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  • 1. Baglione, V
    et al.
    Canestrari, D
    Marcos, JM
    Ekman, Jan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Experimentally increased food resources in the natal territory promote offspring philopatry and helping in cooperatively breeding carrion crows.2006In: Proceedings of the Royal Society series B, Vol. 273, p. 1529-1535Article in journal (Refereed)
  • 2. Balakrishnan, Christopher N.
    et al.
    Ekblom, Robert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Voelker, Martin
    Westerdahl, Helena
    Godinez, Ricardo
    Kotkiewicz, Holly
    Burt, David W.
    Graves, Tina
    Griffin, Darren K.
    Warren, Wesley C.
    Edwards, Scott V.
    Gene duplication and fragmentation in the zebra finch major histocompatibility complex2010In: BMC Biology, ISSN 1741-7007, E-ISSN 1741-7007, Vol. 8, p. 29-Article in journal (Refereed)
    Abstract [en]

    Background: Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC) has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC) sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. Results: The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH) evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. Conclusion: The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving chromosomal fission, gene duplication and translocation in the history of the MHC in birds, and highlight striking differences in MHC structure and organization among avian lineages.

  • 3.
    Barnaby, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Griesser, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    The role of nepotism, cooperation, and competition in the avian families2010Book (Refereed)
    Abstract [en]

    A large number of bird species live in stable groups, and this sets the scene for complex social behaviours, such as cooperative breeding. The vast majority of groups consist of families which arise when young postpone dispersal and remain with their parents beyond independence. However, the factors selecting for the evolution of families and thus also cooperative breeding among birds, are still a challenging puzzle. The currently accepted key explanation for the evolution of families and cooperative breeding focuses on dispersal constraints. While constraints successfully explain within‐population dispersal decisions, they fail as an ultimate explanation because offspring in the majority of species face some sort of dispersal constraint, yet still disperse promptly. Recent alternative explanations focus on the role of philopatry and nepotism, and emphasise a key role of life‐history for the evolution of families. Phylogenetic analyses and field studies have indicated that living in family groups is far more widespread among long‐lived species than short‐lived ones. A long lifespan gives parents the opportunity to invest in their offspring for a prolonged period, while this option is less viable for short‐lived species. Thus, living with nepotistic parents provides offspring with direct fitness benefits that can select for the evolution of family living beyond independence. Nevertheless this generalisation is brought into question since many long‐lived bird species do not live in family groups. An alternative approach attempts to explain family living through the variation in territory quality. Here the incentive to remain with the parents is created by the availability of resources on the natal territory independent of parental nepotism. However, there is not only cooperation, conflicts are also common place in families. Living with independent, sexually mature offspring can lead to conflicts through a change in resource availability or the death of aparent. Therefore families can be expected to be dynamic societies where both parent and offspring decisions depend on each other, and family maintenance depends upon the current ecological conditions. Based on  this background, here we review recent studies that have investigated the processes that facilitate family formation, and which highlight both cooperation and conflict that arises from living in family groups. We examine the strengths of current models and explore ideas for a more coherent framework in which to understand prolonged family association in birds. We argue that two paths lead to family living, depending on the life-history. In medium-short lived species where the postponement of independent reproduction comes at a high cost, offspring can benefit from an association with their parents until the next breeding season. In longer-lived species, offspring actually benefit from postponing the onset of independent reproduction, making family living beyond the first year of life an adaptive strategy, and giving the option for cooperative breeding. These processes are illustrated by 5 species-specific case studies. We then finally suggest a number of key questions to developing a deeper understanding of the evolution of family living in birds.

  • 4.
    Berlin, Sofia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Evolutionary Biology.
    Quintela, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Höglund, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    A multilocus assay reveals high nucleotide diversity and limited differentiation among Scandinavian willow grouse (Lagopus lagopus)2008In: BMC Genetics, ISSN 1471-2156, E-ISSN 1471-2156, Vol. 9, p. 89-Article in journal (Refereed)
    Abstract [en]

    Background: There is so far very little data on autosomal nucleotide diversity in birds, except for data from the domesticated chicken and some passerines species. Estimates of nucleotide diversity reported so far in birds have been high (similar to 10(-3)) and a likely explanation for this is the generally higher effective population sizes compared to mammals. In this study, the level of nucleotide diversity has been examined in the willow grouse, a non-domesticated bird species from the order Galliformes, which also holds the chicken. The willow grouse (Lagopus lagopus) has an almost circumpolar distribution but is absent from Greenland and the north Atlantic islands. It primarily inhabits tundra, forest edge habitats and sub-alpine vegetation. Willow grouse are hunted throughout its range, and regionally it is a game bird of great cultural and economical importance.

    Results: We sequenced 18 autosomal protein coding loci from approximately 15-18 individuals per population. We found a total of 127 SNP's, which corresponds to 1 SNP every 51 bp. 26 SNP's were amino acid replacement substitutions. Total nucleotide diversity (pi(t)) was between 1.30 x 10(-4) and 7.66 x 10(-3) (average pi(t) = 2.72 x 10(-3) +/- 2.06 x 10(-3)) and silent nucleotide diversity varied between 4.20 x 10(-4) and 2.76 x 10(-2) (average pi(S) = 9.22 x 10(-3) +/- 7.43 x 10(-4)). The synonymous diversity is approximately 20 times higher than in humans and two times higher than in chicken. Non-synonymous diversity was on average 18 times lower than the synonymous diversity and varied between 0 and 4.90 x 10(-3) (average pi(a) = 5.08 x 10(-4) +/- 7.43 x 10(3)), which suggest that purifying selection is strong in these genes. F-ST values based on synonymous SNP's varied between -5.60 x 10(-4) and 0.20 among loci and revealed low levels of differentiation among the four localities, with an overall value of F-ST = 0.03 (95% CI: 0.006 -0.057) over 60 unlinked loci. Non-synonymous SNP's gave similar results. Low levels of linkage disequilibrium were observed within genes, with an average r(2) = 0.084 +/- 0.110, which is expected for a large outbred population with no population differentiation. The mean per site per generation recombination parameter (rho) was comparably high (0.028 +/- 0.018), indicating high recombination rates in these genes.

    Conclusion: We found unusually high levels of nucleotide diversity in the Scandinavian willow grouse as well as very little population structure among localities with up to 1647 km distance. There are also low levels of linkage disequilibrium within the genes and the population recombination rate is high, which is indicative of an old panmictic population, where recombination has had time to break up any haplotype blocks. The non-synonymous nucleotide diversity is low compared with the silent, which is in agreement with effective purifying selection, possibly due to the large effective population size.

  • 5.
    Brodin, Yngve
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Andersson, Mathias H.
    The marine splash midge Telmatogon japonicus (Diptera; Chironomidae)-extreme and alien?2009In: Biological Invasions, ISSN 1387-3547, E-ISSN 1573-1464, Vol. 11, no 6, p. 1311-1317Article in journal (Refereed)
    Abstract [en]

    We found all developmental stages of the midge Telmatogeton japonicus (Chironomidae) on offshore windmills near the major Swedish seaport Kalmar in the southern Baltic Sea. This might be the first record of an insect species really inhabiting the offshore areas of the Baltic Sea. A thorough analysis of previous findings of the species, its history in Europe and its ecology indicates that T. japonicus quite likely is an alien species in Europe introduced from the Pacific Ocean. Shipping is probably the vector, as all records in the Baltic Sea and several from the Eastern Atlantic Sea are near major seaports. Our analysis further suggests that T. japonicus might be both advantageous and disadvantageous to native species in the Baltic Sea. T. japonicus should be kept under observation within monitoring programmes as it might expand its distribution as a result of the construction of new windmills in the Baltic Sea and elsewhere in European marine and brackish water habitats.

