Agonistic vocalization behaviour in the male ring-tailed lemur (Lemur catta)

Subordinate submissive responses are predicted by dominant behaviour in a cooperatively breeding fish

In complex social groups, animals rely on communication to facilitate priority access to resources and minimise the costs of conflict. Animals typically have more aggression signals than submission signals. However, some social species do show multiple submission signals, and the context in which these different signals are used is often not well understood. In the current study, we assessed agonistic interactions within groups of the cooperatively breeding daffodil cichlid fish (Neolamprologus pulcher) to investigate the relationship between the aggressive behaviours of the dominant breeding pair, and the submissive responses of the highest ranked subordinate within the group. Daffodil cichlids may respond to aggression by fleeing or by the production of either a tail quiver display or a head up display. Among the two submission signals, the tail quiver display was used more frequently in response to a threat display, while head up displays were produced approximately equally in response to both threat displays and overt aggression. An exaggerated version of the head up display was given more often in response to overt aggression, suggesting a graded submissive response both within and between the two submission signals. Within fish, the frequency of head up displays, but not tail quiver displays, correlated positively with the frequency of threat displays received. The current study helps us to better understand the use of submission signals in a highly social vertebrate and sheds light on submission as an understudied aspect of communication.

Food availability and male deference in the female-dominant ring-tailed lemur, Lemur catta

Female dominance, a trait common to some Malagasy lemurs, has been viewed as an adaptation that decreases intersexual feeding competition. A hypothesized relationship exists between male “deference” (male submission in the absence of female aggression) and food availability. Sauther (1993) suggested that male ring‐tailed lemurs at the Duke Lemur Center (Pereira et al., 1990) show more deference to females than do males in the wild owing to food abundance in captivity. To reexamine the link between food availability and male deference, we studied agonism and foraging in two nonwild ring‐tailed lemur (Lemur catta) populations: the Los Angeles Zoo and St. Catherines Island (SCI). On SCI, we collected data under two feeding conditions: Low Provisions (low food availability) and High Provisions (high food availability). As expected, male deference measures at our study sites were more similar to measures of deference from other studies of L. catta in captivity than in the wild. Additionally, the change at SCI from low to high food availability was associated with increased male deference to females. Interestingly, male proximity to females during foraging at this location did not notably change between the low to high food availability conditions, suggesting that males were food competitors of females just as often under both feeding conditions. The increase in male deference under conditions of high food availability on SCI was due to males withdrawing more rapidly from female approaches during agonistic interactions. Hence, where food is more abundant, male L. catta are more likely to show submission to females, which appears to be a self‐serving means of avoiding female aggression. Lemur males who are well‐fed appear less apt to risk female aggression to obtain resources than more nutritionally stressed males. Our results support the view of female dominance in lemurs as an adaptive evolutionary response to conditions of resource limitation.

As has been hypothesized for this female‐dominant species, male ring‐tailed lemurs act more submissively toward females under conditions of greater food abundance.

Males more rapidly withdraw from approaches by females under conditions of greater food availability.

Male “deference” to females in this species appears to be self‐serving avoidance of aggression by males, not investment in the female.