scholarly journals An intergenerational androgenic mechanism of female intrasexual competition in the cooperatively breeding meerkat

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christine M. Drea ◽  
Charli S. Davies ◽  
Lydia K. Greene ◽  
Jessica Mitchell ◽  
Dimitri V. Blondel ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Intergenerational Transmission ◽  
Early Development ◽  
Cooperative Breeding ◽  
Intrasexual Competition ◽  
Systematic Investigation ◽  
Late Gestation ◽  
Suricata Suricatta ◽  
Cooperatively Breeding ◽  
Dominance Behaviour

AbstractFemale intrasexual competition can be intense in cooperatively breeding species, with some dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction or infanticide. In males, such tendencies bidirectionally link to testosterone, but in females, there has been little systematic investigation of androgen-mediated behaviour within and across generations. In 22 clans of wild meerkats (Suricata suricatta), we show that matriarchs 1) express peak androgen concentrations during late gestation, 2) when displaying peak feeding competition, dominance behaviour, and evictions, and 3) relative to subordinates, produce offspring that are more aggressive in early development. Late-gestation antiandrogen treatment of matriarchs 4) specifically reduces dominance behaviour, is associated with infrequent evictions, decreases social centrality within the clan, 5) increases aggression in cohabiting subordinate dams, and 6) reduces offspring aggression. These effects implicate androgen-mediated aggression in the operation of female sexual selection, and intergenerational transmission of masculinised phenotypes in the evolution of meerkat cooperative breeding.

scholarly journals A heritable androgenic mechanism of female intrasexual competition in cooperatively breeding meerkats

2021 ◽  
Author(s):  
Christine M. Drea ◽  
Charli S. Davies ◽  
Lydia K. Greene ◽  
Jessica Mitchell ◽  
Dimitri V. Blondel ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Intergenerational Transmission ◽  
Early Development ◽  
Cooperative Breeding ◽  
Intrasexual Competition ◽  
Systematic Investigation ◽  
Late Gestation ◽  
Suricata Suricatta ◽  
Cooperatively Breeding ◽  
Dominance Behaviour

AbstractFemale intrasexual competition can be intense in cooperatively breeding species, with the dominant breeder or matriarch limiting reproduction in subordinates via aggression, eviction or infanticide. In males, these tendencies bidirectionally link to testosterone, but in females, there has been no systematic investigation of androgen-mediated behaviour within and across generations. In 22 wild meerkat (Suricata suricatta) clans, we show that matriarchs 1) express peak androgen concentrations during late gestation, 2) when displaying peak feeding competition, dominance, and evictions, and 3) relative to subordinates, produce offspring that are more aggressive in early development. Late-gestation, antiandrogen treatment of matriarchs 4) reduced their dominance behaviour, was associated with infrequent evictions, decreased social centrality within the clan, 5) increased aggression in cohabiting subordinate dams, and 6) reduced their offspring’s aggression. These effects implicate androgen-mediated aggression in the operation of female sexual selection, and intergenerational transmission of ‘masculinised’ phenotypes in the evolution of meerkat cooperative breeding.

scholarly journals Proactive prosociality in a cooperatively breeding corvid, the azure-winged magpie ( Cyanopica cyana )

2016 ◽  
Vol 12 (10) ◽  
pp. 20160649 ◽  
Author(s):  
Lisa Horn ◽  
Clara Scheer ◽  
Thomas Bugnyar ◽  
Jorg J. M. Massen
Keyword(s):  
Cooperative Breeding ◽  
Cooperatively Breeding ◽  
Group Members ◽  
Over Time

One of the contemporary hypotheses concerning the evolution of human altruism is the cooperative breeding hypothesis (CBH) which has recently been tested in non-human primates. Using a similar paradigm, we investigated prosociality in a cooperatively breeding corvid, the azure-winged magpie. We found that the magpies delivered food to their group members at high rates, and unlike other corvids, they did so without any cues provided by others. In two control conditions, the magpies stopped participating over time, indicating that they learned to discriminate prosocial tests from controls. Azure-winged magpies are thus the first birds that experimentally show proactive prosociality. Our findings are in line with the CBH; however, additional corvid species need to be tested in this promising paradigm.

