New Bioacoustics article in PLOS ONE

["Corcoran, Aaron" <>]

Dear Colleagues,

You may find this recently published bioacoustics article of interest. More
information on this subject can also be found at this website: www.sonarjamming.com

Optimal Predator Risk Assessment by the Sonar-Jamming Arctiine Moth
Bertholdia trigona

Abstract. Nearly all animals face a tradeoff between seeking food and mates
and avoiding predation. Optimal escape theory holds that an animal
confronted with a predator should only flee when benefits of flight
(increased survival) outweigh the costs (energetic costs, lost foraging
time, etc.). We propose a model for prey risk assessment based on the
predator's stage of attack. Risk level should increase rapidly from when
the predator detects the prey to when it commits to the attack. We tested
this hypothesis using a predator =96 the echolocating bat =96 whose active
biosonar reveals its stage of attack. We used a prey defense =96 clicking
used for sonar jamming by the tiger moth *Bertholdia trigona*=96 that can b=
e
readily studied in the field and laboratory and is enacted simultaneously
with evasive flight. We predicted that prey employ defenses soon after
being detected and targeted, and that prey defensive thresholds
discriminate between legitimate predatory threats and false threats where a
nearby prey is attacked. Laboratory and field experiments using playbacks
of ultrasound signals and naturally behaving bats, respectively, confirmed
our predictions. Moths clicked soon after bats detected and targeted them.
Also, *B. trigona* clicking thresholds closely matched predicted optimal
thresholds for discriminating legitimate and false predator threats for
bats using search and approach phase echolocation =96 the period when bats
are searching for and assessing prey. To our knowledge, this is the first
quantitative study to correlate the sensory stimuli that trigger defensive
behaviors with measurements of signals provided by predators during natural
attacks in the field. We propose theoretical models for explaining prey
risk assessment depending on the availability of cues that reveal a
predator's stage of attack.


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Aaron J. Corcoran, Ph.D.
Department of Biology
Wake Forest University
www.sonarjamming.com

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