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  • 251.
    Kullberg, Cecilia
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Fransson, Thord
    Naturhistoriska Riksmuseet.
    Vallin, Adrian
    Stockholm University, Faculty of Science, Department of Zoology.
    Magnetic cues and time of season affect fuel deposition in migratory thrush nightingales (Luscinia luscinia)2003In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 270, no 1513, p. 373-378Article in journal (Refereed)
    Abstract [en]

    Bird migration requires high energy expenditure, and long–distance migrants accumulate fat for use as fuel during stopovers throughout their journey. Recent studies have shown that long–distance migratory birds, besides accumulating fat for use as fuel, also show adaptive phenotypic flexibility in several organs during migration. The migratory routes of many songbirds include stretches of sea and desert where fuelling is not possible. Large fuel loads increase flight costs and predation risk, therefore extensive fuelling should occur only immediately prior to crossing inhospitable zones. However, despite their crucial importance for the survival of migratory birds, both strategic refuelling decisions and variation in phenotypic flexibility during migration are not well understood. First–year thrush nightingales (Luscinia luscinia) caught in the early phase of the onset of autumn migration in southeast Sweden and exposed to a magnetic treatment simulating a migratory flight to northern Egypt increased more in fuel load than control birds. By contrast, birds trapped during the late phase of the onset of autumn migration accumulated a high fuel load irrespective of magnetic treatment. Furthermore, early birds increased less in flight–muscle size than birds trapped later in autumn. We suggest that the relative importance of endogenous and environmental factors in individual birds is affected by the time of season and by geographical area. When approaching a barrier, environmental cues may act irrespective of the endogenous time programme.

  • 252.
    Kvarnemo, C.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Mobley, K. B.
    Partridge, C.
    Jones, A. G.
    Ahnesjo, I.
    Evidence of paternal nutrient provisioning to embryos in broad-nosed pipefish Syngnathus typhle2011In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 78, no 6, p. 1725-1737Article in journal (Refereed)
    Abstract [en]

    In two experiments, radioactively labelled nutrients (either (3)H-labelled amino-acid mixture or (14)C-labelled glucose) were tube-fed to brooding male Syngnathus typhle. Both nutrients were taken up by the males and radioactivity generally increased in the brood pouch tissue with time. Furthermore, a low but significant increase of (3)H-labelled amino acids in embryos was found over the experimental interval (48 h), whereas in the (14)C-glucose experiment the radioactivity was taken up by the embryos but did not increase over the experimental time (320 min). Uptake of radioisotopes per embryo did not differ with embryo size. A higher uptake mg(-1) tissue of both (3)H-labelled amino acids and (14)C-labelled glucose was found in smaller embryos, possibly due to a higher relative metabolic rate or to a higher surface-area-to-volume ratio compared to larger embryos. Uptake in embryos was not influenced by male size, embryonic developmental advancement or position in the brood pouch. It is concluded that brooding males provide amino acids, and probably also glucose, to the developing embryos in the brood pouch. (C) 2011 The Authors Journal of Fish Biology (C) 2011 The Fisheries Society of the British Isles

  • 253.
    Kånneby, Tobias
    Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
    New species and new records of freshwater Chaetonotida (Gastrotricha) from Sweden2011In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, Vol. 3115, p. 29-55Article in journal (Refereed)
    Abstract [en]

    Gastrotricha is a small phylum of acoelomatic aquatic invertebrates common in both marine and freshwater environments. The freshwater gastrotrich fauna of Sweden is poorly known and to date only twenty species have been reported. In this study two species of the genus Heterolepidoderma: Heterolepidoderma joermungandri n. sp. and H. trapezoidum n. sp. are described as new to science. Moreover nine species are presented as new to the Swedish fauna. Additional taxonomic information is also given for four species previously reported from the country. In total 7 genera spanning two families, Chaetonotidae and Dasydytidae, are presented and the number of reported freshwater gastrotrichs from the country is increased to 31.

  • 254.
    Kånneby, Tobias
    et al.
    The Swedish Museum of Natural History .
    Todaro, M. Antonio
    Jondelius, Ulf
    The Swedish Museum of Natural History.
    A Phylogenetic approach to species delimitation in freshwater Gastrotricha from Sweden2012In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 683, no 1, p. 185-202Article in journal (Refereed)
    Abstract [en]

    Gastrotricha is a cosmopolitan group of aquatic invertebrates. To date approximately 765 species have been described. This study is the first to deal with species delimitation and cryptic species of freshwater Gastrotricha. Three commonly encountered species, Heterolepidoderma ocellatum, Lepidochaetus zelinkai and Lepidodermella squamata, are investigated for cryptic speciation. Most of the material is based on Swedish specimens but closely related species from other parts of the world are also included. Taxonomic revisions are supported by phylogenies based on 18S rRNA, 28S rRNA and COI mtDNA of freshwater Chaetonotidae from several genera and inferred from Bayesian and maximum likelihood approaches. Heterolepidoderma ocellatum f. sphagnophilum is raised to species level, becoming H. acidophilum n. sp. Moreover, genetic data based on COI indicates high variation between two morphologically very similar groups of Lepidodermella squamata. The extent of cryptic speciation in L. zelinkai appears low. Based on the phylogenetic hypothesis presented in this paper the new species, Lepidodermella intermedia n. sp., from northernSweden is also described. The phylogenetic hypothesis generated show that Chaetonotidae is a non-monophyletic group.  

  • 255.
    Kånneby, Tobias
    et al.
    Naturhistoriska riksmuseet, Enheten för evertebratzoologi.
    Todaro, M. Antonio
    Jondelius, Ulf
    Naturhistoriska riksmuseet, enheten för evertebratzoologi.
    One new species and records of Ichthydium Ehrenberg, 1830 (Gastrotricha: Chaetonotida) from Sweden with a key to the genus2009In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, no 2278, p. 26-46Article in journal (Refereed)
    Abstract [en]

    The freshwater gastrotrich fauna of Sweden is poorly known. Only seven species of freshwater gastrotrichs have been reported so far. This paper is the first in a series of contributions about the Swedish freshwater gastrotrich fauna. Here we describe one new species, Ichthydium skandicum n. sp., from Jamtland, northern Sweden. The new species falls within the boundary of the subgenus Forficulichthys and is morphologically closest to Ichthydium tanytrichum from which it can be differentiated based on the presence of four pairs of dorsal, keeled scales in the posterior trunk region. Moreover, we provide morphometric data for three additional Ichthydium species: I. diacanthum, I. squamigerum and I. tanytrichum, Italian species all of which are reported for the first time outside Italy. Considering the accompanying fauna, a total of thirteen freshwater Gastrotricha are reported for the first time from Sweden. Finally we present a dichotomous key for Ichthydium along with distributional data of the species considered.

