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  • 1.
    Acerbi, Alberto
    et al.
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Ghirlanda, Stefano
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Enquist, Magnus
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology.
    The logic of fashion cycles2012In: PLoS ONE, ISSN 1932-6203, Vol. 7, no 3, e32541- p.Article in journal (Refereed)
    Abstract [en]

    Many cultural traits exhibit volatile dynamics, commonly dubbed fashions or fads. Here we show that realistic fashion-like dynamics emerge spontaneously if individuals can copy others' preferences for cultural traits as well as traits themselves. We demonstrate this dynamics in simple mathematical models of the diffusion, and subsequent abandonment, of a single cultural trait which individuals may or may not prefer. We then simulate the coevolution between many cultural traits and the associated preferences, reproducing power-law frequency distributions of cultural traits (most traits are adopted by few individuals for a short time, and very few by many for a long time), as well as correlations between the rate of increase and the rate of decrease of traits (traits that increase rapidly in popularity are also abandoned quickly and vice versa). We also establish that alternative theories, that fashions result from individuals signaling their social status, or from individuals randomly copying each other, do not satisfactorily reproduce these empirical observations.

  • 2.
    Ahlen, Ingemar
    Executive, Universitet, Swedish University of Agricultural Sciences, Sveriges lantbruksuniversitet, skoglig resurshållning.
    Skydd av biotoper för bevarande av vitryggig hackspett i nedre Dalälven1976Report (Other academic)
    Abstract [sv]

    Den vitryggiga hackspetten Dendrocopos leucotos, som ursprungligen förekommit över nästan hela landet, har under de senaste hundra åren blivit allt sällsyntare och finns nu, förutom i några spridda förekomster av enstaka par eller ensamma fåglar, i landet endast kvar med en fast population i nedre Dalälvsområdet mellan Avesta och Älvkarleby.

    De hotade hackspettarterna har sedan 1974 varit föremål för ekologisk forskning och inventeringsarbete. I bilagda ”information om projekt hackspettars ekologi” 1976-01-18 redovisas projektets syfte och kortfattad redogörelse för arbetet under 1975 ges. Hänvisning kan också göras till tidskriften Vår Fågelvärlds första nummer 1976 där resultat av 1973 års riksinventering av gråspett och vitryggig hackspett redovisas.

  • 3.
    Ahlrot, Ulrica
    Linköping University, Department of Physics, Chemistry and Biology, Biology.
    Welfare in zoo kept felids: A study of resource usage2016Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Due to a large number of felid species being endangered they are subjects of conservation projects both in situ and ex situ. Keeping felids in zoos are problematic with stereotypic behaviours such as pacing and reproduction difficulties often occurring. The aim of this study was to review research and zoo husbandry knowledge about which resources are most important for the welfare of zoo kept felids, and in addition perform behavioural observations in seven felid species in four Swedish zoos to try to find an order of priority of resources. Observations were performed during opening hours in 36 sessions per species and zoo. The results showed that studies of felid resource usage are missing. Zoo husbandry practice is probably based mainly on traditions and anecdotal knowledge. The observations showed that except for minor differences felids behave similarly regardless of species but the use of resources varies. Small felid species seems to be hiding rather than pacing as a way of coping. Elevated resources and areas as well as numerous hiding places are important to felids but many factors might affect the choice of resting places. Therefore it is important to provide the felids with multiple choices. It is also important to evaluate both species and individuals when designing enclosures and providing resources. More multi-institutional studies with large number of individuals of all zoo kept felid species are needed to gather knowledge about felids needs and preferences of resources.

