Architectural and Landscape Risk Factors Associated with Bird–glass Collisions in an Urban Environment

A First Estimate for Canada of the Number of Birds Killed by Colliding with Building Windows

“…Our categorization of buildings into the three classes is simplistic and the building types we allocated to each class are based on crude categorizations of the data derived by Natural Resources Canada (2006). Nonetheless, we believe there is good rationale for broad categorizations based on patterns described in the literature that related mortality to the amount of glass and vegetation or inversely to level of development (e.g., Klem et al 2009, Borden et al 2010, Hager et al 2013. There is also no published or anecdotal evidence that windowless warehouses in industrial parks kill as many birds as mirrored buildings surrounded by lush, bird-attracting vegetation.…”

“…During daytime there are two main mechanisms thought to cause collisions. First, birds may strike transparent panes when a breezeway or other narrow, glassedin feature is in their flight path, presuming they can fly right through it to reach habitat and/or sky on the other side (Ross 1946, Klem et al 2009). Second, birds also strike reflective panes attempting to reach habitat or sky mirrored in the glass surface (Banks 1976, Klem 2006.…”

“…Situational factors contribute to the propensity of buildings to cause mortality. Chief among these seems to be proximity to, and abundance of nearby vegetation, the location of bird attractants, i.e., feeders, and the glass surface area of the structure (Hager et al 2008, Klem et al 2009, Borden et al 2010, Hager et al 2013. Greater vegetation abundance and its maturity, as well as the presence of bird feeders, are assumed to increase the potential number of birds that are available to collide with windows (Vale and Vale 1976, Edgar and Kershaw 1994, Chace and Walsh 2006.…”

Evaluating the Effectiveness of Select Visual Signals to Prevent Bird-window Collisions

“…A localized study in which deterrents are added to or removed from the windows of a house over time would be helpful in determining the most effective deterrent designs for different types of neighborhoods and yards. To date, only a handful of studies have looked at bird-window collision deterrents (Klem 1990, Klem et al 2009, Klem and Saenger 2013, Rössler et al 2015, none of which were conducted in an actual residential setting. As new products are developed, labtype studies are producing supporting evidence for their efficacy (e.g., WindowAlert, http://windowalert.com; American Bird Conservancy BirdTape, http://www.…”

Landscape, Legal, and Biodiversity Threats that Windows Pose to Birds: A Review of an Important Conservation Issue

“…But just as the density of individual birds in the vicinity of windows increases the chance of a fatal strike, the more glass surface the greater probability of providing an illusion resulting in a strike [7,8]. Attractants such as immediate and surrounding vegetation that guide birds to the vicinity of windows, water containers, baths, or impoundments, and bird feeders contribute to increasing fatalities because of greater numbers of individuals in the immediate vicinity of the hazard [6,7,12,[24][25][26].…”