This article is from the source 'bbc' and was first published or seen on . It will not be checked again for changes.
You can find the current article at its original source at http://news.bbc.co.uk/go/rss/-/earth/hi/earth_news/newsid_8593000/8593789.stm
The article has changed 3 times. There is an RSS feed of changes available.
| Version 0 | Version 1 |
|---|---|
| Hyena laughs and giggles decoded | Hyena laughs and giggles decoded |
| (40 minutes later) | |
| The giggling sounds of a hyena contain important information about the animal's status, say scientists. | The giggling sounds of a hyena contain important information about the animal's status, say scientists. |
| In the first study to decipher the hyena's so-called "laugh", they have shown that the pitch of the giggle reveals a hyena's age. | In the first study to decipher the hyena's so-called "laugh", they have shown that the pitch of the giggle reveals a hyena's age. |
| What is more, variations in the frequency of notes used when a hyena makes a noise convey information about the animal's social rank. | What is more, variations in the frequency of notes used when a hyena makes a noise convey information about the animal's social rank. |
| Details of the US-based research are published in the journal BMC Ecology. | |
| Professor Frederic Theunissen from the University of California at Berkeley, US, and Professor Nicolas Mathevon from the Universite Jean Monnet in St Etienne, France, worked with a team of researchers to study 26 captive spotted hyenas held at a field station at Berkeley. | Professor Frederic Theunissen from the University of California at Berkeley, US, and Professor Nicolas Mathevon from the Universite Jean Monnet in St Etienne, France, worked with a team of researchers to study 26 captive spotted hyenas held at a field station at Berkeley. |
| There they recorded the animals' calls in various social interactions, such as when the hyenas bickered over food, and established which elements of each call corresponded to other factors. | There they recorded the animals' calls in various social interactions, such as when the hyenas bickered over food, and established which elements of each call corresponded to other factors. |
| Last year, the researchers published some provisional results from the study. | Last year, the researchers published some provisional results from the study. |
| Now they have confirmed that the pitch of the giggle reveals a hyena's age, while variations in the frequency of notes can encode information about dominant and subordinate status. | Now they have confirmed that the pitch of the giggle reveals a hyena's age, while variations in the frequency of notes can encode information about dominant and subordinate status. |
| "The hyena's laugh gives receivers cues to assess the social rank of the emitting individual," says Professor Theunissen. | "The hyena's laugh gives receivers cues to assess the social rank of the emitting individual," says Professor Theunissen. |
| "This may allow hyenas to establish feeding rights and organise their food-gathering activities." | "This may allow hyenas to establish feeding rights and organise their food-gathering activities." |
| Spotted hyenas (Crocuta crocuta) are mainly nocturnal, living in clans of between 10 and 90 individuals. | Spotted hyenas (Crocuta crocuta) are mainly nocturnal, living in clans of between 10 and 90 individuals. |
| Spotted hyenas make up to 10 different types of vocalisation"Whoops", with long inter-whoop intervals, are primarily used to signal that two individuals have become separated"Grunts" or "soft growls" are emitted when hyenas of the same clan come into close contact | Spotted hyenas make up to 10 different types of vocalisation"Whoops", with long inter-whoop intervals, are primarily used to signal that two individuals have become separated"Grunts" or "soft growls" are emitted when hyenas of the same clan come into close contact |
| Often they hunt cooperatively, but this can generate intense competition as clan mates converge on a kill, fighting over its carcass. | Often they hunt cooperatively, but this can generate intense competition as clan mates converge on a kill, fighting over its carcass. |
| However, among spotted hyenas, females dominate, holding a higher rank than all other males, whatever their age. | However, among spotted hyenas, females dominate, holding a higher rank than all other males, whatever their age. |
| Profs Theunissen and Mathevon's research suggests that the animals convey this status via their laugh or giggle, which they usually make while fighting over food. | Profs Theunissen and Mathevon's research suggests that the animals convey this status via their laugh or giggle, which they usually make while fighting over food. |
| Previously their sounds had been considered a simple gesture of submission, but the new study has allowed researchers to identify exactly which individual hyena makes each giggle, and the circumstances in which they do so. | Previously their sounds had been considered a simple gesture of submission, but the new study has allowed researchers to identify exactly which individual hyena makes each giggle, and the circumstances in which they do so. |
| The information contained within the giggles could be especially important for males new to a clan, as they go immediately to the bottom of the hierarchy when they arrive. | The information contained within the giggles could be especially important for males new to a clan, as they go immediately to the bottom of the hierarchy when they arrive. |
| Getting to know quickly who is who may give these individuals a better chance of improving their own status. | Getting to know quickly who is who may give these individuals a better chance of improving their own status. |
| Giggles could also allow hyenas to recruit allies, for instance when one or two hyenas are outnumbered by lions fighting over the same kill. | Giggles could also allow hyenas to recruit allies, for instance when one or two hyenas are outnumbered by lions fighting over the same kill. |