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Abstract:
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Elephants are at the center of a highly intense debate over whether it is ethical to maintain them in western zoos for purposes of research, education or entertainment and zoos are charged with gathering data to identify the best practices for the animals. Some believe it is inhumane to keep elephants in small enclosures, in unrelated groups that are socially unstimulating, and in climates that are unnatural and harsh (Clubb and Mason, 2002). Others argue it is essential to have elephants in zoos because they play a crucial role in educating the public, as a research resource and as a hedge against extinction. One reason this debate is so polarized is that the criteria used for identifying poor animal welfare are usually subjective, based on anecdotes and lacking in scientific evidence. Scientists need to define objective methods to assess psychological states in animals, including elephants, and develop better tools to measure stress, pain and suffering (Brown et al., in press). This thesis is an attempt to provide scientific backing for elephant management decision making. Using fixed effects and dprobit statistical modeling, this thesis investigates the impact of two potential stressors, air pollution and average daily temperature, on indicators of elephant well-being reproductive ovarian activity and adrenal cortisol secretion. The data was compiled for this analysis and includes biological information obtained from the Smithsonian s Conservation and Research Center, and air pollution and temperature data from the Environmental Protection Agency and Resources for the Future. This fixed effects results reveals that daily PM2.5 and daily temperature impact daily cortisol concentrations and the dprobit results reveal that average daily temperatrue and cortisol concentrations impact the likelihood that an elephant is cyclicng of not. While few realistic policy implications can come from these results, as it is highly unlikely that animals will be relocated, zoos must take these biological and environmental factors into consideration when managing domestic elephants. Extensive further research is necessary to understand the complex mechanisms of stress, cyclicity and how they are impacted by the natural environment. |