The Sydney Funnel Web Spider (Atrax robustus) is an infamous arachnid, known for its potent venom and aggressive defensive posture. Native to a roughly 160-kilometer radius surrounding Sydney, Australia, this ground-dwelling predator’s life revolves around its silk-lined burrow. Its survival depends on a specialized diet and hunting strategy. Understanding what the Sydney Funnel Web eats and how it secures its food provides insight into its natural history.
Primary Prey and Food Sources
The Sydney Funnel Web Spider is a carnivore, relying on a wide array of ground-dwelling organisms. Its diet primarily consists of various insects, the most frequent victims of its ambush hunting technique. These include soft-bodied prey like insect larvae, beetles, and cockroaches.
Other terrestrial invertebrates form a significant part of their meals, including millipedes and native land snails. These spiders are opportunistic feeders, dictated purely by the availability of prey in their immediate habitat.
Larger adult females have been known to capture and consume small vertebrates, such as tiny frogs and lizards that stumble across the spider’s silk trip-lines. All captured food is taken at the edge of the funnel web and dragged back into the safety of the burrow for consumption.
The Funnel Web: An Ambush Hunting Strategy
The spider’s web is not designed to ensnare prey like the sticky, aerial webs of orb-weaving spiders. Instead, the Sydney Funnel Web constructs a silk-lined, tubular burrow that leads to a funnel-shaped entrance. This silk is composed of dry, non-adhesive fibers that extend outward from the burrow opening along the ground surface, forming trip-lines.
The web functions as a highly sensitive vibration detection system, allowing the spider to remain hidden while waiting for a meal. When prey walks across a trip-line, the vibrations are immediately transmitted back to the spider waiting inside the burrow. Sensory hairs on its legs allow it to pinpoint the exact location and size of the disturbance.
Upon detection, the spider executes a rapid, aggressive ambush, rushing out of the burrow entrance. It quickly subdues its prey by injecting venom through its large fangs, ensuring the meal is paralyzed or killed swiftly. Once neutralized, the spider uses its powerful chelicerae to drag the meal back into the silk-lined retreat to be consumed.
Dietary Variations by Life Stage and Environment
Life Stage Differences
The dietary needs and capabilities of the Sydney Funnel Web Spider shift between different life stages. Juvenile spiders (less than 15 mm) target smaller insects and larvae than their adult counterparts. They consume smaller prey until they reach adult size and strength.
Adult female spiders are generally sedentary, spending most of their time deep within their burrows, relying solely on nearby prey availability. Adult males are more active, often wandering extensively during the warmer summer and autumn months in search of females. This seasonal wandering exposes males to greater feeding opportunities, but also greater risks of dehydration and predation.
Environmental Factors
The frequency of feeding is highest during warmer, moister periods when ground-dwelling prey is most abundant. During cooler or drier months, activity slows, and feeding is less frequent as the spiders conserve energy. The spiders also rely on readily available sources of moisture, such as dew or condensation, to maintain hydration, since they rarely leave the burrow to drink.