  • 256.
    Kånneby, Tobias
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
    Todaro, M. Antonio
    Jondelius, Ulf
    Stockholm University, Faculty of Science, Department of Zoology, Systematic Zoology.
    Phylogeny of Chaetonotidae (Gastrotricha) inferred from nuclear and mitochondrial genesManuscript (preprint) (Other academic)
    Abstract [en]

    Chaetonotidae is the largest family within Gastrotricha with almost 400 nominal species, represented in both freshwater and marine habitats. The group is probably non-monophyletic and suffers from a troubled taxonomy. Current classification is to a great extent based on shape and distribution of cuticular structures, characters that are highly variable. We present the most densely sampled molecular study so far where 17 out of 31 genera belonging to Chaetonotida are represented. Bayesian and maximum likelihood approaches based on 18S rDNA, 28S rDNA and COI mtDNA are used to reconstruct relationships within Chaetonotidae. The use of cuticular structures for supra-specific classification within the group is evaluated and the question of dispersal between marine and freshwater habitats is addressed. Moreover the subgeneric classification of Chaetonotus is tested in a phylogenetic context. Our results show high support for a clade containing Dasydytidae nested within Chaetonotidae. Within this clade only 3 genera are monophyletic following current classification. Genera containing both marine and freshwater species never form monophyletic clades and group with other species according to habitat. Marine members of Aspidiophorus appear to be the sister group of all other Chaetonotidae and Dasydytidae, indicating a marine origin of the clade. Halichaetonotus and marine Heterolepidoderma form a monophyletic group in a sister group relationship to freshwater species, pointing towards a secondary invasion to marine environments of these taxa. Our study shows the problems of current classification based on cuticular structures, characters that show homoplasy for deeper relationships.

  • 257. Küker, Susanne
    et al.
    Huber, Nikolaus
    Evans, Alina
    Kjellander, Petter
    Bergvall, Ulrika A
    Department of Ecology, Swedish University of Agricultural Sciences, Grimsö Wildlife Research Station, Riddarhyttan, Sweden.
    Jones, Krista L
    Arnemo, Jon M
    Hematology, serum chemistry, and serum protein electrophoresis ranges for free-ranging roe deer (Capreolus capreolus) in Sweden.2015In: Journal of Wildlife Diseases, ISSN 0090-3558, E-ISSN 1943-3700, Vol. 51, no 1, p. 269-73Article in journal (Refereed)
    Abstract [en]

    We present the first reference ranges for hematology (n = 35 animals), serum biochemistry (n = 62), and serum protein electrophoresis (n = 32) in physically restrained free-ranging roe deer (Capreolus capreolus). Animals were captured in box traps and physically restrained for blood sampling during the winter in Sweden, 2011-13. No clinically significant sex or age differences were found.

  • 258.
    Lagerholm, Vendela K.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden; University of St Andrews, UK.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology. University of California Davis, USA.
    Ehrich, Dorothee
    Ims, Rolf A.
    Killengreen, Siw T.
    Abramson, Natalia I.
    Niemaa, Jukka
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Henttonen, Heikki
    Dalén, Love
    Run to the hills: gene flow among mountain areas leads to low genetic differentiation in the Norwegian lemming2017In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 121, no 1, p. 1-14Article in journal (Refereed)
    Abstract [en]

    The endemic Norwegian lemming (Lemmus lemmus) is an icon for cyclic species, famous since the Middle Ages for its enormous population outbreaks and mass movements. Although the drivers behind this cyclicity have been intensively investigated, virtually nothing is known about the extent to which long-distance dispersal during population peaks actually lead to gene flow among mountain tundra areas. In this article, we use nine microsatellite markers to address this question and analyse range-wide genetic diversity and differentiation between Fennoscandian sub-regions. The results revealed a high genetic variation with a surprisingly weak population structure, comparable to that of much larger mammals. The differentiation was mainly characterized as a genetic cline across the species' entire distribution, and results from spatial autocorrelation analyses suggested that gene flow occurs with sufficiently high frequency to create a genetic patch size of 100 km. Further, we found that for the equivalent distances, the southern sub-regions were genetically more similar to each other than those in the north, which indicates that the prolonged periods of interrupted lemming cyclicity recorded in the northern parts of Fennoscandia have led to increased isolation and population differentiation. In summary, we propose that mass movements during peak years act as pulses of gene flow between mountain tundra areas, and that these help to maintain genetic variation and counteract differentiation over vast geographic distances.

  • 259.
    Lagerholm, Vendela K.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Sandoval-Castellanos, Edson
    Stockholm University, Faculty of Science, Department of Zoology. Swedish Museum of Natural History, Sweden.
    Ehrich, Dorothee
    Abramson, Natalia I.
    Nadachowski, Adam
    Kalthoff, Daniela C.
    Germonpre, Mietje
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology.
    Stewart, John R.
    Dalén, Love
    On the origin of the Norwegian lemming2014In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, no 8, p. 2060-2071Article in journal (Refereed)
    Abstract [en]

    The Pleistocene glacial cycles resulted in significant changes in species distributions, and it has been discussed whether this caused increased rates of population divergence and speciation. One species that is likely to have evolved during the Pleistocene is the Norwegian lemming (Lemmus lemmus). However, the origin of this species, both in terms of when and from what ancestral taxon it evolved, has been difficult to ascertain. Here, we use ancient DNA recovered from lemming remains from a series of Late Pleistocene and Holocene sites to explore the species' evolutionary history. The results revealed considerable genetic differentiation between glacial and contemporary samples. Moreover, the analyses provided strong support for a divergence time prior to the Last Glacial Maximum (LGM), therefore likely ruling out a postglacial colonization of Scandinavia. Consequently, it appears that the Norwegian lemming evolved from a small population that survived the LGM in an ice-free Scandinavian refugium.

