Friends or foe?
Funnel-web spiders are one of the most venomous spiders in the world. But according to JCU PhD Candidate Linda Hernández Duran, these misunderstood creepy crawlies should not be feared.
Australia is home to 35 species of funnel-web spiders and has had 13 recorded deaths caused by their bites — all occurring before antivenom was introduced in 1981. While they have a reputation for being an aggressive and dangerous species, Linda says they are instead defensive.
“Funnel-web spiders are misunderstood animals. They are reactive depending on the level of risk they face, but they are not naturally aggressive, and they typically use venom as a last resort when threatened,” she says.
While most research on funnel-webs has focused on their venom composition, Linda looked specifically at the spider’s behaviour. She studied the activity and aggressiveness of four species of funnel-web spider — Hadronyche valida (border ranges), Hadronyche cerberea (southern tree-dwelling), Hadronyche infensa (Darling Downs) and Atrax robustus (Sydney funnel-webs) — and found their responses varied when placed in different scenarios.
“When faced with stimuli of predation or physical contact, the spiders tend to be more flexible. That is, their behaviour varies depending on the level of risk they are exposed to,” Linda says. “Only the border ranges funnel-web showed consistency in risk-taking behaviour both against a predator and when interacting with other spiders.”
None of the species that were studied were consistently aggressive toward potential predators.
“When I stimulated a physical threat, the spiders reared up into a defensive position, displaying their fangs and expelling venom. But when I used a different stimulus that is a puff of air — stimulating the wing beat movements of a predator or parasite — the spiders didn’t respond or they tried to run away,” Linda says.
This research provides valuable insights into how these animals respond to changing conditions as well as how and when they use their venom.
Basic behaviours
Surprisingly little is known about funnel-web spider behaviour and ecology. Curious, Linda moved from Colombia to Australia in 2019 to study these mysterious arachnids.
“One of the biggest misconceptions about funnel-web spiders is that people will encounter them often. In actuality, they live in burrows, and they depend on the conditions of the burrow to keep them alive. They don’t survive in domestic locations and encounters with them are minimal.”
JCU PhD Candidate Linda Hernández Duran
Funnel-web spiders construct their burrows in moist and humid sheltered environments — under rocks and logs, or in holes and rot-crevices of trees. They are rarely, if ever, found in open environments like a sunlit lawn. Their burrows can be distinguished from other holes in the ground by the presence of their web; the spiders often line the entrance of the burrow with silk ‘trip-lines’, which alert them to when prey is near.
“Funnel-webs only leave the burrow in breeding season, once they reach maturity, which takes about five years. And even then, they leave to find mates and reproduce. Generally, they run and hide from people.”
Due to their specific habitat conditions, funnel-web spiders face a higher risk of extinction.
“These spiders are a short-range endemic species, and they’re not good runners. Because of their restricted ability to disperse, they are vulnerable to disturbance and habitat loss as a result of urbanisation, fragmentation or natural disaster,” Linda says. “They are also reliable bioindicators, meaning we can look at the condition of these animals and assess the health of the environment they live in. Funnel-webs can’t just thrive anywhere. If the environment changes, we will know, because the funnel-webs will completely disappear.”
Linda’s research into the behaviour of funnel-web spiders provides valuable information for the conservation and management of the species, which is critical given the medical importance of their venom.
“Yes, people need to be cautious of funnel-web spiders. But we hope to create more understanding and awareness of these animals and their importance.”