Despite its menacing appearance, the Cook Strait giant weta is reasonably docile, mostly feeding on plants, and tolerating gentle handling by humans (6). A nocturnal species, during the day the Cook Strait giant weta conceals itself amongst grass in a temporary refuge that it makes in the soil surface, or under dead leaves, bark or stones (2) (4). It emerges just after dusk, foraging on the ground or on low-growing bushes and shrubs, where it particularly favours tauhinu flowers (Cassinia leptophylla) (2).
Owing to its solitary and nomadic lifestyle, the Cook Strait giant weta’s reproduction relies upon the male locating a receptive female. This search is facilitated by the strong scent produced by the weta’s body and by its faecal pellets (4) (6), and can involve the male travelling over 250 metres in a single night (4) (8). Once located, the male places a leg over the female’s body and maintains contact until a daytime refuge is found. Here, mating occurs throughout the day and, if the weather is cool and wet, possibly throughout the night as well (8). The female subsequently lays around 200 eggs in the soil and dies. The eggs develop for a few months and hatch in the spring, with the juvenile wetas emerging fully-developed. It takes most of the Cook Strait giant weta’s two year lifespan to reach the full adult size, with growth taking place in a series of about nine moults over a 12 to 18 month period (4).
A number of animals prey on the Cook Strait giant weta, including birds (7), and reptiles such as the tuatara (6). As a defence against predators the Cook Strait giant weta will raise its spiked legs over its head and wave them up and down while making a hissing sound by rapidly rubbing together the overlapping plates on its upper body (5).