Dynamic adjustment of echolocation pulse structure of big-footed myotis (Myotis macrodactylus) in response to different habitats

Abstract

Studying relationships between characteristics of sonar pulses and habitat clutter level is important for the understanding of signal design in bat echolocation. However, most studies have focused on overall spectral and temporal parameters of such vocalizations, with focus less on potential variation in frequency modulation rates (MRs) occurring within each pulse. In the current study, frequency modulation (FM) characteristics were examined in echolocation pulses recorded from big-footed myotis (Myotis macrodactylus) bats as these animals searched for prey in five habitats differing in relative clutter level. Pulses were analyzed using ten parameters, including four structure-related characters which were derived by dividing each pulse into three elements based on two knees in the FM sweep. Results showed that overall frequency, pulse duration, and MR all varied across habitat. The strongest effects were found for MR in the body of the pulse, implying that this particular component plays a major role as M. macrodactylus, and potentially other bat species, adjust to varying clutter levels in their foraging habitats.

Airport noise disturbs foraging behavior of Japanese pipistrelle bats

“…P . abramus showed considerable plasticity in echolocation vocalizations in different foraging habitats, a result that is in line with previous findings (Kalko & Schnitzler, 1993 ; Siemers et al, 2001 ; Wang et al, 2014 ). In open space, echolocation pulses given by foraging P .…”

Social vocalizations of big‐footed myotis (Myotis macrodactylus) during foraging

“…Longer calls may also create more acoustic space that can be used for encoding information about sender identity and food patches, thereby enhancing information transfer between colony members (Bradbury & Vehrencamp 1998). Compared with social calls, echolocation pulses of M. macrodactylus are characterized by a short duration, high frequency, large bandwidth and steep sweep rate (Luo et al 2012;Wang et al 2014b). Short echolocation pulses can increase the width of the overlap-free window and, thus, reduce acoustic masking from background echoes (Schnitzler et al 2003).…”

“…The big-footed myotis (Myotis macrodactylus Temminck, 1840) is a small trawling bat that hunts insects above the water surface (Fukui et al 2006;Wang et al 2014b). It is considered a "least concern" species by the IUCN and is distributed in north-east Asia (Tsytsulina 2008).…”

“…During pregnancy and lactation, adult females emerge from the roost approximately 15 min after sunset and fly directly to their foraging sites. Most studies on M. macrodactylus have covered topics from morphological and behavioral traits to growth and development (Jiang et al 2008;Liu et al 2009;Wang et al 2014a) and from the acoustic structure of echolocation pulses to vocal plasticity for environmental adaptation (Fukui et al 2004;Luo et al 2009;Luo et al 2012;Wang et al 2014b). However, only 2 studies have focused on social calls in M. macrodactylus, including specific aggressive calls under clustering behavior and distress calls in especially dire circumstances (Huang et al 2015;Xiao et al 2018).…”

Биоэхолокация. Вопросы И Задачи С Ответами И Решениями

“…Разновидность волнового уравнения с дополнительным слагаемым в форме функции, зависящей от координаты и времени, (282) называется неоднородным волновым уравнением [31,86,96,42].…”