Note types and coding in parid vocalizations.: II:: The chick-a-dee call of the mountain chickadee (Poecile gambeli)

We describe the chick-a-dee call of the mountain chickadee, Poecile gambeli (Ridgway, 1886), by classifying the various call notes into six types (A, A/B, B, C, D-h, and D). Note-type analyses identify a high degree of similarity among A and A/B notes in the ascending duration, descending duration, and note peak frequency, and among A/B and B notes in the end frequency. This statistical result paralleled disagreements between human sorters where A, A/B, and B notes were most often misclassified. Moreover, virtually all parameters measured showed significant variation across individuals. Therefore, the particular acoustic cues used in the discrimination of note types and individuals remain unknown, but it is likely that a constellation of features is used rather than one or two particularly salient features.