Bird-Friendly Building Design Bird-Friendly Building Design

Plantings on setbacks and rooftops can attract birds to glassthey might otherwise avoid. Photo: Christine Sheppard, ABCVines cover most of these windows, but birds might fly intothe dark spaces on the right. Photo: Christine Sheppard, ABCReflections on home windows are a significant source of bird mortality. The partiallyopened vertical blinds seen here may break up the reflection enough to reduce thehazard to birds. Photo: Christine Sheppard, ABCReflected VegetationGlass that reflects shrubs and trees causes more collisionsthan glass that reflects pavement or grass (Gelb and Delecretaz,2006). Studies have only quantified vegetation within15-50 feet of a façade, but reflections can be visible at muchgreater distances. Vegetation around buildings will bringmore birds into the vicinity of the building; the reflection ofthat vegetation brings more birds into the glass. Taller treesand shrubs correlate with more collisions. It should be keptin mind that vegetation on slopes near a building will reflectin windows above ground level. Studies with bird feeders(Klem et al., 1991) have shown that fatal collisions resultwhen birds fly towards glass from more than a few feet away.Green Roofs and WallsGreen roofs bring habitat elements attractive to birds tohigher levels, often near glass. However, recent work showsthat well designed green roofs can become functionalecosystems, providing food and nest sites for birds. Sitingof green roofs, as well as green walls and rooftop gardensshould therefore be carefully considered, and glass adjacentto these features should have protection for birds.Local ConditionsAreas where fog is common may exacerbate local light pollution(see below). Areas located along migratory pathwaysor where birds gather prior to migrating across large bodiesof water, for example, in Toronto, Chicago, or the southerntip of Florida, expose birds to highly urban environmentsand have caused large mortality events (see Appendix II foradditional information on how migration can influence birdcollisions).LightingInterior and exterior building and landscape lighting canmake a significant difference to collisions rates in any one location.This phenomenon is dealt with in detail in the sectionon lighting.Planted, open atrium spaces lure birds down, then prove dangerous when birds try tofly out to reflections on surrounding windows. Photo: Christine Sheppard, ABC14 Bird-Friendly Building Design