What hyena laughs mean

This is a spotted hyena video.

From the BBC:

Hyena laughs and giggles decoded

By Matt Walker
Editor, Earth News

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.

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.

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.

ScienceDaily (Sep. 23, 2010) — A team from the National Museum of Natural Sciences (CSIC) has analysed the impact of climate change on spotted hyena survival in Europe over 10,000 years ago. These changes played an important role, but the scientists say studies are still needed to look at the influence of human expansion and changes in herbivorous fauna on the definitive extinction of this species across the continent: here.

The giant hyena, Pachycrocuta brevirostris, roamed Africa more than 2.5 million years ago: here.

Extreme Mammals: the Biggest, Smallest, and Most Amazing Mammals of All Time showcases some of our most intriguing relatives, from the speedy to the sloth-like, the towering to the tiny, even the venomous and the armor-clad: here.

From frogs to birds to insects, animals that vocalize in large groups must make themselves heard above the background clamor: here.