Bicycles evoke longer flight-initiation distances and higher intensity escape behaviour of some birds in parks compared with pedestrians

Abstract

Wildlife discriminate between potential threats they encounter and may modulate their escape responses accordingly. Flight-initiation distances (FIDs), the distance at which an animal initiates escape to an approaching threat, can inform separation distances which minimise disturbance. However, FID data are currently lacking for many common human-related stimuli encountered by wildlife. Our aim was to elucidate avian responses to a common human stimulus, bicycles being ridden in parks. We compare FIDs in response to a fast bicycle, slow bicycle and a single walker for a range of Australian birds commonly found in parks. When all 57 species were pooled, bicycles did not evoke longer FIDs than walkers. Single species models revealed that bicycles evoked longer FIDs for four of 12 well-sampled species. The response towards bicycles was more intense (i.e., more likely to involve flying) than to walkers for two of ten species.