Category: Fisheries and Wildlife
Author(s): Meng-Chen Lo
Author(s): Meng-Chen Lo
Description: Capture, handling, and marking techniques are used widely in wildlife research. Marking techniques help biologists track, monitor, and distinguish between individual animals. Many researchers assume that the processes of capture, handling, and marking have little or no effect on research results, a critical assumption. This assumption ignores the possibility of confounding effects and their consequences, potentially compromising study results and animal welfare concerns. Few studies on the impacts of these techniques have been published. Through a literature review, I summarized the methods and techniques used to capture, handle, and mark ungulates and carnivores. The objectives of this review were to evaluate which techniques influence particular species, and develop information useful to researchers in future capture, handling, and marking operations. This report reviewed 164 research papers on carnivores and 165 research papers on ungulates. Fifty-two papers on carnivores and 50 papers on ungulates concluded that handling, marking, and capture do have a variety of effects on behavior, physiology, pathology, and mortality. Different techniques may elicit subtle and completely unexpected behavioral responses among various species or individuals. Capture techniques on ungulates resulted primarily in physiological effects, but more pathological effects were noted in carnivores because of the different bio-mechanical support functions between carnivores and ungulates. More capture myopathy occurred in ungulates than in carnivores. Chemical immobilization was the most widespread method used to restrain animals but this technique also has additional physiological impacts on animals. Cardiovascular complications and hyperthermia were regular and predictable concerns with immobilizing drugs. Application of collars or tags on animals can change an animal's behavior and may cause severe injuries around ears or necks if done incorrectly. Minimizing negative impacts and ascertaining the feasibility of alternative techniques and procedures are important challenges for improving experimental methods and procedures in wildlife research. Moreover, a greater awareness of potential impacts, tests of assumptions, and systematic study of techniques are needed for future wildlife research.