scholarly journals Fighting and mating success in giant Australian cuttlefish is influenced by behavioural lateralization

2019 ◽  
Vol 286 (1898) ◽  
pp. 20182507 ◽  
Author(s):  
Alexandra K. Schnell ◽  
Christelle Jozet-Alves ◽  
Karina C. Hall ◽  
Léa Radday ◽  
Roger T. Hanlon
Keyword(s):  
Mating Success ◽  
Population Level ◽  
Theory Model ◽  
Fundamental Question ◽  
Competitive Interactions ◽  
Intraspecific Interactions ◽  
Stable Strategy ◽  
Evolutionary Consequence ◽  
Fitness Advantage ◽  
Fitness Consequences

Behavioural lateralization is widespread. Yet, a fundamental question remains, how can lateralization be evolutionary stable when individuals lateralized in one direction often significantly outnumber individuals lateralized in the opposite direction? A recently developed game theory model predicts that fitness consequences which occur during intraspecific interactions may be driving population-level lateralization as an evolutionary stable strategy. This model predicts that: (i) minority-type individuals exist because they are more likely to adopt unpredictable fighting behaviours during competitive interactions (e.g. fighting); and (ii) majority-type individuals exist because there is a fitness advantage in having their biases synchronized with other conspecifics during interactions that require coordination (e.g. mating). We tested these predictions by investigating biases in giant Australian cuttlefish during fighting and mating interactions. During fighting, most male cuttlefish favoured the left eye and these males showed higher contest escalation; but minority-type individuals with a right-eye bias achieved higher fighting success. During mating interactions, most male cuttlefish favoured the left eye to inspect females. Furthermore, most male cuttlefish approached the female's right side during a mating attempt and these males achieved higher mating success. Our data support the hypothesis that population-level biases are an evolutionary consequence of the fitness advantages involved in intraspecific interactions.

scholarly journals Intraspecific competition and coordination in the evolution of lateralization

2008 ◽  
Vol 364 (1519) ◽  
pp. 861-866 ◽  
Author(s):  
Stefano Ghirlanda ◽  
Elisa Frasnelli ◽  
Giorgio Vallortigara
Keyword(s):  
Evolutionarily Stable Strategy ◽  
Population Level ◽  
Neural Circuitry ◽  
Brain Lateralization ◽  
Stable Strategy ◽  
Cooperative Interactions ◽  
Strategic Factors ◽  
Left And Right ◽  
Predator Interactions ◽  
Evolutionarily Stable

Recent studies have revealed a variety of left–right asymmetries among vertebrates and invertebrates. In many species, left- and right-lateralized individuals coexist, but in unequal numbers (‘population-level’ lateralization). It has been argued that brain lateralization increases individual efficiency (e.g. avoiding unnecessary duplication of neural circuitry and reducing interference between functions), thus counteracting the ecological disadvantages of lateral biases in behaviour (making individual behaviour more predictable to other organisms). However, individual efficiency does not require a definite proportion of left- and right-lateralized individuals. Thus, such arguments do not explain population-level lateralization. We have previously shown that, in the context of prey–predator interactions, population-level lateralization can arise as an evolutionarily stable strategy when individually asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Here, we extend our model showing that populations consisting of left- and right-lateralized individuals in unequal numbers can be evolutionarily stable, based solely on strategic factors arising from the balance between antagonistic (competitive) and synergistic (cooperative) interactions.

Condition-dependent foraging strategies in a coastal seabird: evidence for the rich get richer hypothesis

2018 ◽  
Vol 30 (2) ◽  
pp. 356-363 ◽  
Author(s):  
Brock Geary ◽  
Scott T Walter ◽  
Paul L Leberg ◽  
Jordan Karubian
Keyword(s):  
Individual Variation ◽  
Multiple Scales ◽  
Foraging Ecology ◽  
Population Level ◽  
Foraging Strategies ◽  
Significant Relationships ◽  
Fitness Consequences ◽  
Brown Pelicans ◽  
The Rich ◽  
Foraging Movements

Abstract The degree to which foraging individuals are able to appropriately modify their behaviors in response to dynamic environmental conditions and associated resource availability can have important fitness consequences. Despite an increasingly refined understanding of differences in foraging behavior between individuals, we still lack detailed characterizations of within-individual variation over space and time, and what factors may drive this variability. From 2014 to 2017, we used GPS transmitters and accelerometers to document foraging movements by breeding adult Brown Pelicans (Pelecanus occidentalis) in the northern Gulf of Mexico, where the prey landscape is patchy and dynamic at various scales. Assessments of traditional foraging metrics such as trip distance, linearity, or duration did not yield significant relationships between individuals. However, we did observe lower site fidelity and less variation in energy expenditure in birds of higher body condition, despite a population-level trend of increased fidelity as the breeding season progressed. These findings suggest that high-quality individuals are both more variable and more efficient in their foraging behaviors during a period of high energetic demand, consistent with a “rich get richer” scenario in which individuals in better condition are able to invest in more costly behaviors that provide higher returns. This work highlights the importance of considering behavioral variation at multiple scales, with particular reference to within-individual variation, to improve our understanding of foraging ecology in wild populations.

scholarly journals The effect of sexual selection on adaptation and extinction under increasing temperatures

2018 ◽  
Vol 285 (1877) ◽  
pp. 20180303 ◽  
Author(s):  
Jonathan M. Parrett ◽  
Robert J. Knell
Keyword(s):  
Sexual Selection ◽  
Environmental Changes ◽  
Population Level ◽  
Offspring Survival ◽  
Positive Effects ◽  
Fitness Consequences ◽  
Indian Meal ◽  
Mating Opportunities ◽  
Entire Experiment ◽  
Positive Effect

Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, Plodia interpunctella, exposed to stable or gradually increasing temperatures. When faced with increasing temperatures, strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid.

