| 1. |
- Abbey-Lee, Robin N., et al.
(författare)
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Effects of monoamine manipulations on the personality and gene expression of three-spined sticklebacks
- 2019
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Ingår i: Journal of Experimental Biology. - Cambridge : The Company of Biologists Ltd. - 0022-0949 .- 1477-9145. ; 222:20
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Tidskriftsartikel (refereegranskat)abstract
- Among-individual behavioral differences (i.e. animal personality) are commonly observed across taxa, although the underlying, causal mechanisms of such differences are poorly understood. Animal personality has been correlated with physiological functions as well as fitness-related traits. Variation in many aspects of monoamine systems, such as metabolite levels and gene polymorphisms, has been linked to behavioral variation. Therefore, here we experimentally investigated the potential role of monoamines in explaining individual variation in personality, using two common pharmaceuticals that respectively alter the levels of serotonin and dopamine in the brain: fluoxetine and ropinirole. We exposed three-spined sticklebacks, a species that shows animal personality, to either chemical alone or to a combination of the two chemicals, for 18 days. During the experiment, fish were assayed at four time points for the following personality traits: exploration, boldness, aggression and sociability. To quantify brain gene expression on short- and longer-term scales, fish were sampled at two time points. Our results show that monoamine manipulations influence fish behavior. Specifically, fish exposed to either fluoxetine or ropinirole were significantly bolder, and fish exposed to the two chemicals together tended to be bolder than control fish. Our monoamine manipulations did not alter the gene expression of monoamine or stress-associated neurotransmitter genes, but control, untreated fish showed covariation between gene expression and behavior. Specifically, exploration and boldness were predicted by genes in the dopaminergic, serotonergic and stress pathways, and sociability was predicted by genes in the dopaminergic and stress pathways. These results add further support to the links between monoaminergic systems and personality, and show that exposure to monoamines can causally alter animal personality.
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| 2. |
- Abbey-Lee, Robin N., et al.
(författare)
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The Influence of Rearing on Behavior, Brain Monoamines, and Gene Expression in Three-Spined Sticklebacks
- 2018
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Ingår i: Brain, behavior, and evolution. - Basel : S. Karger AG. - 0006-8977 .- 1421-9743. ; 91:4, s. 201-213
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Tidskriftsartikel (refereegranskat)abstract
- The causes of individual variation in behavior are often not well understood, and potential underlying mechanisms include both intrinsic and extrinsic factors, such as early environmental, physiological, and genetic differences. In an exploratory laboratory study, we raised three-spined sticklebacks (Gasterosteus aculeatus) under 4 different environmental conditions (simulated predator environment, complex environment, variable social environment, and control). We investigated how these manipulations related to behavior, brain physiology, and gene expression later in life, with focus on brain dopamine and serotonin levels, turnover rates, and gene expression. The different rearing environments influenced behavior and gene expression, but did not alter monoamine levels or metabolites. Specifically, compared to control fish, fish exposed to a simulated predator environment tended to be less aggressive, more exploratory, and more neophobic; and fish raised in both complex and variable social environments tended to be less neophobic. Exposure to a simulated predator environment tended to lower expression of dopamine receptor DRD4A, a complex environment increased expression of dopamine receptor DRD1B, while a variable social environment tended to increase serotonin receptor 5-HTR2B and serotonin transporter SLC6A4A expression. Despite both behavior and gene expression varying with early environment, there was no evidence that gene expression mediated the relationship between early environment and behavior. Our results confirm that environmental conditions early in life can affect phenotypic variation. However, the mechanistic pathway of the monoaminergic systems translating early environmental variation into observed behavioral responses was not detected.
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| 3. |
- Dean, Rebecca, et al.
(författare)
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Male reproductive senescence causes potential for sexual conflict over mating.
- 2010
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 20:13, s. 1192-6
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Tidskriftsartikel (refereegranskat)abstract
- The realization that senescence, age-dependent declines in survival and reproductive performance, pervades natural populations has brought its evolutionary significance into sharper focus. However, reproductive senescence remains poorly understood because it is difficult to separate male and female mechanisms underpinning reproductive success. We experimentally investigated male reproductive senescence in feral fowl, Gallus gallus domesticus, where socially dominant males monopolize access to females and the ejaculates of multiple males compete for fertilization. We detected the signal of senescence on multiple determinants of male reproductive success. The effect of age on status was dependent upon the intensity of intrasexual competition: old males were less likely to dominate male-biased groups where competition is intense but were as likely as young males to dominate female-biased groups. Mating and fertilization success declined sharply with male age largely as a result of population-level patterns. These age-dependent declines translated into sexually antagonistic payoffs: old males fertilized more eggs when they were dominant, but this resulted in females suffering a drastic reduction in fertility. Thus, male senescence causes potential for sexual conflict over mating, and the intensity of this conflict is modulated socially, by the probability of old males dominating reproductive opportunities.
