Image courtesy of Jonathan N. Pruitt, Ecology Letters, 2013.
Lines indicate survival of mating pairs (and their descendants) when outside spiders ("inquilines") were allowed into study-spider areas. Note that numbers of aggressive and mixed groups stayed steady, while dociles declined over time.
Is the key to a species' long-term survival . . . thugs?
This is Sandra Tsing Loh with the Loh Down on Science, saying, among some spider species, maybe.
Ecologist Jonathan Pruit studies social spiders that live in communal webs. Some individuals are docile and coexist peacefully. Others fight no matter what, and have to stay separated.
Pruit wanted to see which personality type fared better over time. So, in the lab, he created mating pairs of spiders, some docile, some aggressive, some mixed. He then placed them in the wild.
As unrelated spider species attacked, aggressive pairs fought to survive, but hardly reproduced. The pacifists? Just had lots of beautiful babies.
Early on, docile pairs were having several times more offspring than aggressive or mixed pairs.
But by the study's end, invaders had destroyed all the pacifists and most of the mixed groups. The fighters? Were almost completely intact.
Pruit says the docile spiders' passiveness results in a short-term reproductive gain but at a long-term survivorship cost.
'Cause life is tough on the web. Hopefully just with spiders.
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