Assessing Injury Rates to Red-tailed Hawks Live-captured Using Three Common Methods

Abstract

Abstract Assessments of the impact of live-capture methods and tools are important to wildlife research and management efforts. Federal regulations (e.g., the Migratory Bird Treaty Act and the Animal Welfare Act) require humane and ethical treatment of migratory birds. Therefore, it is important to conduct live-trapping using methodologies that minimize the potential for injury or mortality. We evaluated the injury rate experienced by red-tailed hawks Buteo jamaicensis captured using three, commonly-used live-traps (i.e., bal-chatri trap, Swedish goshawk trap, and pole trap). Professional wildlife biologists at airports in Illinois live-captured 25 free-ranging red-tailed hawks using bal-chatri traps, 42 red-tailed hawks using Swedish goshawk traps, and 25 red-tailed hawks using pole traps. Of the red-tailed hawks (n = 53) identified by a veterinary forensic pathologist as having one or more capture-related injuries, 85% of the injuries were classified as ‘minor’ (e.g., cuts or scrapes), 13% were classified as ‘moderate’ (e.g., hemorrhaging), and only 2% were classified as ‘severe’ (e.g., fractures). When considering only injuries classified as ‘moderate’ and ‘severe’, we found no difference (χ21 = 0.38, P = 0.54) in the frequency of these injuries among the three trap types. The three live-trap devices we evaluated can be efficient tools that result in minimal risk of injury or death when used by those with proper training and experience to live-capture red-tailed hawks for research purposes, while conducting raptor hazard management activities, or licensed falconers acquiring wild red-tailed hawks.