scholarly journals Mapping early environment using communication deviance: A longitudinal study of maternal sensitivity toward 6-month-old children

2018 ◽  
Vol 31 (04) ◽  
pp. 1501-1511
Author(s):  
Paulo de Sousa ◽  
William Sellwood ◽  
Kirsten Fien ◽  
Helen Sharp ◽  
Andrew Pickles ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Intergenerational Transmission ◽  
Early Development ◽  
Maternal Age ◽  
Maternal Sensitivity ◽  
Focus Of Attention ◽  
Parental Behaviors ◽  
Early Environment ◽  
Infant Distress ◽  
Communication Deviance

AbstractCommunication deviance (CD) reflects features of the content or manner of a person's speech that may confuse the listener and inhibit the establishment of a shared focus of attention. The construct was developed in the context of the study of familial risks for psychosis based on hypotheses regarding its effects during childhood. It is not known whether parental CD is associated with nonverbal parental behaviors that may be important in early development. This study explored the association between CD in a cohort of mothers (n = 287) at 32 weeks gestation and maternal sensitivity with infants at 29 weeks in a standard play procedure. Maternal CD predicted lower overall maternal sensitivity (B = –.385; p < .001), and the effect was somewhat greater for sensitivity to infant distress (B = –.514; p < .001) than for sensitivity to nondistress (B = –.311; p < .01). After controlling for maternal age, IQ and depression, and for socioeconomic deprivation, the associations with overall sensitivity and sensitivity to distress remained significant. The findings provide new pointers to intergenerational transmission of vulnerability involving processes implicated in both verbal and nonverbal parental behaviors.

scholarly journals Intergroup aggression in meerkats

2019 ◽  
Vol 286 (1917) ◽  
pp. 20191993 ◽  
Author(s):  
Mark Dyble ◽  
Thomas M. Houslay ◽  
Marta B. Manser ◽  
Tim Clutton-Brock
Keyword(s):  
Genetic Relatedness ◽  
Group Living ◽  
Lethal Violence ◽  
Suricata Suricatta ◽  
Group Cooperation ◽  
Fitness Consequences ◽  
Cooperatively Breeding ◽  
Adult Sex Ratio ◽  
Violent Conflicts ◽  
Large Groups

Violent conflicts between groups have been observed among many species of group living mammals and can have important fitness consequences, with individuals being injured or killed and with losing groups surrendering territory. Here, we explore between-group conflict among meerkats ( Suricata suricatta ), a highly social and cooperatively breeding mongoose. We show that interactions between meerkat groups are frequently aggressive and sometimes escalate to fighting and lethal violence and that these interactions have consequences for group territories, with losing groups moving to sleeping burrows closer to the centre of their territories following an intergroup interaction and with winning groups moving further away. We find that larger groups and groups with pups are significantly more likely to win contests, but that the location of the contest, adult sex ratio, and mean within-group genetic relatedness do not predict contest outcome. Our results suggest that intergroup competition may be a major selective force among meerkats, reinforcing the success of large groups and increasing the vulnerability of small groups to extinction. The presence of both within-group cooperation and between-group hostility in meerkats make them a valuable point of comparison in attempts to understand the ecological and evolutionary roots of human warfare.

Female Virtual Intrasexual Competition and Its Consequences

2016 ◽  
Author(s):  
Jose C. Yong ◽  
Norman P. Li ◽  
Katherine A. Valentine ◽  
April R. Smith
Keyword(s):  
Sexual Selection ◽  
Physical Attractiveness ◽  
Deep Level ◽  
Intrasexual Competition ◽  
Same Sex ◽  
Short Term ◽  
Psychological States ◽  
Psychological Mechanisms ◽  
Real People ◽  
Key Dimensions

