Do Bats Know Voices of Friends They Hang out With? Bats May Recognize Voices of Other Bats

May 7, 2013 — Is it possible that mammals have the ability to recognize individuals of the same species, whom they know well, by their voice? A new study has found that even in nocturnal, fast-moving animals such as bats, there is an ability to recognize certain vocal aspects of other bats from their social groups. 

The study by Hanna Kastein from the University of Veterinary Medicine in Hannover, Germany, and her colleagues is published in the Springer journal Animal Cognition. 

The authors chose bats for their study as they are social mammals whose aerial lifestyle favors the use of acoustic cues for both orientation and communication. Body contacts among the social groups in the False Vampire bat, Megaderma lyra, suggest individualized relationships. The authors suggest that the ability to recognize individuals by sound may govern the reunion of groups at night roosts. When isolated bats are observed, they emit calls which result in the bat being joined by members of its usual night roosting group, giving weight to the belief that others must recognize his call. 

The researchers used two groups of bats for their study. The groups were kept in separate flight rooms and observed over a minimum of two months. The researchers observed the established body-contact partners and separated bats from their respective groups to evoke the emission of contact calls which they recorded. These calls were then played back to bats which were either body-contact partners, no body-contact partners or unknown bats from another group. The behavior of the experimental bat was measured using the turning reaction of the bat's body towards the loudspeaker emitting the call. 

Continued: http://www.sciencedaily.com/releases/2013/05/130507115539.htm

Crows know familiar human voices

Crows recognise familiar human voices and the calls of familiar birds from other species, say researchers.

The ability could help the intelligent birds to thrive in urban environments; using vocal cues from their human and avian neighbours to find food or be alerted to potential threats.

The team used recordings of human voices and jackdaw calls to test the birds' responses.

They published the findings in the journal Animal Cognition.

Lead researcher Claudia Wascher from the University of Vienna said that, although it was widely known that crows were "very intelligent", most studies had focused on their ability to recognise and communicate with their own species.

"In cities crows live alongside jackdaws, magpies and seagulls, and alongside humans," Dr Wascher told BBC Nature.

"Some of those people might be very nice to the crows and feed them and others might be nasty and chase them away.

"You even get some people hunting crows.

To find out if they might be able to distinguish between these different birds and humans, the researchers studied eight carrion crows kept in the university's aviary.

Continued:  http://www.bbc.co.uk/nature/18025926

Meerkats recognise others' voices

Meerkats recognise another member of their social group by the sound of their voice, according to scientists.

Researchers studying the animals in the Kalahari Desert, South Africa, played recordings of meerkat calls and observed the animals' reactions.

Their discovery, reported in the journal Biology Letters is the first evidence of a non-primate mammal showing vocal recognition in the wild.

The phenomenon could be more widespread in the animal kingdom than thought.

"There's lots of evidence of vocal recognition in primates," explained lead researcher Dr Simon Townsend from the University of Zurich in Switzerland.

"[In primates] you can really test whether they respond to individual vocal recognition."

But this harder to test in other non-primates, he explained, because relationships between individual animals are not as clear.

In meerkats, for example - although they are social animals that live in groups and forage and even raise young together - it is not entirely clear how one animal will respond to another when it hears its call.

To solve this problem, the researchers used a simple audio playback experiment.

They used recordings of the staccato "close calls" that meerkats make continually while they are foraging. "We think the calls mainly function to keep the group together," said Dr Townsend. "But they also tell other individuals, 'I'm here, this is my patch'."

The scientists placed speakers on either side of a foraging meerkat, and played a call from a member of their social group. A few seconds later they played the call of a different member of the same group through a speaker on the opposite side.

Read on...