Fontani, Sara, Stefano Vaglio, Valentina Beghelli, Michela Mattioli, Silvia Bacci & Pier Attilio Accorsi (2014) Fecal Concentrations of Cortisol, Testosterone, and Progesterone in Cotton-Top Tamarins Housed in Different Zoological Parks: Relationship Among Physiological Data, Environmental Conditions, and Behavioral Patterns, Journal of Applied Animal Welfare Science, 17:3, 228-252.
This study examined 3 captive groups of cotton-top tamarins housed in different zoos. The researchers did ethological observations for one year and collected fecal samples to measure stress as unobtrusively as possible. They tested the cortisol, testosterone, and progesterone levels of the three sets of tamarins to see if these were correlated with the stress levels and aggressive behaviors in the animals, and if so, how this occurs. The results showed a strong correlation between the hormones and the behaviors of the tamarins. High cortisol levels were present in the fecal sample when tamarins exhibited aggressive behaviors and stress. The authors show that the stress occurred when the tamarins struggled to create a hierarchy within the colony or when there was social instability within the colony. They also observed that aggressive behavior occurred when the hierarchy was upset. High testosterone levels were also found in one female tamarin that was often isolated, leading the researchers to conclude that isolation can cause stress and therefore an increase in testosterone. The study found that when stress and aggression occurs, progesterone levels decrease. However, progesterone levels can be related to aggression amongst the female tamarins due to their reproductive cycle. Progesterone was related to affiliate behaviors, which are considered more feminine, which may account for why the castrated males had high levels of progesterone than those that were not castrated. The implication of this study was that the most stress experienced by these animals seemed to occur when their own social structure was disrupted.
Main Points, Potential Applications, and Future Research:
- The levels of cortisol and testosterone strongly correlate with the behaviors of tamarins, specifically aggressive behaviors.
- Aggressive behaviors are often the result of instability in the social hierarchy.
- The hormones help to indicate stress levels and the adaptability to the environment of the animals.
- The role progesterone as an indicator of stress in tamarins can be further studied.
Summary by Rachel Cahill