Overview
- University of Exeter scientists report the results in Biology Letters after field tests on 61 herring gulls across nine towns in Cornwall.
- Nearly half of the gulls exposed to a shouted warning flew away within a minute, compared with about 15% to calm speech, while most stayed during robin song.
- The experiment used recordings of the same phrase delivered by five men, with speaking and shouting equalized to the same decibel level to isolate tone.
- Gulls showed greater vigilance and pecked less whenever a male voice played, with walking away more common for calm speech and flight more common for shouting.
- The team recommends vocal deterrence as a peaceful management tactic for a species of conservation concern and notes future tests could assess responses to female voices.