  • 6.
    Brodin, Yngve
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Lundström, Jan O.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Paasivirta, Lauri
    Tavastia yggdrasilia, a new orthoclad midge (Diptera: Chironomidae) from Europe2008In: Aquatic Insects, ISSN 0165-0424, E-ISSN 1744-4152, Vol. 30, no 4, p. 261-267Article in journal (Refereed)
    Abstract [en]

    A new species of the chironomid genus Tavastia was frequently collected in wetlands of the River Dalalven lowlands in central Sweden from 2002 to 2007. Unpublished data revealed that the species has been known from Finland since 1974. The new species T. yggdrasilia can be separated from other Tavastia species by the combination of a gonostylus with strong crista dorsalis in proximal half, AR 0.93-1.16, and wing veins M3+4 and Cu1 without setae. A description of the male and the female is included, as is also a key to the males of the four known species of Tavastia. All records of T. yggdrasilia are from sites with mesotrophic or eutrophic conditions.

  • 7.
    Cassel-Lundhagen, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Sjögren-Gulve, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Berglind, Sven-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Effects of patch characteristics and isolation on relative abundance of the scarce heath butterfly Coenonympha hero (Nymphalidae)2008In: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 12, no 5, p. 477-482Article in journal (Refereed)
    Abstract [en]

    The scarce heath (Coenonympha hero) is an internationally threatened butterfly in Western Europe, where it occurs primarily on hay fields and abandoned arable land in a small-scale agricultural landscape of south-central Scandinavia. Due to afforestation, this habitat is becoming increasingly fragmented in Sweden, and it can be expected that the scarce heath will decline abruptly when threshold conditions for metapopulation persistence are no longer met. We used stepwise polychotomous logistic regression to compare habitat characteristics and isolation measures for patches that harbour large, small or no populations, respectively, in an area of south-western Sweden. We found that patch area, distance to the nearest large population and amount of Galium spp. explained a significant part of the variation in relative abundance among patches. Distance to nearest large population resulted in a better model to predict occupancy than both distance to the nearest inhabited patch and connectivity, which suggests that primarily large populations act as sources for small satellite populations. Today, sites of three of the eight larger populations in the study area have been planted with spruce or pine and will disappear within 20 years. We argue that the disappearance of these patches may very well lead to rapid extinction of the whole metapopulation system.

  • 8.
    Castroviejo-Fisher, Santiago
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    De la Riva, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Vilà, Carles
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Transparent frogs show potential of natural world2007In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 449, no 7165, p. 972-972Article in journal (Refereed)
  • 9. Covas, R
    et al.
    Griesser, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Life history and the evolution of family living in birds2007In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 274, no 1616, p. 1349-1357Article, review/survey (Refereed)
    Abstract [en]

    The reason why some bird species live in family groups is an important question of evolutionary biology that remains unanswered. Families arise when young delay the onset of independent reproduction and remain with their parents beyond independence. Explanations for why individuals forgo independent reproduction have hitherto focused on dispersal constraints, such as the absence of high-quality breeding openings. However, while constraints successfully explain within-population dispersal decisions, they fail as an ultimate explanation for variation in family formation across species. Most family-living species are long-lived and recent life-history studies demonstrated that a delayed onset of reproduction can be adaptive in long-lived species. Hence, delayed dispersal and reproduction might be an adaptive life-history decision rather than ‘the best of a bad job’. Here, we attempt to provide a predictive framework for the evolution of families by integrating life-history theory into family formation theory. We suggest that longevity favours a delayed onset of reproduction and gives parents the opportunity of a prolonged investment in offspring, an option which is not available for short-lived species. Yet, parents should only prolong their investment in offspring if this increases offspring survival and outweighs the fitness cost that parents incur, which is only possible under ecological conditions, such as a predictable access to resources. We therefore propose that both life-history and ecological factors play a role in determining the evolution of family living across species, yet we suggest different mechanisms than those proposed by previous models.

  • 10.
    Eggers, Sönke
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Griesser, Michael
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Nystrand, Magdalena
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Ekman, Jan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Predation risk induces changes in nest-site selection and clutch size in the Siberian jay.2006In: Proceedings of the Royal Society series B, Vol. 273, p. 701-706Article in journal (Refereed)
  • 11.
    Ekblom, Robert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Sæther, Stein Are
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Jacobsson, Pär
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Fiske, Peder
    Sahlman, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Grahn, Mats
    Kålås, John Atle
    Höglund, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Spatial pattern of MHC class II variation in the great snipe (Gallinago media)2007In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 16, no 7, p. 1439-1451Article in journal (Refereed)
    Abstract [en]

    The genes of the major histocompatibility complex (MHC) code for proteins involved in antigen recognition and triggering of the adaptive immune response, and are therefore likely to be under selection from parasites. These selection regimes may vary in space and time. Here we report a strong geographical structure in MHC class II B genes of a migrating bird, the great snipe (Gallinago media). Genetic differentiation in the MHC between two ecologically distinct distributional regions (Scandinavian mountain populations vs. East European lowland populations) was still present after statistically controlling for the effect of selectively neutral variation (microsatellites) using partial Mantel tests. This suggests a role for selection in generating this spatial structure and that it represents local adaptation to different environments. Differentiation between populations within the two regions was negligible. Overall, we found a high number of MHC alleles (50, from 175 individuals). This, together with a tendency for a higher rate of nonsynonymous than synonymous substitutions in the peptide binding sites, and high Tajima's D in certain regions of the gene, suggests a history of balancing selection. MHC variation is often thought to be maintained by some form of balancing selection, but the nature of this selection remains unclear. Our results support the hypothesis that spatial variation in selection regimes contributes to the high polymorphism.

  • 12.
    Ekman, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Cooperation—The role of past and present2007In: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 76, no 2, p. 118-119Article in journal (Refereed)
  • 13.
    Ekman, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Delayed dispersal: youth costs carry lifetime gains2007In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 17, no 11, p. R417-R418Article in journal (Refereed)
    Abstract [en]

    An analysis of reproductive success in the green woodhoopoe Phoeniculus purpures challenges the view that delayed dispersal is costly. Females delaying dispersal for longer had more reproductive events in life and higher lifetime production of offspring.

  • 14.
    Ekman, Jan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Family living among birds.2006In: Journal of Avian Biology, Vol. 37, p. 289-298Article in journal (Refereed)
  • 15.
    Ekman, Jan
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Ericson, PGP
    Out of Gondwanaland; the evolutionary history of cooperative breeding and social behaviour among crows, magpies, jays and allies.2006In: Proceedings of the Royal Society series B, Vol. 273, p. 1117-1125Article in journal (Refereed)
  • 16. Florin, Ann-Britt
    et al.
    Höglund, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Absence of population structure of turbot (Psetta maxima) in the Baltic Sea2007In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 16, no 1, p. 115-126Article in journal (Refereed)
    Abstract [en]

    We found low, albeit significant, genetic differentiation among turbot (Psetta maxima) in the Baltic Sea but in contrast to earlier findings we found no evidence of isolation by distance. In fact temporal variation among years in one locality exceeded spatial variation among localities. This is an unexpected result since adult turbot are sedentary and eggs are demersal at the salinities occurring in the Baltic. Our findings are most likely explained by the fact that we sampled fish that were born after/during a large influx of water to the Baltic Sea, which may have had the consequence that previously locally and relatively sedentary populations became admixed. These results suggest that populations that colonize relatively variable habitats, like the Baltic, face problems. Any adaptations to local conditions that may build up during stable periods may quickly become eroded when conditions change and/or when populations become admixed. Our results indicate that the ability of turbot to survive and reproduce at the low salinity in the Baltic is more likely due to phenotypic plasticity than a strict genetic adaptation to low salinity.

