Investigating the Effects of Urban Features on Bird Window Collisions

Migrant bird species stopping over in urban locations are threatened by a number of anthropogenic causes of mortality, including collisions into reflective glass windows. Annual avian mortality rate, surrounding landscaping, and building characteristics that can potentially predict mortality rate were evaluated on mid-rises on the York University Keele Campus. I predicted that frequency of collisions increases with (1) higher proportional vegetation and proximity of vegetation to buildings, and (2) increased window area. After accounting for surveyor bias and predator removal, the rate of collision was 7.7 4 SD birds/building/year. A negative binomial GLM determined collision frequency to be significantly predicted by proportional vegetation area, distance to vegetation, window area and wall vegetation. Significant interactions occurred between proportional vegetation area and season, distance to vegetation and window type, and wall vegetation and window area. It is strongly recommended that mitigation measures be implemented on high mortality buildings through visual markers.