Hunters gain an advantage if they can remain undiscovered by their prey until it’s too late, and camouflage is an excellent strategy to do so. For the first time, a small jumping spider has been found as having a unique camouflaging activity, with the creative arachnid embellishing its nest till it virtually changes into a cloak of invisibility. The jumping spider Arabia mullion, which is the subject of an article published in PeerJ, is the brains underlying the activity. The study’s authors conducted field surveys in A. mullion’s native eastern Australia, where they observed roughly 115 spiders construct 554 silk retreats — a remarkable effort given how simple they may be missed.
When it comes to living quarters, the web slingers are rather inventive, and these silk structures are part of their “extended phenotypic,” a word that refers to how a creature’s nest may influence its personality. Some spiders hunt in groups in large communal webs, while others dangle from modest structures with a net ready to snare passing prey. A. mullion originally drew the researchers’ attention when they spotted a startling quantity of them on tree trunks and that, unlike other jumping spiders, they would stay in their silk nests during the day. They grabbed roughly 20 spiders, dismantled their nests, and released them to film the formation of the nest.
The film demonstrated that A. mullion utilizes its nest as an opportunity to get creative, creating a mosaic that camouflages the nest utilizing its local environment. The spiders would harvest bark by slicing it off the tree, leaving a scar on the trunk, then scurry back to the silk nest and flip it upside-down to brush the pieces across the bottom.
The meticulous attention to detail may appear to be a lot of work, but unlike more migratory spiders, these creatures looked to be dependant on their silk, camouflaged nests as a permanent home. If you’re going to be spending a lot of time there, it makes sense to put a lot of work into the decor.
The study authors noted, “We discovered that Arasia mullion lived a sedentary life on the surface of tree trunks, where they built, decorated, and occupied their silk dwellings.” “These findings are the first to describe silk decorating behavior in jumping spiders, and they emphasize the uncommon usage of permanent silk retreats to take advantage of a low-complexity, high-exposure environment.” Tree trunks are understudied yet fascinating environments, according to our research.”