Intrasexual competition is a key component of sexual selection. Evolutionarily, women compete for access to and retention of mates on key dimensions that men have evolved to value and prioritize in their long- and short-term mates, in particular physical attractiveness. Such competition evolved to be adaptive in ancestral environments as the perceived competition consisted of real individuals. However, underlying psychological mechanisms for competition are excessively triggered and more continuously engaged in modern environments, because these psychological mechanisms for social comparison and competition, at a deep level, do not differentiate between real people and imagined intrasexual competition in the form of mass media images. Utilizing an evolutionary mismatch framework, this chapter explores ways that women are psychologically influenced by the pervasive presence of virtual same-sex competitors for mates. Various negative psychological states in modern societies (e.g., depression, eating disorders) may be linked to virtual intrasexual competition.

scholarly journals Fine-Scale Population Structure but Limited Genetic Differentiation in a Cooperatively Breeding Paper Wasp

2020 ◽  
Vol 12 (5) ◽  
pp. 701-714 ◽  
Author(s):  
Sarah E Bluher ◽  
Sara E Miller ◽  
Michael J Sheehan
Keyword(s):  
Population Structure ◽  
Genetic Differentiation ◽  
Cooperative Breeding ◽  
Isolation By Distance ◽  
Spatial Scales ◽  
Paper Wasp ◽  
Paper Wasps ◽  
Natal Philopatry ◽  
Continental Scale ◽  
Cooperatively Breeding

Abstract Relatively little is known about the processes shaping population structure in cooperatively breeding insect species, despite the long-hypothesized importance of population structure in shaping patterns of cooperative breeding. Polistes paper wasps are primitively eusocial insects, with a cooperative breeding system in which females often found nests in cooperative associations. Prior mark-recapture studies of Polistes have documented extreme female philopatry, although genetic studies frequently fail to detect the strong population structure expected for highly philopatric species. Together these findings have led to lack of consensus on the degree of dispersal and population structure in these species. This study assessed population structure of female Polistes fuscatus wasps at three scales: within a single site, throughout Central New York, and across the Northeastern United States. Patterns of spatial genetic clustering and isolation by distance were observed in nuclear and mitochondrial genomes at the continental scale. Remarkably, population structure was evident even at fine spatial scales within a single collection site. However, P. fuscatus had low levels of genetic differentiation across long distances. These results suggest that P. fuscatus wasps may employ multiple dispersal strategies, including extreme natal philopatry as well as longer-distance dispersal. We observed greater genetic differentiation in mitochondrial genes than in the nuclear genome, indicative of increased dispersal distances in males. Our findings support the hypothesis that limited female dispersal contributes toward population structure in paper wasps.

Band Structure and Failures of Reproductive Suppression in a Cooperatively Breeding Carnivore, the Slender-Tailed Meerkat (Suricata Suricatta)

Behaviour ◽  
1997 ◽  
Vol 134 (11-12) ◽  
pp. 827-848 ◽  
Author(s):  
David W. Macdonald ◽  
Sean P. Doolan
Keyword(s):  
Band Structure ◽  
Adult Males ◽  
High Turnover ◽  
Reproductive Suppression ◽  
Suricata Suricatta ◽  
Adult Females ◽  
Reproductive Female ◽  
Band Size ◽  
Cooperatively Breeding ◽  
Reproductive Females

AbstractThe extent to which band structure influences the distribution of breeding activity is unknown for the slender-tailed meerkat Suricata suricatta, a cooperatively breeding mongoose. Here we present the residence histories of three focal bands monitored over ten band-years in the southwestern Kalahari, with less detailed data derived from non-focal bands for a further 20 band-years. Mean total band size early in the breeding season was 10, and mean size excluding juveniles was 6.7. Despite a tendency towards females among juveniles, and males among yearlings and adults, sex ratios within each age class did not significantly deviate from unity, but at the population level there were significantly more adult males than reproductive females. A large proportion (71.6%) of adult females bred, and failures of reproductive suppression occurred in 40% of band years. This incidence was high in all years and was not obviously related to environmental conditions. Bands with more than one reproductive female contained significantly more adults and adult females than bands with only a single reproductive female. There was a strong correlation between numbers of reproductive females and numbers of adult females in a band. Most (68%) subordinate females which bred were aged three years or more. Reproductive competition was strong and there was a negative correlation between numbers of adult females, breeding females or adult males and per capita juvenile production. Meerkat bands are unusual among cooperative breeders because many individuals were non-kin and the relative constancy in band size within and between years masked a high turnover of membership: all animals of known origin aged three years or older, were immigrants, although philopatry was commoner among younger animals. Our data show that meerkats employ a range of reproductive strategies: bands exhibiting a spectrum of reproductive suppression coexist, and individuals respond to the opportunities afforded by their social environments.

