As urban landscapes evolve and expand, the interactions between wildlife and developed areas become increasingly complex. Airports, in particular, exhibit characteristics that may seem attractive to certain bird species, including abundant open space and ample perching sites. One such species that has garnered attention due to its critical relationship with airport safety is the Cooper’s Hawk, known scientifically as Accipiter cooperii. A recent study published in the Journal of Raptor Research has shed light on the environmental and biological factors that influence the translocation of these raptors away from airfields, offering an innovative approach to maintaining both public safety and wildlife conservation.
Cooper’s Hawks are agile raptors adept at hunting birds, a skill that can lead them to frequent highly populated areas like the Los Angeles Basin. This adaptability has prompted concerns among aviation authorities regarding the possibility of bird strikes involving aircraft. The ramifications of these incidents can be severe, costing over $1.5 billion annually in damages across the United States. Thus, balancing wildlife conservation with air traffic safety remains a priority.
Over the course of five years, researchers, led by Brian Washburn from the U.S. Department of Agriculture Wildlife Services, conducted an extensive study spanning six airports within the Los Angeles Basin. They engaged in live-capture of over 600 Cooper’s Hawks, equipping each bird with uniquely coded leg bands to track their movements post-capture. This meticulous process allowed the researchers to gain insights into individual hawks’ ages, sexes, and behaviors upon translocation.
Translocation involved relocating hawks to varying distances from their capture sites—specifically 24, 48, 72, and 96 kilometers. The experiment aimed to determine the factors influencing a hawk’s tendency to return to its original site, providing critical data for airport wildlife management protocols. The findings revealed that age, sex, and distance moved dramatically impacted the likelihood of a hawk’s return, leading to recommendations on best practices for managing these populations effectively.
In conjunction with field observations, the study also requested historical data from the Federal Aviation Administration (FAA) on documented Cooper’s Hawk strikes from 1990 to 2023. With a reported 217 strikes over these years, the data indicated a notable uptick, especially post-2014, underscoring the growing significance of this issue. Though the frequency of Cooper’s Hawk strikes is relatively low compared to other raptors, the increasing numbers have sparked concern among aviation safety officials.
Among the more intriguing aspects of the study was the low rate of homing behavior observed among captured hawks. Only about 10% returned to their original airports, which suggests that effective translocation strategies could potentially diminish resident populations of Cooper’s Hawks at busy airfields. The data indicated that hawks aged two years or older, as well as female Cooper’s Hawks, exhibited a higher probability of returning to capture sites, while distance played a crucial role in their movement dynamics; the further the relocation, the less likely a return.
With raptor interactions resulting in substantial economic losses for airlines, it is imperative that airport management teams develop efficient wildlife conflict mitigation strategies. The authors of the study are adamant that for optimal success in keeping the hawks away from airport grounds, translocation efforts should ideally extend beyond 48 kilometers, particularly targeting hatch-year and adult hawks. Young raptors that have not yet established territories are less likely to return, thus increasing the long-term efficacy of these programs.
Moreover, the ramifications of such translocation practices extend beyond just aviation safety. Human-wildlife conflict mitigation efforts that prioritize non-lethal methods not only preserve the integrity of raptor populations but also foster public awareness about the importance of coexistence with local wildlife. As Washburn rightly notes, the study is a significant addition to the portfolio of humane techniques designed to reduce the risk of raptor-aircraft collisions while ensuring raptors continue to thrive in their habitats.
While the findings provide useful insights, continued research remains essential to enhance understanding of post-translocation behavior in Cooper’s Hawks. Future studies utilizing GPS transmitters could elucidate movement patterns and habitat preferences, further refining management practices. Additionally, the researchers suggest that addressing the attractors for Cooper’s Hawks by minimizing their prey—such as House Sparrows and Rock Pigeons—could play a vital role in reducing their presence at airfields.
The ongoing dialogue around raptor conservation versus aviation safety is crucial in evolving strategies for managing wildlife around airports. As leading predators, raptors like Cooper’s Hawks play a significant role in maintaining ecological balance. The integration of scientific findings into management policies not only strengthens measures against potential wildlife hazards but also highlights the importance of collaborative efforts in fostering biodiversity within urban environments.
As we look to the future, the implications of this research may extend beyond just a localized context within the Los Angeles Basin. By disseminating findings to airport authorities and wildlife conservationists worldwide, the strategies developed could serve as a valuable model for a multitude of similar scenarios globally where human activity intersects with wildlife, thereby contributing to both avian preservation and public safety simultaneously.
Subject of Research: Animals
Article Title: Factors Associated with Homing Behavior in Cooper’s Hawks Following Mitigation Translocations from Airports
News Publication Date: 16-Jun-2025
Web References: http://dx.doi.org/10.3356/jrr2465
References: Washburn, Brian E., and Pitlik, Todd J. (2025). Journal of Raptor Research, 59(3): 1-12.
Image Credits: Brian E. Washburn, USDA Wildlife Services
Keywords
Cooper’s Hawk, translocation, wildlife management, aviation safety, raptor conservation, human-wildlife conflict, ecological balance.
