| 1. |
- Cauchard, Laure, et al.
(författare)
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An Experimental Test of a Causal Link between Problem-Solving Performance and Reproductive Success in Wild Great Tits
- 2017
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Ingår i: Frontiers in Ecology and Evolution. - : FRONTIERS MEDIA SA. - 2296-701X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have uncovered relationships between measures of various cognitive performances and proxies of fitness such as reproductive success in non-human animals. However, to better understand the evolution of cognition in the wild, we still have to determine the causality of these relationships and the underlying mechanisms. The cognitive ability of an individual may directly influence its ability to raise many and/or high quality young through for example its provisioning ability. Conversely, large and/or high quality broods may lead to high parental motivation to solve problems related to their care. To answer this question, we manipulated reproductive success through brood size and measured subsequent problem-solving performance in wild great tit parents. Our results show that brood size manipulation did not affect the probability to solve the task. Moreover, solver pairs fledged more young than non-solver pairs independently of brood size treatment in one of the two experimental years and they showed higher nestling provisioning rate in both years. Overall, it shows that problem-solving performance was not driven by motivation and suggest that problem-solvers may achieve higher fledging success through higher provisioning rates. Our study constitutes a first key step toward a mechanistic understanding of the consequences of innovation ability for individual fitness in the wild.
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| 2. |
- Cauchard, Laure, et al.
(författare)
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Effect of an anti-malaria drug on behavioural performance on a problem-solving task : An experiment in wild great tits
- 2016
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Ingår i: Behavioural Processes. - : Elsevier BV. - 0376-6357 .- 1872-8308. ; 133, s. 24-30
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Tidskriftsartikel (refereegranskat)abstract
- Malaria parasites have been shown to decrease host fitness in several species in the wild and their detrimental effects on host cognitive ability are well established in humans. However, experimental demonstrations of detrimental effects on non-human host behaviour are currently limited. In this study, we experimentally tested whether injections of an anti-malaria drug affected short-term behavioural responses to a problem-solving task during breeding in a wild population of great tits (Parus major) naturally infected with malaria. Adult females treated against malaria were more active than control females, even though they were not more likely to solve the task or learn how to do so, suggesting that energetic constraints could shape differences in some behaviours while changes in cognitive performances might require more time for the neural system to recover or may depend mainly on infection at the developmental stage. Alternatively, parasite load might be a consequence, rather than a cause, of inter individual variation in cognitive performance. These results also suggest that inter-individual as well as inter-population differences in some behavioural traits may be linked to blood parasite load.
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| 3. |
- Cauchard, Laure, et al.
(författare)
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Problem-solving performance is correlated with reproductive success in a wild bird population
- 2013
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 85:1, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- Although interindividual variation in problem-solving ability is well documented, its relation to variation in fitness in the wild remains unclear. We investigated the relationship between performance on a problem-solving task and measures of reproductive success in a wild population of great tits, Parus major. We presented breeding pairs during the nestling provisioning period with a novel string-pulling task requiring the parents to remove an obstacle with their leg that temporarily blocked access to their nestbox. We found that nests where at least one parent solved the task had higher nestling survival until fledging than nests where both parents were nonsolvers. Furthermore, clutch size, hatching success and fledgling number were positively correlated with speed in solving the task. Our study suggests that natural selection may directly act on interindividual variation in problem-solving performance. In light of these results, the mechanisms maintaining between-individual variation in problem-solving performance in natural populations need further investigation.
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| 4. |
- Cauchard, Laure, et al.
