Why do some webs have ‘signatures’?

BBC Wildlife contributor Richard Jones answers your wild question.


A few spiders, notably the wasp spider Argiope bruennichi and conical spider Cyclosa conica in the UK, include a conspicuous streak or zigzag of pale, woolly silk through the middle of their web.


But the meaning of the ‘signature’ is still open to debate. Though called a ‘stabilimentum’, it has nothing to do with stability and species across the world build stabilimenta in spiral, cross and ribbon forms. In Cyclosa it may well hide the spider, which further decorates the silk with its own moulted skins and prey remnants.

Some of the more elaborate signatures may act like warning signs, preventing birds colliding with and destroying the web.


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