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  • 201.
    Sievert, Thorbjörn
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behavioural responses of mice to predator odour components2015Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Having means to detect and avoid potential predators is a necessity for prey species. Most mammalian prey species are able to detect odours emitted by predators and to adapt their behaviour accordingly. These odour cues are therefore considered to act as semiochemicals. Predator odours consist of several dozen different odourants. In order to assess if single odourants elicit aversive behavioural reactions, predator-naïve CD-1 mice were presented with six odourants which are part of body-borne odours of different mammalian predator species. A two-compartment chamber was used in order to assess place-preference, motor activity and faecal excretions when the animals were simultaneously presented with a predator odourant and a blank control. Further trials were performed to assess whether the odourant concentrations had an influence on the behaviours. The only odourant that elicited a significant aversion was 3-methyl-1-butanethiol, a compound found in the anal gland secretion of skunks, when presented at a factor of 100 above the olfactory detection threshold of mice. Two other concentrations of 3-methyl-1-butanethiol did not elicit significant behavioural changes. Based on the present study, only one out of six selected predator odourants elicited a significant aversive response in CD-1 mice. This suggests that more than one odour component, or perhaps even the full mixture of odourants, may be necessary for CD-1 mice to respond to a predator odour with aversive behaviour.

  • 202.
    Sievert, Thorbjörn
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Laska, Matthias
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behavioral Responses of CD-1 Mice to SixPredator Odor Components2016In: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 41, no 5, p. 399-406Article in journal (Refereed)
    Abstract [en]

    Mammalian prey species are able to detect predator odors and to display appropriate defensivebehavior. However, there is only limited knowledge about whether single compounds of predatorodors are sufficient to elicit such behavior. Therefore, we assessed if predator-naïve CD-1 mice(n = 60) avoid sulfur-containing compounds that are characteristic components of natural predatorodors and/or display other indicators of anxiety. A 2-compartment test arena was used to assessapproach/avoidance behavior, general motor activity, and the number of fecal pellets excretedwhen the animals were presented with 1 of 6 predator odor components in one compartment anda blank control in the other compartment. We found that 2 of the 6 predator odor components(2-propylthietane and 3-methyl-1-butanethiol) were significantly avoided by the mice. The remaining4 predator odor components (2,2-dimethylthietane, 3-mercapto-3-methylbutan-1-ol, 3-mercapto-3-methylbutyl-1-formate, and methyl-2-phenylethyl sulphide) as well as a nonpredator-associatedfruity odor (n-pentyl acetate) were not avoided. Neither the general motor activity nor the numberof excreted fecal pellets, both widely used measures of stress- or anxiety-related behavior, weresystematically affected by any of the odorants tested. Further, we found that small changes in themolecular structure of a predator odor component can have a marked effect on its behavioralsignificance as 2-propylthietane was significantly avoided by the mice whereas the structurallyrelated 2,2-dimethylthietane was not. We conclude that sulfur-containing volatiles identified ascharacteristic components of the urine, feces, and anal gland secretions of mammalian predatorscan be, but are not necessarily sufficient to elicit defensive behaviors in a mammalian prey species.

  • 203.
    Silfvernagel, Kristin
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Individually tailored internet-based cognitive behavioural therapy for adolescents, young adults and older adults with anxiety2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Anxiety disorders share the feature of excessive fear, anxiety and related behavioural disturbances. Fear is defined as the emotional response to a real or a perceived imminent threat and anxiety is the anticipation of a future threat. The anxiety disorders covered in this thesis are panic disorder with or without agoraphobia, social phobia, post-traumatic stress disorder, generalized anxiety disorder and anxiety disorder not otherwise specified.

    Cognitive behavioural treatment protocols are typically designed to target one specific disorder and falls under the definition of disorder-specific cognitive behavioural therapy. It is however unclear if this is the most optimal approach in regards to the high comorbidity between anxiety disorders and depressive disorders. Internet-based cognitive behavioural therapy has in the past generally been disorder-specific and from above mentioned predicament two alternative treatment approaches emerged, the tailored and the transdiagnostic approach that aims to simultaneously treat both principal and comorbid disorders. Previous trials on internet-based cognitive behavioural therapy have targeted adults in general and relatively few target adolescents, young adults and older adults.

    The aims of this thesis were to further develop and test the effects of tailored internet-based cognitive behavioural therapy on the basis of age, for adolescents, young adults and older adults. Specifically by developing and testing the effects of individually tailored internet-based cognitive behavioural therapy for adolescents with anxiety and comorbid depressive symptoms and by adapting and testing the effects of individually tailored internet-based cognitive behavioural therapy for young adults and older adults with anxiety and comorbid depressive symptoms. These aims were tested in two pilot effectiveness studies (Paper I and III) and two efficacy randomised controlled trials (Paper II and IV). The results from these four trials showed significant results across all outcome measures with overall moderate to large effect sizes. The tentative conclusion based on these results is that tailoring internet-based cognitive behavioural therapy can be a feasible approach in the treatment of anxiety symptoms and comorbid depressive symptoms for adolescents, young adults and older adults. Despite the positive findings of the studies in this thesis, there is a need for more research examining the acceptability and effectiveness of internet-based cognitive behavioural therapy for adolescents, young adults and older adults with anxiety and depression before implementation on a larger scale.

  • 204.
    Silverstein, David N.
    et al.
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for High Performance Computing, PDC. KTH, School of Computer Science and Communication (CSC), Computational Biology, CB. Stockholm Brain Institute, Karolinska Institutet, Sweden.
    Ingvar, Martin
    Karolinska Institutet, Sweden.
    A multi-pathway hypothesis for human visual fear signaling2015In: Frontiers in Systems Neuroscience, ISSN 1662-5137, E-ISSN 1662-5137, Vol. 9, article id 101Article in journal (Refereed)
    Abstract [en]

    A hypothesis is proposed for five visual fear signaling pathways in humans, based on an analysis of anatomical connectivity from primate studies and human functional connectvity and tractography from brain imaging studies. Earlier work has identified possible subcortical and cortical fear pathways known as the “low road” and “high road,” which arrive at the amygdala independently. In addition to a subcortical pathway, we propose four cortical signaling pathways in humans along the visual ventral stream. All four of these traverse through the LGN to the visual cortex (VC) and branching off at the inferior temporal area, with one projection directly to the amygdala; another traversing the orbitofrontal cortex; and two others passing through the parietal and then prefrontal cortex, one excitatory pathway via the ventral-medial area and one regulatory pathway via the ventral-lateral area. These pathways have progressively longer propagation latencies and may have progressively evolved with brain development to take advantage of higher-level processing. Using the anatomical path lengths and latency estimates for each of these five pathways, predictions are made for the relative processing times at selective ROIs and arrival at the amygdala, based on the presentation of a fear-relevant visual stimulus. Partial verification of the temporal dynamics of this hypothesis might be accomplished using experimental MEG analysis. Possible experimental protocols are suggested.

  • 205.
    Sjöström, Desirée
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Behavioural responses in mice exposed to predator odour components2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    It is essential for prey species to be able to detect predators to avoid them. The sense of smell is used by a number of prey species for this purpose. The aim of the present study was to assess if one of the odourants that make up a predator odour is sufficient to induce a behavioural response in mice (Mus musculus). Two predator odourants were used, 2,2-dimethylthietane and methyl-2-phenylethyl sulfide, which are both found in the secretions of natural predators of mice. An odourant found in fruits, n-pentyl acetate, was also used. All three odourants were presented at a concentration that was a factor of 100 above the olfactory detection threshold of mice. Ten adult predator-naïve CD-1 mice were individually put in a two-compartment chamber one of which contained an odourant while the other contained a near-odourless solvent (diethyl phthalate). The results indicated that methyl-2-phenylethyl sulfide was actively avoided by the mice. Towards 2,2-dimethylthietane and n-pentyl acetate, in contrast, the mice behaved indifferent. Further, the results suggest a significant correlation between the number of switches between the two compartments of the test chamber and the test sessions when the animals were presented with n-pentyl acetate, but not when they were presented with the predator odourants. The results support the notion of an innate fear response towards the predator odourant methyl-2-phenylethyl sulfide in mice, but further studies with more animals and different concentrations of the odourants are necessary.

