title: Revisiting adaptations of neotropical katydids (Orthoptera: Tettigoniidae) to gleaning bat predation.
abstract: All animals have defenses against predators, but assessing the effectiveness of such traits is challenging. Neotropical katydids (Orthoptera: Tettigoniidae) are an abundant, ubiquitous, and diverse group of large insects eaten by a variety of predators, including substrate-gleaning bats. Gleaning bats capture food from surfaces and usually use prey-generated sounds to detect and locate prey. A number of Neotropical katydid signaling traits, such as the emission of ultrasonic frequencies, substrate vibration communication, infrequent calling, and ultrasound-evoked song cessation are thought to have evolved as defenses against substrate-gleaning bats. We collected insect remains from hairy big-eared bat (Micronycteris hirsuta) roosts in Panama. We identified insect remains to order, species, or genus and quantified the proportion of prey with defenses against predatory bats based on defenses described in the literature. Most remains were from katydids and half of those were from species with documented defenses against substrate-gleaning bats. Many culled remains were from insects that do not emit mate-calling songs (e.g. beetles, dragonflies, cockroaches, and female katydids), indicating that eavesdropping on prey signals is not the only prey-finding strategy used by this bat. Our results show that substrate-gleaning bats can occasionally overcome katydid defenses.
authors.affiliation: Department of Biological Sciences, Dartmouth College , Hanover , NH , USA.
authors.forename: Hannah
authors.initials: H
authors.lastname: Ter Hofstede
authors.affiliation: Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin , Berlin , Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Voigt-Heucke
authors.affiliation: Zoology Institute, University of Graz , Graz , Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lang
authors.affiliation: Zoology Institute, University of Graz , Graz , Austria.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Römer
authors.affiliation: Smithsonian Tropical Research Institute , Ancon , Panama.
authors.forename: Rachel
authors.initials: R
authors.lastname: Page
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University , Hamilton , Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Faure
authors.affiliation: Department of Biology, Universitat Konstanz , Konstanz , Germany.
authors.forename: Dina
authors.initials: D
authors.lastname: Dechmann
keywords: Chiroptera; Panama; anti-predator defenses; eavesdropping; predator-prey arms race