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| 4. |
- Favati, Anna, 1980-, et al.
(författare)
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Effects of social experience during development on competitive ability and personality traits in male domestic fowl
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The ability to dominate conspecifics and thereby gain access to important resources depends on a number of traits and skills that may be both heritable and influenced by the environment. Experience of dominance relationships during development is a potential source of learning such skills. We here study the relative importance of social experience, personality, and morphological traits on competitive ability in male domestic fowl (Gallus gallus domesticus). By letting males grow up as either a single (dominant) male, as the dominant male of a pair, or as an intermediate ranked male in a group of males, we investigate if competitiveness in social interactions (winning duels) is mainly due to individual qualities or also influenced by social experience. We found that males were consistent over time in their competitive ability. Single raised males were inferior to pair dominant males and group-raised males in competitive ability, while pair dominant and group males did not differ significantly. This indicates that social training is important for future fighting success, but that the social position during development does not have a decisive influence on male fighting success in adulthood. Aggression and comb size, the latter possibly being a proxy for testosterone levels, had a marked effect on competitive ability. Together, our results indicate that certain behavioural and morphological traits are more important than experience of a social position in shaping competitive ability. These findings elucidate the relationship between social dominance and personality.
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| 5. |
- Favati, Anna, 1980-, et al.
(författare)
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Individual aggression, but not winner–loser effects, predicts social rank in male domestic fowl
- 2017
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 28:3, s. 874-882
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Tidskriftsartikel (refereegranskat)abstract
- Many factors can affect the probability for an individual to obtain a high social rank, including size, weaponry, and behavioral attributes such as aggression. Recent experiences of winning or losing can also affect the chances of winning future contests, commonly referred to as “winner–loser effects”. Individuals often differ in behavior in a consistent way, including in aggression, thereby showing differences in personality. However, the relative importance of recent experience and aspects of personality in determining rank, as well as the extent to which winning or losing affects aggression, has rarely been studied. Here, we investigate these questions using male domestic fowl. We matched males for body size, comb size, and aggression in pair-wise duels to: 1) study the effect of contest outcome on aggression and 2) compare the effect of individual aggression and contest experience on future social status in small groups. We found that aggression was a highly repeatable personality trait and that aggression increased after winning and decreased after losing. Nevertheless, such winner–loser effects were not enough to increase the odds of becoming dominant in a small group. Instead, aggressiveness measured prior to a contest experience best predicted future rank. Boldness and exploration did not predict rank and of the 2, only boldness was positively correlated with aggressiveness. We conclude that for male domestic fowl in contests among phenotypically matched contestants, aggressiveness is more important for obtaining high rank than winner–loser effects, or other aspects of personality.
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| 6. |
- Favati, Anna, et al.
(författare)
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Personality predicts social dominance in male domestic fowl
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Individuals in social species commonly form dominance relationships, where dominant individuals enjoy greater access to resources compared to subordinates. A range of factors such as sex, age, body size and prior experiences has to varying degrees been observed to affect the social status an individual obtains. Recent work on animal personality (i.e. consistent variation in behavioural responses of individuals) demonstrates that personality can co-vary with social status, suggesting that also behavioural variation can play an important role in establishment of status. We investigated whether personality could predict the outcome of duels between pairs of morphologically matched male domestic fowl (Gallus gallus domesticus), a species where individuals readily form social hierarchies. We found that males that more quickly explored a novel arena, or remained vigilant for a longer period following the playback of a warning call were more likely to obtain a dominant position. These traits were uncorrelated to each other and were also uncorrelated to aggression during the initial part of the dominance-determining duel. Our results indicate that several behavioural traits independently play a role in the establishment of social status, which in turn can have implications for the reproductive success of different personality types.
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| 7. |
- Favati, Anna, et al.
(författare)
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Social status and personality : stability in social state can promote consistency of behavioural responses
- 2014
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 281:1774
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Tidskriftsartikel (refereegranskat)abstract
- Stability of 'state' has been suggested as an underlying factor explaining behavioural stability and animal personality (i.e. variation among, and consistency within individuals in behavioural responses), but the possibility that stable social relationships represent such states remains unexplored. Here, we investigated the influence of social status on the expression and consistency of behaviours by experimentally changing social status between repeated personality assays. We used male domestic fowl (Gallus gallus domesticus), a social species that forms relatively stable dominance hierarchies, and showed that behavioural responses were strongly affected by social status, but also by individual characteristics. The level of vigilance, activity and exploration changed with social status, whereas boldness appeared as a stable individual property, independent of status. Furthermore, variation in vocalization predicted future social status, indicating that individual behaviours can both be a predictor and a consequence of social status, depending on the aspect in focus. Our results illustrate that social states contribute to both variation and stability in behavioural responses, and should therefore be taken into account when investigating and interpreting variation in personality.
