Researchers in Portugal (Nuno Santos et al., 2017) studied the live-capture of wolves for ecological research to assess the animals’ stress response and the potential benefits of reducing the length of time they are held in traps. Over a six-year period, 15 wolves were captured in Belisle foot snares. The traps were checked twice daily so animals were not held longer than 12 hours. In addition, during the last two years of the study, remote satellite transmitters that signaled when a trap was tripped were used to further reduce the time the wolves spent in the snares.
Radiotelemetry on the wolves after their release revealed that they traveled significantly shorter distances on the first days after having been snared, and that the longer they were snared the longer it took them to get back to traveling greater distances. The study concluded that use of transmitters to shorten the time in snares “significantly reduces several physiological and behavioral mediators of stress.”