| 1. |
- Andersson, Matilda L., et al.
(författare)
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Linking behavioural type with cannibalism in Eurasian perch
- 2021
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Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 16:12
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Tidskriftsartikel (refereegranskat)abstract
- The propensity to kill and consume conspecifics (cannibalism) varies greatly between and within species, but the underlying mechanisms behind this variation remain poorly understood. A rich literature has documented that consistent behavioural variation is ubiquitous across the animal kingdom. Such inter-individual behavioural differences, sometimes referred to as personality traits, may have far-reaching ecological consequences. However, the link between predator personality traits and the propensity to engage in cannibalistic interactions remains understudied. Here, we first quantified personality in Eurasian perch (Perca fluviatilis), measured as activity (time spent moving) and sociability (time spent near conspecifics). We then gave perch of contrasting behavioural types the option to consume either conspecific or heterospecific (roach, Rutilus rutilus) prey. Individual perch characterized by a social-active behavioural phenotype (n = 5) selected roach before being cannibalistic, while asocial-inactive perch (n = 17) consumed conspecific and heterospecific prey evenly. Thus, asocial-inactive perch expressed significantly higher rates of cannibalism as compared to social-active individuals. Individual variation in cannibalism, linked to behavioural type, adds important mechanistic understanding to complex population and community dynamics, and also provides insight into the diversity and maintenance of animal personality.
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| 2. |
- Blake, Chelsea A., et al.
(författare)
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Conspecific boldness and predator species determine predation-risk consequences of prey personality
- 2018
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer-Verlag New York. - 0340-5443 .- 1432-0762. ; 72:8, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Individual variation in the behavior of prey can influence predation risk in complex ways. We ran individual roach (Rutilus rutilus), a common freshwater fish, through a standard refuge emergence protocol to characterize their boldness, a key animal personality trait. We then paired a bold and a shy roach and exposed the pair to one of two predator species that have contrasting hunting modes to ascertain how personality traits shaped their survival during predator encounters. When a paired bold and shy prey fish interacted with a perch predator (active foraging mode), bold and shy prey were consumed in almost equal numbers. However, pike predators (ambush foraging mode) selectively consumed more shy prey, and prey body size and boldness score both contributed significantly to which prey fish was eaten. Our findings support the idea that multiple predators with different foraging modes, and hence differential selection on prey personality, could contribute to maintaining variation in personality in prey populations. Furthermore, for social species, including shoaling fish, the ultimate consequences of an individual’s personality may depend upon the personality of its nearby conspecifics. Significance statement: Animals of the same species often look similar, but individuals show differences in their behavior that can have important consequences, for instance when these individuals interact with predators. The common roach is a freshwater fish that shows inter-individual variation in its propensity to take risks, a key personality trait often termed boldness. Variation in boldness may affect the outcome when roach interact with predators, i.e., if they get eaten or survive. However, we found the impact of roachs’ personality type depends on what species of predatory fish they face. When we put a shy and a bold roach together with predatory perch, the roachs’ personality did not significantly affect which individual was eaten. But when the predator was a pike, the predators selectively ate more shy roach, and the likelihood an individual would be eaten depended on their body size.
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| 3. |
- Meurling, Sara, 1977-
(författare)
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The response in native wildlife to an invading pathogen: Swedish amphibians and Batrachochytrium dendrobatidis
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Emerging infectious diseases are causing mortality and declines in wildlife populations globally. My thesis aims to get as clear a picture as possible of the effect the invasive chytrid fungus Batrachochytrium dendrobatidis has on the Swedish amphibian community.In Paper I I performed a large-scale survey testing for the presence of Bd in three regions in Sweden (Southern, Central and Northern). I sampled 1917 amphibians from 101 localities and found that Bd was widespread in southern and central Sweden, occurring in all nine investigated species and in 45.5 % of the sampled sites with an overall prevalence of 13.8%. I found a positive correlation between the temperature at spawning for each species and species prevalence. Species that require higher temperatures for egg-laying are distributed in the southern parts of the country, which led to a higher prevalence in the southern region.In Paper II, I investigated which local environmental factors in breeding habitats, landscape structure and amphibian community affect the occurrence and prevalence of Bd among breeding sites in southern Sweden. Bd prevalence in the four species with the highest prevalence (Bombina bombina, Bufotes variabilis, Epidalea calamita and Rana arvalis) was higher in ponds surrounded by less mature forest, few wetlands, and higher pH.In Papers III and IV, I looked at species and population differences in responses to Bd infection. I performed an infection experiment described in Paper III, where I exposed individuals from two common Swedish species (moor frog R. arvalis and common toad Bufo bufo) originating from two regions (north and south) with two different strains of Bd (from Sweden and the UK). I found that infection led to lower survival and growth in both species, more so in B. bufo than in R. arvalis. Small size proved to be a strong determinant of survival. As individuals from the northern population were significantly smaller than the southern ones, this may have led to the northern populations being more affected by Bd infection. In Paper IV, I studied variation in MHC Class IIB loci in B. bufo along a latitudinal gradient across Sweden. Variation in MCH genes decreased from south to north. Also, differences in survival from the experiment in Paper III could be explained by MHC haplotypes. I found that survival in the southern region was dependent on both Bd-strain and MHC haplotype.
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| 4. |
- Persson, Anders, et al.
