Year-round monitoring reveals prevalence of fatal bird-window collisions at the Virginia Tech Corporate Research Center

Abstract

Collisions with glass are a serious threat to avian life and are estimated to kill hundreds of millions of birds per year in the United States. We monitored 22 buildings at the Virginia Tech Corporate Research Center (VTCRC) in Blacksburg, Virginia, for collision fatalities from October 2013 through May 2015 and explored possible effects exerted by glass area and surrounding land cover on avian mortality. We documented 240 individuals representing 55 identifiable species that died due to collisions with windows at the VTCRC. The relative risk of fatal collisions at all buildings over the study period were estimated using a Bayesian hierarchical zero-inflated Poisson model adjusting for percentage of tree and lawn cover within 50 m of buildings, as well as for glass area. We found significant relationships between fatalities and surrounding lawn area (relative risk: 0.96, 95% credible interval: 0.93, 0.98) as well as glass area on buildings (RR: 1.30, 95% CI [1.05–1.65]). The model also found a moderately significant relationship between fatal collisions and the percent land cover of ornamental trees surrounding buildings (RR = 1.02, 95% CI [1.00–1.05]). Every building surveyed had at least one recorded collision death. Our findings indicate that birds collide with VTCRC windows during the summer breeding season in addition to spring and fall migration. The Ruby-throated Hummingbird (Archilochus colubris) was the most common window collision species and accounted for 10% of deaths. Though research has identified various correlates with fatal bird-window collisions, such studies rarely culminate in mitigation. We hope our study brings attention, and ultimately action, to address this significant threat to birds at the VTCRC and elsewhere.

Ultraviolet-reflective film applied to windows reduces the likelihood of collisions for two species of songbird

“…Avian collisions with windows are an issue of importance to global conservation as perhaps up to a billion birds die each year when they fly into closed windows ( Klem, 2014 ; Loss et al, 2014 ; Loss, Will & Marra, 2015 ; Ocampo-Peñuela et al, 2016 ; Schneider et al, 2018 ) and the problem is geographically widespread ( Basilio, Moreno & Piratelli, 2020 ). Though external window treatments are generally affordable they can be expensive to apply if not affixed to windows at the time of building construction.…”

“…More than a billion birds die annually in night- and daytime collisions with residential and commercial windows ( Klem, 2014 ; Loss et al, 2014 ; Loss, Will & Marra, 2015 ; Ocampo-Peñuela et al, 2016 ; Schneider et al, 2018 ). It is likely that this pattern of mortality not only creates conservation issues for some avian populations but also raises significant political and socioeconomic barriers to human development of the landscape ( Loss et al, 2014 ; Klem, 2015 ).…”

Flight morphology and visual obstruction predict collision risk in birds

“…Previous studies have provided great insight into the features of urban and suburban environments that pose risk, such as artificial light at night, glass surface area, and proximity to vegetation [3,[6][7][8]11,12]. Our results show how morphology can also explain why some species are more collision-prone than others, owing to their small size, visual obstruction, and maneuverability.…”

“…Additionally, several recent studies have established habitat-related correlates of collision mortality, such as building size and type, glass surface area, light pollution, surrounding land cover, and regional urbanization [6][7][8][9][10]. Behavioural correlates of collisions have also been identified, including nocturnal migration behavior [5,11], insectivory [10,12] and the use of social flight calls [3].…”

Peer Review #3 of "Ultraviolet-reflective film applied to windows reduces the likelihood of collisions for two species of songbird (v0.1)"

“…Avian collisions with windows are an issue of importance to global conservation as perhaps up to a billion birds die each year when they fly into closed windows (Klem, 2014;Loss et al, 2014;Loss, Will & Marra, 2015;Ocampo-Peñuela et al, 2016;Schneider et al, 2018) and the problem is geographically widespread (Basilio et al, 2020). Though external window treatments are generally affordable they can be expensive to apply if not affixed to windows at the time of building construction.…”