| 1. |
- Appelgren, A., et al.
(author)
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Relative fitness of a generalist parasite on two alternative hosts : a cross-infestation experiment to test host specialization of the hen flea Ceratophyllus gallinae (Schrank)
- 2016
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In: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 29:5, s. 1091-1101
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Journal article (peer-reviewed)abstract
- Host range is a key element of a parasite's ecology and evolution and can vary greatly depending on spatial scale. Generalist parasites frequently show local population structure in relation to alternative sympatric hosts (i.e. host races) and may thus be specialists at local scales. Here, we investigated local population specialization of a common avian nest-based parasite, the hen flea Ceratophyllus gallinae (Schrank), exploiting two abundant host species that share the same breeding sites, the great tit Parus major (Linnaeus) and the collared flycatcher Ficedula albicollis (Temminck). We performed a cross-infestation experiment of fleas between the two host species in two distinct study areas during a single breeding season and recorded the reproductive success of both hosts and parasites. In the following year, hosts were monitored again to assess the long-term impact of cross-infestation. Our results partly support the local specialization hypothesis: in great tit nests, tit fleas caused higher damage to their hosts than flycatcher fleas, and in collared flycatcher nests, flycatcher fleas had a faster larval development rates than tit fleas. However, these results were significant in only one of the two studied areas, suggesting that the location and history of the host population can modulate the specialization process. Caution is therefore called for when interpreting single location studies. More generally, our results emphasize the need to explicitly account for host diversity in order to understand the population ecology and evolutionary trajectory of generalist parasites.
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| 2. |
- Appelgren, Anais S. C., et al.
(author)
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Gene flow and adaptive potential in a generalist ectoparasite
- 2018
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In: BMC Evolutionary Biology. - : BMC. - 1471-2148. ; 18
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Journal article (peer-reviewed)abstract
- Background: In host-parasite systems, relative dispersal rates condition genetic novelty within populations and thus their adaptive potential. Knowledge of host and parasite dispersal rates can therefore help us to understand current interaction patterns in wild populations and why these patterns shift over time and space. For generalist parasites however, estimates of dispersal rates depend on both host range and the considered spatial scale. Here, we assess the relative contribution of these factors by studying the population genetic structure of a common avian ectoparasite, the hen flea Ceratophyllus gallinae, exploiting two hosts that are sympatric in our study population, the great tit Paws major and the collared flycatcher Ficedula albicollis. Previous experimental studies have indicated that the hen flea is both locally maladapted to great tit populations and composed of subpopulations specialized on the two host species, suggesting limited parasite dispersal in space and among hosts, and a potential interaction between these two structuring factors. Results: C gallinae fleas were sampled from old nests of the two passerine species in three replicate wood patches and were genotyped at microsatellite markers to assess population genetic structure at different scales (among individuals within a nest among nests and between host species within a patch and among patches). As expected, significant structure was found at all spatial scales and between host species, supporting the hypothesis of limited dispersal in this parasite. Clustering analyses and estimates of relatedness further suggested that inbreeding regularly occurs within nests. Patterns of isolation by distance within wood patches indicated that flea dispersal likely occurs in a stepwise manner among neighboring nests. From these data, we estimated that gene flow in the hen flea is approximately half that previously described for its great tit hosts. Conclusion: Our results fall in line with predictions based on observed patterns of adaptation in this host-parasite system, suggesting that parasite dispersal is limited and impacts its adaptive potential with respect to its hosts. More generally, this study sheds light on the complex interaction between parasite gene flow, local adaptation and host specialization within a single host-parasite system.
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| 3. |
- Bailey, Liam D., et al.
