Essay --

In the world of animals, those at the top of a dominance hierarchy are more beneficial than low-ranking animals1. However, the costs associated with being at the top of a hierarchy remain controversial1. Different studies reported contradictory findings on whether dominant or subordinate animals experienced greater stress levels2-3. Furthermore, Sapolsky4-5 suggested that hierarchy stability could potentially influence the stress levels experienced by high-ranking olive baboons. Given the results from previous literatures, Gesquiere et al.1 created a research question asking how do male savannah baboons (Papio cynocephalus) respond to rank-related stress during stable and unstable hierarchy? They hypothesized that high-ranking males would exhibit higher levels of testosterone and glucocorticoid only when a hierarchy was unstable1. From this hypothesis, they predicted that during the month with unstable hierarchy, the high-ranking male savannah baboons would exhibit greater fecal testosterone (fT) and fecal glucocorticoid (fGC) levels than other males within the hierarchy; however, such phenomenon would not be observed during the month with a stable hierarchy1. To test this prediction, they conducted a long-term study on wild savannah baboons in Amboseli, Kenya1. Over a 9-year period, ecological, behavioral and physiological data including fT and fGC were collected monthly from 125 adult males1. General linear mixed models (GLMMs) were used to predict the de pendent variables, fT and fGC, based on predictor variables including individual rank, hierarchy stability, and an interaction between the two1. Gesquiere et al.1 defined a stable hierarchy as the month when the males with the highest 3 ranking were the same as those in the p... ...nction9. However, a parasitic load in an individual was not only associated the individual immune function but also with how likely it is exposed to the infectious agents9. Hence, parasitic load would not be an accurate indicator of individual immune function9. In contrast, leukocyte count, which was used in another study to investigate immune function, could serve as a better indicator than parasitic load10. In conclusion, going beyond the study conducted by Gesquiere et al., the proposed experiment is significant because it can provide more insights into whether or not suppressed immune function is another potential cost for being at the top of the dominance hierarchy. Also, using leukocyte count as an indicator of immune function instead of parasitic load, the proposed experiment can further elucidate the contradicting findings reported by different literatures. Essay -- In the world of animals, those at the top of a dominance hierarchy are more beneficial than low-ranking animals1. However, the costs associated with being at the top of a hierarchy remain controversial1. Different studies reported contradictory findings on whether dominant or subordinate animals experienced greater stress levels2-3. Furthermore, Sapolsky4-5 suggested that hierarchy stability could potentially influence the stress levels experienced by high-ranking olive baboons. Given the results from previous literatures, Gesquiere et al.1 created a research question asking how do male savannah baboons (Papio cynocephalus) respond to rank-related stress during stable and unstable hierarchy? They hypothesized that high-ranking males would exhibit higher levels of testosterone and glucocorticoid only when a hierarchy was unstable1. From this hypothesis, they predicted that during the month with unstable hierarchy, the high-ranking male savannah baboons would exhibit greater fecal testosterone (fT) and fecal glucocorticoid (fGC) levels than other males within the hierarchy; however, such phenomenon would not be observed during the month with a stable hierarchy1. To test this prediction, they conducted a long-term study on wild savannah baboons in Amboseli, Kenya1. Over a 9-year period, ecological, behavioral and physiological data including fT and fGC were collected monthly from 125 adult males1. General linear mixed models (GLMMs) were used to predict the de pendent variables, fT and fGC, based on predictor variables including individual rank, hierarchy stability, and an interaction between the two1. Gesquiere et al.1 defined a stable hierarchy as the month when the males with the highest 3 ranking were the same as those in the p... ...nction9. However, a parasitic load in an individual was not only associated the individual immune function but also with how likely it is exposed to the infectious agents9. Hence, parasitic load would not be an accurate indicator of individual immune function9. In contrast, leukocyte count, which was used in another study to investigate immune function, could serve as a better indicator than parasitic load10. In conclusion, going beyond the study conducted by Gesquiere et al., the proposed experiment is significant because it can provide more insights into whether or not suppressed immune function is another potential cost for being at the top of the dominance hierarchy. Also, using leukocyte count as an indicator of immune function instead of parasitic load, the proposed experiment can further elucidate the contradicting findings reported by different literatures.