  • 260.
    Laikre, Linda
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Jansson, Mija
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Allendorf, Fred W.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Hunting Effects on Favourable Conservation Status of Highly Inbred Swedish Wolves2013In: Conservation Biology, ISSN 0888-8892, E-ISSN 1523-1739, Vol. 27, no 2, p. 248-253Article in journal (Refereed)
    Abstract [en]

    The wolf (Canis lupus) is classified as endangered in Sweden by the Swedish Species Information Centre, which is the official authority for threat classification. The present population, which was founded in the early 1980s, descends from 5 individuals. It is isolated and highly inbred, and on average individuals are more related than siblings. Hunts have been used by Swedish authorities during 2010 and 2011 to reduce the population size to its upper tolerable level of 210 wolves. European Union (EU) biodiversity legislation requires all member states to promote a concept called “favourable conservation status” (FCS) for a series of species including the wolf. Swedish national policy stipulates maintenance of viable populations with sufficient levels of genetic variation of all naturally occurring species. Hunting to reduce wolf numbers in Sweden is currently not in line with national and EU policy agreements and will make genetically based FCS criteria less achievable for this species. We suggest that to reach FCS for the wolf in Sweden the following criteria need to be met: (1) a well-connected, large, subdivided wolf population over Scandinavia, Finland, and the Russian Karelia-Kola region should be reestablished, (2) genetically effective size (Ne) of this population is in the minimum range of Ne = 500–1000, (3) Sweden harbors a part of this total population that substantially contributes to the total Ne and that is large enough to not be classified as threatened genetically or according to IUCN criteria, and (4) average inbreeding levels in the Swedish population are <0.1.

  • 261.
    Laikre, Linda
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Larsson, Lena C.
    Stockholm University, Faculty of Science, Department of Zoology.
    Palmé, Anna
    Stockholm University, Faculty of Science, Department of Zoology.
    Charlier, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Josefsson, Melanie
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Potentials for monitoring gene level biodiversity: using Sweden as an example2008In: Biodiversity and Conservation, ISSN 0960-3115, E-ISSN 1572-9710, Vol. 17, no 4, p. 893-910Article in journal (Refereed)
    Abstract [en]

    Programs for monitoring biological diversity over time are needed to detect changes that can constitute threats to biological resources. The convention on biological diversity regards effective monitoring as necessary to halt the ongoing erosion of biological variation, and such programs at the ecosystem and species levels are enforced in several countries. However, at the level of genetic biodiversity, little has been accomplished, and monitoring programs need to be developed. We define “conservation genetic monitoring” to imply the systematic, temporal study of genetic variation within particular species/populations with the aim to detect changes that indicate compromise or loss of such diversity. We also (i) identify basic starting points for conservation genetic monitoring, (ii) review the availability of such information using Sweden as an example, (iii) suggest categories of species for pilot monitoring programs, and (iv) identify some scientific and logistic issues that need to be addressed in the context of conservation genetic monitoring. We suggest that such programs are particularly warranted for species subject to large scale enhancement and harvest—operations that are known to potentially alter the genetic composition and reduce the variability of populations.

  • 262.
    Laikre, Linda
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Nilsson, T
    Länsstyrelsen Värmland.
    Primmer, CR
    University of Turku, Finland.
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Allendorf, FW
    University of Montana, USA.
    Importance of Genetics in the Interpretation of Favourable Conservation Status2009In: Conservation Biology, ISSN 0888-8892, E-ISSN 1523-1739, Vol. 23, p. 1378-1381Article in journal (Refereed)
    Abstract [en]

    “Favourable Conservation Status” (FCS) is a central concept in the biodiversity conservation legislation of the European Union (EU). Here, we highlight the importance of incorporating aspects of conservation genetics in interpretation of this concept. Recent documents from the EU Commission indicate that knowledge of conservation genetics has so far been lacking among those who have tried to employ the concept. We think it is crucial that aspects of conservation genetics be incorporated in discussion of this concept and that this be done before the EU Court of Justice takes a position on the legal interpretation of FCS.

  • 263.
    Laikre, Linda
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Palmé, Anna
    Stockholm University, Faculty of Science, Department of Zoology.
    Larsson, Lena C
    Stockholm University, Faculty of Science, Department of Zoology.
    Charlier, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Effekter av spridning av genetiskt främmande populationer: en kartläggning av förutsättningarna för uppföljande studier av utsättningar av djur och växter i Sverige2008Report (Other academic)
  • 264. Lamichhaney, Sangeet
    et al.
    Barrio, Alvaro Martinez
    Rafati, Nima
    Sundström, Görel
    Rubin, Carl-Johan
    Gilbert, Elizabeth R.
    Berglund, Jonas
    Wetterbom, Anna
    Laikre, Linda
    Stockholm University, Faculty of Science, Department of Zoology.
    Webster, Matthew T.
    Grabherr, Manfred
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Andersson, Leif
    Population-scale sequencing reveals genetic differentiation due to local adaptation in Atlantic herring2012In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 109, no 47, p. 19345-19350Article in journal (Refereed)
    Abstract [en]

    The Atlantic herring (Clupea harengus), one of the most abundant marine fishes in the world, has historically been a critical food source in Northern Europe. It is one of the few marine pecies that can reproduce throughout the brackish salinity gradient of the Baltic Sea. Previous studies based on few genetic markers have revealed a conspicuous lack of genetic differentiation between geographic regions, consistent with huge population sizes and minute genetic drift. Here, we present a cost-effective genome-wide study in a species that lacks a genome sequence. We first assembled a muscle transcriptome and then aligned genomic reads to the transcripts, creating an “exome assembly,” capturing both exons and flanking sequences. We then resequenced pools of fish from a wide geographic range, including the Northeast Atlantic, as well as different regions in the Baltic Sea, aligned the reads to the exome assembly, and identified 440,817 SNPs. The great majority of SNPs showed no appreciable differences in allele frequency among populations; however, several thousand SNPs showed striking differences, some approaching fixation for different alleles. The contrast between low genetic differentiation at most loci and striking differences at others implies that the latter category primarily reflects natural selection. A simulation study confirmed that the distribution of the fixation index FST deviated significantly from expectation for selectively neutral loci. This study provides insights concerning the population  structure of an important marine fish and establishes the Atlantic herring as a model for population genetic studies of adaptation and natural selection.

  • 265. Landergren, Peter
    Sea trout, Salmo trutta L., in small streams on Gotland: the coastal zone as a growth habitat for parr2001Doctoral thesis, comprehensive summary (Other academic)
  • 266.
    Lange, Henrik
    Stockholm University, Faculty of Science, Department of Zoology.
    Social dominance and agonistic communication in the great tit2003Doctoral thesis, comprehensive summary (Other academic)
  • 267.
    Larsdotter Mellström, Helena
    Stockholm University, Faculty of Science, Department of Zoology.
    A life history perspective on mating behaviour in the butterfly Pieris napi2009Licentiate thesis, comprehensive summary (Other academic)
  • 268.
    Larsdotter Mellström, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Friberg, Magne
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Borg-Karlson, Anna-Karin
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry.
    Murtazina, Rushana
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry.
    Palm, Mikael
    KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Seasonal polyphenism in life history traits: Time costs of direct development in a butterfly2010In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 64, p. 1377-1383Article in journal (Refereed)
    Abstract [en]

    Insects with two or more generations per year will generally experience different selection regimes depending on the season, and accordingly show seasonal polyphenisms. In butterflies, seasonal polyphenism has been shown with respect to morphology, life history characteristics and behaviour. In temperate bivoltine species, the directly developing generation is more time-constrained than the diapause generation and this may affect various life history traits, such as mating propensity (time from eclosion to mating). Here we test whether mating propensity differs between generations in Pieris napi, along with several physiological parameters, for males sex pheromone synthesis, and for females ovigeny index and fecundity.

