| 1. |
- Brönmark, Christer, et al.
(författare)
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There and back again : migration in freshwater fishes
- 2014
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Ingår i: Canadian Journal of Zoology. - Ottawa : CANADIAN SCIENCE PUBLISHING. - 0008-4301 .- 1480-3283. ; 92:6, s. 467-479
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Tidskriftsartikel (refereegranskat)abstract
- Animal migration is an amazing phenomenon that has fascinated humans for long. Many freshwater fishes also show remarkable migrations, whereof the spectacular mass migrations of salmonids from the spawning streams are the most well known and well studied. However, recent studies have shown that migration occurs in a range of freshwater fish taxa from many different habitats. In this review we focus on the causes and consequences of migration in freshwater fishes. We start with an introduction of concepts and categories of migration, and then address the evolutionary causes that drive individuals to make these migratory journeys. The basis for the decision of an individual fish to migrate or stay resident is an evaluation of the costs and benefits of different strategies to maximize its lifetime reproductive effort. We provide examples by discussing our own work on the causes behind seasonal migration in a cyprinid fish, roach (Rutilus rutilus (L., 1758)), within this framework. We then highlight different adaptations that allow fish to migrate over sometimes vast journeys across space, including capacity for orientation, osmoregulation, and efficient energy expenditure. Following this we consider the consequences of migration in freshwater fish from ecological, evolutionary, and conservation perspectives, and finally, we detail some of the recent developments in the methodologies used to collect data on fish migration and how these could be used in future research.
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| 2. |
- Chapman, Ben, et al.
(författare)
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A foraging cost of migration for a partially migratory cyprinid fish
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- Migration has evolved as a strategy to maximise individual fitness in response to seasonally changing ecological and environmental conditions. However, migration can also incur costs, and quantifying these costs can provide important clues to the ultimate ecological forces that underpin migratory behaviour. A key emerging model to explain migration in many systems posits that migration is driven by seasonal changes to a predation/growth potential (p/g) trade-off that a wide range of animals face. In this study we assess a key assumption of this model for a common cyprinid partial migrant, the roach Rutilus rutilus, which migrates from shallow lakes to streams during winter. By sampling fish from stream and lake habitats in the autumn and spring and measuring their stomach fullness and diet composition, we tested if migrating roach pay a cost of reduced foraging when migrating. Resident fish had fuller stomachs containing more high quality prey items than migrant fish. Hence, we document a feeding cost to migration in roach, which adds additional support for the validity of the p/g model of migration in freshwater systems.
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| 3. |
- Chapman, Ben B, et al.
(författare)
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Patterns of Animal Migration
- 2014
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Ingår i: Animal movement across scales. - : Oxford University Press. - 9780199677184 ; , s. 11-35
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Bokkapitel (refereegranskat)
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| 4. |
- Chapman, Ben, et al.
(författare)
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Partial migration in fishes: causes and consequences.
- 2012
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:2, s. 456-478
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Tidskriftsartikel (refereegranskat)abstract
- Partial migration, where only some individuals from a population migrate, has been widely reported in a diverse range of animals. In this paper, what is known about the causes and consequences of partial migration in fishes is reviewed. Firstly, the ultimate and proximate drivers of partial migration are reflected upon: what ecological factors can shape the evolution of migratory dimorphism? How is partial migration maintained over evolutionary timescales? What proximate mechanisms determine whether an individual is migratory or remains resident? Following this, the consequences of partial migration are considered, in an ecological and evolutionary context, and also in an applied sense. Here it is argued that understanding the concept of partial migration is crucial for fisheries and ecosystem managers, and can provide information for conservation strategies. The review concludes with a reflection on the future opportunities in this field, and the avenues of research that are likely to be fruitful to shed light on the enduring puzzle of partial migration in fishes.
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| 5. |
- Chapman, Ben, et al.
(författare)
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Partial migration in fishes: definitions, methodologies and taxonomic distribution.
- 2012
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:2, s. 479-499
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Tidskriftsartikel (refereegranskat)abstract
- Partial migration, where populations are composed of both migratory and resident individuals, is extremely widespread across the animal kingdom. Researchers studying fish movements have long recognized that many fishes are partial migrants, however, no detailed taxonomic review has ever been published. In addition, previous work and synthesis has been hampered by a varied lexicon associated with this phenomenon in fishes. In this review, definitions and important concepts in partial migration research are discussed, and a classification system of the different forms of partial migration in fishes introduced. Next, a detailed taxonomic overview of partial migration in this group is considered. Finally, methodological approaches that ichthyologists can use to study this fascinating phenomenon are reviewed. Partial migration is more widespread amongst fishes than previously thought, and given the array of techniques available to fish biologists to study migratory variation the future of the field looks promising.
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| 6. |
- Chapman, Ben, et al.
(författare)
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To boldly go: individual differences in boldness influence migratory tendency.
- 2011
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X. ; 14, s. 871-876
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Tidskriftsartikel (refereegranskat)abstract
- Ecology Letters (2011) ABSTRACT: Partial migration, whereby only a fraction of the population migrates, is thought to be the most common type of migration in the animal kingdom, and can have important ecological and evolutionary consequences. Despite this, the factors that influence which individuals migrate and which remain resident are poorly understood. Recent work has shown that consistent individual differences in personality traits in animals can be ecologically important, but field studies integrating personality traits with migratory behaviour are extremely rare. In this study, we investigate the influence of individual boldness, an important personality trait, upon the migratory propensity of roach, a freshwater fish, over two consecutive migration seasons. We assay and individually tag 460 roach and show that boldness influences migratory propensity, with bold individuals being more likely to migrate than shy fish. Our data suggest that an extremely widespread personality trait in animals can have significant ecological consequences via influencing individual-level migratory behaviour.
