02540nas a2200241 4500008004100000022001400041245010300055210006900158260001600227300001600243490000800259520175600267653001302023653002302036653001302059653001202072653001902084653002002103100002102123700001402144700002002158856012002178 2008 eng d a0022-094900aCues for acoustic detection of prey: insect rustling sounds and the influence of walking substrate0 aCues for acoustic detection of prey insect rustling sounds and t cJan-09-2008 a2799 - 28060 v2113 a

When insects walk, they generally produce sounds. These can reveal the walkers' presence and location to potential predators such as owls, bats and nocturnal primates. Additionally, predators might extract information on taxon, palatability, size or profitability from the rustling sounds. In contrast to ear morphology, hearing physiology and psychoacoustics of acoustically oriented predators, little attention has hitherto been paid to the acoustic structure and information content of prey sounds. An important element in the ecology of acoustic prey detection remained virtually unexplored: the influence of the substrate type on rustling sounds. In this study, we analysed amplitude and frequency parameters from insects walking on various natural substrates, in both Germany (Carabus beetles) and Madagascar (various beetles and cockroaches). The data show that rustling sound amplitude and frequency content depend on substrate type. On moist substrates arthropods produced less intense and less broadband rustling sounds than on dry substrates. Sound pressure level was reduced by about 6 dB, halving the detection range for the predator. For a given insect, rustling sound amplitude increased with walking speed. Finally, we found that the previously established correlation of arthropod size and rustling amplitude holds across multiple substrates. Based on these data, we provide for the first time estimates of realistic detection distances in the field. These distances range from below 1 m to over 13 m, depending on the substrate, insect mass, walking speed and background noise level. These estimates are crucial for an understanding of the foraging ecology, foraging efficiency and sensory ecology of acoustic predators.

10aauditory10adetection distance10aforaging10ahearing10aprey detection10asensory ecology1 aGoerlitz, H., R.1 aGreif, S.1 aSiemers, B., M. uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.019596https://syndication.highwire.org/content/doi/10.1242/jeb.01959602235nas a2200241 4500008004100000022001400041245011700055210006900172260002000241490000700261520140700268653001701675653001301692653001901705653002001724653002501744100001201769700001501781700001501796700002001811700002101831856014101852 2013 eng d a1742-568900aGlobal warming alters sound transmission: differential impact on the prey detection ability of echolocating bats0 aGlobal warming alters sound transmission differential impact on  cFeb-07-201321840 v113 a

Climate change impacts the biogeography and phenology of plants and ani- mals, yet the underlying mechanisms are little known. Here, we present a functional link between rising temperature and the prey detection ability of echolocating bats. The maximum distance for echo-based prey detection is physically determined by sound attenuation. Attenuation is more pronoun- ced for high-frequency sound, such as echolocation, and is a nonlinear function of both call frequency and ambient temperature. Hence, the prey detection ability, and thus possibly the foraging efficiency, of echolocating bats and susceptible to rising temperatures through climate change. Using present-day climate data and projected temperature rises, we modelled this effect for the entire range of bat call frequencies and climate zones around the globe. We show that depending on call frequency, the prey detection volume of bats will either decrease or increase: species calling above a cross- over frequency will lose and species emitting lower frequencies will gain prey detection volume, with crossover frequency and magnitude depending on the local climatic conditions. Within local species assemblages, this may cause a change in community composition. Global warming can thus directly affect the prey detection ability of individual bats and indirectly their interspecific interactions with competitors and prey.

10aecholocation10aforaging10aglobal warming10asensory ecology10aspecies interactions1 aLuo, J.1 aKoselj, K.1 aZsebok, S.1 aSiemers, B., M.1 aGoerlitz, H., R. uhttp://rsif.royalsocietypublishing.org/cgi/doi/10.1098/rsif.2013.0961https://syndication.highwire.org/content/doi/10.1098/rsif.2013.096102288nas a2200205 4500008004100000022001400041245011600055210006900171260001600240490000700256520164800263653001301911653001601924653001901940653001301959653001901972100002101991700002002012856005002032 2007 eng d a0269-846300aSensory ecology of prey rustling sounds: acoustical features and their classification by wild Grey Mouse Lemurs0 aSensory ecology of prey rustling sounds acoustical features and  cJan-02-20070 v213 a

1. Predatory mammals and birds from several phylogenetic lineages use prey rustling sounds to detect and locate prey. However, it is not known whether these rustling sounds convey information about the prey, such as its size or profitability, and whether predators use them to classify prey accordingly.

2. We recorded rustling sounds of insects in Madagascar walking on natural substrate and show a clear correlation between insect mass and several acoustic parameters.

3. In subsequent behavioural experiments in the field, we determined whether nocturnal animals, when foraging for insects, evaluate these parameters to classify their prey. We used field-experienced Grey Mouse Lemurs Microcebus murinus in short-term captivity. Mouse Lemurs are generally regarded as a good model for the most ancestral primate condition. They use multimodal sensorial information to find food (mainly fruit, gum, insect secretions and arthropods) in nightly forest. Acoustic cues play a role in detection of insect prey.

4. When presented with two simultaneous playbacks of rustling sounds, lemurs spontaneously chose the one higher above their hearing threshold, i.e. they used the rustling sound's amplitude for classification. We were not able, despite attempts in a reinforced paradigm, to persuade lemurs to use cues other than amplitude, e.g. frequency cues, for prey discrimination.

5. Our data suggests that Mouse Lemurs, when foraging for insects, use the mass–amplitude correlation of prey-generated rustling sounds to evaluate the average mass of insects and to guide their foraging decisions.

10aforaging10aprey choice10aprey selection10aprimates10asize selection1 aGoerlitz, H., R.1 aSiemers, B., M. uhttp://www.blackwell-synergy.com/toc/fec/21/1