  • 206.
    Sjöström, Desirée
    Linköping University, Department of Physics, Chemistry and Biology.
    Gustatory responsiveness of West African Chimpanzees (Pan troglodytes verus) to seven substances tasting sweet to humans2017Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Comparative studies of taste perception have found that primates may differ markedly in their sensitivity for substances perceived as sweet by humans. These findings raise questions about the reason that may underlie these differences in sweet-taste sensitivity between species. The aim of the present study was to assess the taste responsiveness of chimpanzees (Pan troglodytes verus) to seven substances tasting sweet to humans and to compare the results with those of other primate species. Using a two-bottle preference test (1 min) I found that the taste preference thresholds of the chimpanzees for five food-associated carbohydrates ranged between 20-30 mM for sucrose, 20-50 mM for fructose, 60-80 mM for glucose, 50-80 mM for maltose, and 30-80 mM for lactose. Taste preference thresholds for two steviol glycosides ranged from 0.04-0.05 mM for stevioside, and 0.03-0.05 mM for rebaudioside A. The chimpanzees displayed clear preferences for all sweet-tasting substances presented. In line with data obtained in other primates, the taste preference threshold of the chimpanzees for sucrose was lower compared to the other carbohydrates presented and the taste preference thresholds for stevioside and rebaudioside A were lower compared to sucrose. In general, the taste sensitivity of the chimpanzees fell into the range of data reported in other nonhuman primate species. Interestingly, the taste preference thresholds of the chimpanzees reported here are similar to the taste detection thresholds obtained in humans, despite the fact that the former are only a conservative approximation of an animal’s taste sensitivity. This suggests that chimpanzees may be as sweet-taste sensitive as humans.

  • 207. Sköld, H. N.
    et al.
    Amundsen, T.
    Svensson, P. Andreas
    Mayer, I.
    Bjelvenmark, J.
    Forsgren, E.
    Hormonal regulation of female nuptial coloration in a fish2008In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 54, no 4, p. 549-556Article in journal (Refereed)
    Abstract [en]

    Physiological color change in camouflage and mating is widespread among fishes, but little is known about the regulation of such temporal changes in nuptial coloration and particularly concerning female coloration. To better understand regulation of nuptial coloration we investigated physiological color change in female two-spotted gobies (Gobiusculus flavescens). Females of this species develop an orange belly that acts as an ornament. The orange color is caused by the color of the gonads combined with the chromathophore based pigmentation and transparency of the skin. Often during courtship and female-female competition, a rapid increase in orange coloration, in combination with lighter sides and back that increases skin and body transparency, gives the belly an intense 'glowing' appearance. To understand how this increased orange coloration can be regulated we analysed chromatic and transparency effects of neurohumoral agents on abdominal skin biopsies in vitro. We found prolactin and alpha-melanocyte stimulating hormone (MSH) to increase orange coloration of the skin. By contrast, melatonin and noradrenaline increased skin transparency, but had a negative effect on orange coloration. However, mixtures of melatonin and MSH, or melatonin and prolactin, increased both orange coloration and transparency. This effect mimics the chromatic 'glow' effect that commonly takes place during courtship and intra sexual aggression. Notably, not only epidermal chromatophores but also internal chromatophores lining the peritoneum responded to hormone treatments. There were no chromatic effects of the sex steroids 17 beta-estradiol, testosterone or 11-ketotestosterone. We hypothesize that similar modulation of nuptial coloration by multiple hormones may be widespread in nature. (C) 2008 Elsevier Inc. All rights reserved.

  • 208.
    Sköld, Rebecka
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Predatoriskt beteende hos hund (Canis lupus familiaris)2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Domestication of the dog has led to a number of different breeds worldwide. All these breeds were from the beginning bred for a specific purpose. However, the dogs are no longer used in the same order for their main goal. Today dogs are mainly kept for company. Although they are no longer used for the purpose they were developed, their behavior remains in the genes. With this work I want to highlight the predatory behavior that remains in the dog, and how certain breeds exhibit a greater predatory aggressiveness than others. Some breeds are more likely to show this behavior regardless if it is desired or not. Because there are genes that control the dog's behavior, we cannot avoid that some breeds are more likely to perform predatory behaviors and predatory aggression.

  • 209.
    Sopelsa Hall, Emma
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Ex situ lion conservation: Behavioural responses to playbacks of competitors with focus on sex and age differences2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Due to increasing habitat loss, human-lion conflict, poaching and other reasons, African lion (Panthera leo) populations have suffered a drastic decline. The African Lion and Environmental Research Trust (ALERT) is working to stop this pattern and is the first organization with an ex-situ conservation project for lions. Before releasing lions raised by captive-bred adults, they must first be ensured to behave properly to make sure they have the highest chance of survival. One challenge in the wild is encountering and competition with unknown conspecifics. By conducting playback of unfamiliar lion roars, the behaviours of lions under this ex-situ reintroduction program were tested and compared with observations from earlier studies of wild lions. Social interactions were also collected and a social network analysis was done to give information about the social structure in the pride. This in turn was compared with boldness scores, calculated from behavioural responses in the playback experiments. Lastly, I searched for associations between age and sex with both boldness and social interactions.

     

    The studied pride consisted of 12 lions. The lions were more vigilant when a playback consisted of numerous lions vocalizing, but playing more than three lions seemed to make them loose interest, suggesting either habituation or false information. One adult female and the alpha-male were most bold, followed by five sub-adults. Boldness did not vary according to sex or age differences, but the social network analysis showed that some social interactions were more dominated by one sex or age group. These behaviours were in agreement with comparisons of wild prides.

     

    This study showed that captive-bred lions have developed natural social behaviours. Based on the behavioural responses observed by the captive-origin lions to the playbacks of unfamiliar lions, it is unclear whether these lions would appropriately respond when encountered with unfamiliar conspecifics in the wild post-release.

  • 210.
    Srinivasan, Divya
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Martin, Bernard
    University of Michigan, Ann Arbor, USA.
    Emergence of Visuomotor Coordination with Training in Bimanual Movements2012In: Proceedings of the Twelfth International Symposium on the 3D Analysis of Human Movement, 2012Conference paper (Refereed)
  • 211.
    Stach, Robert
    Stockholm University, Faculty of Science, Department of Zoology.
    Migratory routes and stopover behaviour in avian migration2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Migratory birds, some small and light weight as matchboxes, engage in seasonal inter-continental journeys in order to take advantage of the long summer days and abundance of food at northern latitudes to breed and raise their young, and then escape the harsh winters by migrating to lower latitudes. This thesis deals with two important aspects of migration, the routes taken during migration and the birds’ behaviour at stopovers. The migratory routes are for many species unknown, whole or in part, and this is especially true for species that migrate nocturnally. At stopovers birds replenish fuel reserves that powers migratory flight, and studying how birds utilise stopovers is important in order to understand how migration is organised. In this thesis I have used modern tracking technology to study both continental wide movements of thrush nightingales (Luscinia luscinia) and common rosefinches (Carpodacus erythrinus) using small light-level geolocators, and smaller scale movements at a single stopover site of garden warblers (Sylvia borin) using miniature radio-transmitters. I have also studied the fuelling behaviour of garden warblers during autumn migration in the field and in the lab, and great reed warblers (Acrocephalus arundinaceus) at a stopover site on Crete during spring migration after the Sahara crossing. The thesis discusses the significance of several aspects of migration shown by the birds that would have been very difficult to detect without the aid of modern tracking technology, such as loop migration, prolonged stops during migration, multiple wintering sites, and nocturnal relocations at stopover sites. Studies carried out at stopover sites also show that garden warblers and great reed warblers can attain large fuel loads even at sites where they have no barrier to cross and this might be a result of good foraging conditions. The thesis also highlights the importance of combining different techniques when studying stopover behaviour to get reliable estimates on stopover durations and fuel deposition rates as well as the importance of choosing sites preferred by birds when planning stopover studies.

