Behaviour 2019
Variable note structure and diel song rate found in the Connecticut Warbler’s extended song type
Kaitlyn E. Plastino1, Jennifer R. Foote1, Kevin C. Hannah2. 1Algoma University, Sault Ste. Marie, Ontario, Canada; 2Environment and Climate Change Canada, Ottawa, Ontario, Canada

The Connecticut Warbler (Oporornis agilis) is one of the least studied passerines in North America, thus their vocal behaviour has not been well studied. Using autonomous recorders in the Northwestern Ontario boreal forest, we examined this species’ vocal repertoire. We report a novel but rarely used, second song type: an extended song that covers a broader frequency range and is significantly longer and more variable than the species’ primary song. The extended song is similar in composition to the Ovenbird’s (Seiurus aurocapilla) flight song; It includes an introductory segment, several notes from its primary song, and a terminal segment. We found that song length and syllable versatility index varied within and among individuals. We also found that primary songs peaked at dawn and declined through the day while extended songs peaked in evening, suggesting temporal separation. Our work highlights the value of environmental recordings created for survey purposes so that we may answer questions about the vocal behaviour of difficult to study species, in addition to expanding our knowledge of natural history.