Adaptive significance of sex ratio adjustment in semifree-ranging Barbary macaques (Macaca sylvanus) at Salem

1990 ◽  
Vol 27 (4) ◽  
Author(s):  
Andreas Paul ◽  
Jutta Kuester
Keyword(s):  
Sex Ratio ◽  
Adaptive Significance ◽  
Macaca Sylvanus ◽  
Barbary Macaques ◽  
Sex Ratio Adjustment

scholarly journals The Function of Mounts in Free-Ranging Barbary Macaques (Macaca sylvanus)

2021 ◽  
Author(s):  
Simone Anzá ◽  
Bonaventura Majolo ◽  
Federica Amici
Keyword(s):  
Social Relationships ◽  
Sexual Behaviors ◽  
Agonistic Behavior ◽  
Social Bond ◽  
Macaca Sylvanus ◽  
Barbary Macaques ◽  
The Social ◽  
Rank Difference ◽  
Free Ranging ◽  
The Relationship

AbstractGenerally, nonreproductive sex is thought to act as “social grease,” facilitating peaceful coexistence between subjects that lack close genetic ties. However, specifc nonreproductive sexual behaviors may fulfill different functions. With this study, we aimed to test whether nonreproductive mounts in Barbary macaques are used to 1) assert dominance, 2) reinforce social relationships, and/or 3) solve conflicts. We analyzed nonreproductive mounts (N = 236) and postmount behavior in both aggressive and nonaggressive contexts, in 118 individuals belonging to two semi-free-ranging groups at La Montagne des Singes (France). As predicted by the dominance assertion hypothesis, the probability to be the mounter increased with rank difference, especially in aggressive contexts (increasing from 0.066 to 0.797 in nonaggressive contexts, and from 0.011 to 0.969 in aggressive contexts, when the rank difference was minimal vs. maximal). The strength of the social bond did not significantly predict the proportion of mounts across dyads in nonaggressive contexts, providing no support for the relationship reinforcement hypothesis. Finally, in support of the conflict resolution hypothesis, when individuals engaged in postconflict mounts, 1) the probability of being involved in further aggression decreased from 0.825 to 0.517, while 2) the probability of being involved in grooming interactions with each other increased from 0.119 to 0.606. The strength of the social bond between former opponents had no significant effect on grooming occurrence and agonistic behavior after postconflict mounts. Overall, our findings suggest that nonreproductive mounts in Barbary macaques have different functions that are not affected by the strength of the social bond.

Reverse Sex-Ratio Adjustment in an Apparently Outbreeding Wasp, Bracon hebetor

Evolution ◽  
1989 ◽  
Vol 43 (2) ◽  
pp. 465 ◽  
Author(s):  
Karen S. Galloway ◽  
Bruce Grant
Keyword(s):  
Sex Ratio ◽  
Bracon Hebetor ◽  
Sex Ratio Adjustment

scholarly journals Primary sex ratio adjustment to experimentally reduced male UV attractiveness in blue tits

2006 ◽  
Vol 17 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Peter Korsten ◽  
C. (Kate) M. Lessells ◽  
A. Christa Mateman ◽  
Marco van der Velde ◽  
Jan Komdeur
Keyword(s):  
Sex Ratio ◽  
Primary Sex Ratio ◽  
Sex Ratio Adjustment ◽  
Blue Tits

Maternal discrimination of offspring vocalizations in Barbary macaques (Macaca sylvanus)

Primates ◽  
1998 ◽  
Vol 39 (2) ◽  
pp. 231-236 ◽  
Author(s):  
Kurt Hammerschmidt ◽  
Julia Fischer
Keyword(s):  
Macaca Sylvanus ◽  
Barbary Macaques

scholarly journals The comparative biology of second sex ratio evolution within a natural population of a parasitic wasp, Nasonia vitripennis.

