| 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. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- Hayward, A., et al.
(författare)
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Evolutionary associations between host traits and parasite load : insights from Lake Tanganyika cichlids
- 2017
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Ingår i: Journal of Evolutionary Biology. - : WILEY. - 1010-061X .- 1420-9101. ; 30:6, s. 1056-1067
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Tidskriftsartikel (refereegranskat)abstract
- Parasite diversity and abundance (parasite load) vary greatly among host species. However, the influence of host traits on variation in parasitism remains poorly understood. Comparative studies of parasite load have largely examined measures of parasite species richness and are predominantly based on records obtained from published data. Consequently, little is known about the relationships between host traits and other aspects of parasite load, such as parasite abundance, prevalence and aggregation. Meanwhile, understanding of parasite species richness may be clouded by limitations associated with data collation from multiple independent sources. We conducted a field study of Lake Tanganyika cichlid fishes and their helminth parasites. Using a Bayesian phylogenetic comparative framework, we tested evolutionary associations between five key host traits (body size, gut length, diet breadth, habitat complexity and number of sympatric hosts) predicted to influence parasitism, together with multiple measures of parasite load. We find that the number of host species that a particular host may encounter due to its habitat preferences emerges as a factor of general importance for parasite diversity, abundance and prevalence, but not parasite aggregation. In contrast, body size and gut size are positively related to aspects of parasite load within, but not between species. The influence of host phylogeny varies considerably among measures of parasite load, with the greatest influence exerted on parasite diversity. These results reveal that both host morphology and biotic interactions are key determinants of host-parasite associations and that consideration of multiple aspects of parasite load is required to fully understand patterns in parasitism.
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| 7. |
- Løvlie, Hanne
(författare)
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Cryptic Female Choice
- 2016
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Ingår i: Oxfords Bibliographies in Evolutionary Biology. - : Oxford Bibliographies.
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Forskningsöversikt (refereegranskat)abstract
- Sexual selection (see the Oxford Bibliographies article “Sexual Selection”) is a powerful evolutionary force, selecting fortraits that increase the reproductive success of individuals. Before copulation, sexual selection can occur throughintrasexual selection, typically observed as competition among individuals of the same sex for access to mating partnersof the other sex (see Oxford Bibliographies article on Evolutionary Biology “Male-Male Competition”), and intersexualselection, observed as (typically female) mate choice (see Oxford Bibliographies article on Evolutionary Biology “MateChoice”). When females are sexually promiscuous and mate with multiple males (which is more the rule than theexception in the animal kingdom), these two processes have the potential to continue also after copulation: intrasexualselection as sperm competition (Oxford Bibliographies article on Evolutionary Biology “Sperm Competition”), andintersexual selection as cryptic female choice. The term cryptic is applied because this form of female choice can be hardto observe (e.g., when it occurs inside the female reproductive tract) and hard to quantify with classical measures ofreproductive success (e.g., mating success). In addition, this form of female choice is hard to disentangle from otherepisodes of sexual selection (see below). The framework used to understand female choice occurring after (or sometimesduring) copulation is currently somewhat divergent, since some authors adopt a very broad definition of cryptic femalechoice, while others apply a more conservative definition (see discussion of this under Definition and History). Crypticfemale choice is a relatively young research topic (it first started properly after the publication of Eberhard’s seminal bookFemale Control: Sexual Selection by Cryptic Female Choice [Eberhard 1996, cited under General Overviews] in 1996). Itwas realized early on in the history of the field that a broad range of mechanisms across a variety of species exist throughwhich females can potentially bias the outcome of a copulation (e.g., ejaculate ejection, differential sperm storage, spermchoice—see section Mechanisms and Processes Used as Cryptic Female Choice). As a consequence, measures ofprecopulatory processes or sperm competition can be misleading in species with cryptic female choice, due to femalepostcopulatory influences on fertilization. Yet, although there is no doubt that females have great potential to bias paternityat the postcopulatory stage, cryptic female choice is the least studied of the processes through which sexual selection canoccur (e.g., compared to sperm competition, or male-male competition). This is probably because demonstration of crypticfemale choice is notoriously difficult. It can be challenging to separate pre- from postcopulatory processes, the interactionof male adaptations to sperm competition and female influences on fertilization, and variation in differential embryomortality from female-induced biases in paternity (see Potential Pitfalls in the Study of Cryptic Female Choice). Thestudies that have convincingly been able to separate these processes and demonstrate cryptic female choice are currentlyprimarily from insect, bird, and externally fertilizing species (see Mechanisms and Processes Used as Cryptic FemaleChoice). I here present when we may expect to observe cryptic female choice, how females may benefit from crypticfemale choice, some techniques that can
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| 8. |
- Løvlie, Hanne, 1977-
(författare)
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Cryptic female choice
- 2016
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Ingår i: Encyclopedia of Evolutionary Psychological Science. - Cham : Springer. - 9783319169996 ; , s. 1-4
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Bokkapitel (refereegranskat)
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| 9. |
- Løvlie, Hanne, 1977-
(författare)
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Introduction to animal personality
- 2017. - 3
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Ingår i: The ethology of domestic animals. - UK : CABI Publishing. - 9781786391650 ; , s. 104-118
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Bokkapitel (refereegranskat)
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| 10. |
- Løvlie, Hanne, 1977-
(författare)
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Personliga höns
- 2017
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Ingår i: Svenska rasfjäderfäförbundets tidskrift. - Karlstad : Svenska rasfjäderfäförbundets tidskrift. - 1650-7258. ; :4, s. 1-4
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Tidskriftsartikel (populärvet., debatt m.m.)
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