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  • 1.
    Ackefors, Hans
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Global fisheries - threats and opportunities2009In: Fisheries, sustainablity and development: fifty-two authors on coexistence and development of fisheries and aquaculture in developing and developed countries / [ed] Per Wramner, Hans Ackefors et al, Stockholm: Kungl. Skogs- och lantbruksakademien , 2009, p. 35-68-Chapter in book (Other academic)
  • 2.
    Ackefors, Hans
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    The evolution of a worldwide shrimp industry2009In: World Aquaculture, ISSN 1041-5602, Vol. 40, no 3, p. 46-55Article in journal (Refereed)
  • 3.
    Ackefors, Hans
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Är det politikerna eller fiskenäringen som styr fisket?2008In: Kungl. Skogs- och Lantbruksakademiens Tidskrift, ISSN 0023-5350, Vol. 147, no 2, p. 36-43Article in journal (Other (popular science, discussion, etc.))
  • 4. Aguirre, A. A.
    et al.
    Angerbjörn, A.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Tannerfeldt, Magnus
    Stockholm University, Faculty of Science, Department of Zoology.
    Mörner, T.
    Health evaluation of arctic fox (Alopex lagopus) cubs in Sweden2000In: Journal of Zoo and Wildlife Medicine, Vol. 31, no 1, p. 36-40Article in journal (Refereed)
    Abstract [en]

    Hematologic. serum biochemistry, and serum cortisol reference ranges were established and tonsil/rectal bacterial and fecal parasite examinations were performed on 21 wild arctic fox (Alopex lagopus) cubs during July 1996. Several of the hematologic and serum biochemistry values fell within normal ranges for other wild canids or domestic dogs of the same age class. Serum alanine transaminase and creatine phosphokinase values were significantly higher in the youngest cubs. Proteus vulgaris and Escherichia coli were isolated from both tonsilar and rectal swabs of several cubs in all dens. The most common gastrointestinal parasite ova were Toxascaris leonina (59%), Isospora spp. (52%), Uncinaria stenocephala (33%), and Capillaria spp. (26%). Prevalence of T. leonina differed significantly between dens and between age groups. Hematologic and serum biochemistry values and degree of parasitism may be indicators of health, stress, and nutritional status of arctic foxes.

  • 5.
    Andersson, Mathias H.
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Man-made structures as habitat for marine faunal assemblages2008Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Artificial reefs are structures placed in the sea to promote marine life. Although constructions such as oil-rigs, wind farms, bridges and pier pilings are built for other purposes, they could be regarded as artificial reefs as they add new surfaces in the oceans, susceptible to colonization by marine organism. One of the most common constructions in the oceans is cylindrical structures of different materials. Most research of artificial reefs has been conducted in tropical and temperate water and experience and conclusions cannot always be applied to colder waters. Man-made constructions are common in northern European seas, however, few studies are presented in the scientific literature on their impact on the marine ecosystem. The aim of this thesis was to study cylindrical structures of different scale and materials, in order to determine their effect on local fish, algae and sessile invertebrate assemblages. These structures were offshore wind turbines, and pillars of different materials (concrete and steel), situated at the Swedish east and west coast, respectively. They add vertical surfaces into the otherwise empty water column, increasing the probability for fish and invertebrate larvae as well as algae spores and propagules to encounter these high structures, compared to low profile natural or other artificial reefs. Fish species usually associated with rocky reefs and algae communities, i.e. the two spotted goby and the goldsinny-wrasse, showed an increase in abundance  around the introduced cylindrical structures. Similar effect on fish species were found on both the Swedish east and west coast. The observed increase in fish densities  seemed to be caused by added habitat since the pillars and wind turbines provide shelter from predators as well as increased food availability. The latter was either due to the fouling assemblage or change in water movement. The environment created by the introduced structures functions both as nursery and spawning areas since juveniles, adults and gravid fish were recorded in close association with the structures. The fouling community on the vertical surfaces did not resemble the natural assemblages and a difference in recruitment and succession on the pillars of different materials were observed. Further, dissimilar fouling assemblages were observed with other species dominating the assemblages on a fifty year old light-house foundation compared to the seven year old wind turbines, both located in the same area. The sessile filter feeding invertebrates located on the foundations have an advantage in food accessibility towards individuals at the seabed, as the organisms on the foundations are constantly susceptible to the water passing by. In addition, by adding offshore structures in areas previously lacking hard surfaces, non-indigenous species could find new available habitat or the foundations can function as stepping stones into new geographical regions.

  • 6.
    Andersson, Mathias H
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Dock-Åkerman, Emily
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Ubral-Hedenberg, Ramona
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Öhman, Marcus C
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Sigray, Peter
    Stockholm University, Faculty of Science, Department of Meteorology .
    Swimming Behavior of Roach (Rutilus rutilus) and Three-spined Stickleback Gasterosteus aculeatus) in Response to Wind Power Noise and Single tone frequencies2007In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 36, no 8, p. 636-638Article in journal (Refereed)
    Abstract [en]

    Human-induced underwater noise is drastically increasing as the result of offshore installations and human activities in the marine environment. Many of these structures and activities produce low-frequency noise that could potentially disturb or have harmful effects on several species of teleost fishes. Within the next decade, thousands of wind turbines will be in use in coastal and offshore waters and there is increasing concern on how they may influence marine life. The aims of this study were to examine how swimming behavior of roach (Rutilus rutilus) and three-spined stickleback (Gasterosteus aculeatus) were influenced by single-frequency sounds and noise generated by an offshore wind turbine, and the function of sound pressure level.

  • 7.
    Andersson, Mathias H
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Gullström, Martin
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Asplund, Maria E
    Department of Marine Ecology, Göteborg University.
    Öhman, Marcus C
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Importance of Using Multiple Sampling Methodologies for Estimating of Fish Community Composition in Offshore Wind Power Construction Areas of the Baltic Sea2007In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 36, no 8, p. 634-636Article in journal (Refereed)
    Abstract [en]

    It is standard procedure that an Environmental Impact Assessment (EIA) is conducted before larger constructions are built. To adequately describe the impact, methods used in an EIA should be carefully adapted considering both the character of the constructions under development and the environment that will be affected. Various sampling techniques are applied to estimate fish abundances and species composition. Methods used, including trawling, seine and gill netting, angling, echo-sound sampling, fishery data, video recordings, dredging, and visual counts using SCUBA, will all give different estimates of fish community composition.