  • 17. Gonda, A.
    et al.
    Trokovic, N.
    Herczeg, G.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Merilä, J.
    Predation- and competition-mediated brain plasticity in Rana temporaria tadpoles2010In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 23, no 11, p. 2300-2308Article in journal (Refereed)
    Abstract [en]

    An increasing number of studies have demonstrated phenotypic plasticity in brain size and architecture in response to environmental variation. However, our knowledge on how brain architecture is affected by commonplace ecological interactions is rudimentary. For example, while intraspecific competition and risk of predation are known to induce adaptive plastic modifications in morphology and behaviour in a wide variety of organisms, their effects on brain development have not been studied. We studied experimentally the influence of density and predation risk on brain development in common frog (Rana temporaria) tadpoles. Tadpoles grown at low density and under predation risk developed smaller brains than tadpoles at the other treatment combinations. Further, at high densities, tadpoles developed larger optic tecta and smaller medulla oblongata than those grown at low densities. These results demonstrate that ecological interactions - like intraspecific competition and predation risk - can have strong effects on brain development in lower vertebrates.

  • 18.
    Griesser, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Referential calls signal predator behavior in a group-living bird species2008In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 18, no 1, p. 69-73Article in journal (Refereed)
    Abstract [en]

    Predation is a powerful agent of natural selection, driving the evolution of antipredator calls [1]. These calls have been shown to communicate predator category [2-4] and/or predator distance to conspecifics [5-7]. However, the risk posed by predators depends also on predator behavior [8], and the ability of prey to communicate predator behavior to conspecifics would be a selective advantage reducing their predation risk. I tested this idea in Siberian jays (Perisoreus infaustus), a group-living bird species. Predation by hawks, and to a lesser extent by owls, is substantial and the sole cause of mortality in adult jays [9]. By using field data and predator-exposure experiments, I show here that jays used antipredator calls for hawks depending on predator behavior. A playback experiment demonstrated that these prey-to-prey calls were specific to hawk behavior (perch, prey search, attack) and elicited distinct, situation-specific escape responses. This is the first study to demonstrate that prey signals convey information about predator behavior to conspecifics. Given that antipredator calls in jays aim at protecting kin group members [10, 11], consequently lowering their mortality [9], kin-selected benefits could be an important factor for the evolution of predator-behavior-specific antipredator calls in such systems.

  • 19.
    Griesser, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Nystrand, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Vigilance and predation of a forest-living bird species depend on large-scale habitat structure2009In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 20, no 4, p. 709-715Article in journal (Refereed)
    Abstract [en]

    Prey often use visual cues to detect predators, and consequently, many studies have assessed the effect of small-scale habitat structure on prey antipredator vigilance. This scale may be inappropriate to assess the link between habitat structure and vigilance, however, because visually hunting predators often detect prey from several hundred meters away. As a result, large-scale habitat structure could affect both the hunting decisions of predators and antipredator behaviors of prey. Here we investigated the effect of small- and large-scale habitat structure, as well as group composition (kinship) on vigilance allocation of breeders in the Siberian jay Perisoreus infaustus. Vigilance had an antipredator function and was increased after exposure to a predator model. Small-scale habitat structure did not affect vigilance rates, however, habitat structure of the whole territory, measured as the proportion of visual cover, affected vigilance depending on group composition. Breeders with retained offspring (kin) in their group were more vigilant in managed open territories than on pristine dense territories, whereas breeders without kin in their groups did not adjust vigilance rates in relation to large-scaled habitat structure. Earlier studies have revealed that hawks, the main predators of jays, primarily kill non-kin group members living in groups inhabiting open territories. Therefore, we suggest that breeders adjusted their vigilance depending on the habitat-specific predation risk to protect their retained offspring. This demonstrates that large-scale habitat structure affects predator-prey interactions and is crucial to understanding spatial variation in antipredator allocation and mortality.

  • 20.
    Griesser, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Nystrand, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Eggers, Sonke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Ekman, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Social constraints limit dispersal and settlement decisions in a group-living bird species2008In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 19, no 2, p. 317-324Article in journal (Refereed)
    Abstract [en]

    Dispersal is a fundamental process affecting the genetic structure of populations, speciation, and extinction. Nevertheless, our understanding of the evolution of dispersal is limited by our paucity of knowledge on dispersal decisions at the individual level. We investigated the effect of interactions between residents and juvenile dispersers on individual dispersal and settlement decisions in Siberian jays (Perisoreus infaustus). In this group-living bird species, some offspring remain on the parental territory for up to 3 years (retained juveniles) whereas other offspring disperse within 2 months of fledging (dispersers). We found that retained juveniles constrained settlement decisions of dispersers by aggressively chasing dispersers off their territory, resulting in dispersers continuing to disperse and settling in groups without retained juveniles. Experimental removal of male breeders during the dispersal period also demonstrated that dispersers were unable to settle in high-quality breeding openings, which were instead filled by older nonbreeding residents. Rather, dispersers immigrated into groups without retained offspring where they became subordinate group members, queuing for a breeding opening. Also, they preferably settled in groups with short queues where no same-sex juveniles were present. Dispersal did not inflict a cost to dispersers through increased mortality. However, the presence of immigrants was costly for breeders because it increased the rate of conflicts during the breeding season which negatively affected nestling condition. These results demonstrate that resident individuals constrain both dispersal and settlement decisions of dispersers. Social interactions between residents and dispersers can thus be a key factor to understand the evolution of dispersal.

  • 21.
    Griesser, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Nystrand, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Eggers, Sönke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Ekman, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Impact of forestry practices on fitness correlates and population productivity in an open-nesting bird species2007In: Conservation Biology, ISSN 0888-8892, E-ISSN 1523-1739, Vol. 21, no 3, p. 767-774Article in journal (Refereed)
    Abstract [en]

    In the boreal forests of Fennoscandia, over 99% of forest area has been altered by forestry practices, which has created forest with age structures and stand characteristics that differ from primary forest stands. Although many researchers have investigated how forestry affects species abundance, few have assessed how forestry practices affect fitness correlates of species living in altered habitats, and this has negatively affected management efforts. We experimentally addressed the effect of standard forestry practices on fitness correlates of an open-nesting, long-lived bird species typical to boreal forests of Eurasia, the Siberian Jay (Perisoreus infaustus). We used a before-after comparison of reproductive data on the level of territories and found that standard forestry practices had a strong negative effect on the breeding success of jays. Both partial thinning of territories and partial clearcutting of territories reduced future breeding success by a factor of 0.35. Forestry practices reduced territory occupancy. Thus, over the 15 years of the study, productivity of the affected population declined over 50% as a result of territory abandonment and reduced breeding success. Results of previous studies on Siberian Jays suggest that the strong effect of forest thinning on fitness is explained by the fact that most common predators of nests and adults are visually oriented and thus thinning makes prey and nests more visible to predators. The consequences of thinning we observed are likely to apply to a wide range of species that rely on understory to provide visual protection from predators. Thus, our results are important for the development of effective conservation management protocols and for the refinement of thinning practices.

