scholarly journals Competition Drives Group Formation and Reduces Within Nest Relatedness in a Facultatively Social Carpenter Bee

2021 ◽  
Vol 9 ◽  
Author(s):  
Jess L. Vickruck ◽  
Miriam H. Richards
Keyword(s):  
Resource Sharing ◽  
Resource Competition ◽  
Group Formation ◽  
Social Groups ◽  
Fitness Costs ◽  
Short Supply ◽  
Carpenter Bee ◽  
Direct Fitness ◽  
Indirect Fitness ◽  
Almost All

Animals respond to competition among kin for critical breeding resources in two ways: avoidance of direct fitness costs via dispersal of siblings to breed separately, and formation of kin-based societies in which subordinates offset direct fitness costs of breeding competition via altruism and increased indirect fitness. In the facultatively social eastern carpenter bee, nests are a critical breeding resource in perpetually short supply, leading to strong competition among females. Observations of individually marked and genotyped females in conditions of high and low resource competition demonstrate that competition leads to resource sharing and group nesting. However, in contrast to almost all known animal societies, females avoid nesting with relatives, and disperse from their natal nests to join social groups of non-relatives. This is the first example of a structured insect society with cooperation nestmates, the majority of which are unrelated; thus cooperation is more likely based on selection for direct, rather than indirect fitness. By forming social groups of non-kin, females avoid the indirect fitness costs of kin competition among sisters, yet increase their chances of successful reproduction, and thus direct fitness, when forming colonies of non-relatives.

scholarly journals An animal society based on kin competition, not kin cooperation

2019 ◽  
Author(s):  
Jessica L. Vickruck ◽  
Miriam H. Richards
Keyword(s):  
Social Groups ◽  
Fitness Costs ◽  
Short Supply ◽  
Animal Society ◽  
Kin Competition ◽  
Direct Fitness ◽  
Carpenter Bees ◽  
Indirect Fitness ◽  
Strong Competition ◽  
Breeding Resources

AbstractAnimals respond to competition among kin for critical breeding resources in two ways: avoidance of direct fitness costs via dispersal of siblings to breed separately, and formation of kin-based societies in which subordinates offset direct fitness costs of breeding competition via altruism and increased indirect fitness. Here we provide the first evidence that kin competition can promote the evolution of societies based on non-kin cooperation. For eastern carpenter bees, nests are a critical breeding resource in perpetually short supply, leading to strong competition among females. Observations of individually marked and genotyped females demonstrate that sisters disperse from their natal nests to join social groups of nonrelatives. By forming social groups of non-kin, females increase their chances of successful reproduction, while avoiding the indirect fitness cost of competition among sisters.One Sentence SummaryWe describe the first known example of an animal society based on avoidance of kin competition rather than on promotion of kin cooperation.

scholarly journals Fluid Nest Membership Drives Variable Relatedness in Groups of a Facultatively Social Bee

2021 ◽  
Vol 9 ◽  
Author(s):  
Madeleine M. Ostwald ◽  
Romain A. Dahan ◽  
Zachary Shaffer ◽  
Jennifer H. Fewell
Keyword(s):  
Group Composition ◽  
Group Formation ◽  
Group Living ◽  
Migration Behavior ◽  
Ecological Constraints ◽  
Carpenter Bee ◽  
Indirect Fitness ◽  
Fitness Benefits ◽  
Nesting Aggregation ◽  
Social Bee

Kin selection theory has dominated our understanding of the evolution of group living. However, many animal groups form among non-relatives, which gain no indirect fitness benefits from cooperating with nestmates. In this study, we characterized the relatedness and inter-nest migration behavior of the facultatively social carpenter bee, Xylocopa sonorina. Nesting constraints due to costly nest construction in this species give rise to intense intraspecific competition over access to existing nests. We used mark-recapture techniques to characterize patterns of dispersal and nest relocation within a nesting aggregation of spatially clustered nests. Two-thirds of bees relocated at least once during the reproductive season, likely to seek reproductive opportunities in another nest. This fluid nest membership creates opportunities for association among non-relatives. To assess the effects of this dynamic nesting behavior on group relatedness, we used microsatellite analysis to estimate relative relatedness within and between nests in the aggregation. We found that relatedness was variable across sampling years, but that in many cases nestmates were no more related to one another than they were to non-nestmate bees in the population. Together, these results suggest that group composition in X. sonorina may result from strategies to maximize direct fitness. This study supports the hypothesis that factors beyond kinship, such as ecological constraints, are likely to drive group formation in this species.

