Quantitative analysis of vocalisation types in male common cuckoos' "gowk" call complex

Area of Science:

• Bioacoustics
• Animal Communication
• Ornithology

Background:

• Animal vocalizations serve distinct functions for long-range and short-range communication.
• Common cuckoos (Cuculus canorus) possess a simple acoustic repertoire, with male territorial calls being well-known.
• Soft cuckoo calls have been noted but lack systematic acoustic comparison and classification.

Purpose of the Study:

• To systematically survey and acoustically analyze neglected soft vocalizations in common cuckoos.
• To compare the acoustic properties of single gowk, guo, and gowk series calls.
• To classify these soft calls based on bioacoustic analysis.

Main Methods:

• Bioacoustic analysis of common cuckoo soft vocalizations.
• Comparison of single gowk, guo, and gowk series calls.
• Referencing the male's loud advertisement call ("cu-coo") for comparison.

Main Results:

• Three soft call types (gowk series call 1st note, gowk series call 2nd note, and single gowk call) exhibited significant acoustic similarities.
• "Guo" calls were acoustically distinct from the other analyzed soft calls.
• The "gowk" call is structurally integral to the male's gowk series call.

Conclusions:

• Acoustic analysis supports the classification of common cuckoo soft calls.
• The "gowk" call is not structurally separate from the gowk series call.
• This classification provides a foundation for future research on the functional significance of cuckoo vocalizations in social contexts.