Social status does not predict corticosteroid levels in postdispersal male spotted hyenas

Abstract

In social species with low rates of direct male competition levels of corticosteroids should not correlate with social status. Male spotted hyenas acquire social status by observing strict queuing conventions over many years, and thus levels of male–male aggression are low, and male social status and tenure are closely correlated. In this study, we investigated whether the low rate of direct male competition in spotted hyenas was reflected in fecal corticosteroid levels of adult males in the Serengeti National Park. Also, interactions with dominant females may influence corticosteroid levels of males, and it has been suggested recently that males with a long tenure (high rank) are more stressed by females than males with a short tenure (low rank). We tested whether there is a difference in the likelihood of being aggressively challenged by dominant females between long-tenured and short-tenured males. Short-tenured males were more likely to elicit an aggressive response by females than long-tenured males, but previous work suggests that they also interacted less frequently with females, thus avoiding putting themselves in a potentially stressful situation. Thus, as expected, the comparison of males in three different clans revealed no correlation between social status or tenure and fecal corticosteroid levels. However, males of the largest clan had the highest levels of fecal corticosteroids, possibly reflecting higher rates of social interactions in larger clans.