  • 212.
    Stach, Robert
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Fransson, Thord
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    No compensatory fuelling due to late autumn migration in the Garden Warbler Sylvia borinManuscript (preprint) (Other academic)
    Abstract [en]

    Birds migrating late in the migration season may need to compensate for the late departure by increasing migration speed. To increase migration speed late migrants should depart from stopovers along the route with larger fuel loads than early migrants. Both higher migration speeds and increasing fuel loads with the progress of the season have been reported in the literature. Here we test if Garden Warblers (Sylvia borin) show different fuelling strategies when captured on migration in the early or late part of autumn migration and given unlimited access to food. We also included a group of birds that were captured early in the season but held under a light regime with shorter day lengths to simulate thirty days advancement in time. We found no difference in maximum body mass between the groups and all groups reached fairly large fuel loads (mean: 39.2 % of lean body mass). Maximum fuel load was also strongly correlated with fuel deposition rate and this may suggest that Garden Warblers migrate at high speed during the entire season, which leaves little room for increasing speed later in the season.

  • 213.
    Stach, Robert
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Fransson, Thord
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Wide ranging stopover movements and substantial fuelling in first year garden warblers at a northern stopover site2015In: Journal of Avian Biology, ISSN 0908-8857, E-ISSN 1600-048X, Vol. 46, no 3, p. 315-322Article in journal (Refereed)
    Abstract [en]

    Migratory birds use stopovers to replenish their fuel reserves and they generally spend more time at stopover sites than theydo in actual fl ight. When arriving at a new stopover site birds may need to search extensively to fi nd a suitable feeding areaand this search and settling period may aff ect the duration of stopover. Stopover behaviour can thus have profound eff ectson the migratory programme and studies on stopover behaviour are important to understand migratory strategies. Wefollowed 51 fi rst-year garden warblers Sylvia borin with radio-transmitters at an autumn stopover site on the island ofGotland in southern Sweden. Our aim was to determine the distance birds relocated from the coastal capture site whensearching for an area to settle in, and also to establish the duration of stopover and put it in relation to refuelling rate byrecapturing a subset of the radio-tracked individuals. Sixteen birds made an extended stopover ( 2 d), relocated inlandfrom the capture site and settled on average 5.6 km from the capture site, with the longest recorded relocation being fourteenkilometres. Birds that relocated nocturnally settled in areas further away than birds that relocated diurnally. Th irteenbirds that continued migration after a short stop carried larger fuel stores than birds that stopped over longer and theyremained close to the capture site until departure. Th ree birds were re-trapped and showed high fuelling rates, between0.3 and 1.1 g d 1 . Th ey left the stopover site with fuel loads between 40 – 56 percent of lean body mass, which possiblywould have allowed them to reach the Mediterranean area without additional refuelling stops.

  • 214.
    Stach, Robert
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Fransson, Thord
    Geolocators reveal three consecutive wintering areas in the thrush nightingale2012In: Animal Migration, ISSN 2084-8838, Vol. 1, p. 1-7Article in journal (Refereed)
    Abstract [en]

    The winter distribution of many migratory birds wintering in tropical Africa is poorly known. After the crossing of the Sahara Desert, some long-distance migrants typically stay in the Sahel zone for an extended period before continuing migration to their main wintering areas south of the equator. Here we show how two thrush nightingales (Luscinia luscinia) fitted with light-level geolocators, after a six to seven week long stay in the Sahel zone of Sudan, moved to an intermediate area in northern Kenya for a month-long stay before continuing to their final wintering areas in southern Africa. These data indicate that thrush nightingales may use three consecutive wintering sites during their stay in Africa. The migratory movements in Africa between wintering sites are well-coordinated with high precipitation in these areas, suggesting that thrush nightingales track peaks of insect abundance occurring after rains. This three-stage wintering strategy has, to our knowledge, previously not been described, and shows that long-distance migrants can have complex wintering behaviour.

  • 215.
    Strid, Matilda
    Linköping University, Department of Physics, Chemistry and Biology, Biology.
    Does Play Pre-separation Affect Separation Behaviors in Dogs?2018Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Separation anxiety is one of the most common behavioral disorder in companion dogs. Dogs not suffering from separation anxiety may still exhibit separation-related behaviors, which can differ depending on environmental contexts. In the present study, dogs without separation-related problems were video recorded during a short separation (3 min) from, and during reunion with, their owner. Comparison was done between if the dogs had played or been calm pre-separation. The dogs spent most time in proximity to the entrance and gazing towards where the owner left during separation. Their body-position was mostly standing, followed by sitting. All dogs were wining during separation, which occurred approximately four times more than barking. Dogs that had played pre-separation were running around more and had a longer latency to the first movement, compared to when they had been calm pre-separation. During reunion, when dogs had played pre-separation, they wagged their tail more and had a longer latency to lip licking, compared to when they had been calm pre-separation. The separation behaviors that occurred in this study aligns with previous work in this subject. Furthermore, one can suggest that play pre-separation might have an effect on separation behaviors, where speculations can be done if the positive affect associated with play might be the underlying cause for these findings.

  • 216.
    Stålhandske, Sandra
    Stockholm University, Faculty of Science, Department of Zoology.
    Spring Phenology of Butterflies: The role of seasonal variation in life-cycle regulation2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Animals and plants in temperate regions must adapt their life cycle to pronounced seasonal variation. The research effort that has gone into studying these cyclical life history events, or phenological traits, has increased greatly in recent decades. As phenological traits are often correlated to temperature, they are relevant to study in terms of understanding the effect of short term environmental variation as well as long term climate change. Because of this, changes in phenology are the most obvious and among the most commonly reported responses to climate change. Moreover, phenological traits are important for fitness as they determine the biotic and abiotic environment an individual encounters. Fine-tuning of phenology allows for synchronisation at a local scale to mates, food resources and appropriate weather conditions. On a between-population scale, variation in phenology may reflect regional variation in climate. Such differences can not only give insights to life cycle adaptation, but also to how populations may respond to environmental change through time. This applies both on an ecological scale through phenotypic plasticity as well as an evolutionary scale through genetic adaptation. In this thesis I have used statistical and experimental methods to investigate both the larger geographical patterns as well as mechanisms of fine-tuning of phenology of several butterfly species. The main focus, however, is on the orange tip butterfly, Anthocharis cardamines, in Sweden and the United Kingdom. I show a contrasting effect of spring temperature and winter condition on spring phenology for three out of the five studied butterfly species. For A. cardamines there are population differences in traits responding to these environmental factors between and within Sweden and the UK that suggest adaptation to local environmental conditions. All populations show a strong negative plastic relationship between spring temperature and spring phenology, while the opposite is true for winter cold duration. Spring phenology is shifted earlier with increasing cold duration. The environmental variables show correlations, for example, during a warm year a short winter delays phenology while a warm spring speeds phenology up. Correlations between the environmental variables also occur through space, as the locations that have long winters also have cold springs. The combined effects of these two environmental variables cause a complex geographical pattern of phenology across the UK and Sweden. When predicting phenology with future climate change or interpreting larger geographical patterns one must therefore have a good enough understanding of how the phenology is controlled and take the relevant environmental factors in to account. In terms of the effect of phenological change, it should be discussed with regards to change in life cycle timing among interacting species. For example, the phenology of the host plants is important for A. cardamines fitness, and it is also the main determining factor for oviposition. In summary, this thesis shows that the broad geographical pattern of phenology of the butterflies is formed by counteracting environmental variables, but that there also are significant population differences that enable fine-tuning of phenology according to the seasonal progression and variation at the local scale.

