Elephants Elephants - Wildpro - Twycross Zoo

COMMUNICATION
Elephants, being large brained highly social animals, have a complex
repertoire of communication which includes touching, vocalising, olfaction
and body postures. Elephants are tactile animals; family members lean on
each other and frequently touch with the trunk. In a greeting ceremony the
lower ranking animal inserts its trunk into the mouth of the other and trunks
are held out to other animals as a greeting. The trunk is also the olfactory
organ, picking up chemical signals from other elephants. Many postures are
used in communication e.g. spreading the ears and holding them forward is
normally a threat and various trunk movements may signify submissive
behaviour (Langbauer 2000). Thus this combination of posture, vocalisations
and olfaction provide sophisticated means of communication.
The infrasonic range of some elephant vocalisations, much of it below human
hearing thresholds, was only recently discovered. Elephants make these calls
in the larynx; there is a pharyngeal pouch between the tongue and above the
epiglottis. The infrasonic calls have fundamental frequencies ranging from 14-
34 Hz and sound pressure levels as high as 103 dB. Low frequency sounds are
subject to little environmental attenuation, such that they can be audible to
conspecifics several kilometres away, certainly as far as 2-4 km and perhaps
further. Elephants make use of these calls for spatial coordination and in the
search for mates (Langbauer 2000) (Poole et al 1988) (Langbauer et al 1991).
Elephants have four main sounds, (Estes 1991) but a great range of pitch and
duration between each one. Rumbling is the main form of distance
communication and covers a broad range of frequencies, many infrasonic.
Quiet rumbles, audible to human ears, are uttered as a herd feeds. There are
known to be over 27 different low-frequency rumbles (Poole 1999). Elephants
growl when greeting and their voices are individually recognizable. An
increase in volume becomes a roar, when elephants threaten predators or man.
Screaming is used to intimidate opponents and is the adult equivalent of the
juvenile distress call, the squeal. Trumpeting is the sound of excitement and is
produced by blowing through the nostrils hard enough to cause the trunk to
resonate, a long high amplitude squeak. It is usually combined with growling
and screaming. Trumpeting ranges from an expression of alarm or a cry for
help to a greeting.
The musth rumble is a rumble given only by males in musth and the oestrus
call is a distinctive rumble given by females in oestrus, the latter being the
same call that is given post copulation (Poole 1999). Males in musth are
attracted by the oestrus call of females and females in oestrus by the call of
musth males.
Recent work in Amboseli has shown that females can distinguish the
infrasonic contact calls of female family and bond group members and
estimated that the subjects would have to be familiar with the contact calls of
14 families (around 100 adult females) (McComb et al 2000).
Recently it has been postulated that the low frequency high amplitude
vocalizations of elephants have a potential for long distance seismic
transmission (Marchant 2001) (O'Connell-Rodwell et al 2000) (Hart et al 2001b).
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