Black-capped (Poecile atricapillus) and mountain chickadee (Poecile gambeli) contact call contains species, sex, and individual identity features.

The tseet contact call, common to both black-capped and mountain chickadees, is among the most frequently produced call of each species, but has remained little studied until now. In the current study, the authors characterized the tseet call of adult allopatric and sympatric black-capped and mountain chickadees in terms of nine acoustic features in a fashion similar to descriptive accounts of both species' chick-a-dee calls. Summary statistics, the potential for individual coding, and classification by linear discriminant analysis were used to describe the tseet call. The authors were able to correctly classify tseet calls in terms of which group or individual produced it with high accuracy. Furthermore, several acoustic features are highly individualized, indicating that the chickadees may use these features to identify signalers as individuals or members of a particular group.