  • 217. Sukhovey, Yury
    et al.
    Koptyug, Andrey
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
    Petrov, Sergey A.
    The Tyumen Centre of Sciences, Siberian Branch of Russian Academy of Sciences.
    Dotsenko, E. L
    The Tyumen State University, Department of General and Social Psychology.
    Fisher, Tatyana A.
    5The Tyumen Centre of Sciences, Siberian Branch of Russian Academy of Sciences.
    Psycho-immune Partnership in the Dynamic Responses of Living Systems2014In: International Journal of Life Science and Medical Research, ISSN 2226-4566, Vol. 4, no 5, p. 57-50Article in journal (Refereed)
    Abstract [en]

    Present paper outlines certain possibilities for a new approach to the generalized modeling of the dynamics of living organism reaction to the changes in its environment. It is shown that there exists common functional “alignment” of the immune and psychic responses in the living organism reaction to the changes in the environment. This is manifested in the experimentally recorded matching of the response scenarios and activities in the immune and psychic domains. Thus, one may conclude that there exist two functionally matched systems (psychic and immune) tracking the external influences and responding to them. On the other hand it is feasible that one is actually dealing with a complex inseparable psycho-immune system and experimentally monitors different aspects of its activity describing these from two different points of view. Given analysis of available experimental data seems to support both of the above alternatives without giving undoubted preferences to any of them. However treating the situation form the formal logic point of view certain preferences can be given to the concept of an inseparable psycho-immune system modeled in two different ways. This approach can also resolve certain collisions happening with the attempts to describe direct interrelations between psychic and immune domains, and can lead the way to higher-level functionality models of the dynamic responses of the living organisms.

  • 218.
    Sundin, Josefin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology. Norwegian Univ Sci & Technol, Dept Biol, Trondheim, Norway..
    Jutfelt, Fredrik
    Norwegian Univ Sci & Technol, Dept Biol, Trondheim, Norway..
    Effects of elevated carbon dioxide on male and female behavioural lateralization in a temperate goby2018In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 5, no 3, article id 171550Article in journal (Refereed)
    Abstract [en]

    Behavioural abnormality in fishes has been proposed as a significant consequence of the increasing levels of carbon dioxide occurring in the oceans. Negative effects of elevated CO2 have been reported for behaviours such as predator-prey interactions, foraging, hearing and behavioural lateralization. Importantly, the effects vary greatly both within and between species, and some recent studies have shown minimal effects of CO2 on behaviour. Whether the effect of CO2 also varies between males and females is, however, virtually unexplored. According to resource allocation theory; females are expected to be more sensitive to elevated CO2, meaning that non-sex-specific studies may overlook ecologically important differences between the sexes. In this study, we investigated the possible differences between males and females in their response to elevated CO2 by performing behavioural lateralization tests in adult temperate two-spotted gobies, Gobiusculus flavescens. We found that the strength of the side bias (absolute lateralization) was unaffected by the CO2 treatment, and there was no difference between males and females. The control fish were slightly right-biased in their behavioural asymmetry (mean relative lateralization of 14). Exposure to high CO2 affected this pattern, such that treated fish were slightly left-biased (mean relative lateralization of -10), regardless of their sex. The same results were obtained yet again when the study was repeated during a second year. We discuss our results in light of the great variation in lateralization that has been reported to depend on variables such as species, ecological settings and environmental factors.

  • 219.
    Sundin, Josefin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Rosenqvist, Gunilla
    Myhren, Siri
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Algal Turbidity Hampers Ornament Perception, but Not Expression, in a Sex-Role-Reversed Pipefish2016In: Ethology, ISSN 0179-1613, E-ISSN 1439-0310, Vol. 122, no 3, p. 215-225Article in journal (Refereed)
    Abstract [en]

    Sexual ornaments are used both in intra- and intersexual contexts, and these signals have evolved to function in the particular habitat the animal is adapted to. Habitat characteristics may, however, change rapidly due to anthropogenic effects, sometimes at rates too fast for many organisms to adaptively respond. In aquatic ecosystems, eutrophication is currently changing chemical as well as visual properties of the environment. Algae blooms increase water turbidity, and the reduction of water transparency thus has the potential to alter visual ornaments and their perception. However, results are not congruent. Rather, algae turbidity may decrease, increase, or leave ornaments unaffected. The effect seems to depend on exposure time, condition, population and species. Here, we found that the perception of sexual signals, but not their expression, was hampered by turbidity in the sex-role-reversed pipefish Nerophis ophidion. In a laboratory experiment we found that female sexual ornaments (i.e., blue color markings and a skinfold) and fecundity was unaffected by turbidity. Male adaptive mate choice for larger females with large ornament was, however, hampered under turbid conditions, whereas in clear water males choose larger, more ornamented females. Thus, we show that water turbidity had no effect on signal expression but did hamper ornament perception and consequently randomized mate choice.

  • 220.
    Sundin, Josefin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology. Department of Biological and Environmental Sciences, University of Gothenburg.
    Vossen, Laura E.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Nilsson-Sköld, Helen
    Sven Lovén Centre for Marine Infrastructure, University of Gothenburg; Gothenburg Global Biodiversity Centre.
    Jutfelt, Fredrik
    Department of Biological and Environmental Sciences, University of Gothenburg; Department of Biology, Norwegian University of Science and Technology.
    No effect of elevated carbon dioxide on reproductive behaviors in the three-spined stickleback2017In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 28, no 6, p. 1482-1491Article in journal (Refereed)
    Abstract [en]

    Ocean acidification, the reduction in ocean pH resulting from anthropogenic emissions of carbon dioxide (CO2), has been predicted to alter the behavior of fishes. During experimental exposure to CO2 concentrations projected for the year 2100 (~1000 μatm), fish have been reported to display disturbances in activity, learning, behavioral lateralization, and even attraction to predator cues. Reproductive behaviors have received far less attention, despite an intensive research effort on ocean acidification and its ecological importance. Here, we investigate whether elevated levels of CO2 affect reproduction in breeding pairs of the three-spined stickleback, Gasterosteus aculeatus, a model species in behavioral, evolutionary ecology, and environmental toxicology. We found that males under both present day levels (400 μatm) and future levels (1000 μatm) of CO2 developed normal sexual ornaments, pursued normal nest building activi-ties, exhibited similar levels of courtship behaviors and displacement fanning, and had the same mating probability. Moreover, fanning behavior during the paternal care period followed what is expected for the species for males from both treatments, and there was no effect of treatment on the numbers of offspring produced. This study is the first to investigate the effect of elevated CO2 on the com-plete breeding cycle in detail, studying an array of highly fitness-relevant traits. Our study showing surprising resilience of fish repro-duction is an important contribution in order to realistically predict the impacts of future ocean acidification.

  • 221.
    Sundman, Ann-Sofie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Dog behaviour: Intricate picture of genetics, epigenetics, and human-dog relations2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Dogs, Canis familiaris, share the lives of humans all over the world. That dogs, and the behavior of dogs, are of interest to many is therefore no surprise. In this thesis, the main aim has been to identify factors that affect dogs’ behaviours.

    The dog, Canis familiaris, is our first domesticated animal. Since domestication, various types of dogs have developed through adaptation to an environment shared with humans and through our selective breeding, resulting in a unique variation in morphology and behaviour. Although there is an individual variation in the behaviour of dogs, there is also a difference between breeds. Moreover, selection during the last decades has split some breeds into divergent types. Labrador and golden retrievers are divided into a common type, for show and companionship, and a field type, for hunting. By comparing the breed types, we can study the effects of recent selection. In Paper I, we investigate differences in general behavioural traits between Labrador and golden retriever and between common and field type within the two breeds by using results from the standardized behaviour test Dog Mentality Assessment. There were differences between breeds and types for all behavioural traits. However, there was also an interaction between breed and type. Thus, a common/field-type Labrador does not behave like a common/field-type golden retriever. Even though they have been selected for similar traits, the selection has affected the general behavioural traits differently in the two breeds.

