Bird-Friendly Building Design Bird-Friendly ... - Lights Out Indy

Awnings and OverhangsOverhangs have been said to reduce collisions, however,they do not eliminate reflections, and only block glass fromthe view of birds flying above. They are thus of limited effectivenessas a general strategy.Overhangs block viewing of glass from some angles, but do notnecessarily eliminate reflections. Photo: Christine Sheppard, ABCReflections in this angled façade can be seen clearly over a longdistance, and birds can approach the glass from any angle. Photo:Christine Sheppard, ABCUV Patterned GlassBirds can see into the ultraviolet (UV) spectrum of light, arange largely invisible to humans (see page 36). UV-reflectiveand/or absorbing patterns (transparent to humans butvisible to birds) are frequently suggested as the optimalsolution for many bird collision problems. Progress in thesearch for bird-friendly UV glass has been slow, however,due to the inherent technical complexities, and because,in the absence of widespread legislation mandating birdfriendlyglass, only a few glass companies recognize this asa market opportunity. Research indicates that UV patternsneed strong contrast to be effective.Angled GlassIn a study (Klem et al., 2004) comparing bird collisions withvertical panes of glass to those tilted 20 degrees or 40 degrees,the angled glass resulted in less mortality. For thisreason, it has been suggested that angled glass should beincorporated into buildings as a bird-friendly feature. Whileangled glass may be useful in special circumstances, thebirds in the study were flying parallel to the ground fromnearby feeders. In most situations, however, birds approachglass from many angles, and can see glass from many perspectives.Angled glass is not recommended as appropriateor useful strategy. The New York Times printing plant, picturedopposite, clearly illustrates this point. The angled glasscurtain wall shows clear reflections of nearby vegetation,visible from a long distance away.20 Bird-Friendly Building DesignDeeply recessed windows, such as these on Stephen Holl’s Simmons Hall at MIT, canblock viewing of glass from most angles. Photo: Dan Hill