Comment in:

Science. 2005 Jun 24;308(5730):1853-5.

Science. 2005 Oct 28;310(5748):620-1; author reply 620-1.

Allometry of alarm calls: black-capped chickadees encode information about predator size.

Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA. ctemple2@u.washington.edu

Many animals produce alarm signals when they detect a potential predator, but we still know little about the information contained in these signals. Using presentations of 15 species of live predators, we show that acoustic features of the mobbing calls of black-capped chickadees (Poecile atricapilla) vary with the size of the predator. Companion playback experiments revealed that chickadees detect this information and that the intensity of mobbing behavior is related to the size and threat of the potential predator. This study demonstrates an unsuspected level of complexity and sophistication in avian alarm calls.

PMID: 15976305 [PubMed - indexed for MEDLINE]