Credit: Erin Jarvis

Spotted hyenas are a curious species. They are one of the very few mammals that maintain a female-dominated society, and one of the only non-primate species that can recognize relationships between animals to which they are unrelated. And, to the surprise of many, there is a clan of 26 hyenas living in the Berkeley hills. Before you start questioning the safety of your evening jogs above campus, know that the hyenas are part of a captive breeding colony housed at the Field Station for the Study of Behavior, Ecology, and Reproduction (FSSBER), maintained by the University of California, Berkeley. UC Berkeley researchers Frederic Theunissen (professor of psychology), Mary Weldele (psychology and integrative biology), Aaron Koralek (graduate student at the Wills Neuroscience Institute), and Stephen Glickman (professor of psychology and integrative biology) decided to use the hyena colony to decipher a distinctive hyena trait - the giggle, and its meaning in hyena society. Hyena social status is maintained by a complicated social network of coalitions and alliances, which requires an intricate system of communication. Hyenas communicate visually, chemically, and, as a major backdrop to the nightly chorus of the African Savannah, acoustically. The quintessential hyena call is the giggle - a high-pitched sound emitted in bouts that sounds like laughter. "The function of the giggle call is actually very poorly understood," says Aaron Koralek. "This was some of the first work looking at if [the hyena giggle] could potentially serve a social function." The hyena giggle is most frequently emitted by a subordinate competing over a carcass with a dominant member, and previous observations suggested that the giggle was a subordinate call. Research further suggests that the giggle is a frustrated response to wanting something and not getting it: another good reason not to tease a hyena.

This article is part of the Fall 2011 issue.