Scientists Ranked Hundreds of Spider Species by Running Speed. Australia's Huge, Hairy Brown Huntsman Came Out on Top

A newly released scientific analysis has crowned the brown huntsman spider as the speediest runner among 258 arachnid species studied, with the Australian native capable of bursts up to eight miles per hour — fast enough to beat the typical human jogger, at least for a heartbeat. The catch is that the spider can only hold that blistering pace for an instant before slowing down, according to researchers who compiled the comparative data.

The brown huntsman, a broad-bodied, fur-covered spider roughly the size of an open palm, is native to the eastern stretches of Australia. Its reputation for size and speed already unnerves many people who encounter it indoors, where huntsmans are known to dart across walls and ceilings at startling velocity. The new findings give that reputation a scientific backing, placing the species at the very top of a large cross-species speed ranking.

The ranking comes from a study shared on June 15 via bioRxiv, an online repository where researchers post papers before they undergo formal peer review. Because the work has not yet been vetted by outside scientists, its conclusions are considered preliminary, though the dataset itself — drawn from 258 different spider species — is unusually broad for this kind of biomechanical comparison.

The research team assembled the data to dig into a puzzle that goes beyond spiders alone: what actually determines how fast a moving creature can go. Many physical traits scale predictably with body size, but sprinting ability doesn't follow that same simple pattern. Cheetahs, the fastest land animals on Earth, are not the largest predators around — they're solidly mid-sized. That mismatch between bulk and velocity is part of what drew the scientists toward spiders as a test case, since the group includes an enormous range of sizes and body plans.

By pulling together running-speed measurements from spider species collected across different regions of the world, the researchers could compare how leg length, body mass, hairiness and other traits interact to produce a given top speed. The huntsman's win suggests that its particular combination of long, splayed legs and lightweight frame gives it a mechanical edge over both much smaller and much bulkier relatives, even if that advantage only holds for a split second before fatigue or instability sets in.

Beyond settling a curiosity about which arachnid deserves bragging rights, the comparative dataset gives scientists a broader tool for understanding how movement evolved across the spider family tree. Tracing which body features consistently predict fast running, versus traits that turn out to be irrelevant, can reveal how different lineages solved the same evolutionary problem — outrunning predators or catching prey — using very different anatomical solutions.

Because the study is still awaiting peer review, its rankings and conclusions could shift as other scientists scrutinize the methodology and the underlying speed measurements. Researchers in the field will likely look for independent replication of the huntsman's top billing, as well as further work explaining exactly why running speed and body size decouple so sharply in spiders compared with other animal groups. For now, the brown huntsman holds the informal title of fastest spider clocked in the comparison — a fact unlikely to make it any less alarming to people who spot one skittering across a wall.

Source: Smithsonian Magazine