Being faced with unknown environments is a concomitant challenge of species' range expansions... more Being faced with unknown environments is a concomitant challenge of species' range expansions. Strategies to cope with this challenge include the adaptation to local conditions and a flexibility in resource exploitation. The gulls of the <i>Larus argentatus-fuscus-cachinnans</i> group form a system in which ecological flexibility might have enabled them to expand their range considerably, and to colonize urban environments. However, on a population level both flexibility and local adaptation lead to signatures of differential habitat use in different environments, and these processes are not easily distinguished. Using the lesser black-backed gull (<i>Larus fuscus</i>) as a system, we put both flexibility and local adaptation to a test. We compare habitat use between two spatially separated populations, and use a translocation experiment during which individuals were released into novel environment. The experiment revealed that on a population-level flexi...
Being faced with unknown environments is a concomitant challenge of species' range expansions... more Being faced with unknown environments is a concomitant challenge of species' range expansions. Strategies to cope with this challenge include the adaptation to local conditions and a flexibility in resource exploitation. The gulls of the <i>Larus argentatus-fuscus-cachinnans</i> group form a system in which ecological flexibility might have enabled them to expand their range considerably, and to colonize urban environments. However, on a population level both flexibility and local adaptation lead to signatures of differential habitat use in different environments, and these processes are not easily distinguished. Using the lesser black-backed gull (<i>Larus fuscus</i>) as a system, we put both flexibility and local adaptation to a test. We compare habitat use between two spatially separated populations, and use a translocation experiment during which individuals were released into novel environment. The experiment revealed that on a population-level flexibility best explains the differences in habitat use between the two populations. We think that our results suggest that the range expansion and huge success of this species complex could be a result of its broad ecological niche and flexibility in the exploitation of resources. However, this also advises caution when using species distribution models to extrapolate habitat use across space.
Individuals vary in their immune response and, as a result, some are more susceptible to infectio... more Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about which components of immune pathways are responsible for this variation, but understanding these underlying processes could allow us to predict the outcome of infection for an individual, and to manage their health more effectively. In this study, we describe transcriptome-wide variation in immune response (to a standardised challenge) in a wild population of field voles (Microtus agrestis). We find that this variation can be categorised into three main types. We also identify markers, across these three categories, which display particularly strong individual variation in response. This work shows how a simple standardised challenge performed on a natural population can reveal complex patterns of natural variation in immune response.
In the context of the immunocompetence handicap hypothesis, we explored how differences in parasi... more In the context of the immunocompetence handicap hypothesis, we explored how differences in parasite load affect the way in which sexual ornaments codify infor-mation about individual quality. We studied variation in sexual signals in two Ibe-rian populations of the lizard Psammodromus algirus, a species in which sexually active males display a red head coloration. In one population, males were free of tick nymphs, whereas in the other one all males were tick-infested (mean of 12.7 tick nymphs/individual).At the onset of the breeding season, the red-coloured sur-face was larger in the non-parasitized population than in the parasitized one, whereas the opposite was true for colour saturation. We experimentally simulated a bacterial infection (by intraperitoneal injection of lipopolysaccharide) to examine the effects of immune activation on the expression of this sexual ornament. In the non-parasitized population, our treatment caused a reduction in the red-coloured surface of experimental males, whereas in the parasitized population it caused a decrease in colour saturation. In the parasitized population, males that displayed sexual coloration were larger, and had fewer parasites, than uncoloured ones, and inflammatory response to lipopolysaccharide injection in the palm of the hind paw was negatively correlated with colour saturation, but not with colour extension. Thus, we suggest parasites not only constrained the expression of sexual orna-ments, but they also changed the signal properties that conveyed useful information about the quality of their bearers.
<p>(Sisargas (Galicia, Spain); Delta (Ebro delta, Spain); Moerdjik (The Netherlands); Häme ... more <p>(Sisargas (Galicia, Spain); Delta (Ebro delta, Spain); Moerdjik (The Netherlands); Häme (Finland); Kokkola (Finland). Significant differences among populations are denoted by letters.</p><p><sup>ab</sup> denote differences among populations.</p><p>Pathogen prevalence (current protozoan infections and viral serology, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118279#sec002" target="_blank">methods</a>) in the five populations of the study.</p
During migratory journeys, birds may become displaced from their normal migratory route. Experime... more During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from > 60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migrat...
During migratory journeys, birds may become displaced from their normal migratory route. Experime... more During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from > 60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances.
The ability to control infections is a key trait for migrants that must be balanced against other... more The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus) with different migratory strategies. We found higher activity of natural antibodies in long distance migrants from the nominate subspecies L.f.fuscus. Circulating levels of IgY showed large variation at the population level, while immune parameters associated with antimicrobial activity showed extensive variation at the individual level irrespective of population or migratory strategy. Pathogen prevalence showed large geographical variation. However, the seroprevalence of one of the gull-specific subtypes of avian influenza (H16) was associated to the migratory strategy, with lower prevalence among the long-distance migrants, suggesting that migr...
Resumen En esta práctica se estudian la diversidad de la organización y estructura de los represe... more Resumen En esta práctica se estudian la diversidad de la organización y estructura de los representantes del filo Moluscos. Se estudia de forma especial la concha de los grupos más importantes. Se explica la disección de un mejillón, Mytilus edulis Linnaeus, 1758.