    As predicted, individuals of the directly developing generation – who have shorter time for pupal development - are more immature at eclosion; males take longer to synthesize the male sex pheromone after eclosion and also take longer to mate than diapause generation males. Females show the same physiological pattern, the directly developing females lay fewer eggs than diapausing females during the first days of their life. Nevertheless, the directly developing females mate faster after eclosion than diapausing females, indicating substantial adult time stress in this generation and possibly an adaptive value of shortening the pre-reproductive period.

    Our study highlights how time-stress can be predictably different between generations, affecting both life history and behaviour. By analyzing several life history traits simultaneously we adopt a multi-trait approach to examining how adaptations and developmental constraints likely interplay to shape these seasonal polyphenisms.

  • 269.
    Larsdotter Mellström, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Males use sex pheromone assessment to tailor ejaculates to risk of sperm competition in a butterfly2009In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 20, no 5, p. 1147-1151Article in journal (Refereed)
    Abstract [en]

    In polyandrous butterflies males transfer a large, nutritious ejaculate at mating. Larger ejaculates delay female remating and confer an advantage in sperm competition. However, large ejaculates are costly, potentially selecting for male adjustment of ejaculate size to the risk of sperm competition. Here, we test if male ejaculate size in the butterfly Pieris napi varies with male density, and whether males assess sperm competition risk using the male sex pheromone citral as a cue. The results conform to sperm competition theory and showed that male P. napi tailored their reproductive investment in response to the risk of sperm competition; ejaculates transferred by males in the high male density treatments were on average 23% larger than ejaculates transferred at low male densities. The results also show for the first time, that the sex pheromone citral was used by males to assess male density; ejaculates transferred by males in presence of added male sex-pheromone were 19% larger than ejaculates transferred in the control. In conclusion, the study shows how the sex pheromone not only facilitates female acceptance when dispensed by courting males, but also allows males to assess the degree of male competition for matings.

  • 270.
    Larsdotter Mellström, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    What affects mating rate?: Polyandry is higher in the directly developing generation of the butterfly Pieris napi2010In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 80, p. 413-418Article in journal (Refereed)
    Abstract [en]

    Polyandry is common among insects and female insects in general gain directly from mating multiply in terms of increased lifetime reproductive success. Nevertheless, polyandry is not rampant, suggesting that realized polyandry is the outcome of costs and benefits associated with multiple matings. In the bivoltine green-veined white butterfly Pieris napi, females gain from mating multiply as males transfer a substantial nuptial gift along with the sperm at mating. Nonetheless, lifetime number of matings varies between 1 and 6 and 12 % of females mate only once. Here, we explore the reason for this variation and test (1) whether female polyandry is contingent on environmental conditions, specifically whether females can compensate for adverse conditions by mating more often, and (2) whether the level of polyandry differs between the diapausing generation that flies after pupal hibernation, and the directly developing generation, specifically whether females in the more time-constrained summer generation are more polyandrous, possibly as a result of selection for early high mating propensity and thereby shorter pre-reproductive period. Results showed that (1) females do not compensate for adverse conditions by mating more often, and (2) the level of polyandry was higher in the directly developing generation than in the diapause generation. Hence, we argue that differences in time stress and mating propensity between generations interplay in shaping mating frequency, and that the difference in polyandry between generations highlights the importance of integrating developmental pathway and life history.

  • 271.
    Larsson, Lena C.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Charlier, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Laikre, Linda
    Stockholm University, Faculty of Science, Department of Zoology.
    Ryman, Nils
    Stockholm University, Faculty of Science, Department of Zoology.
    Statistical power for detecting genetic divergence–organelle versus nuclear markers2009In: Conservation Genetics, ISSN 1566-0621, E-ISSN 1572-9737, Vol. 10, no 5, p. 1255-1264Article in journal (Refereed)
    Abstract [en]

    Statistical power is critical in conservation for detecting genetic differences in space or time from allele frequency data. Organelle and nuclear genetic markers have fundamentally different transmission dynamics; the potential effect of these differences on power to detect divergence have been speculated on but not investigated. We examine, analytically and with computer simulations, the relative performance of organelle and nuclear markers under basic, ideal situations. We conclude that claims of a generally higher resolving power of either marker type are not correct. The ratio R = FST,organelle/FST,nuclear varies between 1 and 4 during differentiation and this greatly affects the power relationship. When nuclear FST is associated with organelle differentiation four times higher, the power of the organelle marker is similar to two nuclear loci with the same allele frequency distribution. With large sample sizes (n C 50) and several populations or many alleles per locus (C5), the power difference may typically be disregarded when nuclear FST[0.05. To correctly interpret observed patterns of genetic differentiation in practical situations, the expected FSTs and the statistical properties (i.e., power analysis) of the genetic markers used should be evaluated, taking the observed allele frequency distributions into consideration.

  • 272. Lecoeur, Julien
    et al.
    Dacke, Marie
    Floreano, Dario
    Baird, Emily
    Stockholm University, Faculty of Science, Department of Zoology. Lund University, Sweden.
    The role of optic flow pooling in insect flight control in cluttered environments2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 7707Article in journal (Refereed)
    Abstract [en]

    Flight through cluttered environments, such as forests, poses great challenges for animals and machines alike because even small changes in flight path may lead to collisions with nearby obstacles. When flying along narrow corridors, insects use the magnitude of visual motion experienced in each eye to control their position, height, and speed but it is unclear how this strategy would work when the environment contains nearby obstacles against a distant background. To minimise the risk of collisions, we would expect animals to rely on the visual motion generated by only the nearby obstacles but is this the case? To answer this, we combine behavioural experiments with numerical simulations and provide the first evidence that bumblebees extract the maximum rate of image motion in the frontal visual field to steer away from obstacles. Our findings also suggest that bumblebees use different optic flow calculations to control lateral position, speed, and height.

