judge distances precisely.
• It spins no hunting web: it stalks, calculates and leaps. Before jumping it anchors a safety line, so that if it misses it is left hanging and climbs back up.
• Its jump is not powered by muscles: it is driven by a sudden rise in hydraulic pressure in the legs, a system spiders use because they lack extensor muscles at some joints.
• It is inquisitive and turns its head to look at whoever is watching it, behaviour that is unusual in an invertebrate and has made it popular.
• Its courtship is visual too: the male performs a dance with his pedipalps and front legs before the female.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Sunny walls, fences and house fronts of Europe and North America

Sources consulted: Land, trabajos clásicos sobre visión en Salticidae · Nentwig, Spiders of Europe · Buglife