(author)
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Bird populations most exposed to climate change are less sensitive to climatic variation
- 2022
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Journal article (peer-reviewed)abstract
- The phenology of many species shows strong sensitivity to climate change; however, with few large scale intra-specific studies it is unclear how such sensitivity varies over a species’ range. We document large intra-specific variation in phenological sensitivity to temperature using laying date information from 67 populations of two co-familial European songbirds, the great tit (Parus major) and blue tit (Cyanistes caeruleus), covering a large part of their breeding range. Populations inhabiting deciduous habitats showed stronger phenological sensitivity than those in evergreen and mixed habitats. However, populations with higher sensitivity tended to have experienced less rapid change in climate over the past decades, such that populations with high phenological sensitivity will not necessarily exhibit the strongest phenological advancement. Our results show that to effectively assess the impact of climate change on phenology across a species’ range it will be necessary to account for intra-specific variation in phenological sensitivity, climate change exposure, and the ecological characteristics of a population.
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| 4. |
- Bize, Pierre, et al.
(author)
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Negative phenotypic and genetic correlation between natal dispersal propensity and nest-defence behaviour in a wild bird
- 2017
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In: Biology Letters. - : ROYAL SOCIETY. - 1744-9561 .- 1744-957X. ; 13:7
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Journal article (peer-reviewed)abstract
- Natural selection is expected to favour the integration of dispersal and phenotypic traits allowing individuals to reduce dispersal costs. Accordingly, associations have been found between dispersal and personality traits such as aggressiveness and exploration, which may facilitate settlement in a novel environment. However, the determinism of these associations has only rarely been explored. Here, we highlight the functional integration of individual personality in nest-defence behaviour and natal dispersal propensity in a long-lived colonial bird, the Alpine swift (Alms melba), providing insights into genetic constraints shaping the coevolution of these two traits. We report a negative association between natal dispersal and nest-defence (i.e. risk taking) behaviour at both the phenotypic and genetic level. This negative association may result from direct selection if risk-averseness benefits natal dispersers by reducing the costs of settlement in an unfamiliar environment, or from indirect selection if individuals with lower levels of nest defence also show lower levels of aggressiveness, reducing costs of settlement among unfamiliar neighbours in a colony. In both cases, these results highlight that risk taking is an important behavioural trait to consider in the study of dispersal evolution.
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| 5. |
- Boucaud, Ingrid C. A., et al.
(author)
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Interactive vocal communication at the nest by parent Great Tits Parus major
- 2016
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In: Ibis. - : Wiley. - 0019-1019 .- 1474-919X. ; 158:3, s. 630-644
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Journal article (peer-reviewed)abstract
- Although most bird species show monogamous pair bonds and bi-parental care, little is known of how mated birds coordinate their activities. Whether or not partners communicate with each other to adjust their behaviour remains an open question. During incubation and the first days after hatching, one parent - generally the female - stays in the nest for extended periods, and might depend on acoustic communication to exchange information with its mate outside. The Great Tit Parus major is an interesting study system to investigate intra-pair communication at the nest because males address songs to their mate while she is in the nest cavity, and females answer the male from the cavity with calls. However, the function of this communication remains unknown. In this study, we recorded the vocalizations and observed the resulting behaviour of Great Tit pairs around the nest at different breeding stages (laying, incubation and chick-rearing). We observed vocal exchanges (vocalization bouts, alternated on the same tempo, between the female inside the nest and her male outside) in three contexts with different outcomes: (1) the female left the nest, (2) the male entered the box with food, and the female then used specific call types, (3) mates stopped calling but did not leave or enter the nest. The structure of vocal exchanges was globally stable between contexts, but females used calls with an up-shifted spectrum during exchanges, at the end of which they left the nest or the male entered the nest. Birds vocalized more and at higher tempo during exchanges that ended up in feeding inside the nest. Birds also vocalized more during exchanges taking place during laying - a period of active mate guarding - than during incubation. We conclude that vocal exchanges could signal the females' need for food and the males' mate guarding behaviour, and discuss other possible functions of this communication.
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| 6. |
- Cauchard, Laure, et al.
(author)
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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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In: Frontiers in Ecology and Evolution. - : FRONTIERS MEDIA SA. - 2296-701X. ; 5
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Journal article (peer-reviewed)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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| 7. |
- Cauchard, Laure, et al.
