AUTHORS: Tim Angelo A. Lopez, Becky Hansis-O'Neil, Aimee S. Dunlap
ABSTRACT: Tarantulas (Theraposidae) are predatory arachnids that can help control populations of herbivorous arthropods. We have been monitoring populations of the Missouri brown tarantula (Aphonopelma hentzi) in Missouri glades for three seasons and have questions about their welfare during these surveys. Unlike mammals, arthropods are not extensively researched and there only a few known facts about measuring their welfare. Managing stress for wild animals during field surveys is important for reducing the potential negative impacts of research. In mammals, increased heart rate is positively correlated with negative stress and eustress. Using the same logic, we hypothesized that heart rate could be used as a measurement of stress in wild tarantulas. To answer the question of whether heart rate would be a good measurement of stress in wild tarantulas we measured environmental factors that could significantly affect heart rate: body size, body surface temperature, and how long researchers interacted with the tarantula while trying to get them out of their burrows. Alongside the data gathered with these factors, we measured their heart rates using a veterinary doppler flow detector. We predicted that warmer temperatures, smaller animals, and more interaction would be positively associated with heart rate, with interaction time as the most predictive factor.
