BOB HIRSHON (host):
Ravens’ social memories. I’m Bob Hirshon and this is Science Update.
[sfx: raven calls]
You’re listening to the calls of different ravens. And like humans, ravens can identify one another’s voices, and judge whether that voice is friendly or aggressive. Now, cognitive biologists Markus Boeckle and Thomas Bugnyar of the University of Vienna have shown that ravens can remember past friends and foes for at least three years. Boeckle says the ravens react differently to recordings of former aggressors, than to those of friendly birds they once encountered.
MARKUS BOECKLE (University of Vienna, Austria):
They try to elongate their vocal tracts and thus, try to sound much deeper than when they are calling back to a friendly individual.
Humans do the same thing in adversarial situations. Bockle says the ravens may have developed long social memories because they spend many years in their birth territory before venturing out to breed. I’m Bob Hirshon for AAAS, the Science Society.