(author)
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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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In: Behavioural Processes. - : Elsevier BV. - 0376-6357 .- 1872-8308. ; 133, s. 24-30
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Journal article (peer-reviewed)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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| 8. |
- Cauchard, Laure, et al.
(author)
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How to solve novel problems : the role of associative learning in problem-solving performance in wild great tits Parus major
- 2024
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In: Animal Cognition. - : Springer. - 1435-9448 .- 1435-9456. ; 27
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Journal article (peer-reviewed)abstract
- Although problem-solving tasks are frequently used to assess innovative ability, the extent to which problem-solving performance reflects variation in cognitive skills has been rarely formally investigated. Using wild breeding great tits facing a new non-food motivated problem-solving task, we investigated the role of associative learning in finding the solution, compared to multiple other non-cognitive factors. We first examined the role of accuracy (the proportion of contacts made with the opening part of a string-pulling task), neophobia, exploration, activity, age, sex, body condition and participation time on the ability to solve the task. To highlight the effect of associative learning, we then compared accuracy between solvers and non-solvers, before and after the first cue to the solution (i.e., the first time they pulled the string opening the door). We finally compared accuracy over consecutive entrances for solvers. Using 884 observations from 788 great tits tested from 2010 to 2015, we showed that, prior to initial successful entrance, solvers were more accurate and more explorative than non-solvers, and that females were more likely to solve the task than males. The accuracy of solvers, but not of non-solvers, increased significantly after they had the opportunity to associate string pulling with the movement of the door, giving them a first cue to the task solution. The accuracy of solvers also increased over successive entrances. Our results demonstrate that variations in problem-solving performance primarily reflect inherent individual differences in associative learning, and are also to a lesser extent shaped by sex and exploratory behaviour.
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| 9. |
- Cauchard, Laure, et al.
(author)
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Inter-individual variation in provisioning rate, prey size and number, and links to total prey biomass delivered to nestlings in the Collared Flycatcher (Ficedula albicollis)
- 2021
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In: Avian Research. - : BioMed Central (BMC). - 2053-7166. ; 12
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Journal article (peer-reviewed)abstract
- Background: In bird species where offspring growth and survival rely on parents' food provisioning, parents can maximise their fitness by increasing the quantity and/or the quality of preys delivered to their offspring. Many studies have focused on inter-individual variation in feeding rate, yet this measure may not accurately reflect the total amount of food (i.e. energy) provided by parents if there is large variation in the quantity and quality of preys at each feeding. Here, we explored the relative role of individual (sex, age, body condition), breeding (hatching date, brood size) and environmental (temperature) factors on feeding rate, prey number, size and quality, and their contribution to total prey biomass delivered to the nestlings of 164 Collared Flycatcher (Ficedula albicollis) parents in 98 nests.Results: Preys delivered to the nest were mainly larvae (53.6%) and flying insects (45.6%). Feeding rate increased with brood size and age, and was higher in males than females. Mean prey number decreased, but mean prey size increased, as the season progressed and parents feeding their brood with primary larvae brought more preys per visit. Relationships between feeding rate, mean prey number and size remained when taking into account the provisioning quality: parents brought either a large number of small prey or a small number of larger items, and the force of the trade-offs between feeding rate and mean prey number and size depended on the quality of the provisioning of the parents. Whatever the percentage of larvae among preys in the provisioning, the variance in total prey biomass was foremost explained by feeding rate (65.1% to 76.6%) compared to mean prey number (16.4% to 26%) and prey size (2.7% to 4%).Conclusions: Our study shows that variation in feeding rate, prey number, size, but not quality (i.e. percentage of larvae), were influenced by individual factors (sex and age) and breeding decisions (brood size and timing of breeding) and that, whatever the provisioning strategy adopted, feeding rate was the best proxy of the total biomass delivered to the nestlings.
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| 10. |
- Cauchard, Laure, et al.
(author)
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Problem-solving performance is correlated with reproductive success in a wild bird population
- 2013
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In: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 85:1, s. 19-26
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Journal article (peer-reviewed)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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