  • 22.
    Griesser, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Nystrand, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Ekman, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Reduced mortality selects for family cohesion in a social species2006In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 273, no 1596, p. 1881-1886Article in journal (Refereed)
    Abstract [en]

    Delayed dispersal is the key to family formation in most kin-societies. Previous explanations for the evolution of families have focused on dispersal constraints. Recently, an alternative explanation was proposed, emphasizing the benefits gained through philopatry. Empirical data have confirmed that parents provide their philopatric offspring with preferential treatment through enhanced access to food and predator protection. Yet it remains unclear to what extent such benefits translate into fitness benefits such as reduced mortality, which ultimately can select for the evolution of families. Here, we demonstrate that philopatric Siberian jay (Perisoreus infaustus) offspring have an odds ratio of being killed by predators 62% lower than offspring that dispersed promptly after independence to join groups of unrelated individuals (20.6% versus 33.3% winter mortality). Predation was the sole cause of mortality killing 20 out of 73 juveniles fitted with radio tags. The higher survival rate among philopatric offspring was associated with parents providing nepotistic predator protection that was withheld from unrelated group members. Natal philopatry usually involves the suppression of personal reproduction. However, a lower mortality of philopatric offspring can overcome this cost and may thus select for the formation of families and set the scene for cooperative kin-societies.

  • 23. Hawley, D
    et al.
    Lindström, Karin M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Wikelski, M
    Experimentally increased social competition compromises humoral immune response in house finches.2006In: Hormones and Behavior, Vol. 49, p. 417-424Article in journal (Refereed)
  • 24. Hellgren, Olof
    et al.
    Ekblom, Robert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Evolution of a cluster of innate immune genes(beta-defensins) along the ancestral lines of chicken and zebra finch2010In: Immunome Research, ISSN 1745-7580, E-ISSN 1745-7580, Vol. 6, no 1, p. 3-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:Avian beta-defensins (AvBDs) represent a group of innate immune genes with broad antimicrobial activity. Within the chicken genome, previous work identified 14 AvBDs in a cluster on chromosome three. The release of a second bird genome, the zebra finch, allows us to study the comparative evolutionary history of these gene clusters between from two species that shared a common ancestor about 100 million years ago. RESULTS:A phylogenetic analysis of the beta-defensin gene clusters in the chicken and the zebra finch identified several cases of gene duplication and gene loss along their ancestral lines. In the zebra finch genome a cluster of 22 AvBD genes were identified, all located within 125Kbp on chromosome three. Ten of the 22 genes were found to be highly conserved with orthologous genes in the chicken genome. The remaining 12 genes were all located within a cluster of 58 Kbp and are suggested to be a result of recent gene duplication events that occurred after the galliformes- passeriformes split (G-P split) and where no duplications have happened along the chicken line. Within the chicken genome, AvBD6 was found to be a duplication of AvBD7, whereas the gene AvDB14 seems to have been lost along the ancestral line of the zebra finch. The duplicated beta-defensin genes have had a significantly higher accumulation of non-synonymous over synonymous substitutions compared to the genes that have not undergone duplication since the G-P split. The expression patterns of avian beta-defensin genes seem to be well conserved between chicken and zebra finch.CONCLUSION:The genomic comparisons of the beta-defensins gene clusters of the chicken and zebra finch illuminate the evolutionary history of this gene complex. Along their ancestral lines, several gene duplication events have occurred in the passerine line after the galliformes-passeriformes split giving rise to 12 novel genes compared to a single duplication event in the galliformes line. After the duplication events, the duplicated genes have been subject to a relaxed selection pressure compared to the non-duplicated genes, thus supporting models of evolution by gene duplication.

  • 25.
    Hesson, Jenny C.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Lundström, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Halvarsson, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Per, Erixon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Systematic Biology.
    Collado, Amandine
    A sensitive and reliable restriction enzyme assay to distinguish between the mosquitoes Culex torrentium and Culex pipiens2010In: Medical and Veterinary Entomology, ISSN 0269-283X, E-ISSN 1365-2915, Vol. 24, no 2, p. 142-149Article in journal (Refereed)
    Abstract [en]

    Culex pipiens pipiens Linnaeus and Culex torrentium Martini (Diptera: Culicidae) are closely related vector species that exist sympatrically in Europe. The two species are morphologically almost identical and can only be distinguished with certainty by characters of the male genitalia. Hence, correct species identification and conclusions on distribution and vector status are very difficult and often neglected. Therefore, we developed a reliable and simple mitochondrial cytochrome c oxidase subunit I (COI) gene restriction enzyme assay to discriminate between Cx. pipiens and Cx. torrentium, based on the analysis of morphologically identified male specimens. We sequenced approximately 830 bp in the 3′ region of the mitochondrial COI gene of 18 morphologically identified males of Cx. pipiens and Cx. torrentium. Two restriction enzymes (FspBI and SspI) that could distinguish between the two species according to species-specific differences in these sequences were chosen. The restriction enzymes were tested on 227 samples from Sweden and verified by sequencing 44 of them. The enzyme FspBI correctly identified all investigated samples; the enzyme SspI identified all samples except one Cx. torrentium. We hope the method and the findings presented here will help to shed light on the true distribution and relative proportions of the two species in Europe.

  • 26. Holmgren, NMA
    et al.
    Engström, Henri
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Stopover behaviour of spring migrating Wood Warblers Phylloscopus sibilatrix on the island of Capri, Italy.2006In: Ornis Svecica, Vol. 16, p. 34-41Article in journal (Refereed)
  • 27.
    Höglund, Jacob
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Johansson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Beintema, Albert
    Schekkerman, Hans
    Phylogeography of the Black-tailed Godwit Limosa limosa: substructuring revealed by mtDNA control region sequences2009In: Journal of Ornithology = Journal fur Ornithologie, ISSN 0021-8375, E-ISSN 1439-0361, Vol. 150, no 1, p. 45-53Article in journal (Refereed)
    Abstract [en]

    Black-tailed (Limosa limosa) and Hudsonian Godwits (L. haemastica) are sometimes described as a superspecies. The Black-tailed Godwit is further split into three subspecies on the basis of morphological differences ( L. l. limosa, L. l. islandica and L. l. melanuroides). We studied variation in partial mtDNA control region sequences among Black-tailed and Hudsonian Godwits which showed 5% divergence. Black-tailed and Hudsonian Godwits were thus clearly differentiated and the separate species status for the two taxa is validated. All three subspecies described for the Black-tailed Godwit had unique haplotypes but the genetic distances were small (0.3-0.6%). Despite small genetic differences we could not detect any substantial gene flow between any of the subspecies as haplotypes were private to each subspecies. Thus, genetic variation within Black-tailed Godwits showed a clear geographic structure. We found a high proportion of rare private haplotypes in three fringe populations of the nominate subspecies of the Black-tailed Godwit (L. l. limosa) where godwits breed in low numbers, but no genetic variation at all in a sample from the Netherlands where godwits are abundant. This suggests that Dutch Godwits may have been affected by a founder effect.

