Adaptive Flight Strategies in Urban Birds: Unraveling the Intricacies between Flight Initiation Distance and Distances Fled

Abstract

With increased urbanization, more habitats will become less suitable for wildlife, increasing the perceived risk of predation among wildlife. The animals’ perception of predation is usually measured using flight initiation distance (FID). Further, several internal and external factors influence the FID. However, there is still ambiguity on whether these variables influence the FID, as some studies have different results in different geographical locations. This study was undertaken to understand (i) the ’influence of urbanization gradient on the FID of local birds and (ii) the association between FID and DF, as both are based on the principle of “balance between risk and cost of escape”. We collected 438 observations of FID across 22 bird species in and around Berhampur City in Odisha, India. Subsequently, a generalized linear mixed-effects model was employed in our analysis to evaluate the association between FID, DF, and body size. Interestingly, the study suggests FIDs in urban birds (9.48 ± 6.59 m) were noticeably shorter than their rural counterparts (10.00 ± 6.61 m), indicating adaptation to human presence. Subsequently, a significant association between the FID and DF was observed. The findings also reveal a significant relationship between FID and body size, suggesting body size should be considered when creating avian risk assessment frameworks. This study provides reliable proof of birds' behavioral adaptation to urban environments. It opens the door to further urban ecology research, emphasizing the need to understand wildlife responses to urbanization to create effective conservation plans.