  • 8.
    Andersson, Mathias H.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Sigray, Peter
    Stockholm University, Faculty of Science, Department of Meteorology .
    Persson, Leif K. G.
    FOI.
    Wind farm noise influence on the audibility of fishManuscript (preprint) (Other academic)
  • 9.
    Andersson, Mathias H.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Öhman, Marcus C.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Fish and sessile assemblages associated with wind-turbineconstructions in the Baltic Sea2010In: Marine and Freshwater Research, ISSN 1323-1650, E-ISSN 1448-6059, Vol. 61, no 6, p. 642-650Article in journal (Refereed)
    Abstract [en]

    Offshore wind farms are being built at a high rate around the world to meet the demand for renewable energy. We studied fish and sessile communities on and around offshore wind-turbine foundations in the southern Baltic Sea, 7 years after construction, using visual census techniques to determine how fish, sessile-invertebrate and algal communities are affected by the introduction of such structures. Fish assemblages were dominated by two-spotted gobies (Gobiusculus flavescens) that were found in large shoals in close association with the vertical surface. At the seabed, close to the foundation, the black goby (Gobius niger) was recorded in large numbers. The most obvious difference in fish densities was found between wind-power foundations extending through the entire water column and the surrounding open waters. Fouling assemblages on the vertical foundation surfaces and at the seabed just below differed from those at the seabed further away by having higher coverage of blue mussel (Mytilus edulis) and less algal growth. The results from the present study suggest that the introduction of offshore wind turbines in marine waters could have a positive effect on fish numbers and the presence of sessile invertebrates

  • 10.
    Andesson, Mathias H.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Sigray, Peter
    Stockholm University, Faculty of Science, Department of Meteorology .
    Particle motion measured at an operational wind turbine in relation to hearing sensitivity in fishManuscript (preprint) (Other academic)
  • 11.
    Angerbjörn, Anders
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Börjesson, Patrik
    Stockholm University, Faculty of Science, Department of Zoology.
    Brandberg, K.
    Stable isotope analysis of harbour porpoises and their prey from the Baltic and Kattegat/Skagerrak Seas2006In: Marine Biology Research, ISSN 1745-1000, E-ISSN 1745-1019, Vol. 2, no 6, p. 411-419Article in journal (Refereed)
    Abstract [en]

    The by-caught harbour porpoises in commercial fisheries have raised concerns over their conservation status in the Baltic region. One important aspect for management purposes is porpoise movements within the region. We measured stable isotopes in cod, herring and hagfish, species that are important prey for harbour porpoises in the Baltic region. Bone collagen in fish from the marine Kattegat/Skagerrak was significantly enriched in C-13 compared with collagen in fish from the brackish Baltic Sea. However, despite the isotopic variation seen in their prey, we found no difference in C-13 in harbour porpoise collagen from the two areas. In fact, only eight of 24 porpoises had isotope signatures corresponding to those estimated for the diet in the area where they were caught. Our general conclusion is that porpoises move between the Baltic and Kattegat/Skagerrak Seas. Future studies are needed to evaluate the magnitude of these movements.

  • 12.
    Angerbjörn, Anders
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Henttonen, Heikki
    Eide, Nina
    NINA.
    Landa, Arild
    NINA.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Progress report 2007 LIFE03 NAT/S/000073 Saving the Endangered Fennoscandian Alopex lagopus SEFALO+.2007Report (Other (popular science, discussion, etc.))
    Abstract [en]

    In total, 36 litters were recorded in Scandinavia during the summer 2007 of which 0 in Finland, 24 inSweden and 15 in Norway. In 2001 and 2004, when the small rodent cycle was in the same increasephase as this year, we had 9 and 28 litters recorded in Scandinavia, respectively, which means thatthe population has increased strongly during the last six years. However, the population increase hasnot been similar all over Scandinavia. In the southern mountain areas, Helagsfjällen and Borgafjäll,the actions of feeding and red fox removal have been very efficient. The number of litters in theseareas has doubled between each rodent increase year. The Norwegian part of Børgefjell has acted asa control area where no actions have been implemented. There, the number of litters has remainedconstant in increase years during the project period 2001-2007. In the northern mountain areas,Vindelfjällen and areas in Norrbotten, we have not managed to keep a high intensity of actions. Thenumber of litters in these areas has been stable. The reasons for the large variation in extent ofimplemented actions between the mountain areas are mainly logistical problems due to the extent ofthe geographical areas concerned in combination with harsh winter climate. In the northern areas,due to the geographical distances, field workers would have to stay in the field for several days inorder to perform field actions which can be achieved in a single day in the southern mountain areas.

  • 13.
    Bergman, Martin
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Fjärilar, revirslagsmål och parningsframgång2009In: Schedula Ranae, no 1, p. 12-13Article in journal (Other (popular science, discussion, etc.))
  • 14.
    Bergman, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Erratum to: Differences in mate location behaviours between residents and nonresidents in a territorial butterfly2010In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 80, p. 593-Article in journal (Other (popular science, discussion, etc.))
  • 15.
    Bergman, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Territorialitet hos dagfjärilar2011In: Fauna & Flora, Vol. 106, no 1, p. 20-25Article in journal (Other (popular science, discussion, etc.))
  • 16.
    Bergström, Anna
    et al.
    Stockholm University, Faculty of Humanities, Department of Language Education.
    Ljungros, Kristina
    Forsberg Nilsson, Karin
    Ericson, Emilia
    Lindenfors, Patrik
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Stockholm University, Faculty of Humanities, Centre for Cultural Evolution.
    Larhammar, Dan
    Nu hotas kvinnors rätt till sina kroppar2014In: Aftonbladet, ISSN 0349-1145Article in journal (Other (popular science, discussion, etc.))
  • 17.
    Bergström, Lena
    et al.
    Fiskeriverket.
    Lagenfelt, Ingvar
    Fiskeriverket.
    Sundqvist, Frida
    Fiskeriverket.
    Andersson, Mathias H
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Fiskeriundersökning vid Lillgrund: Kontrollprogram för Lillgrunds vindkraftspark2008Report (Other academic)
    Abstract [sv]

    Regeringen gav 2001 tillstånd till uppförande av en vindkraftpark på Lillgrund i Öresund. Underökningarna i det uppföljningsprogram för eventuella effekter på fisk och fiske som tagits fram, omfattar både en period före anläggandet av vindkraftparken och tre år efter idrifttagandet. Programmets provfisken och datainsamling startade med en baslinjestudie under åren 2002 till 2005. Lillgrunds vindkraftpark, med 48 vindkraftverk, togs i full drift i början av år 2008. I föreliggande rapport presenteras de undersökningar som utförts under parkens första driftsår, samt hur dessa förhåller sig till undersökningsresultaten perioden före vindkraftparkens etablering. Utförandet är integrerat med forskningsprogrammet Vindval som finansieras via Naturvårdsverket. Både bentisk och pelagisk fisk ingår i undersökningarna liksom fiskvandring.