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| 8. |
- Favati, Anna, 1980-
(författare)
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The relationship between personality and social dominance in the domestic fowl – a critical perspective
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Social dominance relationships are formed within numerous animal species and reduce costly fights over resources. Dominant individuals often enjoy greater access to important resources such as food and mating partners, and are generally more aggressive, bold, active and explorative compared to subdominant individuals. These behavioural traits can differ among individuals, but they can also be consistent within the individual, thereby describing the individual’s personality type. However, the causal direction of the observed correlation between dominance and personality is not well studied. One possibility is that some personality types have higher chances of obtaining a dominant social position. This would suggest that personality has consequences for fitness. Another possible explanation is that possessing different social positions gives rise to consistent behavioural differences among individuals on various timescales. If social status has a lasting effect on behaviour, social status would constitute a ‘stable state’ that explains some of the diversity of personality types that has been observed in a multitude of animal species. Dominance and personality may also share underlying proximate factors. In this thesis, I investigate the relationship between social dominance and personality using male domestic fowl, Gallus gallus domesticus. The species is group-living with pronounced dominance hierarchies, and dominance increases male access to mating partners. I show that some aspects of personality, exploration, vigilance and in particular aggressiveness, increased a male’s chances of obtaining dominance (paper III, IV, V), and that aggressiveness can be even more important than body weight and ornament size (comb size, paper V) or recent experience of winning or losing (paper IV). Winning a social interaction resulted in an increase in aggressiveness, while a decrease was seen in males that experienced a loss (paper IV). By observing behaviour before and after changes in male dominance relationships, I further show that a recent (2 days earlier) change in social status induced behavioural adjustments to the new social status in activity, exploration and vigilance (paper I). By extending the time of the new social relationship to 3 weeks, I show that such behavioural changes did not continue (paper II). Finally, I show that the social environment during juvenile development had little impact on adult male competitiveness (paper V). Social interactions appear to have several short-term effects on behaviour, but did not contribute significantly to variation and long-term consistency of personality in male fowl. Instead, a male's personality, and in particular his aggressiveness, affected the outcome of dominance interactions. Overall, my studies reveal important consequences of individual differences in behaviour, and contribute to the highly sought-after empirical testing of hypotheses explaining variation in animal personality.
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| 9. |
- Garnham, Laura, et al.
(författare)
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Sophisticated fowl : The complex behaviour andcognitive skills of chickens and red junglefowl
- 2018
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Ingår i: Behavioral Sciences. - Basel, Switzerland : M D P I AG. - 2076-328X. ; 8:13
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Tidskriftsartikel (refereegranskat)abstract
- The world’s most numerous bird, the domestic chicken, and their wild ancestor, the red junglefowl, have long been used as model species for animal behaviour research. Recently, this research has advanced our understanding of the social behaviour, personality, and cognition of fowl, and demonstrated their sophisticated behaviour and cognitive skills. Here, we overview some of this research, starting with describing research investigating the well-developed senses of fowl, before presenting how socially and cognitively complex they can be. The realisation that domestic chickens, our most abundant production animal, are behaviourally and cognitively sophisticated should encourage an increase in general appraise and fascination towards them. In turn, this should inspire increased use of them as both research and hobby animals, as well as improvements in their unfortunately often poor welfare.
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| 10. |
- Garnham, Laura, 1988-, et al.
(författare)
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Variation in inhibitory control does not influence social rank, foraging efficiency, or risk taking, in red junglefowl females
- 2022
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Ingår i: Animal Cognition. - : Springer Heidelberg. - 1435-9448 .- 1435-9456. ; 25, s. 867-879
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Tidskriftsartikel (refereegranskat)abstract
- Individual variation in cognition, seen in many taxa, is not well understood, despite its potential evolutionary consequences. Inhibitory control is an aspect of cognition which differs between individuals. However, how selection could act on this variation remains unclear. First, individual consistency over time of behaviours affected by inhibitory control, and how these behaviours relate to each other, is not well understood. Second, consequences in ecologically relevant contexts of variation in behaviours affected by inhibitory control, are scarcely investigated. Therefore, we explored the temporal consistency and inter-relatedness of two behaviours influenced by inhibitory control (impulsive action and persistence) and how these link to social rank, foraging efficiency, and risk taking in adult female red junglefowl (Gallus gallus). We measured impulsive action in a detour test, and persistence in both a detour test and a foraging test. Impulsive action and persistence, measured in a detour test, were moderately consistent over time, and positively correlated. This implies that selection could act on inhibitory control via these behaviours, and selection on one behaviour could affect the other. However, we found no evidence of links between inhibitory control and social rank, foraging efficiency, or risk taking. This implies that selection may not act on inhibitory control via these measures, and that, in general, there may be a lack of strong selection on inhibitory control. This, in turn, could help explain individual variation in this aspect of cognition. Future research should explore the specificity of when inhibitory control has implications for individuals, and continue to investigate how variation in cognitive traits influences how individuals behave in contexts with potential evolutionary implications.
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