The importance of reporting the distributional criteria of FA

2000 ◽  
Vol 23 (4) ◽  
pp. 623-624
Author(s):  
Sally Walters
Keyword(s):  
Fluctuating Asymmetry ◽  
Mating Success ◽  
Population Level ◽  
Male Mating ◽  
Male Mating Success ◽  
Target Article

Not all of the studies cited in the target article as evidence that fluctuating asymmetry (FA) predicts male mating success demonstrate that the observed asymmetry is, in fact, FA. FA is a population-level pattern of differences between sides. Unless the population-level distributional criteria of bilateral traits are reported, the meaning of asymmetry in individuals is unknown.

scholarly journals The Relationship between Flourishing and Depression in Children in the U.S. Using a Socioecological Perspective

2020 ◽  
Vol 17 (21) ◽  
pp. 8246
Author(s):  
Chang-Yong Jang ◽  
Eun-Hyung Cho ◽  
Yi-Sub Kwak ◽  
TaeEung Kim
Keyword(s):  
Mental Health ◽  
Social Support ◽  
Childhood Depression ◽  
Population Level ◽  
Cross Sectional Study ◽  
Theory Model ◽  
Cross Sectional ◽  
Sociological Factors ◽  
Multiple Dimensions ◽  
The U.S

Children’s flourishing is likely to be associated with achieving a positive mental and physical quality of life, which is considered as an important factor for helping children to overcome psychological adversity during the critical stage of emotional development. This study examined the relationships between children’s flourishing and childhood depression. This was a cross-sectional study using the 2011–2012 National Children’s Health Survey in the U.S. The conceptual framework that guided this study was a modified ecological system theory model. Multiple regressions were performed to investigate the associations between flourishing and pediatric depression, controlling for demographics, physical activity-related behaviors, family and environmental conditions. A total of 45,309 children (representing 33,293,823 children at the population level) were identified in this study (mean age: 13.63 years; female: 48.7%). Children’s childhood depression was highly related to direct parenting functions, individual needs and environmental availabilities and accessibilities from a socioecological perspective. This study revealed multiple dimensions of how sociological factors influence children’s flourishing and mental health. Parents’ involvement in children’s physical activities and family and social support are crucial for children’s flourishing and mental health status. More attention needs to be paid to provide children with family and social support to help them to overcome and reduce childhood depression.

A Bird's-Eye View of Pollination: Biotic Interactions as Drivers of Adaptation and Community Change

2019 ◽  
Vol 50 (1) ◽  
pp. 477-502 ◽  
Author(s):  
Anton Pauw
Keyword(s):  
Community Composition ◽  
Bird Species ◽  
Biotic Interactions ◽  
Population Level ◽  
Community Change ◽  
Plant Evolution ◽  
Relative Fitness ◽  
Fitness Advantage ◽  
Bird Evolution ◽  
Composition I

Nectarivorous birds and bird-pollinated plants are linked by a network of interactions. Here I ask how these interactions influence evolution and community composition. I find near complete evidence for the effect of birds on plant evolution. Experiments show the process in action—birds select among floral phenotypes in a population—and comparative studies find the resulting pattern—bird-pollinated species have long-tubed, red flowers with large nectar volumes. Speciation is accomplished in one “magical” step when adaptation for bird pollination brings about divergent morphology and reproductive isolation. In contrast, evidence that plants drive bird evolution is fragmentary. Studies of selection on population-level variation are lacking, but the resulting pattern is clear—nectarivorous birds have evolved a remarkable number of times and often have long bills and brush-tipped or tubular tongues. At the level of the ecological guild, birds select among plant species via an effect on seed set and thus determine plant community composition. Plants simultaneously influence the relative fitness of bird species and thus determine the composition of the bird guild. Interaction partners may give one guild member a constant fitness advantage, resulting in competitive exclusion and community change, or may act as limiting resources that depress the fitness of frequent species, thus stabilizing community composition and allowing the coexistence of diversity within bird and plant guilds.

scholarly journals Structure of sexual networks determines the operation of sexual selection

2017 ◽  
Vol 115 (1) ◽  
pp. E53-E61 ◽  
Author(s):  
Grant C. McDonald ◽  
Tommaso Pizzari
Keyword(s):  
Sexual Selection ◽  
Mating Success ◽  
Empirical Studies ◽  
Evolutionary Process ◽  
Population Level ◽  
Network Size ◽  
Male Mating ◽  
Male Mating Success ◽  
Sexual Network ◽  
Bateman Gradient