  • 28. Jansson, G
    et al.
    Persson, Å
    Thulin, Carl Gustaf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Var och när uppkommer hybridharar2006In: Svensk Jakt, Vol. 10, p. 76-78Article in journal (Other (popular scientific, debate etc.))
  • 29. Jansson, Gunnar
    et al.
    Thulin, Carl-Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Pehrson, Åke
    Factors related to the occurrence of hybrids between brown hares Lepus europaeus and mountain hares L. timidus in Sweden2007In: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 30, no 5, p. 709-715Article in journal (Refereed)
    Abstract [en]

    Hybridization occurs among many species, and may have implications for conservation as well as for evolution. Interspecific gene flow between brown hares Lepus europaeus and mountain hares L. timidus has been documented in Sweden and in continental Europe, and has probably to some extent occurred throughout history in sympatric areas. What local factors or ecological relationships that correlate with or trigger hybridization between these species has however been unclear. We studied spatial distribution of hybrids between brown hares and mountain hares in Sweden in relation to characteristics of the sampled localities (hunting grounds). In a sample of 70 brown hares collected from 39 populations in south-central Sweden during 2003–2005, 11 (16%) showed introgressed mtDNA from mountain hares. Among the brown hares from their northern range, i.e. in general the most recent establishments, the corresponding figure was 75% (9/12). The frequency of samples with hybrid ancestry increased significantly with latitude, altitude and hilliness, and were higher (p<0.1) in recently established populations and/or where the proportion of arable land was low. Several site-specific parameters were correlated, e.g. latitude as expected to hilliness, and no parameter explained the occurrence of hybrids exclusively. Instead, the appearance of mountain hare mtDNA among brown hares was associated with a conglomerate of parameters reflecting landscapes atypical for the brown hare, e.g. forest dominated and steep areas where the species quite recently was established. We suggest that these abiotic factors mirror the main aspect influencing hybridization frequency, namely the density or relative frequency of the two species. In atypical brown hare landscapes with recent establishment, mountain hares are probably relatively more common. When one species dominate in numbers, or when both species display low densities, increased frequency of hybridization is expected due to low availability of conspecific partners, a phenomenon referred to as Hubbs' principle.

  • 30.
    Johansson, Markus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Piha, Henna
    Kylin, H.
    Merilä, Juha
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Toxicity of six pesticides to common frog (Rana temporaria) tadpoles2006In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 25, no 12, p. 3164-3170Article in journal (Refereed)
    Abstract [en]

    Amphibian species inhabiting agricultural areas may be exposed to pesticides during their aquatic larval phase. We tested the toxicity of six commonly used pesticides on Rana temporaria spawn and tadpoles. In acute tests, tadpoles were exposed to relatively high concentrations of azoxystrobin, cyanazine, esfenvalerate, MCPA ([4-chloro-2-methylphenoxyl acetic acid), permethrin, and pirimicarb for 72 h. Chronic exposure tests were performed from fertilization to metamorphosis with azoxystrobin, cyanazine, and permethrin at concentrations similar to those found in surface waters in agricultural areas in Sweden. The most lethal pesticides in the acute exposure were azoxystrobin, permethrin, and pirimicarb. Also, negative effects on the growth of the tadpoles were observed with azoxystrobin, cyanazine, and permethrin. The chronic exposure at lower pesticide concentrations did not result in increased mortality or impaired growth. However, we found a positive effect of permethrin on growth and size at metamorphosis. The results suggest that the examined pesticides can inflict strong negative effects at high concentrations but have no or relatively weak effects on R. temporaria spawn or tadpoles at concentrations found in Swedish surface waters.

  • 31.
    Johansson, Markus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Primmer, Craig R.
    Merilä, Juha
    Does habitat fragmentation reduce fitness and adaptability?: A case study of the common frog (Rana temporaria)2007In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 16, no 13, p. 2693-2700Article in journal (Refereed)
    Abstract [en]

    Studies examining the effects of anthropogenic habitat fragmentation on both neutral and adaptive genetic variability are still scarce. We compared tadpole fitness-related traits (viz. survival probability and body size) among populations of the common frog (Rana temporaria) from fragmented (F) and continuous (C) habitats that differed significantly in population sizes (C > F) and genetic diversity (C > F) in neutral genetic markers. Using data from common garden experiments, we found a significant positive relationship between the mean values of the fitness related traits and the amount of microsatellite variation in a given population. While genetic differentiation in neutral marker loci (F-ST) tended to be more pronounced in the fragmented than in the continuous habitat, genetic differentiation in quantitative traits (Q(ST)) exceeded that in neutral marker traits in the continuous habitat (i.e. Q(ST) > F-ST), but not in the fragmented habitat (i.e. Q(ST) approximate to F-ST). These results suggest that the impact of random genetic drift relative to natural selection was higher in the fragmented landscape where populations were small, and had lower genetic diversity and fitness as compared to populations in the more continuous landscape. The findings highlight the potential importance of habitat fragmentation in impairing future adaptive potential of natural populations.

  • 32.
    Kölzsch, Andrea
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Saether, Stein Are
    Gustafsson, Henrik
    Fiske, Peder
    Höglund, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Kålås, John Atle
    Population fluctuations and regulation in great snipe: a time-series analysis2007In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 76, no 4, p. 740-749Article in journal (Refereed)
    Abstract [en]

    1. During the last centuries, the breeding range of the great snipe Gallinago media has declined dramatically in the western part of its distribution. To examine present population dynamics in the Scandinavian mountains, we collected and analysed a 19-year time series of counts of great snipe males at leks in central Norway, 1987-2005. 2. The population showed large annual fluctuations in the number of males displaying at lek sites (range 45-90 males at the peak of the mating season), but no overall trend. 3. We detected presence of direct density-dependent mechanisms regulating this population. Inclusion of the density-dependent term in a Ricker-type model significantly improved the fit with observed data (evaluated with Parametric Bootstrap Likelihood Ratio tests and Akaike's Information Criterion for small sample size). 4. An analysis of (a number of a priori likely) environmental covariates suggests that the population dynamics were affected by conditions influencing reproduction and survival of offspring during the summer, but not by conditions influencing survival at the wintering grounds in Africa. This is in contrast to many altricial birds breeding in the northern hemisphere, and supports the idea that population dynamics of migratory nidifugous birds are more influenced by conditions during reproduction. 5. Inclusion of these external factors into our model improved the detectability of density dependence. This illustrates that allowing for external effects may increase statistical power of density dependence tests and thus be of particular importance in relatively short time series. 6. In our best model of the population dynamics, two likely density-independent offspring survival covariates explained 47·3% of the variance in great snipe numbers (predation pressure estimated by willow grouse reproductive success and food availability estimated by the amount of precipitation in June), whereas density dependence explained 35·5%. Demographic stochasticity and unidentified environmental stochasticity may account for the remaining 17·2%.

  • 33.
    Lundström, Jan O.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Pfeffer, Martin
    Phylogeographic Structure and Evolutionary History of Sindbis Virus2010In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 10, no 9, p. 889-907Article in journal (Refereed)
    Abstract [en]

    Sindbis (SIN) virus, Alphavirus, is a mosquito-borne and bird-associated virus with large geographic distribution in the Old World. We investigated the genetic diversity of 59 SIN strains after limited sequencing of their E2 glycoprotein genes. The SIN strains showed maximal diversity of 22.2% at the amino acid (aa) level, and formed five tentative genotypes. The SIN-I genotype included strains from Europe and Africa. Strains from Australia and East Asia formed SIN-II and SIN-III with about 12% and 15% aa divergence from SIN-I. The only isolate from New Zealand was distinct, and constitutes the SIN-V genotype. Isolates from Azerbaijan and China formed genotype SIN-IV with 15.6%-19.1% aa divergence from SIN-I to III and SIN-V. Phylogenetic analyses indicated that Aura virus was present before the recombinant alphavirus lineage arose. This is consistent with a South American origin of the SIN complex, and argue for a spread in North America before reaching Asia and Australia, followed by westward radiation into Africa and Europe. High levels of sequence identities were observed for geographic regions belonging to the same north-south axis, whereas the east-west genetic exchange appears to be limited. The observed phylogeographic structure was confirmed by distinct aa patterns within two-thirds of the structural protein-coding region of SIN virus strains from Saudi Arabia, Asia, and Australia. The present geography of the five SIN genotypes and subclusters within SIN-I correlate with major bird migration patterns.

