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Predator versus prey: locust looming-detector neuron and behavioural responses to stimuli representing attacking bird predators

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Show simple item record Santer, Roger D. Rind, Claire F Simmons, Peter J 2014-07-07T09:15:25Z 2014-07-07T09:15:25Z 2012
dc.description peer-reviewed en_US
dc.description.abstract Many arthropods possess escape-triggering neural mechanisms that help them evade predators. These mechanisms are important neuroethological models, but they are rarely investigated using predator-like stimuli because there is often insufficient information on real predator attacks. Locusts possess uniquely identifiable visual neurons (the descending contralateral movement detectors, DCMDs) that are well-studied looming motion detectors. The DCMDs trigger ‘glides’ in flying locusts, which are hypothesised to be appropriate last-ditch responses to the looms of avian predators. To date it has not been possible to study glides in response to stimuli simulating bird attacks because such attacks have not been characterised. We analyse video of wild black kites attacking flying locusts, and estimate kite attack speeds of 10.861.4 m/s. We estimate that the loom of a kite’s thorax towards a locust at these speeds should be characterised by a relatively low ratio of half size to speed (l/|v|) in the range 4–17 ms. Peak DCMD spike rate and gliding response occurrence are known to increase as l/|v| decreases for simple looming shapes. Using simulated looming discs, we investigate these trends and show that both DCMD and behavioural responses are strong to stimuli with kite-like l/|v| ratios. Adding wings to looming discs to produce a more realistic stimulus shape did not disrupt the overall relationships of DCMD and gliding occurrence to stimulus l/|v|. However, adding wings to looming discs did slightly reduce high frequency DCMD spike rates in the final stages of object approach, and slightly delay glide initiation. Looming discs with or without wings triggered glides closer to the time of collision as l/|v| declined, and relatively infrequently before collision at very low l/|v|. However, the performance of this system is in line with expectations for a last-ditch escape response. en_US
dc.language.iso eng en_US
dc.publisher Public Library of Science en_US
dc.relation.ispartofseries PLoS ONE;7 (11), e50146
dc.subject neuroethological models en_US
dc.subject bird attacks en_US
dc.title Predator versus prey: locust looming-detector neuron and behavioural responses to stimuli representing attacking bird predators en_US
dc.type info:eu-repo/semantics/article en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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