Presentation Title

Gender and Dominance in Hamadryas Baboons and Ring-tailed Lemurs

Faculty Mentor

Dr. Lynne Miller

Start Date

23-11-2019 8:00 AM

End Date

23-11-2019 8:45 AM

Location

7

Session

poster 1

Type of Presentation

Poster

Subject Area

behavioral_social_sciences

Abstract

This study compared sex biases in the hierarchies of hamadryas baboons and ring-tailed lemurs by examining their intersexual aggressions. According to sexual selection theory, behavioral differences between the sexes are motivated by the resources needed for reproductive success: mammalian females require increased caloric intake to raise offspring, while males need only mates. Resource competition produces dominance hierarchies, where rank is often determined by sex. The literature suggests that for hamadryas baboons (who are male-bonded and male-dominant) and ring-tailed lemurs (who are the opposite), both the dominant and subordinate sexes gain fitness benefits from adhering to their “roles.” Hamadryas males gain mating access by kidnapping and herding a harem of females, who in turn gain protection and food access by following a male. Ring-tailed lemurs' seasonal environment sees females routinely displace males to gain sufficient food for childbearing, while males gain mating preference by deferring to females. This study was conducted at the San Diego Zoo, and the subjects were one group of 25 hamadryas baboons and one group of five ring-tailed lemurs. Hypothesis #1 was that if hamadryas baboons are male-dominant, then the majority of intersexual aggressive encounters will be initiated and “won” by males. Hypothesis #2 was that if ring-tailed lemurs are female-dominant, then the majority of intersexual aggressive encounters will be initiated and “won” by females. The data collected were 100% consistent with both predictions, as all intersexual aggressive encounters in the baboon group were initiated and “won” by males, and all intersexual aggression among the lemur group were initiated and “won” by females; additionally, the baboon males used aggression to control females, while the lemur females used aggression to control food, space, or to refuse mating. Such studies provide contextual clues for understanding dominance behaviors in humans, while also demonstrating the problematic behaviors that accompany gender inequality.

This document is currently not available here.

Share

COinS
 
Nov 23rd, 8:00 AM Nov 23rd, 8:45 AM

Gender and Dominance in Hamadryas Baboons and Ring-tailed Lemurs

7

This study compared sex biases in the hierarchies of hamadryas baboons and ring-tailed lemurs by examining their intersexual aggressions. According to sexual selection theory, behavioral differences between the sexes are motivated by the resources needed for reproductive success: mammalian females require increased caloric intake to raise offspring, while males need only mates. Resource competition produces dominance hierarchies, where rank is often determined by sex. The literature suggests that for hamadryas baboons (who are male-bonded and male-dominant) and ring-tailed lemurs (who are the opposite), both the dominant and subordinate sexes gain fitness benefits from adhering to their “roles.” Hamadryas males gain mating access by kidnapping and herding a harem of females, who in turn gain protection and food access by following a male. Ring-tailed lemurs' seasonal environment sees females routinely displace males to gain sufficient food for childbearing, while males gain mating preference by deferring to females. This study was conducted at the San Diego Zoo, and the subjects were one group of 25 hamadryas baboons and one group of five ring-tailed lemurs. Hypothesis #1 was that if hamadryas baboons are male-dominant, then the majority of intersexual aggressive encounters will be initiated and “won” by males. Hypothesis #2 was that if ring-tailed lemurs are female-dominant, then the majority of intersexual aggressive encounters will be initiated and “won” by females. The data collected were 100% consistent with both predictions, as all intersexual aggressive encounters in the baboon group were initiated and “won” by males, and all intersexual aggression among the lemur group were initiated and “won” by females; additionally, the baboon males used aggression to control females, while the lemur females used aggression to control food, space, or to refuse mating. Such studies provide contextual clues for understanding dominance behaviors in humans, while also demonstrating the problematic behaviors that accompany gender inequality.