Alternative Methodology for Handling and Marking Meso-Mammals for Short-Term Research

We evaluated squeeze cages and water-soluble inks and dyes as methods for handling and marking of meso-mammals in a short-term capturerecapture study. Study animals exhibited no adverse physiological impacts from capture or marking techniques. We also observed no negative impacts on trap success for the duration of the study. We found these methods quick (5 minutes maximum hold time), safe (no observed injuries of animals or researchers) and reliable (effective marking and mark retention for a minimum of 12 days). Handling and marking techniques may be inappropriate or cost prohibitive for short-term meso-mammal studies. These studies are often characterized by large numbers of simultaneous animal captures that must be documented and marked quickly with limited personnel, but do not require long-term or permanent markings (e.g., ear tags, branding). Meso-mammals are loosely defined as mammals larger than rodents (though sometimes including the largest rodents) up to roughly foxsized mammals (Vulpes spp.) [1]. Handling and marking meso-mammals is a time intensive, expensive, and potentially dangerous undertaking that requires solid justification and methodological scrutiny. Research has linked wildlife capture, handling, handling duration, and marking with increased mortality and behavioral changes in study subjects; thus highlighting the need for safe and simplified methods [2,3,4,5]. Accepted guidelines now mandate a well-structured protocol that places emphases on the welfare of the study species and the safety of the researcher [6,7]. Current and past researchers have followed a variety of methodologies to balance the needs of the project with the obligations of ethical research. Methodologies for handling and marking generally follow similar frameworks: 1) immobilization either through physical restraint or chemical immobilization, 2) internal marking (e.g., Passive Integrated Transponders [PIT]), and 3) external marking (temporary, semi-permanent, or permanent marking [8]). Many of these techniques are unnecessary or impractical for short-term meso-mammal studies. For example, chemical immobilization often requires large time investments (60120 minutes per animal is typical) as researchers must carefully monitor animals