Hyenas' ability to count helps them decide to fight or flee

Aug 22, 2011

Being able to count helps spotted hyenas decide to fight or flee, according to research at Michigan State University.

When animals fight, the larger group tends to win. In the current issue of , Sarah Benson-Amram, an MSU graduate student studying zoology, showed that hyenas listen to the sound of intruders' voices to determine who has the advantage.

"They're more cautious when they're outnumbered and take more risks when they have the numerical advantage," said Benson-Amram, who conducted the study through MSU's BEACON Center for the Study of Evolution in Action. "Hyenas appear to be as capable as chimpanzees or lions at assessing their advantage."

The finding supports the concept that living in complex , as hyenas, lions and do, is one of the keys to the evolution of big brains, Benson-Amram added.

Even though live in clans of up to 90 individuals, they spend much of the day in much smaller, more vulnerable groups. When researchers played recordings of potential intruders, the hyenas' reaction depended on how many voices they heard compared to how many fellow pack members surrounded them. Groups of three or more hyenas were far more likely to approach the source of sound than pairs or individuals.

This study was the first to show that hyenas can tell the difference between individual voices, and most of the animals in the study could distinguish up to three different voices, said Kay Holekamp, MSU and BEACON researcher, whose field study of spotted hyenas in Kenya has been ongoing for more than 20 years.

"The recordings were taken from hyenas from other parts of Africa," she said. "But even though the voices were unfamiliar, the hyenas in the study were able to tell when they were from the same or different animals."

Explore further: Hermit creepy crawlies: Two new taxa of wood-feeding cockroach from China

Related Stories

Hyenas' laughter signals deciphered

Mar 29, 2010

Acoustic analysis of the 'giggle' sound made by spotted hyenas has revealed that the animals' laughter encodes information about age, dominance and identity. Researchers writing in the open access journal ...

Females avoid incest by causing male relatives to leave home

Aug 15, 2007

Researchers at the University of Sheffield in the UK and Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin, Germany, have found that female hyenas avoid inbreeding with their male relatives by giving them little ...

Neandertals sophisticated and fearless hunters

May 14, 2009

Neandertals, the 'stupid' cousins of modern humans were capable of capturing the most impressive animals. This indicates that Neandertals were anything but dim. Dutch researcher Gerrit Dusseldorp analysed their daily forays ...

Recommended for you

A vegetarian carnivorous plant

7 hours ago

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

epsi00
not rated yet Aug 23, 2011
Hyenas mastered arithmetic, wait until we hear that they have a deep knowledge of algebra and analysis. Future research will show that hyenas have excel in differential geometry, which is, as we know, the key to survival in the bush.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.