  • 18.
    Bergström, Lena
    et al.
    Fiskeriverket.
    Lagenfelt, Ingvar
    Fiskeriverket.
    Sundqvist, Frida
    Fiskeriverket.
    Andersson, Mathias H
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Sigray, Peter
    Stockholm University, Faculty of Science, Department of Meteorology .
    Fiskeriundersökning vid Lillgrund: Kontrollprogram för Lillgrunds vindkraftspark 2009: Fiskeriverkets årsrapport 20092010Report (Other academic)
    Abstract [sv]

    Regeringen gav 2001 tillstånd till uppförande av en vindkraftpark på Lillgrund i Öresund. Underökningarna i det uppföljningsprogram för eventuella effekter på fisk och fiske som tagits fram, omfattar både en period före anläggandet av vindkraftparken och efter idrifttagandet. Programmet startade med en baslinjestudie under åren 2002 till 2005. Lillgrunds vindkraftpark, med 48 vindkraftverk, togs i full drift i början av år 2008. I föreliggande arbetsrapport presenteras de undersökningar som utförts under parkens andra driftår, samt hur dessa förhåller sig till tidigare undersökningsresultat (första driftåret och perioden före vindkraftparkens etablering). Utförandet av undersökningarna är integrerade med forskningsprogrammet Vindval som finansieras via Naturvårdsverket. Alla data och kommentarer är preliminära. Slutrapporten planeras var klar 31 december 2010 och samordnas med rapporterna för Vindval.

  • 19.
    Björkman, Christer
    et al.
    Swedish University for Agricultural Sciences.
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Pettersson, Mats
    Swedish University for Agricultural Sciences.
    Body Size2009In: Encyclopedia of Insects / [ed] Vincent H. Resh, Ring T. Cardé, Amsterdam: Elsevier/Academic Press , 2009, 2, p. 114-116Chapter in book (Other academic)
  • 20.
    Brodin, Yngve
    et al.
    Department of Popular Biology, Evolutionary Centre Uppsala University.
    Andersson, Mathias H
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    The marine splash midge Telmatogonjaponicus (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 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 Telmatogeton japonicus (Chironomidae) onT. 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 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.

  • 21.
    Carlsson, Mikael A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Bisch-Knaden, Sonja
    Schäpers, Alexander
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Mozuraitis, Raimondas
    Hansson, Bill S.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Odour Maps in the Brain of Butterflies with Divergent Host-Plant Preferences2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 8, article id e24025Article in journal (Refereed)
    Abstract [en]

    Butterflies are believed to use mainly visual cues when searching for food and oviposition sites despite that their olfactory system is morphologically similar to their nocturnal relatives, the moths. The olfactory ability in butterflies has, however, not been thoroughly investigated. Therefore, we performed the first study of odour representation in the primary olfactory centre, the antennal lobes, of butterflies. Host plant range is highly variable within the butterfly family Nymphalidae, with extreme specialists and wide generalists found even among closely related species. Here we measured odour evoked Ca2+ activity in the antennal lobes of two nymphalid species with diverging host plant preferences, the specialist Aglais urticae and the generalist Polygonia c-album. The butterflies responded with stimulus-specific combinations of activated glomeruli to single plant-related compounds and to extracts of host and non-host plants. In general, responses were similar between the species. However, the specialist A. urticae responded more specifically to its preferred host plant, stinging nettle, than P. c-album. In addition, we found a species-specific difference both in correlation between responses to two common green leaf volatiles and the sensitivity to these compounds. Our results indicate that these butterflies have the ability to detect and to discriminate between different plant-related odorants.

  • 22.
    Celorio-Mancera, Maria de la Paz
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Sundmalm, Sara M.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Vogel, Heiko
    Rutishauser, Dorothea
    Stockholm University, Science for Life Laboratory (SciLifeLab).
    Ytterberg, A. Jimmy
    Zubarev, Roman A.
    Stockholm University, Science for Life Laboratory (SciLifeLab).
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Chemosensory proteins, major salivary factors in caterpillar mandibular glands2012In: Insect Biochemistry and Molecular Biology, ISSN 0965-1748, E-ISSN 1879-0240, Vol. 42, no 10, p. 796-805Article in journal (Refereed)
    Abstract [en]

    Research in the field of insect-host plant interactions has indicated that constituents of insect saliva play an important role in digestion and affect host chemical defense responses. However, most efforts have focused on studying the composition and function of regurgitant or saliva produced in the labial glands. Acknowledging the need for understanding the role of the mandibular glands in herbivory, we sought to make a qualitative and semi-quantitative comparison of soluble luminal fractions between mandibular and labial glands of Vanessa gonerilla butterfly larvae. Amylase and lysozyme were inspected as possible major enzymatic activities in the mandibular glands aiding in pre-digestion and antimicrobial defense. Although detected, neither of these enzymatic activities was prominent in the luminal protein preparation of a particular type of gland. Proteins isolated from the glands were identified by mass spectrometry and by searching an EST-library database generated for four other nymphalid butterfly species, in addition to the public NCBI database. The identified proteins were also quantified from thedata using “Quanty”, an in-house program. The proteomic analysis detected chemosensory proteins as the most abundant luminal proteins in the mandibular glands. In comparison to these proteins, the relative amounts of amylase and lysozyme were much lower in both gland types. Therefore, we speculate that the primary role of the mandibular glands in Lepidopteran larvae is chemoreception which may include the detection of microorganisms on plant surfaces, host plant recognition and communication with conspecifics.