  • 273.
    Lehmann, Philipp
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Jyväskylä, Finland.
    Kaunisto, Sirpa
    Kostal, Vladimir
    Margus, Aigi
    Zahradnickova, Helena
    Lindström, Leena
    Comparative Ecophysiology of Cold-Tolerance-Related Traits: Assessing Range Expansion Potential for an Invasive Insect at High Latitude2015In: Physiological and Biochemical Zoology, ISSN 1522-2152, E-ISSN 1537-5293, Vol. 88, no 3, p. 254-265Article in journal (Refereed)
    Abstract [en]

    Survival at high latitude requires the capability to cope with seasonally imposed stress, such as low winter temperatures or large temperature fluctuations. The Colorado potato beetle, Leptinotarsa decemlineata, is an invasive pest of potato that has rapidly spread from low latitudes to higher latitudes. During the last 30 years, a decrease in range expansion speed is apparent in Europe. We use a comparative approach to assess whether this could be due to an inability of L. decemlineata to cope with the harsher winters encountered at high latitude, when compared to two native northern chrysomelid beetles with similar overwintering ecology. We investigated several cold-tolerance-related physiological traits at different time points during winter. Cold tolerance followed a latitudinal pattern; the northern species were more tolerant to short-term subzero temperatures than the invasive L. decemlineata. The other northern species, the knotgrass leaf beetle, Chrysolina polita, was found to tolerate internal freezing. Interestingly, the pattern for overwinter survival at 5 degrees C was the opposite and higher in L. decemlineata than the northern species and could be related to behavioral differences between species in overwintering location selection and a potential physiological trade-off between tolerance to cold shock and to chronic cold exposure. Furthermore, while the northern species accumulated large amounts of different sugars and polyols with probable cryoprotectant functions, none were detected in L. decemlineata at high concentrations. This lack of cryoprotectant accumulation could explain the difference in cold tolerance between the species and also suggests that a lack of physiological capacity to tolerate low temperatures could slow further latitudinal range expansion of L. decemlineata.

  • 274.
    Lehmann, Philipp
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. University of Jyväskylä, Finland.
    Lyytinen, Anne
    Piiroinen, Saija
    Lindström, Leena
    Is a change in juvenile hormone sensitivity involved in range expansion in an invasive beetle?2015In: Frontiers in Zoology, ISSN 1742-9994, E-ISSN 1742-9994, Vol. 12, article id 20Article in journal (Refereed)
    Abstract [en]

    Introduction: It has been suggested that rapid range expansion could proceed through evolution in the endocrinological machinery controlling life-history switches. Based on this we tested whether the Colorado potato beetle, Leptinotarsa decemlineata, which has rapidly expanded its range across latitudinal regions in Europe, and shows photoperiodic adaptation in overwintering initiation, has different sensitivities to juvenile hormone (JH) manipulation along a latitudinal gradient. Results: A factorial experiment where beetles were reared either under a long or short day photoperiod was performed. Hormone levels were manipulated by topical applications. An allatostatin mimic, H17, was used to decrease and a juvenile hormone III analogue, pyriproxyfen, was used to increase the hormone levels. The effects of photoperiod and hormone manipulations on fecundity and overwintering related burrowing were monitored. Application of H17 decreased fecundity but did not induce overwintering related burrowing. Manipulation with pyriproxyfen increased fecundity and delayed burrowing. While small population-dependent differences in responsiveness to the topical application treatments were observed in fecundity, none were seen in overwintering related burrowing. Conclusions: The results indicate that the rapid photoperiodic adaptation manifested in several life-history and physiological traits in L. decemlineata in Europe is unlikely a result of population dependent differences in JH III sensitivity. While other endocrine factors cannot be ruled out, more likely mechanisms could be genetic changes in upstream elements, such as the photoperiodic clock or the insulin signaling pathway.

  • 275.
    Leimar, Olof
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Norberg, Ulf
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Habitat preference and habitat exploration in two species of satyrine butterflies2003In: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 26, p. 474-480Article in journal (Refereed)
  • 276.
    Leimar, Olof
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Sasaki, Akira
    Doebeli, Michael
    Dieckmann, Ulf
    Limiting similarity, species packing, and the shape of competition kernels2013In: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 339, p. 3-13Article in journal (Refereed)
    Abstract [en]

    A traditional question in community ecology is whether species' traits are distributed as more-or-less regularly spaced clusters. Interspecific competition has been suggested to play a role in such structuring of communities. The seminal theoretical work on limiting similarity and species packing, presented four decades ago by Robert MacArthur, Richard Levins and Robert May, has recently been extended. There is now a deeper understanding of how competitive interactions influence community structure, for instance, how the shape of competition kernels can determine the clustering of species' traits. Competition is typically weaker for greater phenotypic difference, and the shape of the dependence defines a competition kernel. The clustering tendencies of kernels interact with other effects, such as variation in resource availability along a niche axis, but the kernel shape can have a decisive influence on community structure. Here we review and further extend the recent developments and evaluate their importance.

  • 277.
    Liao, Sifang
    Stockholm University, Faculty of Science, Department of Zoology.
    The role of insulin signaling during development, reproductive diapause and aging in Drosophila Melanogaster2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The insulin/insulin-like growth factor signaling pathway exists from invertebrates to vertebrates and it can regulate various biological processes, including development, metabolism, stress resistance and lifespan. In Drosophila, eight insulin-like peptides (DILP1-8) have been found. The specific function of each DILP is not fully known, especially for DILP1. In paper I, we found that dilp1 is specifically expressed in the brain insulin producing cells (IPCs), and it is mainly expressed from early pupa until few days of adult life, which correspond to non-feeding stages. The expression of dilp1 can last for at least 9 weeks of adult life when newborn virgin flies are induced to enter reproductive diapause. In addition, we found that the expression of dilp1 is under regulation by other dilps. Also larva-derived fat body, short neuropeptide F (sNPF) and juvenile hormone can affect dilp1 expression. We found that mutation of dilp1 affects female reproduction and starvation resistance. In paper II, we found that reproductive diapause can extend Drosophila life span, and at the same time ameliorate behavioral senescence, including negative geotaxis, activity rhythms and exploratory walking. Age-related changes in neuromuscular junction (NMJ) in abdominal muscle cannot be found in diapause-induced aging flies. The levels of several neuromodulators in the brain, including pigment dispersion factor (PDF), tyrosine hydroxylase (TH) and short neuropeptide F (sNPF), decreased significantly in normally aging flies, but less so in diapausing flies. In paper III, we show that mutation of dilp1 leads to a reduced organismal bodyweight, whereas overexpression increases it during the nonfeeding pupal stage. Overexpression of dilp1 additionally increases body size of flies, but reduces stores of larval-derived energy. This results in decreased starvation tolerance and increased feeding in newborn flies. In paper IV, we found that dilp1 expression is needed to extend lifespan in dilp2 mutant flies. Single dilp1 mutation has no effect on female lifespan, whereas transgene expression of dilp1 in flies with dilp1-dilp2 double mutant genetic background increased the lifespan. Furthermore, dilp1 and dilp2 interact to control circulating sugar, starvation resistance in a redundant or synergistic way.

