258 | Field Studies and Ethics greater than those experienced by captive animals, whose lives are already changed by the conditions under which they live This is so for different types of experiments that not have to involve trapping, handling, or marking individuals Consider experimental procedures that include visiting the home ranges, territories, or dens of animals, manipulating food supply, changing the size and composition of groups by removing or adding individuals, playing back vocalizations, depositing scents or odors, distorting body features, using dummies, and manipulating the gene pool All of these manipulations can change the behavior of individuals, including their movement patterns, how they utilize space, the amount of time they devote to various activities including hunting, antipredatory behavior, and various types of social interactions including caregiving, social play, and dominance interactions These changes can also influence the behavior of groups as a whole, including group hunting or foraging patterns, caregiving behavior, and dominance relationships, and also influence non-targeted individuals Lastly, there are individual differences in responses to human intrusion Field workers are becoming more sensitive to how their presence and methods of study influence the animals they are studying In a study evaluating long-term capture and handling effects on bears, wildlife researcher and veterinarian Marc Cattet and his colleagues discovered that we really not know much about bears, and we could be gathering spurious data in the absence of this knowledge Bears captured for research are more prone to injuries and death One bear suffered from such “a severe case of capture myopathy—a kind of muscle meltdown some captured animals suffer when they overexert themselves trying to escape— that its chest, bicep and pectoral muscles were pure white and as brittle as chalk.” Blood analyses of 127 grizzlies caught in Alberta between 1999 and 2005 revealed a significant number of those animals showed signs of serious stress for alarmingly long periods of time after they were processed and released back in the wild and about two-thirds of the animals caught in leg-hold traps suffered muscle injuries Animal activist and carnivore expert Camilla Fox has shown that there are extensive negative effects of trapping many different species that significantly compromise their wellbeing and thus their behavior, and produce misleading results Consider what she wrote about trapping aquatic animals in the Encyclopedia of Animal Behavior: Leghold and submarine traps act by restraining the animals underwater until they drown Most semi-aquatic animals, including mink, muskrat, and beaver, are adapted to diving by means of special oxygen conservation mechanisms The experience of drowning in a trap must be extremely terrifying: animals have displayed intense and violent struggling and were found to take up to four minutes for mink nine minutes for muskrat, and ten to thirteen minutes for beaver to die Mink have been shown to struggle frantically prior to loss of consciousness, an indication of extreme trauma Because most animals trapped in aquatic sets struggle for more than three minutes before losing consciousness,