Representation of different exact numbers of prey by a spider-eating predator
Working memory is important for Portia africana, a salticid spider that specialises in eating other spiders
Abstract
Jumping spiders (family Salticidae) have the capacity to see fine details related to their prey. Working memory is important for Portia africana, a salticid spider that specialises in eating other spiders, to survive and succeed in capturing prey.
The investigators hypothesised that the salticid spider relies on assessing specific cardinal numbers of prey. They used a method where a test subject is allowed to preview a scene, which is blocked out and returned with some elements altered. (In this case the number of prey.) They were able to determine that the immature stage (body length 5.0 mm) of Portia africana, has the capacity to figure out the exact number of spiders in its view, including those capable of eating it. The findings suggest that Portia characterises 1 and 2 as separate, but 3 or more as a single category that the authors call ‘many’.
This is an output of the ‘Strategies by which Miniature Predators Use Highly Structured Working Memory’ project. It is partly funded by the UK Department for International Development, a core donor of the International Centre of Insect Physiology and Ecology.
Citation
Cross F. R. and Jackson R. R. (2017) Representation of different exact numbers of prey by a spider-eating predator. Interface Focus: A theme supplement of Journal of the Royal Society Interface 7, https://doi.org/10.1098/rsfs.2016.0035
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Representation of different exact numbers of prey by a spider-eating predator