Animals talking to each other – and us

Just as humans have developed effective ways to communicate with one another, fellow members of the animal kingdom have evolved ingenious ways to convey information. Sally Sherwen reports.

From African elephants using infrasonic rumbles to stay in contact with herd members several kilometres away, to peacocks displaying their flashy tail feathers to attract females, the animal kingdom is buzzing with messages.

This ability to communicate is a crucial component of an animal’s life and without this ability, animals would be unable to effectively ensure their genetic material is passed on to the next generation.

Professor Mark Elgar from the Department of Zoology at the University of Melbourne explains that animals use signals to communicate to both members of the same species and members of different species.

“These signals come in a range of forms including auditory, such as bird songs, chemical such as pheromones or scent marking, visual such as body gestures or colouration, tactile such as grooming, vibrational such as spiders drumming on their webs, and even electrical,” he says.

And although solitary animals will have to communicate with potential mating partners at some stage in their life, communication becomes increasingly important as species become more social.

“Some of the most social of all animals are bees, ants and termites. In these animals, profoundly co-operative behaviour is achieved by complex communication between nest-mates, via pheromones, and even dancing,” Professor Elgar says.

“In honeybees survival depends on co-operation, so if an individual finds a food source they will actually use what is called a ‘waggle dance’ to communicate the distance and direction of food to nest-mates.

“The waggle dance is in the shape of a figure eight where the direction and duration of waggle runs are closely correlated with the direction and distance to the patch of flowers.”

But Professor Elgar’s research has shown that communication in the animal world can sometimes be exploited.

“For example, when a meat ant worker is alarmed by danger such as the presence of workers from another colony, she will release an alarm pheromone. But spiders can also detect this alarm pheromone and use it as a cue to locate the alarmed ants, who are so pre-occupied by the threat of other ants that they fall easy prey to the spider.”

Understanding animal signalling is one of the Department of Zoology’s strengths.

While Professor Elgar is focused on signalling in the insect world, Associate Professor Raoul Mulder works with a team of researchers on signalling in various species of birds. An important aspect of this research involves exploring how humans can influence animal behaviour and signalling.

PhD student in the Department of Zoology, Dominique Potvin, recently showed that human noise can influence signalling in silvereyes – a native Australian bird. Ms Potvin found that silvereyes adjust their songs and calls in order to be heard more effectively in noisy city areas. The birds do this by raising the frequencies of their songs and singing more slowly.

This kind of research is critical for the conservation of birds in urban areas because scientists need to understand the conditions animals need to thrive, including areas that allow effective signalling behaviour, Ms Potvin explains.

Another important aspect of animal communication is the use of colour patterns and ornaments. Dr Devi Stuart-Fox, also from the Department of Zoology, researches the function of specific colour patterns and visual signals in various species of lizards.

Lake Eyre Dragons are a species of lizard that lives on the barren salt crusts of Lake Eyre. Females have bright orange colour patches on their throats and bellies during the breeding season, and at certain times when males are present they flip onto their backs exposing their bright orange colouration.

Dr Stuart-Fox was interested in unravelling the function of this colouration and behaviour.

The team found that the orange colouration signals reproductive condition as the females develop this colouration just as they become sexually receptive.

However what puzzled the researchers was that even when the females were unreceptive and had mated, they kept the orange colouration and would display flipping behaviour to prevent unwanted matings.

Further studies revealed that predators actually avoid models of flipped over females with bright orange patches even though they are very conspicuous. This suggests that the colouration initially serves to stimulate male courtship but when used in conjunction with the flipping behaviour it can also be a means to deter both males and predators.

Such research into communication in the animal kingdom is important because it contributes to a better understanding of processes generating diversity in nature.

And the better we understand nature, the better we can protect it.
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This article originally appeared in Voice, Volume 8 Number 1.

Main image: Zoos Victoria