  • 23.
    Celorio-Mancera, Maria de la Paz
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Wheat, Christopher W.
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Huss, Mikael
    Stockholm University, Science for Life Laboratory (SciLifeLab).
    Vezzi, Francesco
    Stockholm University, Science for Life Laboratory (SciLifeLab).
    Neethiraj, Ramprasad
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Reimegård, Johan
    Stockholm University, Science for Life Laboratory (SciLifeLab).
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Evolutionary history of host use, rather than plant phylogeny, determines gene expression in a generalist butterfly2016In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 16, article id 59Article in journal (Refereed)
    Abstract [en]

    Background: Although most insect species are specialized on one or few groups of plants, there are phytophagous insects that seem to use virtually any kind of plant as food. Understanding the nature of this ability to feed on a wide repertoire of plants is crucial for the control of pest species and for the elucidation of the macroevolutionary mechanisms of speciation and diversification of insect herbivores. Here we studied Vanessa cardui, the species with the widest diet breadth among butterflies and a potential insect pest, by comparing tissue-specific transcriptomes from caterpillars that were reared on different host plants. We tested whether the similarities of gene-expression response reflect the evolutionary history of adaptation to these plants in the Vanessa and related genera, against the null hypothesis of transcriptional profiles reflecting plant phylogenetic relatedness. Result: Using both unsupervised and supervised methods of data analysis, we found that the tissue-specific patterns of caterpillar gene expression are better explained by the evolutionary history of adaptation of the insects to the plants than by plant phylogeny. Conclusion: Our findings suggest that V. cardui may use two sets of expressed genes to achieve polyphagy, one associated with the ancestral capability to consume Rosids and Asterids, and another allowing the caterpillar to incorporate a wide range of novel host-plants.

  • 24.
    Celorio-Mancera, Maria de la Paz
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Wheat, Christopher W.
    Stockholm University, Faculty of Science, Department of Zoology, Population Genetics.
    Vogel, Heiko
    Söderlind, Lina
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Nylin, Sören
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Mechanisms of macroevolution: polyphagous plasticity in butterfly larvae revealed by RNA-Seq2013In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 22, no 19, p. 4884-4895Article in journal (Refereed)
    Abstract [en]

    Transcriptome studies of insect herbivory are still rare, yet studies in model systems have uncovered patterns of transcript regulation that appear to provide insights into how insect herbivores attain polyphagy, such as a general increase in expression breadth and regulation of ribosomal, digestion- and detoxification-related genes. We investigated the potential generality of these emerging patterns, in the Swedish comma, Polygonia c-album, which is a polyphagous, widely-distributed butterfly. Urtica dioica and Ribes uva-crispa are hosts of P. c-album, but Ribes represents a recent evolutionary shift onto a very divergent host. Utilizing the assembled transcriptome for read mapping, we assessed gene expression finding that caterpillar life-history (i.e. 2nd vs. 4th-instar regulation) had a limited influence on gene expression plasticity. In contrast, differential expression in response to host-plant identified genes encoding serine-type endopeptidases, membrane-associated proteins and transporters. Differential regulation of genes involved in nucleic acid binding was also observed suggesting that polyphagy involves large scale transcriptional changes. Additionally, transcripts coding for structural constituents of the cuticle were differentially expressed in caterpillars in response to their diet indicating that the insect cuticle may be a target for plant defence. Our results state that emerging patterns of transcript regulation from model species appear relevant in species when placed in an evolutionary context.

  • 25.
    Celorio-Mancera, Maria de la Paz
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Ytterberg, A. Jimmy
    Rutishauser, Dorothea
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Zubarev, Roman A.
    Effect of host plant and immune challenge on the levels of chemosensory and odorant-binding proteins in caterpillar salivary glands2015In: Insect Biochemistry and Molecular Biology, ISSN 0965-1748, E-ISSN 1879-0240, Vol. 61, p. 34-45Article in journal (Refereed)
    Abstract [en]

    More than half of the proteome from mandibular glands in caterpillars is represented by chemosensory proteins. Based on sequence similarity, these proteins are putative transporters of ligands to gustatory receptors in sensory organs of insects. We sought to determine whether these proteins are inducible by comparing, both qualitatively and quantitatively, the salivary (mandibular and labial) proteomes from caterpillars (Vanessa cardui) reared on different plants and artificial diet containing either bacteria or bacterial cell-walls. We included a treatment where the caterpillars were switched from feeding on artificial diet to plant material at some point in their development. Additionally, we evaluated the degree of overlap between the proteomes in the hemolymph-filled coelom and salivary glands of caterpillars reared on plant material. We found that the quality and quantity of the identified proteins differed clearly between hemolymph-filled coelome, labial and mandibular glands. Our results indicated that even after molting and two-day feeding on a new diet, protein production is affected by the previous food source used by the caterpillar. Candidate proteins involved in chemosensory perception by insects were detected: three chemosensory (CSPs) and two odorant-binding proteins (OBPs). Using the relative amounts of these proteins across tissues and treatments as criteria for their classification, we detected hemolymph- and mandibular gland-specific CSPs and observed that their levels were affected by caterpillar diet. Moreover, we could compare the protein and transcript levels across tissues and treatment for at least one CSP and one OBP. Therefore, we have identified specific isoforms for testing the role of CSPs and OBPs in plant and pathogen recognition. We detected catalase, immune-related protein and serine proteases and their inhibitors in high relative levels in the mandibular glands in comparison to the labial glands. These findings suggest that the mandibular glands of caterpillars may play an important role protecting the caterpillar from oxidative stress, pathogens and aiding in digestion. Contamination with hemolymph proteins during dissection of salivary glands from caterpillars may occur but it is not substantial since the proteomes from hemolymph, mandibular and labial glands were easily discriminated from each other by principal component analysis of proteomic data.

  • 26.
    Dalerum, Fredrik
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Kunkel, K.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Shults, B. S.
    Diet of wolverines (Gulo gulo) in the western Brooks Range, Alaska2009In: Polar Research, ISSN 0800-0395, E-ISSN 1751-8369, Vol. 28, no 2, p. 246-253Article in journal (Refereed)
    Abstract [en]

    Migratory caribou herds are an important component of the North American tundra. We investigated the wolverine (Gulo gulo) diet in the migratory range of the Western Arctic Caribou Herd in north-western Alaska. Within this area, caribou are absent or occur at low densities for large parts of the year, and thus show a strong seasonality in abundance. Analyses of stomach and colon contents suggested that wolverines primarily consumed caribou during the winter, and that the dietary dependence was related more to caribou mortality than to caribou abundance in the area. We also found indications that wolverines may switch between moose and caribou during periods of low caribou abundance, but that such a switch did not affect wolverine body condition. Our results thus support previous observations that wolverines primarily consume ungulates. However, a better knowledge of how alternative food sources are utilized will be necessary to predict the dietary and demographic responses of wolverines to variations in caribou abundance. We also suggest that further efforts should be made to investigate the effects of other ungulate-dependent predators on wolverine feeding ecology, because such predators may function both as competitors and as suppliers of carrion for scavenging.