  • 4.
    Almberg, Johan
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Variation in proactive - reactive personality types in the red junglefowl2013Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    It has been shown in many species that individuals exhibit consistent differences in behaviour over time and/or across situations. These differences in behaviour are called personality. One way to categorise personality types typically used for rodents, is along a proactive-reactive gradient, which describes how individuals cope with stressful challenges. Proactive individuals pay less attention to their environment, form routines easily and take longer to adapt when routines are broken compared to reactive individuals. Avian species have to date rarely been described along this gradient, thus the generality of this description across species is unclear. The present study has investigated variation in proactivity-reactivity in red junglefowl chicks (Gallus gallus). To observe the chicks’ coping styles, a proactive-reactive test was conducted where the chicks were trained to form a routine, which was then broken. Their behavioural response to this was recorded and used as a measure for proactivity-reactivity. The behavioural response was then linked to individual behavioural variation in additional personality assays. Individuals that were more vigilant in the proactive-reactive test often uttered stress calls and took longer to complete the test. In contrast, individuals that walked more and did not utter stress calls had a shorter time to complete the test. These findings can be used to describe proactive red junglefowl chicks; those that are more stressed when routines are broken, compared to calmer reactive individuals. I found no difference in routine formation between proactive and reactive red junglefowl chicks, suggesting that what describes proactive and reactive individuals may vary across species.

  • 5.
    Almbro, Maria
    et al.
    Centre for Evolutionary Biology, University of Western Australia.
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Season, sex and flight muscle investment affect take-off performance in the hibernating small tortoiseshell butterfly Agalis urticae (Lepidoptera: Nymphalidae)2011In: The Journal of Research on the Lepidoptera, ISSN 0022-4324, Vol. 44, 77-84 p.Article in journal (Refereed)
    Abstract [en]

    Flight ability is generally expected to increase with relative flight muscle mass. Changes in weight can therefore be expected to influence the capacity to rapidly take-off, which can determine mating success and predator avoidance. This study examined the influence of relative flight muscle mass, sex, and season on free take-off flight ability in a butterfly model (Aglais urticae) that undergoes adult winter hibernation. Mass change and take-off flight ability (velocity and take-off angle), was predicted to fluctuate with season (before, during and after hibernation) and sex (due to reproductive investment). Our results indeed showed changes in take-off ability in relation to both parameters. Females maintained velocity across seasons but reduced take-off angles during and after hibernation. Male flight speed increased during and after hibernation, whereas take-off angles were significantly reduced during hibernation. Finally, we showed that investment in relative flight muscle mass increased velocity in female, but not in male butterflies.

  • 6.
    Andersson, Elin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology. IFM.
    Dogs´understanding of human pointing gestures2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    To investigate the ability for animals to understand human communication signals and the communication between animals and humans, scientists often investigate the understanding of human gestural cues. Dogs (Canis lupus familiaris) which have a long history of co-evolution with humans have been shown to make good use of human gestural cues. In the present study I investigated whether dogs in general understand a human pointing gesture and if there are differences between sex, age or breeds. In total 46 dogs of different breeds participated in the study. The study was carried out in a dog center in Linköping, Hundens och djurens beteendecenter. To test if dogs understand human pointing gestures, a two-way object choice test were used, where an experimenter pointed at a baited bowl at a distance of three meter from the dog. The results showed that dogs in general can understand human pointing gestures. However, no significant differences were found for sex, age or breeds. As a conclusion, I found that dogs in general can understand human pointing gestures, but sex, age or breed did not affect the ability.

  • 7.
    Aplin, L. M.
    et al.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England.;Univ Calif Davis, Dept Anthropol, Davis, CA 95616 USA..
    Firth, J. A.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Farine, D. R.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England.;Univ Calif Davis, Dept Anthropol, Davis, CA 95616 USA.;Smithsonian Trop Res Inst, Ancon, Italy..
    Voelkl, B.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Crates, R. A.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Culina, A.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Garroway, C. J.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Hinde, C. A.
    Wageningen Univ, Dept Anim Sci, Behav Ecol Grp, NL-6700 AP Wageningen, Netherlands..
    Kidd, L. R.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Psorakis, I.
    Univ Oxford, Math Inst, Oxford, England..
    Milligan, N. D.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Radersma, R.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England.;Lund Univ, Dept Biol, Evolutionary Ecol Unit, Lund, Sweden..
    Verhelst, B. L.
    Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Sheldon, B. C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics. Univ Oxford, Dept Zool, Edward Grey Inst Field Ornithol, Oxford OX1 3PS, England..
    Consistent individual differences in the social phenotypes of wild great tits, Parus major2015In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 108, 117-127 p.Article in journal (Refereed)
    Abstract [en]