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| 7. |
- Hansson, Lars-Anders, et al.
(författare)
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A lake as a microcosm : Reflections on developments in aquatic ecology
- 2013
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Ingår i: Aquatic Ecology. - : Springer Science and Business Media LLC. - 1386-2588 .- 1573-5125. ; 47, s. 125-135
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we aim at relating Forbes' remarkable paper on "The lake as a microcosm", published 125 years ago, to the present status of knowledge in our own research group. Hence, we relate the observations Forbes made to our own microcosm, Lake Krankesjon in southern Sweden, that has been intensively studied by several research groups for more than three decades. Specifically, we focus on the question: Have we made any significant progress or did Forbes and colleagues blaze the trail through the unknown wilderness and we are mainly paving that intellectual road? We conclude that lakes are more isolated than many other biomes, but have, indeed, many extensions, for example, input from the catchment, fishing and fish migration. We also conclude that irrespective of whether lakes should be viewed as microcosms or not, the paper by Forbes has been exceptionally influential and still is, especially since it touches upon almost all aspects of the lake ecosystem, from individual behaviour to food web interactions and environmental issues. Therefore, there is no doubt that even if 125 years have passed, Forbes' paper still is a source of inspiration and deserves to be read. Hence, although aquatic ecology has made considerable progress over the latest century, Forbes might be viewed as one of the major pioneers and visionary scientists of limnology.
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| 8. |
- Hulthén, Kaj
(författare)
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Causes and consequences of individual variation in anti-predator traits
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Predation imposes a potent evolutionary force on prey, moulding the evolution of traits and diversification of species, and can furthermore have powerful ecological consequences. We know that different species vary in how they cope with their natural enemies, and, consequently, a huge range of anti-predator defences are displayed in nature. Yet there is a growing recognition that, if we zoom into a certain species, or even into a single population of animals, there is still a huge and intriguing amount of individual trait variation. In this thesis I investigate what drives individual variation in anti-predator traits, and the implications of this variation for individual animals in two contrasting systems. Specifically, I explore what underlies inter-individual variation in an induced morphological defence in crucian carp and additionally investigate individuality in migratory strategy, risk-taking behaviour and morphology in another common freshwater fish, the roach. I document links between personality-trait variation and anti-predator strategies suggesting that some individuals engage in compensatory strategies to offset some of the costs associated with one trait with the benefits of another. Individuals with a risk-prone personality type (bold individuals) express a greater morphological defence (crucian carp) and are more likely to undertake a winter migration away from predator-rich lakes (roach) as compared to shyer ones. I also show that bold individuals pay a higher predation cost than individuals that adopt a risk-averse behavioural strategy. Furthermore, roach individuals exposed to perceived predation risk (i.e. to a live predator) prior to the migratory period have a higher migration propensity as compared to roach not experiencing experimental predation risk. I also show that variation in migratory timing differs seasonally, and that, at an individual level, survival is strongly linked with the timing of spring but not with autumn migration. Hence, individual variation in the timing of the migratory journey has powerful fitness consequences. Finally, I explore the morphological correlates of migratory behaviour. I show that body morphology is related to migratory life history, as fish from open lakes (with migration opportunity) and migratory individuals from a partially migratory population have more slender, hydrodynamic morphologies as compared to specimens from closed lakes (no migration opportunity) and residents. In summary, my results highlight the powerful role that ecological forces, such as predation, can have in shaping patterns of individual variation in wild populations of animals, and, importantly, that these different behavioural strategies can have profound consequences for survival and thereby individual fitness. Individual variation in survival as a function of phenotype is the raw material upon which natural selection acts, and yet the ecological drivers of evolution remain poorly studied in many wild populations. Working at the individual level in the wild poses significant challenges, but can provide rich insights into the mechanisms of the interplay between ecosystem dynamics and evolutionary processes.
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| 9. |
- Hulthén, Kaj, et al.
(författare)
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Express yourself: bold individuals induce enhanced morphological defences.
- 2014
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954 .- 0962-8452. ; 281:1776
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Tidskriftsartikel (refereegranskat)abstract
- Organisms display an impressive array of defence strategies in nature. Inducible defences (changes in morphology and/or behaviour within a prey's lifetime) allow prey to decrease vulnerability to predators and avoid unnecessary costs of expression. Many studies report considerable interindividual variation in the degree to which inducible defences are expressed, yet what underlies this variation is poorly understood. Here, we show that individuals differing in a key personality trait also differ in the magnitude of morphological defence expression. Crucian carp showing risky behaviours (bold individuals) expressed a significantly greater morphological defence response when exposed to a natural enemy when compared with shy individuals. Furthermore, we show that fish of different personality types differ in their behavioural plasticity, with shy fish exhibiting greater absolute plasticity than bold fish. Our data suggest that individuals with bold personalities may be able to compensate for their risk-prone behavioural type by expressing enhanced morphological defences.
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| 10. |
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