  • 27. Dalerum, Fredrik
    et al.
    Kunkel, Kyran
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Shults, Brad
    Patterns of δ13C and δ15N in wolverine (Gulo gulo) tissues from the Brooks Range, Alaska.2009In: Current Zoology, Vol. 55, p. 188-192Article in journal (Refereed)
    Abstract [en]

    Knowledge of carnivore diets is essential to understand how carnivore populations respond demographically to variations in prey abundance. Analysis of stable isotopes is a useful complement to traditional methods of analyzing carnivore diets. We used data on d13C and d15N in wolverine tissues to investigate patterns of seasonal and annual diet variation in a wolverine (Gulo gulo) population in the western Brooks Range, Alaska, USA. The stable isotope ratios in wolverine tissues generally reflected that of terrestrial carnivores, corroborating previous diet studies on wolverines. We also found in variation in d13C and d15N both between muscle samples collected over several years as well as between tissues with different assimilation rates, even after correcting for isotopic fractionation. This suggests both annual and seasonal diet variation. Our results indicate that data on d13C and d15N holds promise for qualitative assessments of wolverine diets changes over time. Such temporal variation may be important indicators of ecological responses to environmental perturbations, and we suggest that more refined studies of stable isotopes may be an important tool when studying temporal change in diets of wolverines and similar carnivores.

  • 28.
    Dalén, Love
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    DNA analysis on fox faeces and competition induced niche shifts2004In: Molecular Ecology, ISSN 0962-1083, Vol. 13, no 8, p. 2389-2392Article in journal (Refereed)
    Abstract [en]

    Interference competition can force inferior competitors to change their distribution patterns. It is, however, possible that the dominant competitor poses a higher threat during certain times of the year, for example during reproduction. In such cases, the inferior competitor is expected to change its distribution accordingly. We used a molecular species identification method on faeces to investigate how the spatial overlap between arctic and red foxes changes between seasons. The results show that arctic and red foxes are sympatric during winter, but allopatric in summer as arctic foxes retreat to higher altitudes further from the tree-line during the breeding season

  • 29. Daruvala, Dinky
    et al.
    Dannefjord, Per
    Lindenfors, Patrik
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Sturmark, Christer
    Slopa statligt stöd till homofoba trossamfund2015In: Aftonbladet, ISSN 1103-9000Article in journal (Other (popular science, discussion, etc.))
  • 30.
    Dimitrova, Marina
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Merilaita, Sami
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology.
    Avoiding detection: effects of prey pattern regularity, background matching and complexity of the habitat backgroundManuscript (preprint) (Other academic)
    Abstract [en]

    In this study we test how aspects of prey colour pattern regularity affect crypsis and how visual complexity of the background affects prey detection. We performed two predation experiments with artificial prey and backgrounds, using blue tits (Cyanistes caeruleus) as predators. In the first experiment we found that a prey pattern consisting of variable element shapes did not compensate for mismatching pattern elements, because a variable pattern with some mismatching element shapes was easier to detect than a variable pattern with background-matching element shapes only. Contrary to a previous hypothesis, a pattern with regular, background-matching element shapes was not easier to detect than the pattern with variable, background-matching shapes. All prey types were easier to detect on a simple than on a complex background with more diverse and complex element shapes. In the second experiment we used prey pattern consisting of invariable, background-matching elements and tested how spatial regularity of the elements affects crypsis. We found that on a complex background the spatially irregular prey with randomly placed pattern elements was more difficult to detect than the regular prey with all elements aligned, but on a simple background both prey types were equally easy to detect. Here background complexity was due to element shape complexity only. In conclusion, our study shows that spatial regularity of prey pattern but not regularity due to invariable pattern element shapes deteriorates crypsis. Visually complex habitat backgrounds and specifically those consisting of elements with complex shapes make detection of cryptic prey difficult.

  • 31.
    Dimitrova, Marina
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Merilaita, Sami
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Prey concealment: visual background complexity and prey contrast distribution2010In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 21, no 1, p. 176-181Article in journal (Refereed)
    Abstract [en]

    A prey may achieve camouflage through background matching and through disruptive coloration. Background matching is based on visual similarity between the prey and its background, whereas disruptive coloration emphasizes the use of highly contrasting pattern elements at the body outline to break up the body shape of the prey. Another factor that may influence prey detection, but has been little studied, is the appearance of the visual characteristics of the background. We taught blue tits (Cyanistes caeruleus) to search for artificial prey and manipulated the appearance of the prey and the background. We studied the effect of diversity of shapes in the background on prey detection time. We also studied the differing predictions from background matching and disruptive coloration with respect to contrast level and location of high-contrast elements in prey patterning. We found that visual background complexity did indeed increase prey detection time. We did not find differences in detection time among prey types. Hence, detection time was not affected by contrast within prey patterning, or whether the prey patterning matched only a sub-sample or all the shades present in the background. Also, we found no effect of the spatial distribution of shades (highest contrast placed marginally or centrally) on detection times. We conclude that background complexity is important for the evolution of prey coloration. We suggest that it may facilitate concealment and favor the evolution of camouflage over warning coloration. Preference for visually complex backgrounds might provide prey with a so far untested means to decrease predation risk.

  • 32.
    Dimitrova, Marina
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology. Stockholm University, Faculty of Science, Department of Zoology.
    Stobbe, Nina
    University of Freiburg, Department of Evolutionary Biology and Animal Ecology.
    Schaefer, H. Martin
    University of Freiburg, Department of Evolutionary Biology and Animal Ecology.
    Merilaita, Sami
    Stockholm University, Faculty of Science, Department of Zoology, Department of Animal Ecology. Stockholm University, Faculty of Science, Department of Zoology.
    Concealed by conspicuousness: distractive prey markings and backgrounds2009In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 276, no 1163, p. 1905-1910Article in journal (Refereed)
    Abstract [en]

    High-contrast markings, called distractive or dazzle markings, have been suggested to draw and hold theattention of a viewer, thus hindering detection or recognition of revealing prey characteristics, such asthe body outline.We tested this hypothesis in a predation experiment with blue tits (Cyanistes caeruleus) andartificial prey. We also tested whether this idea can be extrapolated to the background appearanceand whether high-contrast markings in the background would improve prey concealment. We comparedsearch times for a high-contrast range prey (HC-P) and a low-contrast range prey (LC-P) in a high-contrastrange background (HC-B) and a low-contrast range background (LC-B). The HC-P was more difficult todetect in both backgrounds, although it did not match the LC-B. Also, both prey types were more difficultto find in the HC-B than in the LC-B, in spite of the mismatch of the LC-P. In addition, the HC-P wasmore difficult to detect, in both backgrounds, when compared with a generalist prey, not mismatchingeither background. Thus, we conclude that distractive prey pattern markings and selection of microhabitatswith distractive features may provide an effective way to improve camouflage. Importantly, high-contrastmarkings, both as part of the prey coloration and in the background, can indeed increase prey concealment.

