These Spiders Transform into Giant Lookalikes to Scare Off Predators
Spiders scare away predators by apparently growing
By Gennaro Tomma edited by Sarah Lewin Frasier
This spider web structure presents the illusion of a larger, intimidating spider.
Richard Kirby
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What’s scarier than a spider? A very large spider, of course. A new defensive tactic takes advantage of this idea: Researchers have documented spiders building giant spider-like silhouettes on their webs to ward off predators.
These decoys are an example of “web decorations” that some spiders are known to produce, often to avoid being eaten, avoid bird strikes, or attract prey. Such ornaments come in many shapes and sizesbut this is the first time that scientists have documented a spider-shaped setting.
From 2012 to 2022, a research team collected sightings of these unusual webs in Peru, the Philippines and Madagascar, focusing on around 300 individuals of the genus. Cyclosis which are usually only a few millimeters long. The researchers published their results In Ecology and evolution.
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Spider lookalikes are made of prey carcasses, plant debris and other organic matter. They have a central structure from which “legs” extend. The team proposes that the constructions primarily serve as defense against predators such as hummingbirds or helicopter damselflies. But different species can use them in different ways.
In Peru, spiders appear to use the lures “like puppets,” says study co-author Phillip Torres, an entomologist and television host. “They’ll be on top of the figure and they’ll shake the web, so they’ll pretend to be a bigger spider.” Small predators may be frightened by a larger spider, and predators that specialize in eating the smaller, true arachnid may want to avoid a large spider. In the Philippines, spiders tend to hide inside the structure and wait for the predator to leave.
Dinesh Rao, an ecologist at Veracruzana University in Mexico, who was not involved in the study, points out that determining the precise function of the constructs requires more research: “You need either careful observations or experimental conditions to actually observe how [predators] respond to these structures.
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