(författare)
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Effects of enrichment on simple aquatic food webs
- 2001
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Ingår i: The American Naturalist. ; 157:6, s. 654-669
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Tidskriftsartikel (refereegranskat)abstract
- Simple models, based on Lotka-Volterra types of interactions between predator and prey, predict that enrichment will have a destabilizing effect on
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| 5. |
- Randsalu Wendrup, Linda, et al.
(författare)
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Combining limnology and palaeolimnology to investigate recent regime shifts in a shallow, eutrophic lake
- 2014
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Ingår i: Journal of Paleolimnology. - : Springer Science and Business Media LLC. - 0921-2728 .- 1573-0417. ; 51:3, s. 437-448
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we demonstrate that an integrated approach, combining palaeolimnological records and limnological monitoring data, can increase our understanding of changing ecological patterns and processes in shallow lakes. We focused on recent regime shifts in shallow Lake Krankesjon, southern Sweden, including the collapse of the clear-water state in 1975 and its subsequent recovery in the late 1980s. We used diatom, hydrocarbon and biogenic silica sediment records, in concert with limnological data sets on nutrient concentrations, water clarity, chlorophyll-a and water depth, to investigate the shifts. The shift from clear to turbid conditions was abrupt and occurred over 1 to 2 years, whereas recovery of the clear-water state was more gradual, taking 4-5 years. In 1978, shortly after the first regime shift in water clarity, the diatom community underwent a significant shift. It became less diverse, with decreased abundance of epiphytic and planktonic taxa. Despite rising phosphorus concentrations and lower abundance of submerged macrophytes, Lake Krankesjon has remained in the clear-water state over the past 20 years, although this state seems to be increasingly unstable and susceptible to collapse. The complex reactions of the entire lake ecosystem to major changes in lake-water clarity, as shown by the palaeolimnological variables investigated in this study, emphasize the importance of careful lake and catchment management if a stable, clear-water state is desired.
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| 6. |
- Svanbäck, Richard, et al.
(författare)
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The interaction between predation risk and food ration on behavior and morphology of Eurasian perch
- 2017
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 7:20, s. 8567-8577
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Tidskriftsartikel (refereegranskat)abstract
- The risk of both predation and food level has been shown to affect phenotypic development of organisms. However, these two factors also influence animal behavior that in turn may influence phenotypic development. Hence, it might be difficult to disentangle the behavioral effect from the predator or resource-level effects. This is because the presence of predators and high resource levels usually results in a lower activity, which in turn affects energy expenditure that is used for development and growth. It is therefore necessary to study how behavior interacts with changes in body shape with regard to resource density and predators. Here, we use the classic predator-induced morphological defense in fish to study the interaction between predator cues, resource availability, and behavioral activity with the aim to determine their relative contribution to changes in body shape. We show that all three variables, the presence of a predator, food level, and activity, both additively and interactively, affected the body shape of perch. In general, the presence of predators, lower swimming activity, and higher food levels induced a deep body shape, with predation and behavior having similar effect and food treatment the smallest effect. The shape changes seemed to be mediated by changes in growth rate as body condition showed a similar effect as shape with regard to food-level and predator treatments. Our results suggests that shape changes in animals to one environmental factor, for example, predation risk, can be context dependent, and depend on food levels or behavioral responses. Theoretical and empirical studies should further explore how this context dependence affects fitness components such as resource gain and mortality and their implications for population dynamics.
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| 7. |
- Vinterstare, Jerker, et al.
(författare)
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Predation risk and the evolution of a vertebrate stress response : Parallel evolution of stress reactivity and sexual dimorphism
- 2021
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Ingår i: Journal of Evolutionary Biology. - : John Wiley & Sons. - 1010-061X .- 1420-9101. ; 34:10, s. 1554-1567
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Tidskriftsartikel (refereegranskat)abstract
- Predation risk is often invoked to explain variation in stress responses. Yet, the answers to several key questions remain elusive, including the following: (1) how predation risk influences the evolution of stress phenotypes, (2) the relative importance of environmental versus genetic factors in stress reactivity and (3) sexual dimorphism in stress physiology. To address these questions, we explored variation in stress reactivity (ventilation frequency) in a post-Pleistocene radiation of live-bearing fish, where Bahamas mosquitofish (Gambusia hubbsi) inhabit isolated blue holes that differ in predation risk. Individuals of populations coexisting with predators exhibited similar, relatively low stress reactivity as compared to low-predation populations. We suggest that this dampened stress reactivity has evolved to reduce energy expenditure in environments with frequent and intense stressors, such as piscivorous fish. Importantly, the magnitude of stress responses exhibited by fish from high-predation sites in the wild changed very little after two generations of laboratory rearing in the absence of predators. By comparison, low-predation populations exhibited greater among-population variation and larger changes subsequent to laboratory rearing. These low-predation populations appear to have evolved more dampened stress responses in blue holes with lower food availability. Moreover, females showed a lower ventilation frequency, and this sexual dimorphism was stronger in high-predation populations. This may reflect a greater premium placed on energy efficiency in live-bearing females, especially under high-predation risk where females show higher fecundities. Altogether, by demonstrating parallel adaptive divergence in stress reactivity, we highlight how energetic trade-offs may mould the evolution of the vertebrate stress response under varying predation risk and resource availability.
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