| 1. |
- 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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| 2. |
- Eriksson, P, et al.
(författare)
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Current Husbandry of Red Pandas (Ailurus fulgens) in Zoos
- 2010
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Ingår i: ZOO BIOLOGY. - : John Wiley and Sons, Ltd. - 0733-3188 .- 1098-2361. ; 29:6, s. 732-740
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Tidskriftsartikel (refereegranskat)abstract
- The endangered red panda (Ailurus fulgens) is held in zoos worldwide. The aim of this study was to examine how red pandas are kept and managed in captivity and to compare it with the management guidelines. Sixty-nine zoos, mainly from Europe but also from North America and Australia/New Zealand, responded to our survey. The results revealed that in general zoos follow the management guidelines for most of the investigated issues. The average enclosure is almost four times larger than the minimum size recommended by the management guidelines, although seven zoos have smaller enclosures. About half the zoos do not follow the guidelines concerning visitor access and number of nest boxes. Other issues that may compromise animal welfare include proximity of neighboring carnivore species and placement of nest boxes. Zoo Biol 29: 732-740, 2010. (C) 2010 Wiley-Liss, Inc.
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| 3. |
- Favati, Anna, et al.
(författare)
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The ontogeny of personality traits in the redjunglefowl, Gallus gallus
- 2016
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Ingår i: Behavioral Ecology. - : Oxford University Press. - 1045-2249 .- 1465-7279. ; 27:2, s. 484-493
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Tidskriftsartikel (refereegranskat)abstract
- Consistent behavioral differences among individuals, that is, personality, are described in numerous species. Nevertheless, thedevelopment of behavioral consistency over ontogeny remains unclear, including whether the personality of individuals is consistentthroughout life, and if adult personality can be predicted already at young age. We investigated the ontogeny of personality in thered junglefowl (Gallus gallus) by scoring personality of hatchlings at 5 time points through adulthood, including before and after themajor developmental stages of becoming independent and sexual mature. We use the conceptual framework laid out by Stamps andGroothuis (2010a) to holistically investigate the observed changes in behavioral response over ontogeny. We demonstrate that meanvalues of behavioral responses changed across ontogeny and stabilized after independence. Rank-order consistencies of behavioralresponses were overall low across independence and sexual maturation. Only in 1 case could low rank-order consistencies potentiallybe explained by different phenotypes displaying different amounts of change in behavior; more explorative individuals decreased inexploration after independence, while less explorative individuals remained so. Correlations among behavior varied across ontogenyand weakened after sexual maturation. Our results demonstrate that both absolute values and consistency of behavioral traits maychange across ontogeny and that individual developmental trajectories and adult personality only to some extent can be predictedearly in life. These results have implications for future studies on personality, highlighting that the life stage at which individuals arescored affects the observed consistency of behavioral responses.
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| 4. |
- 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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| 5. |
- Jarnemo, Anders, et al.
(författare)
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Managing landscapes for multiple objectives : Alternative forage can reduce the conflict between deer and forestry
- 2014
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Ingår i: Ecosphere. - Washington : Ecological Society of America. - 2150-8925 .- 2150-8925. ; 5:8
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Tidskriftsartikel (refereegranskat)abstract
- Deer (Cervidae) cause considerable damage to forest plantations, crops, and protected habitats. The most common response to this damage is to implement strategies to lower population densities. However, lowering deer density may not always be desirable from hunting, recreational, or conservation perspectives. Therefore, knowledge is needed about additional factors beyond deer density that affect damage levels, and management actions that consider competing management goals. We studied the relationships between levels of bark-stripping by red deer (Cervus elaphus) on Norway spruce (Picea abies) and (1) relative deer density indices (pellet group count and deer harvest data), (2) availability of alternative natural forage (cover of forage species) and (3) proportion forest in the landscape, both at a forest stand scale and at a landscape scale. Extensive variation in damage level was evident between the six study areas. On a stand scale, the proportion of spruce damaged was positively related to pellet group density, indicating the importance of local deer usage of stands. In addition, available alternative forage in the field layer within spruce stands and proportion forest surrounding stands was negatively related to damage level. On the landscape scale, damage level was negatively related to availability of forage in the field and shrub layers and proportion forest, but was not related to any of the relative deer density indices. Increasing alternative forage may thus decrease damage and thereby reduce conflicts. Additionally, the proportion of forest in the landscape affects damage levels and should thus be considered in landscape planning and when forecasting damage risk. The relationship between local deer usage of stands and damage level suggests that future studies should try to separate the effects of local deer usage and deer density. © 2014 Jarnemo et al.