scholarly journals Reproductive traits and floral visitors of Aechmea distichantha plants growing in different habitats of a South American xerophytic forest

Rodriguésia ◽  
2018 ◽  
Vol 69 (2) ◽  
pp. 385-396 ◽  
Author(s):  
Rodrigo M. Freire ◽  
Ignacio M. Barberis ◽  
José L. Vesprini
Keyword(s):  
Reproductive Traits ◽  
Climatic Conditions ◽  
Similar Proportion ◽  
South American ◽  
The Sun ◽  
Carpenter Bee ◽  
Carpenter Bees ◽  
Vegetative Traits ◽  
Floral Visitors ◽  
Almost All

Abstract Aechmea distichantha, a widely-distributed facultative epiphytic bromeliad species, is present from rainforests to xerophytic forests. At its southernmost distribution (Humid Chaco) it grows in the understory and forest edges. This animal-pollinated bromeliad shows high phenotypic plasticity on its vegetative traits, but there is no information about plasticity on its reproductive traits. Infructescences from shade plants were heavier, had longer rachis, more spikelets, higher number of fruits/spikelet and higher number of seeds/fruit than those from sun plants, but they presented similar number of open flowers. The number of visitation events was similar in both habitats, but more flowers were visited in the sun than in the shade. Flowers were visited by seven species (six insects and one hummingbird). In the sun, the carpenter bee was the most frequent visitor and visited almost all flowers, whereas in the shade different species of visitors attained similar proportion of visits and number of visited flowers. Despite visitation events were similar in both habitats, plants growing in the shade set more seeds/fruit than plants growing in the sun. The higher proportion of visits accomplished by carpenter bees compared to hummingbirds is probably a consequence of the climatic conditions in the austral location of these populations.

Age-dependent fitness costs of alarm signaling in aphids

2003 ◽  
Vol 81 (5) ◽  
pp. 757-762 ◽  
Author(s):  
Edward B Mondor ◽  
Bernard D Roitberg
Keyword(s):  
Alarm Pheromone ◽  
Fourth Instar ◽  
Fitness Cost ◽  
Fitness Costs ◽  
Alarm Signal ◽  
Offspring Production ◽  
Direct Fitness ◽  
Alarm Signaling ◽  
Pea Aphids ◽  
Age Dependent

For an alarm signal to evolve, the benefits to the signaler must outweigh the costs of sending the signal. Research has largely focused on the benefits of alarm signaling, and the costs to an organism of sending an alarm signal are not well known. When attacked by a predator, aphids secrete cornicle droplets, containing an alarm pheromone, for individual protection and to warn clonemates. As aphid alarm pheromone is synthesized de novo in a feedback loop with juvenile hormone, we hypothesized that the secretion of cornicle droplets may result in a direct fitness cost to the emitter. We show that the secretion of a single cornicle droplet by pre-reproductive (third- and fourth-instar) pea aphids, Acyrthosiphon pisum, directly altered the timing and number of offspring produced. Third-instar pea aphids delayed offspring production but produced more offspring overall than non-secreting aphids, demonstrating a life-history shift but no significant fitness cost of droplet secretion. Fourth-instar pea aphids also delayed offspring production but produced the same number of offspring as non-secretors, resulting in a direct fitness cost of droplet secretion. Offspring production by adult, reproductive pea aphids that secreted a cornicle droplet did not differ from that of non-secretors. Thus, the fitness costs of secreting cornicle droplets containing an alarm signal are age-dependent.

scholarly journals Males harm females less when competing with familiar relatives

2017 ◽  
Vol 284 (1867) ◽  
pp. 20171984 ◽  
Author(s):  
Samuel J. Lymbery ◽  
Leigh W. Simmons
Keyword(s):  
Egg Production ◽  
Callosobruchus Maculatus ◽  
Genetic Relatedness ◽  
Inclusive Fitness ◽  
Fitness Costs ◽  
Offspring Production ◽  
Social Familiarity ◽  
Indirect Fitness ◽  
Opposite Sex ◽  
Female Lifespan