    In paper II, we were interested in dogs’ human-directed social skills. Dogs have a high social competence when it comes to humans. Two experiments commonly used to study these skills are the problem-solving test, where dogs’ human-directed behaviours when faced with a problem are measured, and the pointing test, where dogs are tested on how well they understand human gestures. We compared the social skills of German shepherds and Labrador retrievers, and of common- and field-type Labradors. Labradors were more successful in the pointing test and German shepherds stayed closer to their owners during the problem solving. Among Labrador types, the field type had more human eye contact than the common type. Importantly, when comparing the two experiments, we found no positive correlations between the problem-solving test and the pointing test, suggesting that the two tests measure different aspects of human-directed social behaviour in dogs.

    A previous study has identified two suggestive genetic regions for human-directed social behaviours during the problem-solving test in beagles. In paper III, we show that these SNPs are also associated to social behaviours in Labrador and golden retrievers. Moreover, the Labrador breed types differed significantly in allele frequencies. This indicates that the two SNPs have been affected by recent selection and may have a part in the differences in sociability between common and field type.

    The behaviour of dogs cannot simply be explained by genetics, there is also an environmental component. In paper IV, we study which factors that affect long-term stress in dogs. Long-term cortisol can be measured by hair samples. We found a clear synchronization in hair cortisol concentrations between dogs and their owners. Neither dogs’ activity levels nor their behavioural traits affected the cortisol, however, the personality of the owners did. Therefore, we suggest that dogs mirror the stress level of their owners.

    The mediator between genes and the environment is epigenetics, and one epigenetic factor is DNA methylation. In paper V, we compared methylation patterns of wolves and dogs as well as dog breeds. Between both wolves and dogs and among dogs there were substantial differences in methylated DNA regions, suggesting that DNA methylation is likely to contribute to the vast variation among canines. We hypothesize that epigenetic factors have been important during domestication and in breed formation.

    In this thesis, I cover several aspects on how dogs’ behaviours can be affected, and paint an intricate picture on how genetics, epigenetics, and human-dog relations forms dog behaviour.

  • 222.
    Sundman, Ann-Sofie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Johnsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Similar recent selection criteria associated with different behavioural effects in two dog breeds2016In: Genes, Brain and Behavior, ISSN 1601-1848, E-ISSN 1601-183X, Vol. 15, no 8, p. 750-756Article in journal (Refereed)
    Abstract [en]

    Selection during the last decades has split some established dog breeds into morphologically and behaviourally divergent types. These breed splits are interesting models for behaviour genetics since selection has often been for few and well-defined behavioural traits. The aim of this study was to explore behavioural differences between selection lines in golden and Labrador retriever, in both of which a split between a common type (pet and conformation) and a field type (hunting) has occurred. We hypothesized that the behavioural profiles of the types would be similar in both breeds. Pedigree data and results from a standardized behavioural test from 902 goldens (698 common and 204 field) and 1672 Labradors (1023 and 649) were analysed. Principal component analysis revealed six behavioural components: curiosity, play interest, chase proneness, social curiosity, social greeting and threat display. Breed and type affected all components, but interestingly there was an interaction between breed and type for most components. For example, in Labradors the common type had higher curiosity than the field type (F1,1668 = 18.359; P < 0.001), while the opposite was found in goldens (F1,897 = 65.201; P < 0.001). Heritability estimates showed considerable genetic contributions to the behavioural variations in both breeds, but different heritabilities between the types within breeds was also found, suggesting different selection pressures. In conclusion, in spite of similar genetic origin and similar recent selection criteria, types behave differently in the breeds. This suggests that the genetic architecture related to behaviour differs between the breeds.

  • 223.
    Sundström, Peter
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Multiple sclerosis in Västerbotten county, northern Sweden2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    One out of several distinguishing features of multiple sclerosis (MS) is the epidemiological variation of geographic distribution. Population-based studies on the prevalence and incidence of MS in Sweden have previously been performed only in Göteborg. Another feature of MS is the clinical variation between individuals. To a large extent data on the clinical characteristics of MS come from studies on cases frequenting MS clinics and therefore, may be biased. Also rare are population-based studies of the consequences of MS-related incapacity on socio­economic factors. As for MS aetiology, both environment and genes are involved. Human herpesviruses are often the main suspected environmental aetiological agents.

    Our aim was to estimate the prevalence of MS in Västerbotten County for 1 January 1990, the incidence during a 10-year period 1988-97, and the prevalence 31 December 1997; and also to present detailed clinical data including onset symptoms and the disability distribution for the latter two MS populations. Furthermore, we wanted to estimate the prevalence of sick leave, professional assistance, and housing; and also, to study the risk factors for sick leave. In order to investigate the association between MS and human herpesviruses, samples were identified in two regional population-based serumbank registers. This linkage identified samples collected from before MS-onset in 73 MS cases and after MS onset in 161 cases The prevalence and incidence populations were identified through multiple sources. Diagnostic ascertainment, the reliability of clinical data, and additional information were assured from a questionnaire with follow-up interview and neurological examination.

    The onset adjusted crude prevalence of MS was 125/100,000 (95% CI: 112-140) in January 1990, and 154/100,000 (95% Cl: 139-170) in December 1997. The increase was mainly attributable to a higher incidence than mortality. The crude incidence rate 1988-97 was 5.2/100,000 (95% CI: 4.4-6.2). The disability distribution in the 1997 prevalence population in Västerbotten was compared to the disability distribution in a Canadian MS population, which has been used for publications on the natural history of MS. One difference from the Canadian studies appears to be the better recognition of cases with more benign disease. Nevertheless almost half of prevalent MS cases aged 18-64 years were fully sick-listed, and one-fourth of all prevalent cases received professional assistance. High disability level was the strongest predictor for sick leave. All MS cases showed signs of past Epstein-Barr virus (EBV) infection. High activity to EBV (EBNA-1 but not VCA) and human herpesvirus 6 (HHV-6) significantly (borderline significance for HHV-6) increased the risk to develop MS.

    These estimates show that Västerbotten County is a high risk area for MS. Both incidence and prevalence were significantly higher when compared to estimates from Göteborg. The comparison with the Canadian MS population shows that MS might be a slightly more benign disease than previously recognized. Still, the consequences of MS regarding socio-economic aspects are considerable. We suggest that EBV is a prerequisite for the development of MS. Individuals that will develop MS exhibit an altered immune response against the EBV virus characterised by high activities to EBNA-1 in the absence of high VCA activities, this being most pronounced in the five-year period preceding MS onset. A pathogenetic role is suggested for EBV and remains possible also for HHV-6.

  • 224.
    Svemer, Frida
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    A mutation in the TSHR gene - how does it affect social and fear related behaviours in chickens?2012Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Thyroid hormones are well known important to be in development and growth in birds and that signaling of thyrotropin (TSH) regulates the photo induced seasonal reproduction. A mutation at the thyroid stimulating hormone receptor (TSHR) gene in domestic breeds of chicken could be involved in the release of the photoperiodic regulation. Furthermore, TSH can affect a wide range of domestication related phenotypes, such as behaviour, growth rate and pigmentation. The aim of this study was to investigate the behaviours expressed in the different genotypes on the TSHR gene in chickens. Four standard tests were conducted, aerial predator, fear of human, social dominance and tonic immobility. An advanced intercross line of chickens between red junglefowl and White leghorn was used. Male domestic type chickens explored more, showed more less fear behaviours and showed least fear behaviours in the fear of human test. Increased activity and flight response has been interpreted as a lower fear response, which is in line with this study. The wild type chickens showed more social dominance than domestic type chickens which are in line with previous results. In tonic immobility there was a difference between the wild type male and heterozygous male chickens in latency until first head movement. The conclusion of this study is that there is a difference between the wild type and domestic type chickens. This indicates that the TSHR gene is involved in behavioural changes during domestication, but whether it is due to passive or active selection is the question.