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| 6. |
- Lagisz, Malgorzata, et al.
(författare)
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Optimism, pessimism and judgement bias in animals: A systematic review and meta-analysis
- 2020
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Ingår i: Neuroscience and Biobehavioral Reviews. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0149-7634 .- 1873-7528. ; 118
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Forskningsöversikt (refereegranskat)abstract
- Just as happy people see the proverbial glass as half-full, optimistic or pessimistic responses to ambiguity might also reflect affective states in animals. Judgement bias tests, designed to measure these responses, are an increasingly popular way of assessing animal affect and there is now a substantial, but heterogeneous, literature on their use across different species, affect manipulations, and study designs. By conducting a systematic review and meta-analysis of 459 effect sizes from 71 studies of non-pharmacological affect manipulations on 22 non-human species, we show that animals in relatively better conditions, assumed to generate more positive affect, show more optimistic judgements of ambiguity than those in relatively worse conditions. Overall effects are small when considering responses to all cues, but become more pronounced when non-ambiguous training cues are excluded from analyses or when focusing only on the most divergent responses between treatment groups. Task type (go/no-go; go/go active choice), training cue reinforcement (reward-punishment; reward-null; reward-reward) and sex of animals emerge as potential moderators of effect sizes in judgement bias tests.
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| 7. |
- Løvlie, Hanne, et al.
(författare)
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A cry for help : female distress calling during copulation is context dependent
- 2014
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Ingår i: Animal Behaviour. - : Elsevier. - 0003-3472 .- 1095-8282. ; 92, s. 151-157
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Tidskriftsartikel (refereegranskat)abstract
- Owing to selection for increased mating propensity, males often expose females to sexual harassment.Consequently, females may evolve counterstrategies to retain control of mating. Females can do thisdirectly by resisting copulations, or indirectly by manipulating other males to intervene and prevent thecopulation. Uttering copulation calls may be one indirect method for females to trigger male intervention.Copulation calls are commonly observed in mammals, primarily in primates, and also in some birds.Female fowl, Gallus gallus, sometimes utter calls during copulation, particularly in forced copulationswith low-ranking males. These loud calls, called distress calls, attract other males and can result indisruption of the copulation, and subsequent mating with the intervening male if he is high ranking.Consequently, uttering such calls can act both to abort a coerced copulation and to generate novel opportunitiesfor females to copulate with higher-ranking males. Nevertheless, uttering loud calls can carrycosts, such as attracting predators. Females are therefore predicted to utter copulation calls primarilywhen doing so offers benefits, which for female fowl requires the presence of another high-ranking male.We tested this prediction by altering the social environment of female domestic fowl, G. g. domesticus.We found that females uttered copulation calls more frequently during copulations in the presence ofdominant ‘observer’ males than in their absence. Thus, we provide evidence of context-dependent utteranceof female calls during copulations in a bird. This type of female vocalization is rarely investigatedin nonprimate vertebrates, but increased research in this field offers potential to improve understandingof female mate choice strategies and the dynamics of sexual selection.
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| 8. |
- Neville, Vikki, et al.
