Many people encountering a large, fast-moving spider often wonder if they have come across a huntsman. Their appearance often sparks curiosity or concern. This common question arises due to their reputation and general unfamiliarity with spider species. Understanding the distinctions between various large spiders can help alleviate apprehension and provide clarity.
Huntsman Spiders in New Zealand: The Truth
Huntsman spiders are not native to New Zealand. However, several species have been introduced from Australia and have established localized populations. The Avondale spider (Delena cancerides), a type of huntsman, arrived in the early 1900s, likely via imported timber, and is primarily found in the Auckland suburb of Avondale. Another species, the Christchurch huntsman (Isopedella victorialis), has been recorded in the Christchurch area since 2005. More recently, sightings of the grey Sydney huntsman (Isopeda villosa) in places like Napier suggest a wider establishment of these introduced species.
Understanding Huntsman Spiders
Huntsman spiders are recognized by their large, flattened bodies and long, crab-like legs. Their leg joints are rotated, allowing their legs to spread out sideways. These spiders typically display shades of brown or grey, sometimes with banded legs, and are covered in fine fur. An average huntsman spider can have a leg span of up to 15 centimeters, though some species, like the Avondale spider, can reach up to 20 centimeters.
Huntsman spiders are active, nocturnal hunters that pursue prey rather than building webs for capture. They use silk primarily for egg sacs and creating retreats in sheltered areas. Their habitats include loose bark on trees, rock crevices, logs, and often human dwellings like sheds, garages, and cars. Huntsman spiders are generally not aggressive towards humans and prefer to flee when disturbed. Their bites are minor, resulting in localized pain and swelling.
Large Spiders Commonly Found in New Zealand
New Zealand hosts several large spider species often mistaken for huntsman spiders due to their size and swift movements. The vagrant spider (Uliodon species) is a native New Zealand spider found throughout the country. These spiders are medium to large, with body lengths ranging from 8 to 20 millimeters and leg spans up to 50 millimeters.
They are dark brown to reddish-brown, often featuring a distinct pattern on their abdomen, and are fast-moving nocturnal hunters that do not build webs for prey. Vagrant spiders inhabit various environments, including gardens, native forests, and can be found indoors in garages or attics. Their bite is harmless, causing mild irritation or swelling.
Another common large spider is the nursery web spider (Dolomedes species), endemic to New Zealand. Adult females can have a leg span of 6 centimeters or more, and a body length of up to 18 millimeters. These spiders are pale brown or grayish, sometimes with a yellowish stripe, and are known for constructing white “nursery webs” on shrubs to protect their young, rather than for hunting. They are ambush hunters capable of running on water and even diving underwater. Nursery web spiders are widespread across New Zealand, found in diverse habitats from sea level to subalpine regions.
How to Tell Them Apart
Distinguishing huntsman spiders from other large spiders in New Zealand involves observing a few key physical and behavioral characteristics. A telling feature of a huntsman spider is its leg orientation; their legs spread out sideways, giving them a crab-like appearance, unlike most other spiders whose legs bend vertically. Huntsman spiders also possess a flattened body.
Huntsman spiders are active hunters and do not construct webs to capture prey. In contrast, nursery web spiders build silken structures for protecting their young, not for trapping food. Vagrant spiders are also hunters and do not build capture webs, but their leg arrangement is not crab-like. Observing a spider’s leg posture and whether it builds a web for hunting can provide clear clues for identification.