  • 278.
    Liao, Te-Yu
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Kullander, Sven O.
    Fang, Fang
    Phylogenetic position of rasborin cyprinids and monophyly of major lineages among the Danioninae, based on morphological characters (Cypriniformes: Cyprinidae)2011In: Journal of Zoological Systematics and Evolutionary Research, ISSN 0947-5745, E-ISSN 1439-0469, Vol. 49, no 3, p. 224-232Article in journal (Refereed)
    Abstract [en]

    The cyprinid subfamily Danioninae is one of the most important fish groups due to its inclusion of the model fish, Danio rerio. Molecular investigations have shown that species traditionally placed in the Danioninae are non-monophyletic, divided into two groups corresponding to the Danioninae and Opsariichthyinae. The Danioninae are further divided into three lineages, i.e. chedrins, danionins and rasborins. However, morphological characters determining the foregoing groups are unknown. To investigate the interrelationships among major lineages within the Danioninae, a phylogenetic analysis based on 43 morphological characters from 34 taxa was conducted. Parsimony analysis recovers the Danioninae and Opsariichthyinae to be distinguished by the Y-shaped ligament, absent in the Danioninae while present in the Opsariichthyinae. The Danioninae are divided into two tribes, Danionini and Rasborini. The Rasborini, including Boraras, Brevibora, Horadandia, Kottelatia, Rasbora, Rasboroides, Rasbosoma, Trigonopoma and Trigonostigma, are diagnosed by presence of dark supra-anal pigment and subpeduncular streak as well as presence of the rasborin process on epibranchial 4. The Danionini are composed of two subtribes, Danionina and Chedrina, the Danionina including Chela, Danio, Devario, Microdevario and Microrasbora, and the Chedrina comprising Chelaethiops, Esomus, Luciosoma, Megarasbora, Mesobola, Nematabramis, Opsarius, Raiamas and Salmophasia. The Danionina are diagnosed by the unossified interhyal and presence of the danionin foramen in the horizontal limb of the cleithrum while the Chedrina are characterized by the postcleithrum absent or greatly reduced and approximately normal to abdominal ribs when present.

  • 279.
    Liao, Te-Yu
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Ünlü, Erhan
    Kullander, Sven
    Western boundary of the subfamily Danioninae in Asia (Teleostei, Cyprinidae): derived from the systematic position of Barilius mesopotamicus based on molecular and morphological data2011In: Zootaxa, ISSN 1175-5326, E-ISSN 1175-5334, no 2880, p. 31-40Article in journal (Refereed)
  • 280.
    Liljeblad, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Phylogeny and evolution of gall wasps: (Hymenoptera: Cynipidae)2002Doctoral thesis, comprehensive summary (Other academic)
  • 281.
    Liljestrand Rönn, Johanna L.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hotzy, Cosima
    Do longer genital spines in male seed beetles function as better anchors during mating?2012In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 83, no 1, p. 75-79Article in journal (Refereed)
    Abstract [en]

    In a wide variety of taxa, males are equipped with harmful structures on their genitalia such as hooks, barbs or spines. The proximate function of these structures and the evolutionary forces behind their evolution have been discussed and investigated during the last few decades. One model system in which these structures have attracted particular attention is the Callosobruchus seed beetle group. The main suggestion for the occurrence of genital spines in this group of species has been that their primary function is to act as an anchor during mating, to aid the male in staying attached to the female. This would prevent females terminating copulation prematurely, or would hinder take-overs by rival males. We used five populations of Callosobruchus seed beetles, with differing lengths of the male genital spines, to test whether longer spines provide males with an enhanced attachment during mating. This was tested both with and without male competition in the form of rival males present or not during focal copulations. We found that males from populations with longer spines did not stay in copula for longer than males from populations with shorter spines. In addition, females mating with males with longer genital spines suffered a fitness cost in terms of lower lifetime offspring production. In conclusion, we did not find any support for the hypothesis that the primary function of genital spines in seed beetles is to serve as an anchor.

  • 282.
    Lind, Johan
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Centre for the Study of Cultural Evolution.
    Bivarg Philanthus triangulum2017In: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 112, no 3, p. 42-42Article in journal (Other (popular science, discussion, etc.))
  • 283.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Book review of Sturkie's Avian Physiology, 2000 (ed) G.C. Whittow2001In: Ornis Svecica, ISSN 1102-6812, Vol. 11, no 4, p. 268-270Article, book review (Other (popular science, discussion, etc.))
  • 284.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Book review of Wings over Falsterbo, 2004, (ed) L. Karlsson2005In: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 147, p. 428-Article, book review (Other (popular science, discussion, etc.))
  • 285.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Escape flight in moulting tree sparrows (Passer montanus)2001In: Functional Ecology, ISSN 0269-8463, E-ISSN 1365-2435, Vol. 15, no 1, p. 29-35Article in journal (Refereed)
    Abstract [en]
    • 1 Impaired predator evasion in birds as a cost in different life-history periods has received increasing attention in the last decade. Evasive abilities in birds have been found to be detrimentally affected by migratory fuel load, reproduction and moult. These results suggest that during these periods of their lives birds suffer from increased predation risk due to impaired evasive abilities.
    • 2 Theoretically, moult should have a detrimental effect on flight, and empirical work on starlings has shown impaired escape ability due to moult. However, a recent theoretical investigation found a surprisingly small effect of moult on flight in birds.
    • 3 In this study, 31 Tree Sparrows, a sedentary species with a slow moult, were used to investigate the effect of natural and manipulated moult on escape ability. No effect was found due to natural moult, however, when experimentally increasing moult gap size a strong negative effect was found.
    • 4  With support from empirical and theoretical work, this is the first study to suggest that slow moult may not increase predation risk due to impaired evasive abilities. Compensatory physiological adaptations probably cause this result and may be very important during moult.
    • 5 Predation risk is probably an important factor in the evolution of moult patterns and moult strategies.
  • 286.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology. Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Centre for the Study of Cultural Evolution.
    Mytomspunna vridvingar - om en dröm som gick i uppfyllelse2014In: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 109, no 2, p. 2-6Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Ett tips på Facebook vägledde zoologen Johan Lind till hans livs entomologiska dröm, nämligen att få se och fotografera vridvingar. Dessa sällan observerade insekter har en fascinerande livscykel, som delvis pågår inuti sälgsandbin eller andra insekter.