(författare)
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The relationship between plumage colouration, problem-solving and learning performance in great tits Parus major
- 2017
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Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 48:9, s. 1246-1253
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies suggest that individuals with better problem-solving and/or learning performance have greater reproductive success, and that individuals may thus benefit from choosing mates based on these performances. However, directly assessing these performances in candidate mates could be difficult. Instead, the use of indirect cues related to problem-solving and/or learning performance, such as condition-dependent phenotypic traits, might be favored. We investigated whether problem-solving and learning performance on a novel non-foraging task correlated with sexually selected plumage colouration in a natural population of great tits Parus major. We found that males successful in solving the task had darker blue-black crowns than non-solvers, and that males solving the task more rapidly over multiple attempts (i.e. learners) exhibited blue-black crowns with higher UV chroma and shorter-wavelength hues than non-learners. In contrast, we found no link between behavioural performance on the task and the yellow breast colouration in either sex. Our findings suggest that blue-black crown colouration could serve as a signal of problem-solving and learning performance in wild great tit males. Further research remains necessary to determine whether different sexually selected traits are used to signal cognitive performance for mate choice, either directly (i.e. cognitive performance influencing individual's health and ornamentation through diet for example) or indirectly (i.e. due to a correlation with a third factor such as individual quality or condition).
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| 5. |
- Dibnah, Alex J., et al.
(författare)
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Vocally mediated consensus decisions govern mass departures from jackdaw roosts
- 2022
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822. ; 32:10, s. 455-456
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Tidskriftsartikel (refereegranskat)abstract
- In the early morning, large groups of up to hundreds or even thousands of roosting birds, sometimes comprising the entire roost population, often take off together in sudden mass departures. These departures commonly occur in low-light conditions and structurally complex habitats where access to visual cues is likely to be restricted. Roosting birds are often highly vocal, leading us to hypothesise that vocalisations, which can propagate over large distances, could provide a means of enabling individuals to agree on when to depart — that is to establish a consensus1 — and thus coordinate the timing of mass movements. Investigations of the role of acoustic signals in coordinating collective decisions have been limited to honeybees2 and relatively small vertebrate groups (<50 individuals)3–5 and have rarely included experimental validation2,3. Here, by combining field recordings with a large-scale experimental manipulation, we show that jackdaws (Corvus monedula) use vocalisations to coordinate mass departures from winter roosts. This provides empirical evidence for vocally-mediated consensus decision-making in large vertebrate groups.
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| 6. |
- Garnham, Laura, 1988-
(författare)
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Causes and Consequences of Impulsivity in Red Junglefowl
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Throughout the animal kingdom, animals vary in cognition (i.e., how they acquire, process, store, and act on environmental information). Yet, the causes and consequences of this variation are currently unclear. Inhibitory control is one such aspect of cognition that typically varies between individuals within all species investigated. Variation in inhibitory control underlies variation in impulsivity (i.e., the tendency to act without planning or considering the consequences). The causes and consequences of variation in impulsivity are, themselves, rarely explored, despite that these may have important ecological and evolutionary implications. My thesis (spanning 5 papers), therefore, aimed to fill some of these gaps by taking a holistic approach and investigating causes and consequences of variation in impulsivity (specifically, impulsive action and persistence measured in a detour task) in red junglefowl (Gallus gallus) males and females, chicks and adults. The red junglefowl was an ideal species for this investigation. Firstly, they show individual variation in impulsivity throughout their lives. They are also typically food motivated, and easily habituated to handling and new situations, which means they commonly willingly participate in behavioural and cognitive tests. Furthermore, they are precocial, which means that they can be hatched and raised without mothers, thus reducing parental effects. Finally, the large, accumulated knowledge of red junglefowl behaviour and cognition aids interpretations regarding this. As differences in experience early in life have been found to affect impulsivity, papers I and II empirically explored whether variation in two previously uninvestigated experiences in early life (exposure to enrichment, and social group size, respectively) influenced impulsivity. The dopaminergic and serotonergic systems are important signalling systems in the brain, which have been found to link to impulsivity in other species. Therefore, in paper I, I also explored if variation in impulsive action and persistence was connected to variation in dopaminergic or serotonergic gene expression. As impulsivity links to inhibitory control, in looking at