  • 34.
    Lundström, Jan O.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Schäfer, Martina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Petersson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Persson Vinnersten, Thomas Z.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population Biology.
    Landin, J.
    Brodin, Yngve
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population Biology.
    Production of wetland Chironomidae (Diptera) and the effects of using Bacillus thuringiensis israelensis for mosquito control2010In: Bulletin of entomological research, ISSN 0007-4853, E-ISSN 1475-2670, Vol. 100, no 1, p. 117-125Article in journal (Refereed)
    Abstract [en]

    Massive mosquito nuisance problems, caused by the flood-water mosquito Aedes sticticus, occur after floods in the flood plains of the River Dalalven, central Sweden. Since 2002, the biological mosquito larvicide Bacillus thuringiensis var. israelensis (Bti) has been used to control these mosquitoes. Here, we report results from the first six years of monitoring Chironomidae, the most Susceptible non-target organisms, in three wetlands with Bti-treatment against mosquitoes and in three wetlands without treatment. Emergence traps were used for continuous insect sampling from May to September each year, 2002-2007, and were emptied once a week. A total of 21,394 chironomids of 135 species were collected, and the Subfamily Orthocladiinae dominated the fauna followed by Chironominae and Tanypodinae. The annual chironomid production in the wetlands was low, with ail average of 1.91.7 individuals per m(2) and 42 g ash-free dry weight per m(2) We found no reduced production of chironomids at neither family, nor subfamily level, in Bti-treated as compared to untreated wetlands. This is the first long-term follow-up study of the possible effects of Bti-based mosquito larval control oil chironomid species production. In the short-term view, one species had higher production in treated areas. In the long-term view, four species had higher and one species had lower production in treated areas. We conclude that the B3ti-based control of floodwater mosquitoes does not cause and, major direct negative effects on chironomid production, and therefore does not seem to induce any risk for indirect negative effects on birds, bats or any other predators feeding on chironomids.

  • 35. Mihalca, A.D.
    et al.
    Fictum, P.
    Skoric, M.
    Sloboda, M.
    Kärvemo, Simon
    SLU.
    Ghira, I.
    Carlsson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Modry, D.
    Severe Granulomatous Lesions in Several Organs from Eustrongylides Larvae in a Free-ranging Dice Snake, Natrix tessellata2007In: Veterinary Pathology, ISSN 0300-9858, Vol. 44, no 1, p. 103-105Article in journal (Refereed)
    Abstract [en]

    During an extensive study regarding the epidemiology of larval Eustrongylides infestation in a free-ranging endangered population of dice snakes (Natrix tessellata) from Histria, Romania, an adult female was euthanized to evaluate pathologic changes. Parasites appeared as nodules at various locations: in subcutaneous connective tissues, on the serosae of the intestines and liver. Histologic sections revealed nematode larvae surrounded by a capsule, forming a parasitic granuloma with 3 layers: macrophage layer, lymphocyte layer, and fibrous capsule. Differences between newly formed and mature granulomas consisted mainly in the eosinophilic infiltration. Other types of parasitic granulomas of reptiles are discussed in comparison with our findings.

  • 36. Navedo, Juan G.
    et al.
    Orizaola, Germán
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Masero, Jose A.
    Overdijk, Otto
    Sanchez-Guzman, Juan M.
    Long-distance travellers stopover for longer: a case study with spoonbills staying in North Iberia2010In: Journal of Ornithology = Journal fur Ornithologie, ISSN 0021-8375, E-ISSN 1439-0361, Vol. 151, no 4, p. 915-921Article in journal (Refereed)
    Abstract [en]

    Long-distance migration is widespread among birds, connecting breeding and wintering areas through a set of stopover localities where individuals refuel and/or rest. The extent of the stopover is critical in determining the migratory strategy of a bird. Here, we examined the relationship between minimum length of stay of PVC-ringed birds in a major stopover site and the remaining flight distance to the overwintering area in the Eurasian spoonbill (Platalea l. leucorodia) during four consecutive autumn migrations. We also analysed the potential effect of timing (arrival date), as well as the role of experience in explaining stopover duration of spoonbills. Overall, birds wintering in Africa, and facing long-distance travel from the stopover site (ca. 3,000 km) stay for longer (2.7 +/- A 0.4 days) than Iberian winterers (1.5 +/- A 0.2 days) that perform a much shorter migration (ca. 800 km). These differences were consistent between years. Stopover duration was not significantly affected by the age of the bird. However, there was a significant reduction as migration advanced. Our results suggest that spoonbills develop different stopover strategies depending on the expected distance to the wintering grounds. Adults, especially long-distance migratory ones, could reduce the potential negative effects of density-dependence processes by avoiding stopover at the end of the migration period. These findings are of significant relevance for understanding differences in migratory behaviour within single populations, especially for declining waterbirds, as well as stress the relevance of preserving stopover localities for the conservation of intraspecific diversity in migratory species.

  • 37. Nikinmaa, Mikko
    et al.
    Leveelahti, Lotta
    Dahl, Emma
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Rissanen, Eeva
    Rytkonen, Kalle T.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Population origin, development and temperature of development affect the amounts of HSP70, HSP90 and the putative hypoxia-inducible factor in the tadpoles of the common frog Rana temporaria2008In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 211, no 12, p. 1999-2004Article in journal (Refereed)
    Abstract [en]

    We raised Rana temporaria tadpoles from three different populations from southern, mid and northern Sweden (the total north-to-south distance between populations is approximately 1500 km) at two temperatures, and measured the differences in HSP70, HSP90 and putative HIF-1 alpha levels (Rana temporaria HIF-1 alpha was sequenced in the present study) with immunoblotting. The levels of the studied proteins increased with developmental stage. Also, the levels increased with latitude at the lower but not at the higher developmental temperature. This shows that there is a clear difference between the populations at the molecular level but that this difference can be modified by the environmental conditions experienced during development. The proteins analyzed may be involved in the regulation of developmental processes. If this is the case, the tadpoles from the northernmost population have the most advanced complement of regulatory proteins at developmental stages approaching metamorphosis.

  • 38.
    Nystrand, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Associating with kin affects the trade-off between energy intake and exposure to predators in a social bird species2007In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 74, no 3, p. 497-506Article in journal (Refereed)
    Abstract [en]

    Individuals have to trade-off energy intake against the risk of predation when foraging. However, in group-living species, social interference will limit the range of choices for subordinate individuals. The trade-off between foraging and predation risk may be even more complex in species that associate in family groups because relatives can provide benefits to each other that are withheld from nonrelatives. As a consequence, nonrelatives may be forced to take greater risks to gain similar amounts of energy as relatives. Here, I investigate how the energy–risk trade-off varies among individuals in a social, group-living species, the Siberian jay, Perisoreus infaustus. Groups in this species consist of a breeding pair, together with retained offspring and/or nonrelated immigrants. I manipulated food quality at feeding sites that differed in their visibility to predators and observed the differences in foraging patterns between different group members. Adults and their offspring fed more often at the protected feeding site when it contained high-quality food, but switched to the more exposed site when this site offered higher quality food than the protected site. In contrast, immigrants spent a similar amount of time at each feeding site, independent of food quality. Birds generally spent more time waiting for access to the high-quality food source and protected feeding site, and family members generally harassed immigrants that tried to access these sites. None the less, all birds had a similar overall food intake, suggesting that immigrants pay substantially higher costs than other members to attain the equivalent level of energy intake.