  • 33. Edman, Per
    et al.
    Lindenfors, Patrik
    Stockholm University, Faculty of Humanities, Centre for Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Martinsson, Anders
    Svensson, Erik
    Westerstrand, Magnus
    Kolkraften en svart fläck på Sveriges klimatsamvete2009In: NewsmillArticle in journal (Other (popular science, discussion, etc.))
  • 34.
    Elmhagen, Bodil
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Åtgärdsprogram för fjällräv 2008-2012 : (Vulpes lagopus) : hotkategori: akut hotad2009Report (Other academic)
  • 35.
    Elmhagen, Bodil
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Hellström, Peter
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Kindberg, Jonas
    Changes in vole and lemming fluctuations in northern Sweden 1960-2008 revealed by fox dynamics2011In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 48, no 3, p. 167-179Article in journal (Refereed)
    Abstract [en]

    Cyclic dynamics with extensive spatial synchrony has long been regarded as characteristic of key herbivores at high latitudes. This contrasts to recent reports of fading cycles in arvicoline rodents in boreal and alpine Fennoscandia. We investigate the spatio-temporal dynamics of boreal red fox and alpine arctic fox in Sweden as a proxy for the dynamics of their main prey, voles and Norwegian lemming, respectively. We analyse data from five decades, 1960-2008, with wavelets and autocorrelation approaches. Cyclic dynamics were identified with at least one method in all populations (arctic fox n = 3, red fox n = 6). The dynamics were synchronous between populations, or coupled with a 1-yr lag, in 8 of 13 pairwise comparisons. Importantly though, the dynamics were heterogeneous in space and time. All analytical approaches identified fading cycles in the three arctic fox populations and two northern red fox populations. At least one method identified similar patterns in three southern red fox populations. Red fox dynamics were cyclic in the 1970s primarily, while arctic fox dynamics was cyclic until the late 1980s or early 1990s. When cyclic, 4-yr cycles dominated in arctic fox and northern red fox, whilst 3-4-yr cycles was found in southern red foxes. Significant cyclic regimes reappeared in the 1990s or 2000s in two red fox populations and one arctic fox population. Cycles and regionally coupled dynamics appeared associated in northern arctic and red foxes. This study supports accumulating evidence which suggests that cyclic and synchronous patterns in the dynamics of lemmings and voles are nonstationary in space and time. Furthermore, the similar patterns of change in both fox species indicate that persistence of cycles is governed by similar mechanisms in lemmings and voles.

  • 36. Ericson, Emilia
    et al.
    Gustafsson, Ulf
    Lindenfors, Patrik
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Sturmark, Crister
    Humanisterna tar barns religionsfrihet på allvar2015In: Svenska dagbladet, ISSN 1101-2412, no 28 aprilArticle in journal (Other (popular science, discussion, etc.))
  • 37.
    Erlandsson, Rasmus
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Limitations of a weaker competitor – Implications of territory quality on the reproductive output of a tundra specialistManuscript (preprint) (Other academic)
  • 38.
    Erlandsson, Rasmus
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Hasselgren, Malin
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Norén, Karin
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    The resource dispersion hypothesis – a test with a cyclic mesopredatorManuscript (preprint) (Other academic)
  • 39.
    Erlandsson, Rasmus
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Wagenius, Sofie
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Indirect effects of prey fluctuation on survival of juvenile arctic fox (Vulpes lagopus): a matter of maternal experience and litter attendance2017In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 95, p. 239-246Article in journal (Refereed)
    Abstract [en]

    Reproductive experience affects juvenile survival in a wide range of species with possible links to differences in foraging capacity and predation. Using supplementary feeding, we aimed to limit direct effect of prey abundance to investigate indirect effects of small-rodent availability and maternal experience on juvenile summer survival rates in an endangered population of arctic fox (Vulpes lagopus (L., 1758)). We used data spanning 7 years, included a complete small-rodent cycle, comprising 49 litters and 394 cubs. The effect of small-rodent abundance on juvenile survival depended on maternal breeding experience. Cubs born by first-time-breeding females had lower survival rate when small-rodent abundance was low compared with juveniles born to experienced mothers who remained unaffected. It was unlikely due to starvation, as physical condition was unrelated to survival. Instead, we favour the explanation that intraguild predation was an important cause of mortality. There was a negative relationship between survival and amount of time cubs were left unattended, suggesting that parental behaviour affected predation. We propose that a prey switch related to small-rodent abundance caused fluctuations in intraguild predation pressure and that inexperienced females were less able to cope with predation when small rodents were scarce.

  • 40.
    Erlandsson, Rasmus
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Stoessel, Marianne
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Skånes, Helle
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Wennbom, Marika
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    An innovative use of orthophotos – Possibilities to assess plant productivity from colour infrared aerial orthophotosManuscript (preprint) (Other academic)
  • 41. Fernández-Aguilar, Xavier
    et al.
    Mattsson, Roland
    Meijer, Tomas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Osterman-Lind, Eva
    Gavier-Widén, Dolores
    BPrieefa cormsmounniecamtiona (syn Capillaria) plica associated cystitisin a Fennoscandian arctic fox (Vulpes lagopus: acase report2010In: Acta Veterinaria Scandinavica, ISSN 1751-0147, E-ISSN 1751-0147, Vol. 52, no 39Article in journal (Refereed)
    Abstract [en]

    The bladderworm Pearsonema (syn Capillaria) plica affects domestic dogs and wild carnivores worldwide. A highprevalence in red foxes (Vulpes vulpes) has been reported in many European countries. P. plica inhabits the lower urinarytract and is considered to be of low pathogenic significance in dogs mostly causing asymptomatic infections. However,a higher level of pathogenicity has been reported in foxes. A severe cystitis associated with numerous bladderwormswas found in a captive arctic fox (Vulpes lagopus) originating from the endangered Fennoscandian arctic foxpopulation. To our knowledge this is the first description of P. plica infection in an arctic fox.

