Habitat connectivity influences distance fled but not flight-initiation distance in urban woodland birds

Habitat destruction and fragmentation in urban contexts increasingly brings humans into close proximity with wildlife. Animals respond to humans using anti-predator responses, especially escape, with responses influenced by the behavioural and life history traits specific to the species or individual, as well as the nature of the incursion and the surrounding environment. While many studies examine broad-scale habitat characteristics (i.e., habitat type) in the context of escape response, few investigate fine-scale aspects of the local habitat in which an escape response occurs that could influence these broader trends. In this study, I test the ‘habitat connectivity hypothesis’, which predicts a higher cost of escape within less connected habitats due to the lack of protective cover; therefore, individuals are more likely to accommodate greater risk before escape responses are initiated when compared with individuals in more connected habitat. I analyse 272 flight-initiation distances (FIDs) of four species of woodland birds in urban Victoria, south-eastern Australia. A negative effect of habitat connectivity (the proportion of trees in the escape route) on distance fled was evident for all four study species, suggesting a higher cost of escape associated with lower connectivity as predicted by the ‘habitat connectivity hypothesis’. A positive effect of habitat connectivity on FID occurred only for Noisy Miner Manorina melanocephala indicating that habitat is not an important factor considered in the escape response of all woodland birds, due perhaps to the variety and abundances of refugia available to them throughout the landscapes in which they are adapted to. These results suggest that the ‘habitat connectivity hypothesis’ warrants further investigation to determine if these effects are evident across other taxa in contrasting landscapes. This information could be used to better inform management practices of habitat frequently exposed to human disturbance in order to reduce the impacts on wildlife.