  • 287.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Reduced take-off ability in robins due to migratory fuel load1999In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 46, no 1, p. 65-70Article in journal (Refereed)
    Abstract [en]

    Recent studies have shown that large fuel loads in small birds impair flying ability. This is the first study to show how migratory fuel load affects flying ability, such as velocity and height gained at take-off in a predator escape situation, in a medium-distance migrant, and whether they adjust their take-off according to predator attack angle. First-year robins (Erithacus rubecula) were subjected to simulated attacks from a model merlin (Falco columbarius), and take-off velocity and angle were analysed. Robins with a wing load of 0.19 g cm−2 took off at a 39% lower angle than robins with a wing load of 0.13 g cm−2, while velocity remained unaffected. The robins did not adjust their angle of ascent in accordance with the predator's angle of attack. Since many predators rely on surprise attacks, a difference in flight ability due to varying fuel loads found in migrating robins can be important for birds' chances of survival when actually attacked.

  • 288.
    Lind, Johan
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology.
    Skräntärna i skyddad verkstad2015In: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 110, no 3, p. 12-14Article in journal (Other (popular science, discussion, etc.))
  • 289.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    To eat or not to eat, that is the question: Being too heavy may make a bird vulnerable to predators2000In: Interpretive Birding Bulletin, Vol. 1, p. 12-14Article in journal (Other (popular science, discussion, etc.))
  • 290.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Tree sparrow, Passer montanus, freezing in the presence of a sparrowhawk, Accipiter nisus2002In: Ornis Svecica, Vol. 12, p. 214-215Article in journal (Refereed)
  • 291.
    Lind, Johan
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Centre for the Study of Cultural Evolution.
    Tropikhavens okända djur2017In: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 112, no 2, p. 32-36Article in journal (Other (popular science, discussion, etc.))
  • 292.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Varför bry sig om sin vikt?2002In: Fåglar i Stockholmstrakten, Vol. 31, p. 28-33Article in journal (Other (popular science, discussion, etc.))
  • 293.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    What determines the probability of surviving predator attacks in bird migration?: The relative importance of vigilance and fuel load2004In: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 231, no 2, p. 223-227Article in journal (Refereed)
    Abstract [en]

    Migrating birds must accumulate fuel during their journeys and this fuel load should incur an increased risk of predation. Migratory fuelling should increase individual mass-dependent predation risk for two reasons. First, acquisition costs are connected to the increased time a bird must spend foraging to accumulate the fuel loads and the reduced predator detection that accompanies foraging. Second, birds with large fuel loads have been shown to suffer from impaired predator evasion which makes them more vulnerable when actually attacked. Here, I investigate the relative importance of these two aspects of mass-dependent predation risk and I have used published data and a hypothetical situation for a foraging bird to investigate how much migratory fuelling in terms of escape performance and natural variation in predator detection contribute to individual risk during foraging. Results suggest that for birds foraging close to protective cover the negative impact of fuel load on flight performance is very small, whereas variation in time to predator detection is of great importance for a bird's survival. However, the importance of flight performance for predation risk increases as the distance to cover increases. Hence, variation in predator detection (and vigilance) probably influences individual survival much more than migratory fuel load and consequently, to understand risk management during migration studies that focus on vigilance and predator detection during fuelling are much needed

  • 294.
    Lind, Johan
    et al.
    University of St Andrews.
    Cresswell, Will
    University of St Andrews.
    Determining the fitness consequences of anti-predation behavior2005In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 16, p. 945-956Article in journal (Refereed)
    Abstract [en]

    Any animal whose form or behavior facilitates the avoidance of predators or escape when attacked by predators will have a greater probability of surviving to breed and therefore greater probability of producing offspring (i.e., fitness). Although in theory the fitness consequences of any antipredation behavior can simply be measured by the resultant probability of survival or death, determining the functional significance of antipredation behavior presents a surprising problem. In this review we draw attention to the problem that fitness consequences of antipredation behaviors cannot be determined without considering the potential for reduction of predation risk, or increased reproductive output, through other compensatory behaviors than the behaviors under study. We believe we have reached the limits of what we can ever understand about the ecological effects of antipredation behavior from empirical studies that simply correlate a single behavior with an apparent fitness consequence. Future empirical studies must involve many behaviors to consider the range of potential compensation to predation risk. This is because antipredation behaviors are a composite of many behaviors that an animal can adjust to accomplish its ends. We show that observed variation in antipredation behavior does not have to reflect fitness and we demonstrate that few studies can draw unambiguous conclusions about the fitness consequences of antipredation behavior. Lastly, we provide suggestions of how future research should best be targeted so that, even in the absence of death rates or changes in reproductive output, reasonable inferences of the fitness consequences of antipredation behaviors can be made.

  • 295.
    Lind, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Gustin, Marco
    LIPU.
    Sorace, Alberto
    Instituto Superiore di Sanità.
    Compensatory bodily changes during moult in tree sparrows, Passer montanus, in Italy2004In: Ornis Fennica, ISSN 0030-5685, Vol. 81, no 2, p. 75-83Article in journal (Refereed)
    Abstract [en]

    To cope with fluctuating environments animals have evolved reversible phenotypic flexibility.Some birds demonstrate this phenomenon by changing mass and flight muscle according to changes in wing loading. During moult, birds suffer from reduced wing area because feathers are shed and replaced, resulting in a wing loading increase. Moult is rather well studied in birds, but the perspective of phenotypic flexibility has been neglected. Therefore,we tested predictions generated from experimental studies by collecting information about bodymass, flightmuscle size and fat stores from an Italian population of Tree Sparrows (Passer montanus) to investigate if they compensate physiologically for the wing area reductions they suffer from during moult. Our results did not corroborate predictions based on experimental studies; that is, the Tree Sparrows did not reduce body mass and increase in flight muscle size as a response to wing area reductions during midmoult. Instead, body mass increased throughout moult, flight muscle size did not change, and fat stores decreased asmoult progressed. To further investigate compensatory changes, we analysed bodily differences in midmoult between birds differing in moult gap size. Again, contrary to predictions from experimental studies, birds having larger moult gaps were found to have higher body mass. These birds were also found to keep the ratio between flight muscle size and body mass constant over the day whereas birds with small moult gaps reduced this ratio over the day. Birds with large moult gaps ere also found to store less fat than birdswith small gaps. Physiological constraints may help to explain these results and underlying reasons for the observed variation in bodily regulation in birds are discussed.