the effect of group size on impulsivity, paper II explored the hypotheses that social environment affects cognition (e.g., that social environments which are assumed to be more cognitively demanding will lead to better cognitive performance, a.k.a., the social intelligence hypothesis). To uncover potential mechanisms by which group size could affect impulsivity, besides from variation in cognitive demand, paper II also investigated if behaviours that could covary with group size linked to impulsivity. As emotional arousal has been linked to impulsivity, in another species, and impulsivity is implicated in welfare issues, paper III looked into how both positive and negative affective states (which can be used to measure welfare) related to impulsivity. Prior to my thesis, whether variation in impulsivity could potentially affect animal welfare was scarcely explored. To better understand the potential consequences of impulsivity, and, thus, how selection could act on impulsivity, papers IV and V looked at potential implications of variation in impulsivity for social status (paper IV and V), foraging efficiency, and risk taking (paper V). My results showed that impulsivity could be consistent over time periods of weeks (in chicks, paper II) to months (in adults, paper V). Thus, impulsivity describes a characteristic of the individual. However, individuals could still learn to become less impulsive (paper I). Exposure to enrichment in early life could affect how impulsively individuals behaved. Environmental enrichment increased impulsivity, as did cognitive enrichment to a greater degree (paper I). Impulsive action, and persistence, correlated somewhat with brain gene expression of dopaminergic and serotonergic genes (DRD1, TPH; paper I). The social group size individuals experimentally experienced in early life did not affect their impulsivity (paper II). However, variation in impulsivity was connected to variation in activity, boldness, neophobia, and stress (paper II). Further, more impulsive individuals had less negative, more positive, affective states, but only when they were young chicks, and not as older chicks or adults (paper VI). No links were found between impulsivity and social status (paper IV and V), foraging efficiency, or risk taking (paper V). Taken together, paper I suggests that underlying explanations to observed individual variation in impulsivity could include variation in early life experiences and in dopaminergic and serotonergic gene expression, while paper II suggests that impulsivity may not be influenced by social aspects early in life. Papers II and III demonstrate that variation in impulsivity can associate with variation in behaviours and affective states (though these associations may vary over ontogeny), with the latter finding implying that variation in impulsivity could have welfare implications. Papers IV and V indicate that variation in impulsivity may have limited consequences for individuals in contexts that could affect reproduction or survival. Thus, it may not necessarily be costly to individuals if they are more impulsive than others. This, in turn, could help explain why variation in inhibitory control exists, because limited consequences of variation could result in low selection against variation. Overall, through the investigations conducted in its 5 papers, my thesis improves our understanding the potential causes and consequences of variation in impulsivity. As impulsivity is underlain by an aspect of cognition (inhibitory control), in exploring the causes and consequences of variation in impulsivity, my thesis also provides knowledge on causes and consequences of individual variation in cognition.
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| 7. |
- Griffith, Simon C., et al.
(författare)
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Variation in reproductive success across captive populations: Methodological differences, potential biases and opportunities
- 2017
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Ingår i: Ethology. - : Wiley. - 1439-0310 .- 0179-1613. ; 123:1, s. 1-29
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding of fundamental organismal biology has been disproportionately influenced by studies of a relatively small number of ‘model’ species extensively studied in captivity. Laboratory populations of model species are commonly subject to a number of forms of past and current selection that may affect experimental outcomes. Here, we examine these processes and their outcomes in one of the most widely used vertebrate species in the laboratory – the zebra finch (Taeniopygia guttata). This important model species is used for research across a broad range of fields, partly due to the ease with which it can be bred in captivity. However despite this perceived amenability, we demonstrate extensive variation in the success with which different laboratories and studies bred their subjects, and overall only 64% of all females that were given the opportunity, bred successfully in the laboratory. We identify and review several environmental, husbandry, life-history and behavioural factors that potentially contribute to this variation. The variation in reproductive success across individuals could lead to biases in experimental outcomes and drive some of the heterogeneity in research outcomes across studies. The zebra finch remains an excellent captive animal system and our aim is to sharpen the insight that future studies of this species can provide, both to our understanding of this species and also with respect to the reproduction of captive animals more widely. We hope to improve systematic reporting methods and that further investigation of the issues we raise will lead both to advances in our fundamental understanding of avian reproduction as well as to improvements in future welfare and experimental efficiency.
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