The evolution of many animal colours is thought to be driven by selection from visually guided predators.
Yet research has largely focused on large vertebrate predators such as birds while ignoring smaller,
terrestrial invertebrate predators. This is despite clear evidence that small invertebrate predators are
important regulators of prey densities in a variety of ecosystems. Jumping spiders are small voracious
predators that feed on a wide variety of prey in thefield. They are capable of colour discrimination, but
little is known about whether they attend to the colour of their prey during foraging. We examined
colour biases by offeringHabronattus pyrrithrixjumping spiders arrays of artificially coloured juvenile
crickets. We found thatfield-collectedH. pyrrithrixshowed populationwide colour biases; across age and
sex categories, attack rates were lowest on red and yellow prey (colours commonly used as warning
colours) and highest on blue prey. We retested the same individuals after they were housed for several
weeks in the laboratory and found that their colour biases had weakened to statistically undetectable
levels. We also found that colour preferences in individual spiders were not consistent over time, suggesting that the populationwide colour biases that we observed were not simply driven by consistent
preferences of a subset of individuals. Finally, we tested colour preferences in a separate group of naïve,
laboratory-raised spiders and found similar biases favouring blue prey, with low attack rates on red,
yellow and green. Our study provides thefirst evidence that both experienced and naïve jumping spiders
show colour biases when foraging and suggests that these biases may result from both innate and
learned components. We argue that more attention to such understudied predators may provide a more
holistic and accurate understanding of the suite of selective pressures that drive the evolution of prey
colour patterns, particularly in small invertebrates.
2014 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.