  • 225. Svenska Naturskyddsföreningen, Sandvikenkretsen
    Områden av intresse för den vetenskapliga och kulturella naturvården: Sammanställd av svenska Naturskyddsföreningen Sandvikenkretsen Arbetsgruppen för naturinventeringar1972Report (Other academic)
    Abstract [sv]

    1972:7 Områden av intresse för den vetenskapliga och kulturella naturvården

    Följande sammanställning avser att presentera de viktigare områden/objekt som framkommit vid en översiktlig naturinventering i Gävleborgs län.

    Vi utfört endast en detaljinventering av det material som omnämns i denna sammanställning. Detta område är körsjön i Sandviken kommun.

  • 226.
    Svensson, P. Andreas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Adaptations and strategies for paternal care in a desert-dwelling fish. 2009Conference paper (Refereed)
    Abstract [en]

    Parental care enhances offspring development and survival, but also imposes costs to the caring parent by reducing, for example, future reproduction. This is especially true in species with paternal care, that is, where the male cares for the offspring. Both anatomical and behavioural adaptations are expected to have evolved in order to economize paternal care. The Australian desert goby is a sexually dimorphic species that expresses exclusive paternal care. Males have larger pectoral fins relative to females, possibly to assist in the fanning of the eggs. Males also strategically adjust their parental effort to maximise their fitness. In laboratory experiments, we found that males with larger fins fanned at a lower frequency. The presence of ready-to-spawn females led to a reduction in paternal care effort suggesting a temporal trade-off between care of existing eggs and courtship of additional females. In addition, both the degree and type of filial cannibalism was related to the size of the clutch, and, therefore, female quality. Our results suggest that desert gobies have evolved both morphological adaptations and behavioural strategies to balance the costs and benefits of paternal care.

  • 227.
    Svensson, P. Andreas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Female coloration and beneficial egg carotenoids2006Conference paper (Refereed)
  • 228.
    Svensson, P. Andreas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Female coloration and beneficial egg carotenoids2007Conference paper (Other academic)
  • 229.
    Svensson, P. Andreas
    Department of Biology, NTNU, Trondheim.
    Female coloration, egg carotenoids and reproductive success: gobies as a model system2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In two-spotted gobies (Gobiusculus flavescens), females develop an orange belly as they approach sexual maturity. Toward the end of the single breeding season, males become rare and females compete for spawnings. Nest-holding males then prefer females with more colourful bellies and this trait has been suggested to act as a female ornament. I found a positive relationship between belly coloration and the coloration of the underlying gonads. This shows that belly coloration honestly reflects egg pigmentation, mainly because the transparency of the abdominal skin allows other fish to see the gonads directly. The factors contributing to variation in the nuptial coloration of female G. flavescens was examined in a series of investigations (Paper I). When gonads matured they became more colourful while the abdominal skin became more transparent. This caused an increase in nuptial coloration as females approached maturity. However, there was considerable variation in belly coloration also among fully mature females. Mature females had more colourful bellies late in the breeding season, partly due to an increase in gonad carotenoid concentration but also due to a seasonal increase in skin coloration. Analyses of gonads from wild-caught female G. flavescens showed the three main carotenoids to be astaxanthin, idoxanthin and adonixanthin (34%, 23% and 21% of the total carotenoid concentration, respectively). Compared to females of the five other gobiid species found in the same area, G. flavescens had much more colourful bellies. The unique ornamentation of G. flavescens females was achieved by the concurrent exaggeration of all signal components: gonad coloration, skin coloration and skin transparency. To understand how gonad and skin pigmentation interact in the nuptial coloration of female G. flavescens, the role of skin chromatophores was examined in detail (Paper II). Noradrenaline caused aggregation of chromatophore pigment and was used to experimentally reduce the contribution of skin chromatophores to the nuptial coloration. Interestingly, the aggregation of skin pigment weakened the positive relationship between belly and gonad coloration, despite an increase in skin transparency. The results show that female G. flavescens have a potential to use skin chromatophores to rapidly alter their nuptial coloration, thereby affecting the efficacy with which information about gonad coloration is conveyed.  

     

    Carotenoid-based ornamentation has often been suggested to signal mate quality, and species with such ornaments have frequently been used in studies of sexual selection. Carotenoids can be beneficial to animals in various ways, especially during sensitive life stages such as embryonic development. However, empirical work has so far provided equivocal evidence of beneficial effects of carotenoids in vivo. Because males invest heavily in offspring during incubation, the evolution of the male mate preference can be explained if colourful females provide males with eggs of higher quality. This hypothesis was tested by letting males spawn with naturally ‘colourful’ and ‘drab’ females, and comparing several reproductive parameters (Paper III).   

     

    Colourful females produced slightly larger clutches and eggs with significantly higher concentrations of total carotenoids than drab females, but their clutches were not of higher quality. In addition, there were no significant relationships between egg carotenoids and clutch quality. These results call into question a link between female nuptial coloration and offspring quality. In a second study, females were given two diets, differing only in carotenoid concentration (Paper IV). Females given carotenoid- rich feed attained a stronger nuptial coloration, laid more carotenoid-rich eggs and were more likely to spawn. This group also produced larvae that had a stronger phototactic response, suggesting higher offspring quality. This result suggests a direct benefit for males that choose to mate with colourful females. Other measures of reproductive success commonly reported in the literature, such as fertilization rate, hatching success and offspring susceptibility to starvation, were not affected by maternal carotenoid supply.

    In this thesis I have established a link between female ornamentation and egg carotenoid concentration, as well as a relationship between egg carotenoid concentration and offspring quality. The work constitute a uniquely detailed description of factors affecting variation in a nuptial signal and in its different components, and relate these to current theory on signal evolution.  

  • 230.
    Svensson, P. Andreas
    Norwegian University of Science and Technology.
    Female coloration, egg carotenoids and reproductive success gobies as a model system, PhD Thesis2006Doctoral thesis, comprehensive summary (Other academic)
  • 231.
    Svensson, P. Andreas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Female two-spotted gobies display egg carotenoid status2004Conference paper (Other academic)
  • 232.
    Svensson, P. Andreas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Female two-spotted gobies display egg carotenoid status.2004Conference paper (Refereed)
  • 233.
    Svensson, P. Andreas
    Monash University.
    Gobies and carotenoids2008Conference paper (Other academic)
    Abstract [en]

    In the thirty years since John Endler's seminal work on guppies, carotenoid based signals have become a large and growing topic in behavioural ecology, especially in birds and fishes. Carotenoids are common pigments in animal signals,but they are also important as antioxidants and provitamins. Their dual role in ornaments and physiology make carotenoids ideally suited for answering questions about honest signalling. However, testing the theoretical predictions is not always straightforward, and properly designed experiments are a rather recent phenomenon. In many birds and fishes, females incorporate large quantities of carotenoids into eggs, but the reasons for this are only partially understood. For example, many species seem to do fine without carotenoids. I will briefly introduce carotenoids in signalling before discussing their role in gobies, based on work in nordic gobies.

  • 234.
    Svensson, P. Andreas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Gobies as biomarkers.2006Conference paper (Other academic)
  • 235. Svensson, P. Andreas
    Shoaling decisions in the two-spotted goby,Gobiusculus flavescens. MSc thesis.2000Report (Other academic)
    Abstract [en]

    Shoaling behavior of young-of-year Gobiusculus flavescens was studied in the lab and in the field outside Kristineberg Marine Research Station, in the Gullmar fjord, Sweden. Natural shoals varied in size from a few to several hundred fish, and were found to be assorted by body size. The structure of the shoals was very dynamic, and any particular group of individuals was unlikely to stay together for more than a few hours. In aquarium experiments, individual G. flavescens preferred joining a small shoal of conspecifics to being on their own. Also, larger shoals were preferred over smaller shoals. Large fish preferred the company of fish of matching body size. Small fish, however, did not show size assortative preferences. Focal fish showed no significant preference for shoaling with familiar compared to unfamiliar fish, not even under predator threat. The results are discussed in view of theories concerning the adaptive basis of shoaling behavior, such as dilution, confusion and oddity effects.