Genetics ◽  
1990 ◽  
Vol 124 (2) ◽  
pp. 385-396 ◽  
Author(s):  
S H Orzack
Keyword(s):  
Sex Ratio ◽  
Parasitic Wasp ◽  
Comparative Biology ◽  
Significant Heterogeneity ◽  
Regression Analyses ◽  
Nasonia Vitripennis ◽  
Second Sex ◽  
Sex Ratio Adjustment ◽  
Optimality Models ◽  
Isofemale Strains

Abstract Correlation and regression analyses indicate that isofemale strains extracted from a population of the parasitic wasp, Nasonia vitripennis, differ in the fit of their second sex ratios (those produced in previously parasitized hosts) to the predictions of the theory of optimal facultative sex ratio adjustment. Under the theory's simple assumptions about population structure, there is significant heterogeneity of fitnesses among the isofemale strains. The reasons underlying these types of heterogeneity must be understood before we can make statements about the nature of sex ratio evolution in this species. These results suggest that comparative analyses are essential for testing the qualitative predictions of optimality models.

scholarly journals Is There a “Right” Side of Communicating Friendship? Lateralization of Social Interactions in Zoo Barbary macaques (Macaca sylvanus)

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3288
Author(s):  
Marzia Baldachini ◽  
Barbara Regaiolli ◽  
Miquel Llorente ◽  
David Riba ◽  
Caterina Spiezio
Keyword(s):  
Social Interaction ◽  
Social Interactions ◽  
Group Level ◽  
Social Ranking ◽  
Macaca Sylvanus ◽  
Barbary Macaques ◽  
Focal Animal ◽  
The Social ◽  
Side Preference ◽  
The Right

Social laterality in non-human primates has started to attract attention in recent years. The positioning of individuals during social interactions could possibly suggest the nature of a relationship and the social ranking of the subjects involved. The subjects of the present study were 12 adult Barbary macaques (Macaca sylvanus) housed in a zoological garden. We carried out fourteen 210-min video-recorded sessions and we used a focal animal sampling method to collect the position of the subjects during different social interactions. Data on the position of each macaque during three types of social interactions were collected (approach, proximity and affiliative contacts). Moreover, we focused on the outcomes of dyadic agonistic encounters to build the hierarchy of the colony. For each social interaction, two conditions were considered: the side preference (being kept on the left or on the right) and the sagittal preference (being kept in front or on the rear). Bouts of preference of different positions were collected for different social interactions (approach, proximity and contacts). No group-level side preferences were found for any social interaction, suggesting that both hemispheres might be complemental and balance each other during intraspecific communication. For the sagittal preference, we found a group-level bias for proximity, with macaques being kept in front rather than on the rear by close conspecifics. This might be due to the need to detect emotions and intentions of conspecifics. Moreover, high-ranking individuals are kept more frontally than on the rear when in proximity with other macaques. More studies are needed to better investigate social laterality, possibly distinguishing more categories of social interaction, and detecting other variables that might influence the positioning preferences.

scholarly journals Recruitment sex ratios in gray-tailed voles (Microtus canicaudus) in response to density, sex ratio, and season

2003 ◽  
Vol 81 (8) ◽  
pp. 1306-1311 ◽  
Author(s):  
Monica L Bond ◽  
Jerry O Wolff ◽  
Sven Krackow
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Resource Competition ◽  
Sex Ratios ◽  
Female Offspring ◽  
High Population ◽  
Reproductive Value ◽  
High Population Density ◽  
Adult Sex Ratio ◽  
Sex Ratio Adjustment

We tested predictions associated with three widely used hypotheses for facultative sex-ratio adjustment of vertebrates using eight enclosed populations of gray-tailed voles, Microtus canicaudus. These were (i) the population sex ratio hypothesis, which predicts that recruitment sex ratios should oppose adult sex-ratio skews, (ii) the local resource competition hypothesis, which predicts female-biased recruitment at low adult population density and male-biased recruitment at high population density, and (iii) the first cohort advantage hypothesis, which predicts that recruitment sex ratios should be female biased in the spring and male biased in the autumn. We monitored naturally increasing population densities with approximately equal adult sex ratios through the spring and summer and manipulated adult sex ratios in the autumn and measured subsequent sex ratios of recruits. We did not observe any significant sex-ratio adjustment in response to adult sex ratio or high population density; we did detect an influence of time within the breeding season, with more female offspring observed in the spring and more male offspring observed in the autumn. Significant seasonal increases in recruitment sex ratios indicate the capacity of female gray-tailed voles to manipulate their offspring sex ratios and suggest seasonal variation in the relative reproductive value of male and female offspring to be a regular phenomenon.

Sign in / Sign up

Export Citation Format

Share Document