  • 296.
    Lind, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hollén, Linda
    Stockholm University, Faculty of Science, Department of Zoology.
    Smedberg, Erik
    Stockholm University, Faculty of Science, Department of Zoology.
    Svensson, Ulrika
    Stockholm University, Faculty of Science, Department of Zoology.
    Vallin, Adrian
    Stockholm University, Faculty of Science, Department of Zoology.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology.
    Detection distance influencing escape behaviour in two parids (Parus major and P. caeruleus)2003In: Journal of Avian Biology, ISSN 0908-8857, E-ISSN 1600-048X, Vol. 34, no 3, p. 233-236Article in journal (Refereed)
    Abstract [en]

    When birds are attacked by aerial predators they should benefit by adjusting their escape to the prevailing attack situation. One important factor likely to affect escape decisions of prey, to our knowledge not previously studied, is the distance at which the attacking predator is detected. We investigated if great tits Parus major and blue tits P. caeruleus alter their escape behaviour to two different detection distances (2.3 m and 1m) by simulating surprise attacks using a predator model. Both species used the information about detection distance when escaping by increasing the escape angle at the shorter detection distance. In addition, blue tits adjusted to the shorter detection distance by dodging sideways more frequently. Great tits escaped initially steeper and faster than blue tits, whereas blue tits increased escape angle and speed more than great tits along the measured distance after taking wing

  • 297.
    Lind, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology.
    Body-building and concurrent mass loss: flight adaptations in tree sparrows2001In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 268, no 1479, p. 1915-1919Article in journal (Refereed)
    Abstract [en]

    Environmental changes are responsible for the evolution of flexible physiology and the extent of phenotypic plasticity in the regulation of birds' organ size has not been appreciated until recently. Rapid reversible physiological changes during different life–history stages are virtually only known from long–distance migrants, and few studies have focused on less extreme aspects of organ flexibility. During moult, birds suffer from increased wing loading due to wing–area reductions, which may impair flight ability. A previous study found that tree sparrows' escape flight (Passer montanus) is unaffected during moult, suggesting compensatory aptness. We used non–invasive techniques to study physiological adaptations to increased wing loading in tree sparrows. As wing area was reduced during natural moult the ratio of pectoral–muscle size to body mass increased. When moult was completed this ratio decreased. We show experimentally a novel, strategic, organ–flexibility pattern. Unlike the general pattern, where body mass is positively coupled to pectoral–muscle size, tree sparrows responded within 7 days to reductions in wing area by reducing body mass concurrently with an increase in pectoral–muscle size. This rapid flexibility in a non–migratory species probably reflects the paramount importance and long history of flight in birds.

  • 298.
    Lind, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Jöngren, Fredrik
    Stockholm University, Faculty of Science, Department of Zoology.
    Nilsson, Jenny
    Stockholm University, Faculty of Science, Department of Zoology.
    Schönberg Alm, David
    Stockholm University, Faculty of Science, Department of Zoology.
    Strandmark, Alma
    Stockholm University, Faculty of Science, Department of Zoology.
    Information, predation risk and foraging decisions during mobbing in great tits, Parus major2005In: Ornis Fennica, ISSN 0030-5685, Vol. 82, p. 89-96Article in journal (Refereed)
    Abstract [en]

    Tomaximise survival during foraging animalsmust decide when and for how long foraging should be interrupted in order to avoid predators. Previous experiments have shown that birds that hear other individuals’alarm calls resume feeding later than those that see a flying predator.However, the responses of prey animals to enemies are highly context-dependent. We therefore investigated how birds respond to a threat less serious than a flying hawk depending on different amount of information about the predator. We used Great Tits dyadswhere one individual saw a perchedmodel predator (sender), whereas the other individual could only hear the conspecific’s mobbing calls (receiver). The sender responded appropriately as shown by comparing their responses to how they responded to a control.We also found that while senders were exposed to the predator, receivers became more wary and reduced their activity level. However, despite the receivers having less information about predation risk they still did not prolong the time they took to resume foraging. Hence, once the mobbing ceased (and consequently the transmission of information about the predator stopped) therewas no effect of only having second-hand information. This also shows that receiver’s rely upon the sender’smobbing calls suggesting that mobbing calls may act as honest signals of the prevailing predation risk. In conclusion, our results support the view that responses of prey to predators are highly context-dependent and that birds’ anti-predator responses are a result of an interaction between the amount of information and the level of the threat.

  • 299.
    Lind, Johan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Kaby, Ulrika
    Stockholm University, Faculty of Science, Department of Zoology.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology.
    Split-second escape decisions in blue tits (Parus caeruleus)2002In: Die Naturwissenschaften, ISSN 0028-1042, E-ISSN 1432-1904, Vol. 89, no 9, p. 420-423Article in journal (Refereed)
    Abstract [en]

    Bird mortality is heavily affected by birds of prey. Under attack, take-off is crucial for survival and even minor mistakes in initial escape response can have devastating consequences. Birds may respond differently depending on the character of the predator's attack and these split-second decisions were studied using a model merlin (Falco columbarius) that attacked feeding blue tits (Parus caeruleus) from two different attack angles in two different speeds. When attacked from a low attack angle they took off more steeply than when attacked from a high angle. This is the first study to show that escape behaviour also depends on predator attack speed. The blue tits responded to a high-speed attack by dodging sideways more often than when attacked at a low speed. Escape speed was not significantly affected by the different treatments. Although they have only a split-second before escaping an attack, blue tits do adjust their escape strategy to the prevailing attack conditions.

  • 300.
    Lindberg, Bo G.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Oldenvi, Sandra
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Steiner, Håkan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Medium from gamma-irradiated Escherichia coli bacteria stimulates a unique immune response in Drosophila cells2014In: Developmental and Comparative Immunology, ISSN 0145-305X, E-ISSN 1879-0089, Vol. 46, no 2, p. 392-400Article in journal (Refereed)
    Abstract [en]

    It is well known that gamma-irradiated, non-dividing bacteria can elicit potent immune responses in mammals. Compared to traditional heat or chemical inactivation of microbes, gamma -irradiation likely preserves metabolic activity and antigenic features to a larger extent. We have previously shown that antimicrobial peptides are induced in Drosophila by peptidoglycan fragments secreted into the medium of exponentially growing bacterial cultures. In this study, we gamma-irradiated Escherichia coil cells at a dose that halted cell division. The temporal synthesis and release of peptidoglycan fragments were followed as well as the potential of bacterial supernatants to induce immune responses in Drosophila S2 cells. We demonstrate that peptidoglycan synthesis continues for several days post irradiation and that monomeric peptidoglycan is shed into the medium. Whole transcriptome analysis revealed a strong immune response against the bacterial medium. The response to medium taken directly post irradiation shows a large overlap to that of peptidoglycan. Medium from prolonged bacterial incubation does, however, stimulate a selective set of immune genes. A shift towards a stress response was instead observed with a striking induction of several heat shock proteins. Our findings suggest that gamma-irradiated bacteria release elicitors that stimulate a novel response in Drosophila.

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