  • 236.
    Svensson, P. Andreas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Strategic male courtship effort in a desert-dwelling fish.2008Conference paper (Refereed)
    Abstract [en]

    Strategic allocation of male mating effort is expected if females vary greatly in reproductive value and/or the costs of mating for males are high. Here, we conducted experiments investigating male signalling effort in the Australian desert goby, Chlamydogobius eremius. Males in this species exhibit elaborate courtship of females and exclusive parental care. In the first experiment, we offered focal males two females presented simultaneously in a dichotomous choice design. We found that males preferentially courted the larger of the two females. We found that the same was also true when, in a second experiment, males were presented with females sequentially. Intriguingly, the order of presentation appeared to be important, with males adjusting their courtship depending on the size of the female encountered previously. Our study highlights male mate choice as an important source of variation in male signalling effort.

  • 237.
    Svensson, P. Andreas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Techniques for incubating and analyzing goby eggs.2006Conference paper (Other academic)
  • 238.
    Svensson, P. Andreas
    Deakin Univeristy.
    The interval between sexual encounters affect male courtship tactics.2011Conference paper (Other academic)
    Abstract [en]

    Courtship displays can enhance male mating success, but are often costly. Thus, instead of courting all females indiscriminately, males could strategically adjust their signalling effort by directing greater courtship towards females of higher reproductive quality. However, plasticity in male courtship intensity remains a largely neglected aspect of sexual selection. Theory predicts that the expression of such plasticity should depend on both the order, and the rate, with which potential mates are encountered. We tested these predictions in a fish, the Australian desert goby, Chlamydogobius eremius. Males preferentially courted the larger of two simultaneously encountered females, probably because larger females are also more fecund. We then investigated male courtship under different sequential scenarios, that is, presenting one female at a time. We found a "previous female effect", with males adjusting their signalling output based on the size of the female they had encountered previously. However, males did not adjust their courtship in this way when the interval between female presentations was longer. Thus, both variation in mate quality, mate encounter rate and previous experiences affected male reproductive decisions. Our findings underscore the importance of considering temporal aspects of mate encounters when trying to understand how mate selection operates in nature.

  • 239.
    Svensson, P. Andreas
    Monash University.
    The interval between sexual encounters affect male courtship tactics2010Conference paper (Other academic)
    Abstract [en]

    Courtship displays can enhance male mating success, but are often costly. Thus, instead of courting all females indiscriminately, males could strategically adjust their signalling effort by directing greater courtship towards females of higher reproductive quality. However, plasticity in male courtship intensity remains a largely neglected aspect of sexual selection. Theory predicts that the expression of such plasticity should depend on both the order, and the rate, with which potential mates are encountered. We tested these predictions in a fish, the Australian desert goby, Chlamydogobius eremius. Males preferentially courted the larger of two simultaneously encountered females, probably because larger females are also more fecund. We then investigated male courtship under different sequential scenarios, that is, presenting one female at a time. We found a "previous female effect", with males adjusting their signalling output based on the size of the female they had encountered previously. However, males did not adjust their courtship in this way when the interval between female presentations was longer. Thus, both variation in mate quality, mate encounter rate and previous experiences affected male reproductive decisions. Our findings underscore the importance of considering temporal aspects of mate encounters when trying to understand how mate selection operates in nature.

  • 240. Svensson, P. Andreas
    et al.
    Barber, I.
    Forsgren, E.
    Shoaling behaviour of the two-spotted goby2000In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 56, no 6, p. 1477-1487Article in journal (Refereed)
    Abstract [en]

    Naturally formed shoals of adult Gobiusculus flavescens in a Swedish fjord ranged in size from a few individuals to several hundred fish and were sorted by body size. Shoal composition was highly dynamic and any particular group was unlikely to remain together for more than a few hours. Shoaling tendency of juveniles in laboratory experiments was high, and consistent preferences were demonstrated for numerically larger shoals. Large test fish preferred to associate with shoals composed of large, over shoals composed of small fish, whereas small test fish associated with both size classes equally. The ecological importance of shoaling in small shallow water fish is discussed, and possible mechanisms for the observed patterns are proposed. (C) 2000 The Fisheries Society of the British Isles.

  • 241.
    Svensson, P. Andreas
    et al.
    School of Biological Sciences, Monash University 3800, Clayton,VIC, Australia.
    Blount, J. D.
    Forsgren, E.
    Amundsen, T.
    Female ornamentation and egg carotenoids of six sympatric gobies2009In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 75, p. 2777–2787-Article in journal (Refereed)
    Abstract [en]

    Belly colouration, gonad carotenoid concentration and skin transparency were quantified in gravid Gobiusculus flavescens, as well as in females of five sympatric gobies where belly ornamentation has not been described. Although G. flavescens females did, indeed, have far more colourful bellies than the other species, this could only in part be explained by a high concentration of total gonad carotenoids. Comparable, or occasionally higher, carotenoid levels were found in the gonads of other species. Instead, the unusual ornamentation of G. flavescens arises from a unique combination of carotenoid-rich gonads and a highly transparent abdominal skin.

  • 242. Svensson, P. Andreas
    et al.
    Forsgren, E.
    Amundsen, T.
    Nilsson Sköld, H.
    Chromatic interaction between egg pigmentation and skin chromatophores the nuptial coloration of female two-spotted gobies2005In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 208, p. 4391-4397Article in journal (Refereed)
    Abstract [en]

    In two-spotted gobies (Gobiusculus flavescens Fabricius 1779), females develop an orange belly as they approach sexual maturity. Bright belly coloration is preferred by males and has been suggested to act as a female ornament. This coloration is unusual in that it originates partly from pigmentation of the abdominal skin but also from strongly pigmented gonads directly visible through the skin. In addition, females have been observed to temporarily become more colourful during courtship and competition. To understand how gonad and skin pigmentation interact in this nuptial coloration, the potential for colour modification via regulation of skin chromatophores was investigated. Noradrenaline caused aggregation of chromatophore pigment and was used to experimentally reduce the contribution of skin chromatophores to the nuptial coloration. Chromatophore pigment aggregation caused bellies to become less colourful and abdominal skin biopsies to become less colourful and more transparent. There was a strong positive relationship between belly coloration and the coloration of the underlying gonads. This shows that belly coloration honestly reflects egg pigmentation, mainly because the transparency of the abdominal skin allows other fish to see the gonads directly. Interestingly, when noradrenaline caused pigment to aggregate and thereby increased the transparency of the skin, the relationship between belly and gonad coloration weakened. We conclude that female G. flavescens have a potential to use skin chromatophores to rapidly alter their nuptial coloration, thereby affecting the efficacy with which information about gonad coloration is conveyed.

  • 243.
    Svensson, P. Andreas
    et al.
    Monash Univ, Sch Biol Sci, Clayton, Vic 3800, Australia.
    Lehtonen, T. K.
    Monash Univ, Sch Biol Sci, Clayton, Vic 3800, Australia.
    Wong, B. B. M.
    Monash Univ, Sch Biol Sci, Clayton, Vic 3800, Australia.
    The interval between sexual encounters affects male courtship tactics in a desert-dwelling fish2010In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 64, no 2, p. 1967-1970Article in journal (Refereed)
    Abstract [en]

    Courtship displays are often important in determining male mating success but can also be costly. Thus, instead of courting females indiscriminately, males might be expected to adjust their signalling effort strategically. Theory, however, predicts that such adjustments should depend on the rate with which males encounter females, a prediction that has been subject to very little empirical testing. Here, we investigate the effects of female encounter rate on male courtship intensity by manipulating the time interval between sequential presentations of large (high quality) and small (low quality) females in a fish, the Australian desert goby Chlamydogobius eremius. Males that were presented with a small female immediately after a large female reduced their courtship intensity significantly. However, males courted large and small females with equal intensity if the interval between the sequential presentations was longer. Our results suggest that mate encounter rate is an important factor shaping male reproductive decisions and, consequently, the evolutionary potential of sexual selection.