(författare)
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Pharmacological manipulations of judgement bias: A systematic review and meta-analysis
- 2020
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Ingår i: Neuroscience and Biobehavioral Reviews. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0149-7634 .- 1873-7528. ; 108, s. 269-286
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Forskningsöversikt (refereegranskat)abstract
- Validated measures of animal affect are crucial to research spanning numerous disciplines. Judgement bias, which assesses decision-making under ambiguity, is a promising measure of animal affect. One way of validating this measure is to administer drugs with affect-altering properties in humans to non-human animals and determine whether the predicted judgement biases are observed. We conducted a systematic review and meta-analysis using data from 20 published research articles that use this approach, from which 557 effect sizes were extracted. Pharmacological manipulations overall altered judgement bias at the probe cues as predicted. However, there were several moderating factors including the neurobiological target of the drug, whether the drug induced a relatively positive or negative affective state in humans, dosage, and the presented cue. This may partially reflect interference from adverse effects of the drug which should be considered when interpreting results. Thus, the overall pattern of change in animal judgement bias appears to reflect the affect-altering properties of drugs in humans, and hence may be a valuable measure of animal affective valence.
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| 9. |
- Sorato, Enrico, et al.
(författare)
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Heritabilities and co-variation among cognitive traits in red junglefowl
- 2018
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Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences. - London, United Kingdom : The Royal Society Publishing. - 0962-8436 .- 1471-2970. ; 373:1756
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Tidskriftsartikel (refereegranskat)abstract
- Natural selection can act on between-individual variation in cognitive abilities, yet evolutionary responses depend on the presence of underlying genetic variation. It is, therefore, crucial to determine the relative extent of genetic versus environmental control of these among-individual differences in cognitive traits to understand their causes and evolutionary potential. We investigated heritability of associative learning performance and of a cognitive judgement bias (optimism), as well as their covariation, in a captive pedigree-bred population of red junglefowl (Gallus gallus, n > 300 chicks over 5 years). We analysed performance in discriminative and reversal learning (two facets of associative learning), and cognitive judgement bias, by conducting animal models to disentangle genetic from environmental contributions. We demonstrate moderate heritability for reversal learning, and weak to no heritability for optimism and discriminative learning, respectively. The two facets of associative learning were weakly negatively correlated, consistent with hypothesized trade-offs underpinning individual cognitive styles. Reversal, but not discriminative learning performance, was associated with judgement bias; less optimistic individuals reversed a previously learnt association faster. Together these results indicate that genetic and environmental contributions differ among traits. While modular models of cognitive abilities predict a lack of common genetic control for different cognitive traits, further investigation is required to fully ascertain the degree of covariation between a broader range of cognitive traits and the extent of any shared genetic control.
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| 10. |
- Tsuboi, Masahito, et al.
(författare)
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Comparative support for the expensive tissue hypothesis : Big brains are correlated with smaller gut and greater parental investment in Lake Tanganyika cichlids
- 2015
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 69:1, s. 190-200
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Tidskriftsartikel (refereegranskat)abstract
- The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the energetic requirements of encephalization are suggested to impose considerable constraints on brain size evolution. Three main hypotheses concerning how energetic constraints might affect brain evolution predict covariation between brain investment and (1) investment into other costly tissues, (2) overall metabolic rate, and (3) reproductive investment. To date, these hypotheses have mainly been tested in homeothermic animals and the existing data are inconclusive. However, there are good reasons to believe that energetic limitations might play a role in large-scale patterns of brain size evolution also in ectothermic vertebrates. Here, we test these hypotheses in a group of ectothermic vertebrates, the Lake Tanganyika cichlid fishes. After controlling for the effect of shared ancestry and confounding ecological variables, we find a negative association between brain size and gut size. Furthermore, we find that the evolution of a larger brain is accompanied by increased reproductive investment into egg size and parental care. Our results indicate that the energetic costs of encephalization may be an important general factor involved in the evolution of brain size also in ectothermic vertebrates.
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