PhD‐theses - Ethologische Gesellschaft

Masters and Diplom theses
THE ACOUSTIC RECOGNITION SYSTEM OF WILD BOARS (SUS SCROFA)
lka Bürgener
smanti@gmx.net
Research Update
Diploma thesis, supervised by Dr. R. Wanker and Prof. Dr. J. Schneider, Department of Biology,
Zoological Institute & Museum, University of Hamburg
Species, which live in complex social systems, evolve a broad vocal repertoire. Wild boars
(Sus scrofa) live in matrilineal groups with a pattern of fission‐fusion and use a wide range of
vocalizations. Several studies investigated the ability of individual recognition in both
domestic pigs (Sus scrofa domestica) and wild boars but it is unknown to which extend
acoustic cues are involved. Aim of this study was to examine the recognition ability by
acoustic cues of wild boars, and more specifically to determine whether their vocalizations
possess individual signatures and whether there are group‐specific calls. Furthermore I
investigated whether infrasonic elements are present in long‐distance communication of the
wild boars . I recorded the vocalizations of four wild boar groups in four different wildlife
parks. The contact grunts were measured, analysed and classified by individuals. Playback
experiments were carried out with one group to test the ability to discriminate familiar and
unfamiliar conspecifics by their grunts. I found that contact grunts contain both individual
and group‐specific signatures, but the playback experiment failed to verify that they can
discriminate conspecifics by their contact grunts. Furthermore it turns out that wild boars do
not use infrasonic calls for long‐distance communication, but their grunts contain very low
frequencies, which may reach into the infrasonic range. These grunts were uttered in
conflict situations, suggesting that the wild boars may intensify their aggressive message
with these low frequencies.
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