scholarly journals Adult sex ratios and their implications for cooperative breeding in birds

2017 ◽  
Vol 372 (1729) ◽  
pp. 20160322 ◽  
Author(s):  
Jan Komdeur ◽  
Tamás Székely ◽  
Xiaoyan Long ◽  
Sjouke A. Kingma
Keyword(s):  
Sex Ratio ◽  
Cooperative Breeding ◽  
Adult Population ◽  
Sex Ratios ◽  
Bird Species ◽  
Dispersal Distance ◽  
Sex Bias ◽  
Wide Range ◽  
Cooperatively Breeding ◽  
Using Data

Cooperative breeding is a form of breeding system where in addition to a core breeding pair, one or more usually non-breeding individuals provide offspring care. Cooperative breeding is widespread in birds, but its origin and maintenance in contemporary populations are debated. Although deviations in adult sex ratio (ASR, the proportion of males in the adult population) have been hypothesized to influence the occurrence of cooperative breeding because of the resulting surplus of one sex and limited availability of breeding partners, this hypothesis has not been tested across a wide range of taxa. By using data from 188 bird species and phylogenetically controlled analyses, we show that cooperatively breeding species have more male-biased ASRs than non-cooperative species. Importantly, ASR predicts helper sex ratio: in species with more male-biased ASR, helper sex ratio is also more male biased. We also show that offspring sex ratios do not predict ASRs, so that the skewed ASRs emerge during the period when individuals aim to obtain a breeding position or later during adulthood. In line with this result, we found that ASR (among both cooperatively and non-cooperatively breeding species) is inversely related to sex bias in dispersal distance, suggesting that the cost of dispersal is more severe for the further-dispersing sex. As females usually disperse further in birds, this explains the generally male-biased ASR, and in combination with benefits of philopatry for males, this probably explains why ASR is more biased in cooperatively breeding species. Taken together, our results suggest that a sex bias in helping in cooperatively breeding species relates to biased ASRs. We propose that this relationship is driven by sex-specific costs and benefits of dispersal and helping, as well as other demographic factors. Future phylogenetic comparative and experimental work is needed to establish how this relationship emerges. This article is part of the themed issue ‘Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies’.

scholarly journals The determinants of dominance relationships among subordinate females in the cooperatively breeding meerkat

Behaviour ◽  
2014 ◽  
Vol 151 (1) ◽  
pp. 89-102 ◽  
Author(s):  
N.K. Thavarajah ◽  
M. Fenkes ◽  
T.H. Clutton-Brock
Keyword(s):  
Reproductive Success ◽  
Competitive Advantage ◽  
Reproductive Skew ◽  
Breeding Female ◽  
Suricata Suricatta ◽  
Dominance Relationships ◽  
Dominance Structure ◽  
Starting Point ◽  
Cooperatively Breeding ◽  
Group Members

In cooperatively breeding species with high reproductive skew, a single breeding female is dominant to all other group members, but it is not yet known if there are consistent dominance relationships among subordinates. In this study on meerkats (Suricata suricatta), we used naturally observed dominance assertions and submissive interactions within dyads of subordinate females to investigate: (i) whether or not a dominance structure exists among them and what factors influence dominance relationships; and (ii) how dominance may influence the future reproductive success of subordinate females. Our study indicates that superiority in age and weight provide a competitive advantage during conflicts among subordinate females and that females who consistently dominate in these contests are subsequently more likely to attain a dominant breeding position. This provides a starting point for further investigations into dominance structure among subordinates in meerkat societies and other cooperative breeders.

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