  • 39.
    Nystrand, Magdalena
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Population and conservation biology.
    Influence of age, kinship, and large-scale habitat quality on local foraging choices of Siberian jays.2006In: Behavioral Ecology, Vol. 17, p. 503-509Article in journal (Refereed)
  • 40. O'Gorman, Eoin J.
    et al.
    Pichler, Doris E.
    Adams, Georgina
    Benstead, Jonathan P.
    Cohen, Haley
    Craig, Nicola
    Cross, Wyatt F.
    Demars, Benoit O. L.
    Friberg, Nikolai
    Gislason, Gisli Mar
    Gudmundsdottir, Rakel
    Hawczak, Adrianna
    Hood, James M.
    Hudson, Lawrence N.
    Johansson, Liselotte
    Johansson, Magnus P.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Junker, James R.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Manson, J. Russell
    Mavromati, Efpraxia
    Nelson, Daniel
    Olafsson, Jon S.
    Perkins, Daniel M.
    Petchey, Owen L.
    Plebani, Marco
    Reuman, Daniel C.
    Rall, Bjoern C.
    Stewart, Rebecca
    Thompson, Murray S. A.
    Woodward, Guy
    Impacts of Warming on the Structure and Functioning of Aquatic Communities: Individual-to Ecosystem-Level Responses2012In: Advances in Ecological Research, Vol 47: Global Change in Multispecies Systems, Pt 2, Elsevier, 2012, p. 81-176Chapter in book (Refereed)
    Abstract [en]

    Environmental warming is predicted to rise dramatically over the next century, yet few studies have investigated its effects in natural, multi-species systems. We present data collated over an 8-year period from a catchment of geothermally heated streams in Iceland, which acts as a natural experiment on the effects of warming across different organisational levels and spatiotemporal scales. Body sizes and population biomasses of individual species responded strongly to temperature, with some providing evidence to support temperature size rules. Macroinvertebrate and meiofaunal community composition also changed dramatically across the thermal gradient. Interactions within the warm streams in particular were characterised by food chains linking algae to snails to the apex predator, brown trout These chains were missing from the colder systems, where snails were replaced by much smaller herbivores and invertebrate omnivores were the top predators. Trout were also subsidised by terrestrial invertebrate prey, which could have an effect analogous to apparent competition within the aquatic prey assemblage. Top-down effects by snails on diatoms were stronger in the warmer streams, which could account for a shallowing of mass-abundance slopes across the community. This may indicate reduced energy transfer efficiency from resources to consumers in the warmer systems and/or a change in predator-prey mass ratios. All the ecosystem process rates investigated increased with temperature, but with differing thermal sensitivities, with important implications for overall ecosystem functioning (e.g. creating potential imbalances in elemental fluxes). Ecosystem respiration rose rapidly with temperature, leading to increased heterotrophy. There were also indications that food web stability may be lower in the warmer streams.

  • 41.
    Orizaola, German
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Dahl, Emma
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Compensating for delayed hatching across consecutive life-history stages in an amphibian2010In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 119, no 6, p. 980-987Article in journal (Refereed)
    Abstract [en]

    Environmental conditions experienced early in the ontogeny can have a strong impact on individual fitness and performance later in life. Organisms may counteract the negative effects of poor developmental conditions by developing compensatory responses in growth and development. However, previous studies on compensatory responses have largely ignored the effects that poor embryonic conditions could have during the later life stages. In this study, we examined the effects of artificially delayed development in early life over two later life history transitions by investigating the compensatory growth of larval moor frogs Rana arvalis in response to temperature variation during embryonic development, and the associated costs during the larval 'and postmetamorphic stages. Low temperature during embryonic stage lead to delayed hatching at smaller size. The groups with delayed embryonic development showed strong compensatory growth during the larval stage, and reached similar metamorphic size than the controls in a shorter time. However, the most strongly delayed group was not able to fully catch up the total development time. These compensatory responses were found in the absence of photoperiod cues indicating that the delay in embryonic development was sufficient to initiate the compensatory response in larval growth and development. No apparent costs of compensatory growth were detected in terms of morphology or locomotor performance at the juvenile stage. We found that compensatory responses can be activated as early as at the embryonic stage and extend over several consecutive life history transitions, mitigating the effects of poor conditions experienced early in development. Potential short-term costs in natural environments and the occurrence of long-term costs, which prevent the generalisation of a faster larval life style, are discussed.

  • 42.
    Orizaola, German
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Growing with kin does not bring benefits to tadpoles in a genetically impoverished amphibian population2008In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 86, no 1, p. 45-50Article in journal (Refereed)
    Abstract [en]

    The effect of intraspecific competition can be modified through the interaction with genetic relatedness among the competing individuals. Theory of kin selection predicts that organisms should modify their behaviour to increase the fitness of their relatives and consequently their inclusive fitness. However, in populations with low genetic variation, the recognition of kin and nonkin individuals could be compromised. In this study, we tested the influence of density and relatedness on larval development in a genetically impoverished population of the pool frog (Rana lessonae Camerano, 1882), exposing individuals from four families to two densities and to competition by full-sibling and nonkin larvae. Larvae in high-density treatment were smaller than those in low-density treatment. No effect of kin, or interaction between density and kin, was detected. However, significant differences were detected in body size among the families and high heritability for size was found in both densities. Lack of variation in recognition alleles may explain the lack of kin effects on growth, whereas variation has been maintained in life-history traits either owing to their polygenic inheritance or owing to maternal effects.

  • 43.
    Orizaola, Germán
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Quintela, María
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Climatic adaptation in an isolated and genetically impoverished amphibian population2010In: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 33, no 4, p. 730-737Article in journal (Refereed)
    Abstract [en]

    The capacity of populations to respond adaptively to environmental change is essential for their persistence. Isolated populations often harbour reduced genetic variation, which is predicted to decrease adaptive potential, and can be detrimental under the current scenarios of global change. In this study, we examined climatic adaptation in larval life history traits in the pool frog Rana lessonae along a latitudinal gradient across the northern distribution area of the species, paying special attention to the isolated and genetically impoverished fringe populations in central Sweden. Larvae from eight populations within three geographic areas (Poland, Latvia and Sweden) were reared under three temperatures (19, 22 and 26 degrees C) in a common garden laboratory experiment. We found clear evidence for latitudinal adaptation in R. lessonae populations, larvae from higher latitudes growing and developing faster than low-latitude ones. Larvae from the Swedish populations were able to compensate for the effects of cooler temperatures and a shorter growth season with genetically higher growth and development rates (i.e. countergradient variation) in the two higher temperature treatments, but there was no difference among the populations at the lowest temperature treatment, which is likely to be close to the temperature limiting growth in R. lessonae. Our results demonstrate that isolated and genetically impoverished populations can be locally adapted, and identify the Swedish fringe populations as a significant conservation unit adapted to the northern environmental conditions.

  • 44.
    Persson, M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Räsänen, Katja
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Merilä, Juha
    Maternally determined adaptation to acidity in Rana arvalis: Are laboratory and field estimates of embryonic stress tolerance congruent?2007In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 85, no 7, p. 832-838Article in journal (Refereed)
    Abstract [en]

    Geographic variation indicating local adaptation, as well as its quantitative genetic basis, is commonly investigated in common garden experiments in the laboratory. However, the applicability of laboratory results to the complex conditions experienced by populations in the wild may be limited. Our previous laboratory experiments showed maternally determined local adaptation in embryonic acid-stress tolerance (viz. survival) of the moor frog, Rana arvalis Nilsson, 1842. Here we tested whether this laboratory finding holds even when embryos are exposed to acid stress in the wild. We conducted reciprocal crosses between an acid-origin population and a neutral-origin population of R. arvalis and transplanted the embryos to an acid site (pH ~4) in the field. Embryonic survival was much lower in the field experiment than in previous laboratory experiments, but, consistent with laboratory work, embryos from acid-origin females had threefold higher survival than embryos from neutral-origin females. These results suggest that laboratory tests can provide appropriate estimates of among population variation, as well as the quantitative genetic basis of acid-stress tolerance in amphibians.

