Bird collisions in windows of Centro Universitario Victoria, Tamaulipas, México

Abstract

Bird collisions in diverse man-made structures (e.g., glass windows) are the second most important mortality factor only after cat predation in urban landscapes in North America. Bird collisions have been estimated to cause approximately 988 million deaths annually in the Unites States and Canada alone for these factors. We assessed bird-windows collision frequency at the Centro Universitario Victoria (CUV) of the Universidad Autónoma de Tamaulipas in northeastern Mexico between August 2015 and September 2016. We used periodic walks in permanent transects searching for dead birds around the perimeter (3-m wide strip) of four buildings in two daily sessions (09:00-10:00 h y 16:00-17:00 h) at the cuv. We recorded 21 individual birds from 16 species hitting windows of the cuv Fifty percent of the recorded bird species were residents and 15 collisions out of the total were fatal. White-winged Dove (Zenaida asiatica) and Broad-billed Hummingbird (Cynanthus latirostris) were the species with the greatest incidence with four and three individuals respectively. We also detected five resident bird species showing agonistic behavior to­wards their reflection on window glasses in the campus facilities. We discuss some alternatives to mitigate (e.g., use of color strips attached to windows) the number of bird collisions. The 16 bird species that collided with the windows at the cuv represented the 5.2 % of the total bird species richness recorded for Victoria Municipality. We urge for more bird studies using systematic methodologies, including simultaneous point counts to account for species prevalence at the study site, to document the impact of urbanization on bird populations and communities in different urban centers and landscapes of Mexico. Determining what factors drive collision rates will aide in developing effective management actions in order to reduce collisions at different spatial and temporal scales.