Sexual selection is a fundamental evolutionary process but remains debated, particularly in the complexity of polyandrous populations where females mate with multiple males. This lack of resolution is partly because studies have largely ignored the structure of the sexual network, that is, the pattern of mate sharing. Here, we quantify what we call mating assortment with network analysis to specify explicitly the indirect as well as direct relationships between partners. We first review empirical studies, showing that mating assortment varies considerably in nature, due largely to basic properties of the sexual network (size and density) and partly to nonrandom patterns of mate sharing. We then use simulations to show how variation in mating assortment interacts with population-level polyandry to determine the strength of sexual selection on males. Controlling for average polyandry, positive mating assortment, arising when more polygynous males tend to mate with more polyandrous females, drastically decreases the intensity of precopulatory sexual selection on male mating success (Bateman gradient) and the covariance between male mating success and postcopulatory paternity share. Average polyandry independently weakened some measures of sexual selection and crucially also impacted sexual selection indirectly by constraining mating assortment through the saturation of the mating network. Mating assortment therefore represents a key—albeit overlooked—modulator of the strength of sexual selection. Our results show that jointly considering sexual network structure and average polyandry more precisely describes the strength of sexual selection.

scholarly journals Conspecifics, not plant reproductive tissues, reduce omnivore prey consumption

2019 ◽  
Author(s):  
S. Rinehart ◽  
J.D. Long
Keyword(s):  
Population Level ◽  
Field Studies ◽  
Predation Rate ◽  
Scale Insect ◽  
Prey Consumption ◽  
Intraspecific Interactions ◽  
Conspecific Density ◽  
Reproductive Tissues ◽  
Consumption Rates ◽  
Per Capita

AbstractPlant reproductive tissues (PRTs) can decrease (via reduced consumption) or increase (via numerical response) an omnivores consumption of animal prey. Although PRTs can increase predation pressure through numerical responses of omnivores, PRTs may also suppress predation by increasing omnivore interactions with conspecifics. Despite this potential, studies of the impacts of PRTs on predation by omnivores often overlook the effect of these tissues on intraspecific interactions between omnivores. We designed three studies to examine how PRTs and conspecific density impact prey consumption by ladybeetle omnivores. First, we assessed how PRTs impact scale insect consumption by isolated ladybeetles. Second, we measured how PRTs influence ladybeetle prey suppression when numerical responses were possible. Third, because initial experiments suggested the consumption rates of individual ladybeetles depended upon conspecific density, we compared per capita consumption rates of ladybeetles across ladybeetle density. PRTs did not influence prey consumption by isolated ladybeetles. When numerical responses were possible, PRTs did not influence total predation on prey despite increasing ladybeetle density, suggesting that PRTs decreased per capita prey consumption by ladybeetles. The discrepancy between our lab and field studies is likely a consequence of differences in ladybeetle density - the presence of only two other conspecifics decreased per capita prey consumption by 76%. Our findings suggest that PRTs may not alter the population level effects of omnivores on prey when omnivore numerical responses are offset by reductions in per capita predation rate.

scholarly journals How does individual variation in sociality influence fitness in prairie voles?

2019 ◽  
Author(s):  
Anne C. Sabol ◽  
Connor T. Lambert ◽  
Brian Keane ◽  
Nancy G. Solomon ◽  
Ben Dantzer
Keyword(s):  
Social Network ◽  
Social Behavior ◽  
Individual Variation ◽  
Mating Success ◽  
Social Connections ◽  
Prairie Voles ◽  
Network Analyses ◽  
Fitness Consequences ◽  
Opposite Sex ◽  
Social Network Analyses

AbstractComparative studies aid in our understanding of specific conditions favoring the initial evolution of different types of social behaviors, yet there is much unexplained intraspecific variation in the expression of social behavior that comparative studies have not yet addressed. The proximate causes of this individual variation in social behavior within a species have been examined in some species but its fitness consequences have been less frequently investigated. In this study, we quantified the fitness consequences of variation in the sociality of prairie voles (Microtus ochrogaster). We characterized sociality of voles in semi-natural enclosures using an automated behavioral tracking system paired with social network analyses to quantify the degree of spatial and temporal co-occurrence of different voles. We then assessed the relationship between sociality with mating success (number of different conspecifics with which an individual produced offspring) and reproductive success (total number of offspring surviving to first capture). We measured the number of social connections each individual had with all voles and only with opposite-sex voles by calculating unweighted degree through social network analyses. Both female and male voles varied in the number of social connections they had with all conspecifics and with opposite-sex conspecifics. Voles with an intermediate number of social connections with voles of both sexes had higher mating success overall. In our analyses that considered all social connections with voles of both sexes, voles with an intermediate number of social connections produced more offspring. Males with a very high or low number of social connections also had the lowest average body mass. Overall, our results suggest some limit on the fitness benefits of sociality. Although there was substantial individual-variation in our measure of vole social behavior, intermediate levels of social connections may be most favorable.

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