Sexual conflict occurs when reproductive partners have different fitness optima, and can lead to the evolution of traits in one sex that inflict fitness costs on the opposite sex. Recently, it has been proposed that antagonism by males towards females should be reduced when they compete with relatives, because reducing the future productivity of a female would result in an indirect fitness cost for a harmful male. We tested this prediction in the seed beetle Callosobruchus maculatus , the males of which harm females with genital spines and pre-copulatory harassment. We compared lifespan, lifetime egg production and lifetime offspring production among females housed with groups of males that varied in their familiarity and relatedness. Females produced significantly more eggs and offspring when grouped with males who were both related and familiar to each other. There was no effect of male relatedness or familiarity on female lifespan. Our results suggest that males plastically adjust their harmfulness towards females in response to changes in inclusive fitness payoffs, and that in this species both genetic relatedness and social familiarity mediate this effect.

Niemcy w Warszawie po raz pierwszy. Nowsze opracowania na temat niemieckiej okupacji 1915–1918

2019 ◽  
Vol 63 (1 (464)) ◽  
pp. 129-140
Author(s):  
Maciej Górny
Keyword(s):  
World War Ii ◽  
World War I ◽  
Social Life ◽  
Social Groups ◽  
Point Of View ◽  
World War ◽  
Proper Place ◽  
The Many ◽  
Almost All ◽  
The Great War

The article describes the newer works devoted to the occupation of Polish lands, especially of Warsaw during World War I. Recently, this subject, so far neglected, has drown the attention of numerous scientists, both from Poland and from abroad. Their point of view is different not only from the older perspectives, but also from the perspectives of slightly newer works on the other occupied areas and emphasizing the connection between the experience of the Great War and genocide during World War II. In the most precious fragments, the new historiography gives a very wide image of social life, in which the proper place is taken by previously marginalised social groups. Differently from the older works, the policy of the occupants on the Polish lands is not treated only as a unilateral dictate, but rather as a dynamic process of negotiation, in which the strength and position of each of the (many) sides has been changed. And, this change is accompanied by the new arrangements concerning almost all aspects of the German policy and the conditions of living during World War I.

Male Sexual Orientation and Avuncularity in Canada: Implications for the Kin Selection Hypothesis

2011 ◽  
Vol 11 (3-4) ◽  
pp. 339-352 ◽  
Author(s):  
Deanna L. Forrester ◽  
Doug P. VanderLaan ◽  
Paul L. Vasey ◽  
Jessica L. Parker
Keyword(s):  
Kin Selection ◽  
Sexual Attraction ◽  
Altruistic Behavior ◽  
Adult Males ◽  
Social Tolerance ◽  
Fitness Costs ◽  
Future Directions ◽  
Selection Hypothesis ◽  
Indirect Fitness ◽  
Male Sexual Orientation

AbstractAndrophilia refers to sexual attraction and arousal to adult males, whereas gynephilia refers to sexual attraction and arousal to adult females. The Kin Selection Hypothesis (KSH) posits that genes for male androphilia can persist if androphilic males offset the fitness costs of not reproducing directly by enhancing indirect fitness. In theory, by directing altruistic behavior toward kin, androphilic males can increase the reproduction of kin, thereby enhancing indirect fitness. Evidence supporting the KSH has been documented in Samoa. Samoan transgendered, androphilic males, known locally as fa’afafine, are socially accepted by the majority of Samoans. In contrast, no supportive evidence has been garnered from other cultures (i.e., USA, UK, Japan) that are characterized by less social tolerance toward male androphiles. Tests of the KSH in Canada might be more likely to yield findings consistent with Samoa because Canadian social and political attitudes toward male androphiles are markedly more tolerant and accepting. Here, we compared the willingness of Canadian androphilic men, gynephilic men, and androphilic women to invest in nieces and nephews as well as in non-kin children. Consistent with the KSH and findings from Samoa, androphilic men exhibited a significantly greater cognitive dissociation between altruistic tendencies directed toward kin versus non-kin children relative to gynephilic men and androphilic women. The present study, therefore, provides some tentative support for the KSH from a culture other than Samoa. Findings and future directions for research are considered within the context of the existing cross-cultural literature.

scholarly journals POTENTIAL OF MULTI-TEMPORAL UAV-BORNE LIDAR IN ASSESSING EFFECTIVENESS OF SILVICULTURAL TREATMENTS

2017 ◽  
Vol XLII-2/W6 ◽  
pp. 393-397 ◽  
Author(s):  
U. Vepakomma ◽  
D. Cormier
Keyword(s):  
Resource Competition ◽  
Distribution Patterns ◽  
Forest Stand ◽  
Partial Cutting ◽  
Silvicultural Treatments ◽  
Short Period ◽  
The Difference ◽  
Silvicultural System ◽  
Individual Trees ◽  
Almost All

