1. Classification & Vision (The Defining Feature)

Feature Description

Family Salticidae (from the Latin salticus, meaning 'dancer' or 'leaping').

Size Small to medium, typically ranging from 4 mm to 15 mm in length.

Appearance Compact, robust, and often hairy body with short, stout legs. They are frequently brightly coloured, iridescent, or have striking patterns.

Eyes Eight eyes in three rows, with the four anterior eyes on the face. Their Anterior Median Eyes (AME) are huge, forward-facing, and act like high-resolution binoculars, providing keen eyesight, including stereoscopic colour vision (some species can see into the UV range).

Vision Use Sight is their primary sense, used for hunting, navigation, courtship, and species recognition. They are known for their curiosity, often turning their entire cephalothorax (head section) to face and observe things (including humans).

2. Hunting and Locomotion

• Hunting Method: They are active, diurnal (daytime) hunters and do not use webs to catch prey. They hunt like a miniature leopard:

  1. Stalking: They use their wide-angle side eyes to detect motion, then swivel to focus their high-resolution main eyes.

  2. Pouncing: They stalk their prey stealthily, then execute a precise, agile leap to pounce.

• The Jump: The jump is powered not just by muscle, but by a sudden, hydraulic increase in blood pressure to their rear legs. They can leap many times their own body length.

• The Safety Line: Before every jump, and whenever they move, they attach a silk filament (a dragline) to the surface. If they miss or fall, the silk acts as a bungee cord to save them.

• Diet: They are generalist predators, feeding on small insects, flies, mosquitoes, and other spiders.

3. Silk Use and Habitat

• Prey Capture Webs: NO. They do not build webs to trap food.

• Silk Retreats: YES. They use silk to construct small, flattened, cocoon-like silken shelters called retreats or "pup tents." These are usually built under bark, rocks, leaves, or in quiet corners indoors (like near window frames or behind furniture).

  • They use these retreats for resting, molting, overwintering (hibernating), and laying eggs.

• Habitat in Alberta: Found almost everywhere—gardens, on walls, on fences, in grass, on shrubs, and frequently indoors, as they seek sunny surfaces to hunt.

4. Reproduction and Life Cycle

• Courtship: Males perform elaborate, species-specific courtship "dances" that involve intricate visual displays using their front legs, pedipalps (small appendages near the mouth), and often colourful body parts to attract the female.

• Egg Sac: The female lays a clutch of eggs (often 50-200) inside a densely woven silk egg sac, which is usually constructed inside her secure silk retreat.

• Maternal Care: The female will typically guard the egg sac and the newly hatched spiderlings until they disperse, often a few weeks after hatching.

• Lifespan: Most species live for about one to two years.

5. Interaction with Humans

• Toxicity: Like all spiders, they possess venom, but it is not medically significant to humans.

• Bite Risk: They are non-aggressive and extremely unlikely to bite. A bite would only occur if they were trapped or severely provoked, and it is usually compared to a minor, brief sting. They are far more likely to jump away.