The high-output singing displays of a lekking bat encode information
on body size and individual identity
Cory A. Toth
Received: 14 September 2017 /Revised: 23 April 2018 / Accepted: 27 April 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
A growing body of research suggests that songs are an important part of the courtship behavior of many bat species, however
there is little information on the basic characteristics of these vocalizations, or how they may function as a courtship signal.
Lekking male lesser short-tailed bats (Mystacina tuberculata) appear to use vocal displays as a primary method for attracting
mates, but it is unclear if these vocalizations constitute songs, and what characteristics females may use for mate selection. We
recorded 16 lekking males and described the frequency and temporal properties of their vocalizations. We identified four notes
(upsweeps, downsweeps, trills, and tones) that comprise courtship vocalizations, and males produced these notes either singly, or
combined them linearly to form composite syllables. We classified 51 distinct syllable types (with an average of 29 types per
male), with four (trills, upsweep-trills, trill-downsweeps, and upsweep-trill-downsweeps) comprising 69% of all syllables pro-
duced. The duration of trill-downsweeps scaled negatively with forearm length (a proxy for body size in bats), and all four main
syllable types showed evidence of individuality. Based on the behavioral characteristics and contexts of these courtship vocal-
izations, we posit that this behavior constitutes singing. Furthermore, M. tuberculata potentially has one of the highest sustained
song outputs yet described. Our results suggest the singing displays of M. tuberculata are signals that provide useful, honest cues
of male characteristics and identity to females, and are as complex as the songs of many passerines.
Male courtship displays are predicted to honestly advertise aspects of male traits. Like many birds, some bat species produce songs
to attract mates, but the characteristics of these songs are not well understood within the context of sexual selection. We demon-
strate that the courtship vocalizations of Mystacina tuberculata – a species that likely relies on singing as its primary method of
mate attraction – are a complex set of signals. Males have large syllable repertoires, encode four of their most-common syllables
with individual signatures, and have one of the highest recorded song outputs for either birds or bats. Moreover, the length of one of
the most commonly used syllable types is inversely related to male size, providing females the opportunity to appraise male size by
auditory cues alone. Our work is part of a growing body of research demonstrating singing behavior in bats.
Songs are generally defined as long, complex vocaliza-
tions produced by males during the breeding season,
and serve the dual purpose of attracting mates and re-
pelling rivals (Catchpole and Slater 2003; Collins 2004).
Singing is typically associated with passerines, and bird-
song has been studied intensively since the 1950s
(Marler 2004). By contrast, singing is relatively rare in
mammals (Smotherman et al. 2016) and has thus re-
ceived comparatively less attention. However, increasing
research suggests that singing is an important behavior
for some bats.
Communicated by M. Knoernschild
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s00265-018-2496-4) contains supplementary
material, which is available to authorized users.
* Cory A. Toth
School of Biological Sciences, University of Auckland,
Auckland, New Zealand
Present address: Department of Biological Sciences, Boise State
University, Boise, USA
Present address: School of Earth, Environmental and Biological
Sciences, Queensland University of Technology, Brisbane, Australia
Behavioral Ecology and Sociobiology (2018) 72:102