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available and which resulted from a wide range in building height, type of glass, indoor <br />and outdoor landscaping, interior light management, window to wall ratio, and <br />structural context of the facade. This variation contributed to a robust bird -window <br />collision rate represented by a wide 95% confidence interval. Even at the low end of the <br />interval, the death toll would be excessive, amounting to >131,00o bird deaths over 100 <br />years, and this prediction preceeds any adjustments for the proportion of carcasses not <br />found due to searcher error and carcass removal by scavengers. <br />Note that 15 (83%) of the 18 sources of fatality rates cited above were published after the <br />2007 EIR, and a third of them were published the same year or after the 2018 SEIR. <br />Guidance on how to design buildings and reduce the collision hazards of glass also were <br />produced since the 2007 EIR (see below). These new reports and guidance documents <br />provided new information of substantial importance. The level of impact I predicted <br />from data in these reports would be significant, especially considering that the predicted <br />fatality rate can be largely prevented by implementing appropriate mitigation measures. <br />Below I will discuss hypothesized bird -window collision factors, and I will recommend <br />mitigation measures. <br />Bird -Window Collision Factors <br />Below is a list of collision factors I found in the scientific literature. Following this list <br />are specific notes and findings taken from the literature and my own experience. <br />(1) Inherent hazard of a structure in the airspace used for nocturnal migration or other <br />flights <br />(2) Window transparency, falsely revealing passage through structure or to indoor <br />plants <br />(3) Window reflectance, falsely depicting vegetation, competitors, or open airspace <br />(4) Black hole or passage effect <br />(5) Window or facade extent, or proportion of facade consisting of window or other <br />reflective surface <br />(6) Size of window <br />(7) Type of glass <br />(8) Lighting, which is correlated with window extent and building operations <br />(9) Height of structure (collision mechanisms shift with height above ground) <br />(10) Orientation of fagade with respect to winds and solar exposure <br />(11) Structural layout causing confusion and entrapment <br />(12) Context in terms of urban -rural gradient, or surrounding extent of impervious <br />surface vs vegetation <br />(13) Height, structure, and extent of vegetation grown near home or building <br />(14) Presence of birdfeeders or other attractants <br />(15) Relative abundance <br />(16) Season of the year <br />(17) Ecology, demography and behavior <br />(18) Predatory attacks or cues provoking fear of attack <br />(19) Aggressive social interactions <br />0 <br />