title: Acoustic Mechanisms of a Species-Based Discrimination of the chick-a-dee Call in Sympatric Black-Capped (Poecile atricapillus) and Mountain Chickadees (P. gambeli).
abstract: Previous perceptual research with black-capped and mountain chickadees has demonstrated that these species treat each other's namesake chick-a-dee calls as belonging to separate, open-ended categories. Further, the terminal dee portion of the call has been implicated as the most prominent species marker. However, statistical classification using acoustic summary features suggests that all note-types contained within the chick-a-dee call should be sufficient for species classification. The current study seeks to better understand the note-type based mechanisms underlying species-based classification of the chick-a-dee call by black-capped and mountain chickadees. In two, complementary, operant discrimination experiments, both species were trained to discriminate the species of the signaler using either entire chick-a-dee calls, or individual note-types from chick-a-dee calls. In agreement with previous perceptual work we find that the D note had significant stimulus control over species-based discrimination. However, in line with statistical classifications, we find that all note-types carry species information. We discuss reasons why the most easily discriminated note-types are likely candidates to carry species-based cues.
authors.affiliation: Songbird Neuroethology Laboratory/BioCognition Unit, Department of Psychology, University of Alberta Edmonton, AB, Canada.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Guillette
authors.forename: Tara M
authors.initials: TM
authors.lastname: Farrell
authors.forename: Marisa
authors.initials: M
authors.lastname: Hoeschele
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Sturdy