New Estimates for Bird Collisions
February 10, 2014 by Pete Marra
Building collisions, and particularly collisions with windows, are a major anthropogenic threat to birds, with rough estimates of between 100 million and 1 billion birds killed annually in the United States. However, no current U.S. estimates are based on systematic analysis of multiple data sources.
We reviewed the published literature and acquired unpublished datasets to systematically quantify bird–building collision mortality and species-specific vulnerability. Based on 23 studies, we estimate that between 365 and 988 million birds (median = 599 million) are killed annually by building collisions in the U.S., with roughly 56% of mortality at low-rises, 44% at residences, and <1% at high-rises.
Based on >92,000 fatality records, and after controlling for population abundance and range overlap with study sites, we identified several species that are disproportionately vulnerable to collisions at all building types.
In addition, several species listed as national Birds of Conservation Concern due to their declining populations were identified to be highly vulnerable to building collisions, including the species depicted below.
The identification of these six migratory species with geographic ranges limited to eastern and central North America reflects seasonal and regional biases in the currently available building-collision data. Most sampling has occurred during migration and in the eastern U.S. Further research across seasons and in underrepresented regions is needed to reduce this bias.
Nonetheless, we provide quantitative evidence to support the conclusion that building collisions are second only to feral and free-ranging pet cats, which are estimated to kill roughly four times as many birds each year, as the largest source of direct human-caused mortality for U.S. birds.
This article summarizes the information in this scientific paper:
Loss, S. R., T. Will, S. S. Loss, and P. P. Marra. 2014. Bird–building collisions in the United States: Estimates of annual mortality and species vulnerability. The Condor 116(1):8–23.
- Linking Place-based Citizen Science with Large-scale Conservation Research: A Case Study of Bird-building Collisions and the Role of Professional Scientists
- Full Annual Cycle Climate Change Vulnerability Assessment For Migratory Birds of the Upper Midwest and Great Lakes Region
- Early Detection of Emerging Zoonotic Diseases with Animal Morbidity and Mortality Monitoring
- State of the Birds 2014
- Ecological Change on California's Channel Islands from the Pleistocene to the Anthropocene
- Refining Estimates of Bird Collision and Electrocution Mortality at Power Lines in the United States
- Estimation of bird-vehicle collision mortality on U.S. roads
- New Population Statistics Reveal Island Scrub-Jay Among United States’ Rarest Bird Species
- A Second Home May Shore up Island Scrub Jay's Future
- Smithsonian Scientists Find Declining Rainfall Is a Major Influence for Migrating Birds