  • 244.
    Svensson, P. Andreas
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. Monash University, Australia.
    Lehtonen, Topi K.
    Monash University, Australia ; University of Turku, Finland.
    Wong, Bob B. M.
    Monash University, Australia.
    A high aggression strategy for smaller males2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8, article id e43121Article in journal (Refereed)
    Abstract [en]

    Male-male conflict is common among animals, but questions remain as to when, how and by whom aggression should be initiated. Factors that affect agonistic strategies include residency, the value of the contested resource and the fighting ability of the two contestants. We quantified initiation of aggression in a fish, the desert goby, Chlamydogobius eremius, by exposing nest-holding males to a male intruder. The perceived value of the resource ( the nest) was manipulated by exposing half of the residents to sexually receptive females for two days before the trial. Resident male aggression, however, was unaffected by perceived mating opportunities. It was also unaffected by the absolute and relative size of the intruder. Instead resident aggression was negatively related to resident male size. In particular, smaller residents attacked sooner and with greater intensity compared to larger residents. These results suggest that resident desert goby males used set, rather than conditional, strategies for initiating aggression. If intruders are more likely to flee than retaliate, small males may benefit from attacking intruders before these have had an opportunity to assess the resident and/or the resource.

  • 245. Svensson, P. Andreas
    et al.
    Malm, T.
    Engkvist, R.
    Distribution and host plant preference of Idotea baltica (Pallas) (Crustacea Isopoda) on shallow rocky shores in the central Baltic Sea2004In: Sarsia, ISSN 0036-4827, E-ISSN 1503-1128, Vol. 89, no 1, p. 1-7Article in journal (Refereed)
    Abstract [en]

    Partially due to the mass occurrence of the isopod Idotea baltica, the perennial fucoid vegetation in the Baltic Sea has been destroyed over large areas and replaced by filamentous algae. With a combination of field investigations and laboratory experiments, we tested whether I. baltica preferred Fucus serratus to the dominant red alga Polysiphonia fucoides. In the field, the I. baltica density was higher inside F. serratus than P. fucoides patches when measured per unit area, but the situation was reversed if measured per biomass algae. Diet in the field was well correlated with the distribution of the isopods. A large proportion of the isopod faecal pellets collected in the field contained remnants of microalgae, planktonic animals, and bacteria, but the dominating material was always cells from the actual host plant. In a host plant preference experiment, I. baltica distributed evenly between the two host plant types, but the isopods grazed more heavily on F. serratus: We conclude that although F. serratus is the preferred food item in a choice situation, P. fucoides appears to have the potential to support the I. baltica population with food and shelter. A possible relationship between the weak host plant preference and the low stocks of predatory fish is discussed.

  • 246.
    Svensson, P. Andreas
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Nilsson-Sköld, Helen
    University of Gothenburg.
    Skin biopsies as tools to measure fish coloration and colour change2011In: Skin Biopsy - Perspectives / [ed] Uday Khopkar, InTech, 2011Chapter in book (Other academic)
  • 247.
    Svensson, P. Andreas
    et al.
    Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
    Pélabon, C.
    Blount, J. D.
    Forsgren, E.
    Bjerkeng, B.
    Amundsen, T.
    Temporal variability in a multicomponent trait: nuptial coloration of female two-spotted gobies2009In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 20, no 2, p. 346-353Article in journal (Refereed)
  • 248. Svensson, P. Andreas
    et al.
    Pélabon, C.
    Blount, J. D.
    Surai, P. F.
    Amundsen, T.
    Does female nuptial coloration reflect egg carotenoids and clutch quality in the two-spotted goby (Gobiusculus flavescens, Gobiidae)?2006In: Functional Ecology, ISSN 0269-8463, E-ISSN 1365-2435, Vol. 20, p. 689-698Article in journal (Refereed)
    Abstract [en]

    1. Carotenoid based ornamentation has often been suggested to signal mate quality and species with such ornaments have frequently been used in studies of sexual selection. 2. FemaleGobiusculus flavescens(two-spotted goby) develop colourful orange bellies during the breeding season. Belly coloration varies among mature females, and previous work has shown nest holding males to prefer females with more colourful bellies. Since males invest heavily in offspring during incubation, the evolution of this preference can be explained if colourful females provide males with eggs of higher quality. 3. We tested this hypothesis by allowing males to spawn with 'colourful' and 'drab' females and comparing parameters including egg carotenoid concentration, clutch size, hatchability and larval viability between groups. We also investigated relationships between egg carotenoid concentration and clutch quality parameters. 4. Eggs from colourful females had higher concentrations of total carotenoids than eggs from drab females. Colourful females produced slightly larger clutches, but no measure of offspring quality differed between the two groups. Belly coloration quantified in photographs prior to spawning was a good predictor of egg carotenoid concentration, but there were no significant relationships between egg carotenoids and the measures of clutch quality. Females with high levels of egg carotenoids spawned slightly earlier, however, possibly because they were more ready to spawn or because of male mate choice. 5. We found that colourful females provided males with slightly larger clutches and eggs that contained more carotenoids, but despite this, the offspring were not of higher quality. Our results call into question the generality of a causal link between egg carotenoids and offspring quality.

  • 249.
    Svensson, P. Andreas
    et al.
    Monash University, Australia.
    Wong, B. B. M.
    Monash University, Australia.
    Carotenoid-based signals in behavioural ecology: a review2011In: Behaviour, ISSN 0005-7959, E-ISSN 1568-539X, Vol. 148, no 2, p. 131-189Article in journal (Refereed)
    Abstract [en]

    Carotenoids are among the most prevalent pigments used in animal signals and are also important for a range of physiological functions. These concomitant roles havemade carotenoidbased signals a popular topic in behavioural ecology while also causing confusion and controversy. After a thorough background, we review the many pitfalls, caveats and seemingly contradictory conclusions that can result from not fully appreciating the complex nature of carotenoid function. Current controversies may be resolved through a more careful regard of this complexity, and of the immense taxonomic variability of carotenoid metabolism. Studies investigating the physiological trade-offs between ornamental and physiological uses of carotenoids have yielded inconsistent results. However, in many studies, homeostatic regulation of immune and antioxidant systems may have obscured the effects of carotenoid supplementation. We highlight how carefully designed experiments can overcome such complications. There is also a need to investigate factors other than physiological trade-offs (such as predation risk and social interactions) as these, too, may shape the expression of carotenoidbased signals.Moreover, the processes limiting signal expression individuals are likely different from those operating over evolutionary time-scales. Future research should give greater attention to carotenoid pigmentation outside the area of sexual selection, and to taxa other than fishes and birds.

  • 250.
    Symons, N.
    et al.
    Monash Univ, Sch Biol Sci, Melbourne, Vic 3004, Australia .
    Svensson, P. Andreas
    Monash Univ, Sch Biol Sci, Melbourne, Vic 3004, Australia .
    Wong, B. B. M.
    Monash Univ, Sch Biol Sci, Melbourne, Vic 3004, Australia .
    Do Male Desert Gobies Compromise Offspring Care to Attract Additional Mating Opportunities?2011In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 6, no 6, p. e20576-Article in journal (Refereed)
    Abstract [en]

    Males often play a critical role in offspring care but the time and energy invested in looking after young can potentially limit their ability to seek out additional mating opportunities. Recent studies, however, suggest that a conflict between male parental effort and mating effort may not always be inevitable, especially if breeding occurs near the nest, or if parental behaviours are under sexual selection. Accordingly, we set out to experimentally investigate male care and courtship in the desert goby Chlamydogobius eremius, a nest-guarding fish with exclusive paternal care. Despite courtship occurring near the nest, we found that when egg-tending males were given the opportunity to attract additional females, they fanned their eggs less often, engaged in shorter fanning bouts, and spent more of their time outside their nests courting. Our findings highlight the importance of understanding the circumstances under which reproductive tradeoffs are expected to occur and how these, in turn, operate to influence male reproductive decisions.

23456 201 - 250 of 281
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