Social Behaviour and Communication in Elephants - 2
Acoustic communication refers to sound production and hearing. Elephants have a wide range of sounds that they
can emit all with different intensities and for different purposes such as securing their defence,
attracting mates, co-ordinating movement and generally announcing their needs.
These sounds include growls, trumpets, squeals, skrieks and low frequency vocalisations.
Growling and rumbling is the most commonly used vocal production in elephants and is used as a
means of communication between individuals and families; however, it can also be used in an
aggressive tone between females and calves as a disciplinary measure. (Wilson, 2000)
Video of Angry Elephants Trumpeting & Rumbling
Scientists have now discovered that elephants can produce infrasonic sound from 1- 20Hz
that humans cannot hear and these sounds can travel over long distances, as well as seismic signals,
which are like mini earthquakes that allow elephants to position each other in relation
to their own location. (Braden, 2003)
One study suggested that low frequency vocalisations transmitted between females is
used as a reproductive strategy by males, specifically in African elephants (Loxonodonta africana).
The levels of intensity of these vocalisations vary depending on which reproductive state the females are in.
Males use these vocalisations as a strategy to search for herds with high vocal production as this
means that they are close to the ovulation period. Males also rely on passive communication between
herds by "eavesdropping" to increase his chances of locating a female in the follicular phase and when
in close proximity, using chemical and visual cues as more reliable signals. (Leong et al 2003)
Another study suggests that this "eavesdropping" tactic can also provide an opportunity to
recognise signals by conspecifics and this was supported as playback calls made from family
and bond groups resulted in a strong positive response of the elephants used in
the experiment. (McComb et al 2000) Therefore, indicating that elephants have a highly
organised network as they can develop and accumulate the knowledge to recognise signals
from extensive populations of conspecifics.
Visual Communication Fig 3. Trunk raised in threatening stance
Visual communication refers to expressions, postures, displays or movement of ears, jaws, trunk and the
like, and how elephants are able to use their sense of sight to determine what message the signaller
is trying to portray.
Head and trunk postures can be used for different types of communication such
as communication between individuals but also between rivals to display threats (See Fig 3).
These visual signals can be of either high or low intensity; at low intensity the animal stands
tall, but at high intensity i.e. during threat, the animal moves
forward towards the enemy lifting its ears and extending its trunk forward. The "forward trunk swish" signal
is used towards a smaller rival where the trunk is rolled up and is suddenly lashed forward. (Wilson, 2000)
To signal dominance, the elephant will appear taller, with its head high above its shoulders and ears spread wide.
A subordinate elephant appears the opposite, with its ears kept back and its head lying low. (Granli et al 2006)
The trunk is thus an important aspect in visual communication.
Chemical communication is an energetically efficient process which involves the secretion of chemical signals
as long lasting messages. They produce a wide range of odour signals and these odours are carried by secretions
from various sources such as skin glands, reproductive tract, urine, faeces and expired air.
Fig 4. Temporal gland secretion
Secretions are also produced from the temporal gland; a multi-lobed sac which secretes a viscous,
strong smelling liquid located between the eye and ear (See Fig 4). These secretions are released in great
quantities especially when the animal is excited or under stress, suggesting that the gland is
under autonomic control. (Wilson 2000)
These odour signals are sensed by the receivers' chemo-receptors and
are used for many communicative functions such as trail marking, individual recognition and alarm.
Elephants have a highly developed olfactory system which has given them an acute sense of smell that
enables the elephant to transfer the chemical into a message.
It has been discovered that elephants
can discriminate human friends from unfamiliar humans; African elephants situated in Kenya's Amboseli National
Park do not react to the scent or colour of local farmers' garments, but react aggressively and hysterically
to the scent and colour of clothing worn by Masai Warriors. (McKenna, 2007)
This illustrates that elephants
can learn by association as different ethnic groups can have different risks to elephants.
Elephants also use chemical communication to detect an individuals' reproductive state.
Females prefer males in musth which means they have high testosterone levels and because of this they
secrete a fluid from their temporal gland. While in musth they also dribble urine that carries a powerful odour which
females can detect.
Musth males are in a good physical condition (Wyatt, 2003) and are more dominant
competitively so females prefer to mate with them rather than those not in the musth phase.
This strategy applies to both African and Asian (Elephas maximus) elephants. (Ramussen et al 1998)
Tactile Communication Fig 5. Using trunk to pull
vegetation off tall tree
Tactile communication is how they use touch to communicate between individuals and they do this
primarily with their trunk. Their trunk is used for a variety of different functions such
as drinking water, ripping vegetation off tall trees (See Fig 5), smelling individuals and so on,
but more importantly for their tactile sense.
Elephants use their trunks to explore unfamiliar territories,
objects and to exchange touches with unfamiliar individuals passing through the bush.
With regards to reproduction, courting elephants communicate with one another by intertwining their trunks.
In addition, feet are also important for their tactile sense as they have soft skin
which can sense and hear seismic vibrations through the ground produced by other elephants.
The interiors of elephants' feet are filled with Pacinian corpuscles, vibration sensors that are layered and
covered in a slimy gel. Vibrations are transmitted through these layers which result in a nerve
signal that is sent to the brain.
Their trunks are also used in similar fashion by simply laying them
on the ground as they too contain vibration sensors. (Braden, 2003)