Silvicultural treatments are practiced to control resource competition and direct forest stand development to meet management objectives. Effective tracking of thinning and partial cutting treatments help in timely mitigation and ensuring future stand productivity. Based on a study conducted in autumn 2015, our findings in a white pine dominant forest stand in Petawawa (Ontario, Canada) showed that almost all individual trees were detectable, structure of individual trees and undergrowth was well pronounced and underlying terrain below dense undisturbed canopy was well captured with UAS based Riegl Vux-1 lidar even at a range of 150 m. Thereafter, the site was re-scanned the following summer with the same system. Besides understanding the difference in distribution patterns due to foliage conditions, co-registering the two datasets, in the current study, we tested the potential of quantifying effectiveness of a partial cutting silvicultural system especially in terms of filling of 3D spaces through vertical or lateral growth and mortality in a very short period of time.

scholarly journals The evolution of infanticide by females in mammals

2018 ◽  
Author(s):  
Dieter Lukas ◽  
Elise Huchard
Keyword(s):  
Reproductive Output ◽  
Mammalian Species ◽  
Female Aggression ◽  
Fitness Costs ◽  
Qualitative Synthesis ◽  
Female Infanticide ◽  
Taxonomic Distribution ◽  
Competitive Behaviour ◽  
Indirect Fitness ◽  
Critical Resources

AbstractIn most mammalian species, females regularly interact with kin, and it may thus be difficult to understand the evolution of some aggressive and harmful competitive behaviour among females, such as infanticide. Here, we investigate the evolutionary determinants of infanticide by females by combining a quantitative analysis of the taxonomic distribution of infanticide with a qualitative synthesis of the circumstances of infanticidal attacks in published reports. Our results show that female infanticide is widespread across mammals and varies in relation to social organization and life-history, being more frequent where females breed in groups and have intense bouts of high reproductive output. Specifically, female infanticide occurs where the proximity of conspecific offspring directly threatens the killer’s reproductive success by limiting access to critical resources for her dependent progeny, including food, shelters, care or a social position. In contrast, infanticide is not immediately modulated by the degree of kinship among females, and females occasionally sacrifice closely related juveniles. Our findings suggest that the potential direct fitness rewards of gaining access to reproductive resources have a stronger influence on the expression of female aggression than the indirect fitness costs of competing against kin.

scholarly journals Inclusive Fitness of Male and Facultatively Social Female Nesting Behavior in the Socially Polymorphic Bee, Ceratina australensis (Hymenoptera: Xylocopinae)

2020 ◽  
Author(s):  
Robert L Oppenheimer ◽  
Sandra M Rehan
Keyword(s):  
Inclusive Fitness ◽  
Demographic Data ◽  
Empirical Studies ◽  
Relative Fitness ◽  
Natal Nest ◽  
Carpenter Bee ◽  
Nesting Sites ◽  
Indirect Fitness ◽  
Reproductive Females ◽  
Mating Biology

Abstract Male hymenopterans do not typically provide help with nest construction or maintenance. This is thought to be due to the decreased relatedness of males to their siblings compared to sisters, and selection for outbreeding resulting in male dispersal from natal nesting sites. However, some instances of male ‘helping’ behaviors have been observed and can usually be explained by increased access to mating with resident females. Here we report on the first observations of cohabiting males within the nests of reproductive females of the facultatively social small carpenter bee, Ceratina australensis. Social nesting in C. australensis occurs at a consistently low rate across populations. We used microsatellites markers to determine relatedness, combined with 3 yr of nest demographic data collected across three populations, to assess the relative fitness of reproductive, nonreproductive, and male individuals cohabiting in reproductive nests. We found that males were brothers of reproductive females, both remaining in their natal nest. However, there was no evidence that they were mating with their sisters across all nests observed. Males in reproductive nests did not gain any direct or indirect fitness benefits as they did not sire any brood and their presence did not increase brood productivity or survivorship. It is possible that males were waiting to mate with nieces who had not yet emerged. Why males were tolerated remains unknown. Mating biology is an important consideration in social theory which requires additional empirical studies. Future long-term studies are needed to capture unusual social behaviors including male nesting behaviors.

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