  • 42.
    Friberg, Magne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Karlsson, Bengt
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Life-history polyphenism in the Map butterfly (Araschnia levana): developmental constraints versus season-specific adaptations2010In: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 12, p. 603-615Article in journal (Refereed)
    Abstract [en]

    Hypothesis: Different generations of a seasonally polyphenic butterfly allocate their resources differently between dispersal ability and reproduction to fit the environmental circumstances specific to the seasonal environment of each generation.

    Organism: Map butterfly (Araschnia levana).

    Site of experiments: The Department of Zoology/Tovetorp Research Station, Stockholm University.

    Methods: We estimated fecundity by assessing the amount of the limiting resource nitrogen that individuals of each generation allocated to their abdomens. We studied dispersal ability by assessing thorax nitrogen content, and by studying flight ability of both generations in a suite of temperatures.

    Results: Individuals of the summer generation performed longer sustained flights than individuals of the spring generation in all temperatures except the warmest treatment. In males, abdomen nitrogen content was poorly correlated with thorax nitrogen content. Thus males do not need to trade off nitrogen between the tissues. However, female thorax and abdomen nitrogen contents were strongly positively correlated, and although summer females were better flyers than spring females, they still allocated disproportionately more nitrogen to the reproductive tissue in the abdomen. We conclude that the divergent allocation patterns between different Map butterfly generations are better understood in terms of developmental constraints acting on spring butterflies, rather than by season-specific adaptations.

  • 43.
    Friberg, Magne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology. Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Nya rön om skogs- och ängsvitvingar: Vem är vem i fjärilsvärlden?2009In: Flora och Fauna, Vol. 104, no 1, p. 12-17Article, review/survey (Other (popular science, discussion, etc.))
  • 44.
    Gamberale-Stille, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Bragée, Carolina
    Stockholm University, Faculty of Science, Department of Zoology.
    Tullberg, Birgitta S.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Higher survival of aposematic prey in close encounters with predators – an experimental study of detection distance.2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 78, p. 111-116Article in journal (Refereed)
    Abstract [en]

    Aposematic animals are often conspicuous. It has been hypothesized that one function of conspicuousness in such prey is to be detected from afar by potential predators: the ‘detection distance hypothesis’. The hypothesis states that predators are less prone to attack at long detection range because more time is allowed for making the ‘correct’ decision not to attack the unprofitable prey. The detection distance hypothesis has gained some experimental support in that time-limited predators make more mistakes. To investigate effects of prey presentation distance we performed two experiments. First, in experiment 1, we investigated at what distance chicks, Gallus gallus domesticus, could see the difference in colour between aposematic and plain mealworms. Birds chose the correct track in a two-way choice when prey were at 20, 40 and 60 cm distance but not at 80 cm. Second, in experiment 2, fifth-instar larvae of the aposematic bug Lygaeus equestris were presented to experienced chicks at 2, 20 or 60 cm distance. We found no difference in attack probability between distances. However, prey mortality was significantly lower for the shortest presentation distance. In conclusion, we found no support for the hypothesis that aposematic prey benefit from long-range detection; in fact they benefit from shortdistance detection. This result, and others, suggests that the conspicuousness of aposematic prey at a distance may simply be a by-product of an efficient signalling function after detection.

  • 45.
    Garpe, Kajsa C
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Öhman, Marcus C
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Non-random habitat use by coral reef fish recruits in Mafia Island Marine Park, Tanzania2007In: African Journal of Marine Science, ISSN 1814-232X, Vol. 29, no 2, p. 187-199Article in journal (Refereed)
    Abstract [en]

    The habitat use by nearly 3 000 reef fish recruits, comprising 56 taxa, at seven sites in Mafia Island Marine Park, Tanzania, were examined. The study was carried out following the 1998 global coral bleaching event and all sites but one were dominated by dead coral and rubble. Mean recruit densities ranged between 0.1 m-2 and 0.7 m-2 among sites. Although live coral represented only 15% of the overall substrate composition, almost half of all observed recruits were found associated with this substrate. Pooled across all sites, 46% of the recruits used live coral cover in disproportion to availability. Principal component analyses were applied to explore microhabitat use by the 11 most common recruit taxa in comparison to availability. Among these taxa, 10 exhibited nonrandom microhabitat use and six associated with live coral in disproportion to availability. A comparison with the adult fish community revealed that adult abundances of four of the six coral selective recruit taxa were significantly correlated with live coral. The study demonstrated that reef fish recruits use microhabitats non-randomly and that a substantial proportion is selective towards live coral.

  • 46.
    Gibbs, Melanie
    et al.
    Centre for Ecology and Hydrology, Oxon, UK.
    Van Dyck, Hans
    Behavioural ecology and conservation group, Université catholique de Louvain, Belgium.
    Karlsson, bengt
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Reproductive placticity, ovarian dynamics and maternal effects in response to temperature and flight in Pararge aegeria2010In: Journal of insect physiology, ISSN 0022-1910, E-ISSN 1879-1611, Vol. 56, no 9, p. 1275-1283Article in journal (Refereed)
    Abstract [en]

    In nature, ovipositing females may be subjected to multiple extrinsic and intrinsic environmental factors simultaneously. To adequately assess a species response to environmental conditions during oviposition it may therefore be necessary to consider the interaction between multiple intrinsic and extrinsic factors simultaneously. Using the butterfly, Pararge aegeria, this study examined the combined effects of extrinsic (temperature and flight) and intrinsic (body mass and age) factors on ovarian dynamics, egg provisioning and reproductive output, and explored how these effects subsequently influenced offspring fitness when egg-stage development occurred in a low humidity environment. Both temperature- and flight- mediated plasticity in female reproductive output was observed, and there were strong temperature by flight interaction effects for the traits oocyte size and egg mass. As females aged, mean daily fecundity differed across temperature treatments, but not across flight treatments. Overall, temperature had more pronounced effects on ovarian dynamics than flight. Flight mainly influenced egg mass via changes in relative water content. A mismatch between the physiological response of females to high temperature and the requirements of their offspring had a negative impact on offspring fitness via effects on egg hatching success.

