Evaluating the drivers of bird-window collisions in North America / EREN Bird-window Collisions Project
Stephen B. Hager, Department of Biology, Augustana College, Rock Island, Illinois stevehager@augustana.edu, 309.794.3439
Bradley J. Cosentino, Department of Biology, Hobart and William Smith Colleges, Geneva, New York (cosentino@hws.edu)

Welcome to the EREN Bird-window Collisions website! This site provides information on a continent-wide collaborative research project that seeks to understand the factors influencing bird-window collisions.
"EREN" references the Ecological Research as Education Network (EREN), which is assisting in identifying potential collaborators and offering helpful advice.

The page you are currently on explains the basic features and needs of the project. You may find details on the project's objectives, protocols, and collaborator policies on the Project Description page.


Birds that reside in urban settings face numerous human-related threats to survival, including mortality from bird-window collisions (BWCs). Despite the knowledge that BWCs have occurred since humans began constructing sheet glass in the walls of buildings, we know little about the factors that affect collisions across large spatial scales. We are testing the hypothesis that the magnitude of BWCs within and among urban areas reflects landscape structure and functional connectivity.

We are currently seeking collaborators from throughout North America to assist us in evaluating the drivers of BWCs.
Collaborators need not have a background in ornithology, but
should possess strong organizational skills and attention to detail.

Basic methods
All collaborators are provided with complete and standardized research protocols that assist in the process of selecting study buildings, measuring environmental and structural factors, and conducting bird carcass surveys.

History of the project
In 2013, the EREN network enabled collaboration among 13 sites in the eastern United States and central Mexico to assess the drivers of BWCs. Our short term goals were to (1) complete a pilot field season in fall 2013 to test and refine project methods and protocols in time for the first official field season in fall 2014, and (2) conduct a preliminary analysis of the data collected.

Results from the 2013 pilot field season suggested that project protocols and methods performed well. Indeed, we found strong potential to assess the drivers of BWCs at the continent scale in future field seasons.

We found 91 bird carcasses (N = 39 species) resulting from window collisions for all sites, combined. Analyses of the pilot data suggested that the most supported model explaining the number of carcasses included window area, local vegetation, and broad-scale development. Buildings with the most carcasses had high window area. Number of carcasses had weak positive associations with green space in the immediate vicinity of buildings and developed land in the broader landscape.

Professional development outcomes since Fall 2013
The project has provided inquiry-based educational opportunities for 189 undergraduate students and 21 faculty/professional researchers at collaborator sites. Students at three campuses participated in professional development activities, e.g., poster presentations at local scientific meetings, which stemmed from their research on bird-window collisions.

Results from the pilot 2013 field season will be presented in a symposium at the 2014 Ecological Society of America (ESA) meeting in Sacramento, CA. The symposium session (#9742) is titled "The Ecological Research as Education Network (EREN): Merging Teaching and Research Through Continental-scale Collaborative Projects".

Detailed information about this research project
  1. The project's rationale, objectives, and general methods are found at the Project Description page.
  2. Protocols for selecting and digitizing study buildings, conducting carcass surveys, measuring window area, and collaborator site information.
  3. Information for IACUC.
  4. Education Materials on bird-window collisions for use in classes and internships/independent study with students. Includes a case study and journal club workshop.
  5. Locations of current collaborators.
Contact Information
Please email the project's PI's, Steve Hager (stevehager@augustana.edu) or Brad Cosentino (cosentino@hws.edu), with any questions or comments.