Being faced with unknown environments is a concomitant challenge of species' range expansions... more Being faced with unknown environments is a concomitant challenge of species' range expansions. Strategies to cope with this challenge include the adaptation to local conditions and a flexibility in resource exploitation. The gulls of the <i>Larus argentatus-fuscus-cachinnans</i> group form a system in which ecological flexibility might have enabled them to expand their range considerably, and to colonize urban environments. However, on a population level both flexibility and local adaptation lead to signatures of differential habitat use in different environments, and these processes are not easily distinguished. Using the lesser black-backed gull (<i>Larus fuscus</i>) as a system, we put both flexibility and local adaptation to a test. We compare habitat use between two spatially separated populations, and use a translocation experiment during which individuals were released into novel environment. The experiment revealed that on a population-level flexi...
Being faced with unknown environments is a concomitant challenge of species' range expansions... more Being faced with unknown environments is a concomitant challenge of species' range expansions. Strategies to cope with this challenge include the adaptation to local conditions and a flexibility in resource exploitation. The gulls of the <i>Larus argentatus-fuscus-cachinnans</i> group form a system in which ecological flexibility might have enabled them to expand their range considerably, and to colonize urban environments. However, on a population level both flexibility and local adaptation lead to signatures of differential habitat use in different environments, and these processes are not easily distinguished. Using the lesser black-backed gull (<i>Larus fuscus</i>) as a system, we put both flexibility and local adaptation to a test. We compare habitat use between two spatially separated populations, and use a translocation experiment during which individuals were released into novel environment. The experiment revealed that on a population-level flexibility best explains the differences in habitat use between the two populations. We think that our results suggest that the range expansion and huge success of this species complex could be a result of its broad ecological niche and flexibility in the exploitation of resources. However, this also advises caution when using species distribution models to extrapolate habitat use across space.
Individuals vary in their immune response and, as a result, some are more susceptible to infectio... more Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about which components of immune pathways are responsible for this variation, but understanding these underlying processes could allow us to predict the outcome of infection for an individual, and to manage their health more effectively. In this study, we describe transcriptome-wide variation in immune response (to a standardised challenge) in a wild population of field voles (Microtus agrestis). We find that this variation can be categorised into three main types. We also identify markers, across these three categories, which display particularly strong individual variation in response. This work shows how a simple standardised challenge performed on a natural population can reveal complex patterns of natural variation in immune response.
In the context of the immunocompetence handicap hypothesis, we explored how differences in parasi... more In the context of the immunocompetence handicap hypothesis, we explored how differences in parasite load affect the way in which sexual ornaments codify infor-mation about individual quality. We studied variation in sexual signals in two Ibe-rian populations of the lizard Psammodromus algirus, a species in which sexually active males display a red head coloration. In one population, males were free of tick nymphs, whereas in the other one all males were tick-infested (mean of 12.7 tick nymphs/individual).At the onset of the breeding season, the red-coloured sur-face was larger in the non-parasitized population than in the parasitized one, whereas the opposite was true for colour saturation. We experimentally simulated a bacterial infection (by intraperitoneal injection of lipopolysaccharide) to examine the effects of immune activation on the expression of this sexual ornament. In the non-parasitized population, our treatment caused a reduction in the red-coloured surface of experimental males, whereas in the parasitized population it caused a decrease in colour saturation. In the parasitized population, males that displayed sexual coloration were larger, and had fewer parasites, than uncoloured ones, and inflammatory response to lipopolysaccharide injection in the palm of the hind paw was negatively correlated with colour saturation, but not with colour extension. Thus, we suggest parasites not only constrained the expression of sexual orna-ments, but they also changed the signal properties that conveyed useful information about the quality of their bearers.
<p>(Sisargas (Galicia, Spain); Delta (Ebro delta, Spain); Moerdjik (The Netherlands); Häme ... more <p>(Sisargas (Galicia, Spain); Delta (Ebro delta, Spain); Moerdjik (The Netherlands); Häme (Finland); Kokkola (Finland). Significant differences among populations are denoted by letters.</p><p><sup>ab</sup> denote differences among populations.</p><p>Pathogen prevalence (current protozoan infections and viral serology, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118279#sec002" target="_blank">methods</a>) in the five populations of the study.</p
During migratory journeys, birds may become displaced from their normal migratory route. Experime... more During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from > 60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migrat...
During migratory journeys, birds may become displaced from their normal migratory route. Experime... more During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from > 60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances.
The ability to control infections is a key trait for migrants that must be balanced against other... more The ability to control infections is a key trait for migrants that must be balanced against other costly features of the migratory life. In this study we explored the links between migration and disease ecology by examining natural variation in parasite exposure and immunity in several populations of Lesser Black-backed Gulls (Larus fuscus) with different migratory strategies. We found higher activity of natural antibodies in long distance migrants from the nominate subspecies L.f.fuscus. Circulating levels of IgY showed large variation at the population level, while immune parameters associated with antimicrobial activity showed extensive variation at the individual level irrespective of population or migratory strategy. Pathogen prevalence showed large geographical variation. However, the seroprevalence of one of the gull-specific subtypes of avian influenza (H16) was associated to the migratory strategy, with lower prevalence among the long-distance migrants, suggesting that migr...
Resumen En esta práctica se estudian la diversidad de la organización y estructura de los represe... more Resumen En esta práctica se estudian la diversidad de la organización y estructura de los representantes del filo Moluscos. Se estudia de forma especial la concha de los grupos más importantes. Se explica la disección de un mejillón, Mytilus edulis Linnaeus, 1758.
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