  • 47.
    Gotthard, Karl
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Berger, David
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Bergman, Martin
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Merilata, Sami
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    The evolution of alternative morphs: density-dependent determination of larval colour dimorphism in a butterfly2009In: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 98, no 2, p. 256-266Article in journal (Refereed)
    Abstract [en]

    Understanding the ultimate causes for the presence of polymorphisms within populations requires knowledge of how the expression of discrete morphs is regulated. In the present study, we explored the determination mechanism of a colour dimorphism in larvae of the butterfly Pararge xiphia (Satyrinae: Nymphalidae) with the ultimate aim of understanding its potential adaptive value. Last-instar larvae of P. xiphia develop into either a green or a brown morph, although all individuals are invariably green during the preceding three instars. A series of laboratory experiments reveal that morph development is strongly environmentally dependent and not the result of alternative alleles at one locus. Photoperiod, temperature, and in particular larval density, all influenced morph determination. The strong effect of a high larval density in inducing the brown morph parallels other known cases of density-dependent melanization in Lepidopteran larvae. Because melanization is often correlated with increased immune function, this type of determination mechanism is expected to be adaptive. However, the ecology and behaviour of P. xiphia larvae suggests that increased camouflage under high-density conditions may be an additional adaptive explanation. We conclude that the colour dimorphism of P. xiphia larvae is determined by a developmental threshold that is influenced both by heredity and by environmental conditions, and that selection for increased immune function and camouflage under high-density conditions may be responsible for maintaining the dimorphism. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 256–266.

  • 48.
    Granquist, Sandra
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Marine and Freshwater Research Institute, Iceland.
    Esparza-Sala, Rodrigo
    Hauksson, Erlingur
    Karlsson, Olle
    Jónsdóttir, Ingibjörg G.
    Angerbjörn, Anders
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Prey consumption of Harbour seals (Phoca vitulina) in north western Iceland: Comparing DNA metabarcoding and morphological analysesManuscript (preprint) (Other academic)
    Abstract [en]

    Understanding ecological relationships between humans and marine predators is challenging, but crucial for the implementation of sustainable management practices. Comprehensive estimation of pinniped diet is essential for assessing their interaction with commercial fisheries as well as to increase knowledge on ecological interactions and food webs. In Iceland, salmonid fisheries are economically important and harbour seals are often culled in the vicinity of salmon estuaries to prevent potential seal predation on salmonid stocks. There is a lack of information on harbour seal diet, and due to uncertainty of the accuracy of methods traditionally used to estimate harbour seal diet (e.g. hard-part analysis of faeces) it is necessary to improve analysis methods. In this study, we investigated the diet of harbour seals hauling out in an estuary area in north western Iceland between June and September of 2010 and 2011 by DNA analysis of prey in faeces using DNA barcoding. The results were compared to previously published results from morphological analysis. Our results showed that harbour seals mainly consumed sand eels, flatfishes, gadoids, herring and capelin. Species consumed by the seals were at large in agreement with species availability in the area. The results from molecular and morphological analysis were similar in regards of important prey species. However the species diversity was lower in the morphological analysis and 37.5% of the samples included prey items that were unidentifiable in the morphological analysis. Notably, despite salmon, trout and char availability in the study area, neither of the methods found evidence of salmonids in the harbour seal diet. Since the main reason for culling harbour seals in Iceland is to reduce predation on salmonids, the finding that salmonids are not important prey species is important in terms of management implications, especially in the light of a recent severe decline in the Icelandic harbour seal population.

  • 49.
    Gustafsson, Anders
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Lindenfors, Patrik
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology. Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Human size evolution: no allometric relationship between male and female stature2004In: Journal of Human Evolution, ISSN 0047-2484, E-ISSN 1095-8606, Vol. 47, no 4, p. 253-266Article in journal (Refereed)
    Abstract [en]

    In many animal groups, sexual size dimorphism tends to be more pronounced in species with large body size. Similarly, in a previous cross-cultural analysis, male and female stature in humans were shown to be positively allometrically related, indicating a similar relationship where populations with larger stature were more dimorphic. In this study, we re-examine the hypothesis of an allometric relationship between the sexes using phylogenetic methodology. First, however, we tested whether there exist phylogenetic signals in male and female stature. Data on mean stature from 124 human populations was gathered from the literature. A phylogenetic test showed that male and female stature were significantly associated with phylogeny. These results indicate that comparative methods that to some degree incorporate genetic relatedness between populations are crucial when analyzing human size evolution in a cross-cultural context. Further, neither non-phylogenetic nor phylogenetic analyses revealed any allometric relationship between male and female stature. Thus, we found no support for the idea that sexual dimorphism increases with increasing stature in humans

  • 50.
    Heidel-Fischer, Hanna
    et al.
    Department of Entomology, Max Planck Institute for Chemical Ecology.
    Freitak, Dalial
    Department of Entomology, Max Planck Institute for Chemical Ecology.
    Janz, Niklas
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Soderlind, Lina
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Vogel, Heiko
    Department of Entomology, Max Planck Institute for Chemical Ecology.
    Nylin, Soren
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Phylogenetic relatedness and host plant growth form influence gene expression of the polyphagous comma butterfly (Polygonia c-album).2009In: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 10, no 1, p. 506-Article in journal (Refereed)
    Abstract [en]

    ABSTRACT: BACKGROUND: The mechanisms that shape the host plant range of herbivorous insect are to date not well understood but knowledge of these mechanisms and the selective forces that influence them can expand our understanding of the larger ecological interaction. Nevertheless, it is well established that chemical defenses of plants influence the host range of herbivorous insects. While host plant chemistry is influenced by phylogeny, also the growth forms of plants appear to influence the plant defense strategies as first postulated by Feeny (the "plant apparency" hypothesis). In the present study we aim to investigate the molecular basis of the diverse host plant range of the comma butterfly (Polygonia c-album) by testing differential gene expression in the caterpillars on three host plants that are either closely related or share the same growth form. RESULTS: In total 120 differentially expressed genes were identified in P. c-album after feeding on different host plants, 55 of them in the midgut and 65 in the restbody of the caterpillars. Expression patterns could be confirmed with an independent method for 14 of 27 tested genes. Pairwise similarities in upregulation in the midgut of the caterpillars were higher between plants that shared either growth form or were phylogenetically related. No known detoxifying enzymes were found to be differently regulated in the midgut after feeding on different host plants. CONCLUSIONS: Our data suggest a complex picture of gene expression in response to host plant feeding. While each plant requires a unique gene regulation in the caterpillar, both phylogenetic relatedness and host plant growth form appear to influence the expression profile of the polyphagous comma butterfly, in agreement with phylogenetic studies of host plant utilization in butterflies.

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