  • 45.
    Quintela, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Berlin, Sofia
    Wang, Biao
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Höglund, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Genetic diversity and differentiation among Lagopus lagopus populations in Scandinavia and Scotland: evolutionary significant units confirmed by SNP markers2010In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 19, no 12, p. 2380-2393Article in journal (Refereed)
    Abstract [en]

    Single Nucleotide Polymorphism in four Scandinavian populations of willow grouse (Lagopus lagopus) and two Scottish populations of red grouse (Lagopus lagopus scoticus) were assessed at 13 protein-coding loci. We found high levels of diversity, with one substitution every 55 bp as an average and a total of 76 unlinked parsimony informative SNPs. Different estimators of genetic diversity such as: number of synonymous and non-synonymous sites, average number of alleles, number and percentage of polymorphic loci, mean nucleotide diversity (pi(s), pi(a)) and gene diversity at synonymous and non-synonymous sites showed higher diversity in the northern populations compared to southern ones. Strong levels of purifying selection found in all the populations together with neutrality tests conforming to neutral expectations agree with large effective population sizes. Assignment tests reported a clear distinction between Scandinavian and Scottish grouse suggesting the existence of two different evolutionary significant units. The divergence time between willow and red grouse ranging between 12 500 and 125 000 years, in conjunction with the presence of 'specific' markers for each subspecies prompt a reassessment of the taxonomical status of the Scottish red grouse.

  • 46.
    Quintela, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Thulin, Carl-Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Höglund, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Detecting hybridization between willow grouse (Lagopus lagopus) and rock ptarmigan (L. muta) in Central Sweden through Bayesian admixture analyses and mtDNA screening2010In: Conservation Genetics, ISSN 1566-0621, E-ISSN 1572-9737, Vol. 11, no 2, p. 557-569Article in journal (Refereed)
    Abstract [en]

    Willow grouse (L. lagopus) and rock ptarmigan (L. muta) are sibling species with similar phenotypic and life histories that coexist sympatrically in wide areas of their distribution range. These grouse are amongst the most popular game birds in Scandinavia but contrary to other quarry species, no restocking with captive-bred animals has ever been performed. The discovery of two individuals with intermediate plumage features evoked the question of possible hybridization events between both species, an idea that did not seem too unlikely on the basis of habitat overlap. Thus, to assess whether any genetic exchange is occurring, we used different Bayesian-based admixture analyses of multilocus genotypes determined at twelve microsatellite loci. We also obtained mitochondrial COI-sequences from a selected number of individuals to infer the maternal geneflow and potential introgression. The capacity of our panel of microsatellite markers to detect hybridization was verified using assignments of simulated genotypes. We then evaluated the extent of hybridization in an actual sample of 111 individuals collected in a 100-km(2) area in the Scandinavian mountain range. An admixed condition was verified in one of the suspected hybrids, that seemed to carry a L. muta genotype with partial L. lagopus introgression. In addition, more than 4% of L. lagopus showed signs of hybridization under the most conservative scenario with respect to discrepancies between population assignment methods. This was unexpected, given that no L. lagopus displayed any apparent intermediate plumage features. Furthermore, interspecific geneflow of mtDNA haplotypes was lower than expected; which suggests that Haldane's rule might apply for these two grouse species. Hence, plumage identification of hybrid ancestry is not always reliable and might lead to biases in the estimation of hybridization rates. Hybridisation may be expected to increase if the climate gets warmer as the habitat overlap between the species will become more extensive. We discuss whether hybridisation is a threat to the long-term survival of any of the two species.

  • 47.
    Rogell, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Population and Conservation Biology.
    Genetic variation and local adaptation in peripheral populations of toads2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Northern fringe populations generally have low amounts of genetic variation and inhabit habitats where specific adaptations are needed. On the Swedish west coast, the natterjack toad (Bufo calamita) inhabits skerry islands. I have examined: I) adaptation to two environmental stressors in this habitat; II) the genetic population structure within the skerry habitat; III) the effects of neutral genetic variation, selection and genetic drift on trait divergence within the skerry habitat; and IV) the effects of genetic variation on fitness under three thermal conditions of varying stressfulness. V) I have also studied the impact of putative local adaptations on the Scandinavian green toad (Bufo viridis) conservation programme. The results suggest that the skerry natterjack toads are locally adapted to the desiccation risk in their habitat. However, despite inhabiting a more saline habitat, they had a lower salinity tolerance when compared to their conspecifics in the more general habitat. The lowered salinity tolerance is most likely explained by the presence of negative genetic correlations between salinity tolerance and desiccation avoidance and suggests that the occurrence of multiple environmental stressors may constrain adaptation. Within the skerry habitat, the toads exhibited a strong population structure with populations differing in their levels of genetic variation. Moreover, within the skerry habitat, the results suggest uniform selection pressures. However, correlations between trait values and neutral genetic variation suggest that inbreeding depression may affect trait values and thus potentially constrain adaptation. In the natterjack toad, fitness costs associated with lack of genetic variation were only present under benign conditions and not under more natural conditions. This suggests that environmental stress masks inbreeding depression in these traits under natural conditions. In the study regarding the Scandinavian green toads, I found that one population inhabiting a saline habitat had a higher salinity tolerance than other populations in less saline habitats. This suggests the presence of local adaptation, which should be acknowledged in the green toad conservation programme. Several of the northern fringe populations of toads fulfill the criteria of being Evolutionary Significant Units and their conservation thus should be prioritized.

    List of papers
    1. The interaction of multiple environmental stressors affects adaptation to a novel habitat in the natterjack toad Bufo calamita
    Open this publication in new window or tab >>The interaction of multiple environmental stressors affects adaptation to a novel habitat in the natterjack toad Bufo calamita
    Show others...
    2009 (English)In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 22, no 11, p. 2267-2277Article in journal (Refereed) Published
    Abstract [en]

    The potential to adapt to novel environmental conditions is a key area of interest for evolutionary biology. However, the role of multiple selection pressures on adaptive responses has rarely been investigated in natural populations. In Sweden, the natterjack toad Bufo calamita inhabits two separate distribution areas, one in southernmost Sweden and one on the west coast. We characterized the larval habitat in terms of pond size and salinity in the two areas, and found that the breeding ponds of the western populations run higher desiccation risk and had higher salinity than the ponds used by the southern populations. In a common garden experiment manipulating salinity and temperature, we found that toads from the west coast populations were locally adapted to shorter pond duration as indicated by their higher development and growth rates. However, despite being subjected to higher salinity stress in nature, west coast toads had a poorer performance in saline treatments. We found that survival in the saline treatments in the west coast populations was positively affected by larger body mass and longer larval period. Furthermore, we found negative genetic correlations between body mass and growth rate and their non-adaptive plastic responses to salinity. These results implicate that the occurrence of multiple environmental stressors needs to be accounted for when assessing the adaptive potential of organisms and suggest that genetic correlations may play a role in constraining adaptation of natural populations.

    Keywords
    Trade-offs, genetic correlations, evolutionary change, natural selection, life-history traits
    National Category
    Biological Sciences
    Research subject
    Population Biology
    Identifiers
    urn:nbn:se:uu:diva-107340 (URN)10.1111/j.1420-9101.2009.01842.x (DOI)000271049500013 ()
    Available from: 2009-08-06 Created: 2009-08-06 Last updated: 2017-12-13Bibliographically approved
    2. Genetic structure in peripheral populations of the natterjack toad, Bufo calamita, as revealed by AFLP
    Open this publication in new window or tab >>Genetic structure in peripheral populations of the natterjack toad, Bufo calamita, as revealed by AFLP