Hope College Faculty and Student Research Project: Continent-wide analysis of how urbanization affects bird-window collision mortality in North America
In the fall of 2014, Dr. Kathy Winnett-Murray and five Hope research students participated in an EREN (http://erenweb.org/) collaborative research network project studying the effects of building size and urbanization on bird window collisions. The Hope College research students that gathered data for the Hope College site were Michael Barrows (’15), Nicholas Gibson (’17), Emily Kindervater (’15), Courtney Lohman (’16), and Alexandria Vandervest (’15).
The bird-window collision project was replicated at 40 college/university sites across North America and the results of this continent-wide study were recently published in the on-line journal Biological Conservation.
ABSTRACT-
Characteristics of buildings and land cover surrounding buildings influence the number of bird-window collisions, yet little is known about whether bird-window collisions are associated with urbanization at large spatial scales. We initiated a continent-wide study in North America to assess how bird-window collision mortality is influenced by building characteristics, landscaping around buildings, and regional urbanization. In autumn 2014, researchers at 40 sites (N = 281 buildings) used standardized protocols to document collision mortality of birds, evaluate building characteristics, and measure local land cover and regional urbanization. Overall, 324 bird carcasses were observed (range = 0–34 per site) representing 71 species. Consistent with previous studies, we found that building size had a strong positive effect on bird-window collision mortality, but the strength of the effect on mortality depended on regional urbanization. The positive relationship between collision mortality and building size was greatest at large buildings in regions of low urbanization, locally extensive lawns, and low-density structures. Collision mortality was consistently low for small buildings, regardless of large-scale urbanization. The mechanisms shaping broad-scale variation in collision mortality during seasonal migration may be related to habitat selection at a hierarchy of scales and behavioral divergence between urban and rural bird populations. These results suggest that collision prevention measures should be prioritized at large buildings in regions of low urbanization throughout North America.
A link to the full paper can be found here.
Not surprisingly, bigger buildings are more deadly for birds, but the real beauty of this study is in elucidating a larger-scale pattern that only emerged by comparing many sites – that large buildings are especially bad if they sit in a less developed landscape that is more attractive to birds (i.e. one that has lots of greenspace and low structural density). This insight allows for prioritization of collision prevention measures at buildings where impacts can be predicted to be greatest.
It is important to recognize not only that a project of this scale is only possible through a large-scale collaborative network of institutions, but that on-campus collaboration at the local level was equally important in the successful completion of the study here at Hope. Thank you to the many people on our campus that allowed for us to participate and accomplishing this project!
Dr. Kathy Winnett-Murray
Professor of Biology – Hope College
Holland, MI 49423
email: winnetmurray@hope.edu