    Despite growing interest in animal social networks, surprisingly little is known about whether individuals are consistent in their social network characteristics. Networks are rarely repeatedly sampled; yet an assumption of individual consistency in social behaviour is often made when drawing conclusions about the consequences of social processes and structure. A characterization of such social phenotypes is therefore vital to understanding the significance of social network structure for individual fitness outcomes, and for understanding the evolution and ecology of individual variation in social behaviour more broadly. Here, we measured foraging associations over three winters in a large PIT-tagged population of great tits, and used a range of social network metrics to quantify individual variation in social behaviour. We then examined repeatability in social behaviour over both short (week to week) and long (year to year) timescales, and investigated variation in repeatability across age and sex classes. Social behaviours were significantly repeatable across all timescales, with the highest repeatability observed in group size choice and unweighted degree, a measure of gregariousness. By conducting randomizations to control for the spatial and temporal distribution of individuals, we further show that differences in social phenotypes were not solely explained by within-population variation in local densities, but also reflected fine-scale variation in social decision making. Our results provide rare evidence of stable social phenotypes in a wild population of animals. Such stable social phenotypes can be targets of selection and may have important fitness consequences, both for individuals and for their social-foraging associates.

  • 8.
    Aronsson, Marianne
    Stockholm University, Faculty of Science, Department of Zoology.
    Colour patterns in warning displays2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In aposematism a prey species use bright colours, often combined with a black contrasting pattern, to signal unprofitability as prey to potential predators. Although there are several different hypotheses about the presence of these internally contrasting patterns, there is little experimental evidence of any beneficial effects. In this thesis I have used bird predators and artificial prey signals to investigate if the contrasting internal patterns in warning displays may have evolved to increase signal efficacy, especially regarding the speed of avoidance learning. In paper I the relative importance of colour and pattern in avoidance learning was studied. The conclusion was that birds primarily attend to colour, not pattern, when learning the discrimination, which was further supported by the results in paper II-IV, all suggesting a secondary role of patterns. In paper II I show that predators may to some degree use patterns for discrimination, if they convey important information about prey quality. The predators showed a hierarchical way of learning warning colour components, where colour is learned to a higher degree than pattern. In paper III I investigate if internal contrasting patterns promote avoidance learning by increasing conspicuousness as prey-to-background contrast does. The study did not support this idea, as the presence of internal black patterns did not improve avoidance learning on a colour matching background. In paper IV, however, I show that the presence of many internal colour boundaries resulted in faster avoidance learning on a multi-coloured background, and predator generalization favoured more internal boundaries, while there was no effect of pattern regularity. From these studies I conclude that internal pattern contrasts may function to increase the efficacy of the warning colour, its salience, and as a means for aposematic prey to be discriminated from harmful mimics. However, the major finding is the importance of colour over pattern.

  • 9.
    Aronsson, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology.
    Evidence of signaling benefits to contrasting internal color boundaries in warning coloration2013In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 24, no 2, 349-354 p.Article in journal (Refereed)
    Abstract [en]

    It has been suggested that the common existence of regular patterning in aposematic prey animals makes them stand out from the background, improving detection and recognition. Another suggestion is that internal patterns could have a similar positive effect on predator aversion learning as prey-to-background contrast. We used wild caught blue tits (Cyanistes caeruleus) and artificial prey signals to investigate if internal color boundaries, pattern regularity and pattern symmetry affect learning. Birds in different treatments were trained, on a complex background, to discriminate between artificial prey with different nonrewarding color stimuli with a black pattern and rewarding stimuli without a black pattern, followed by a generalization test. This study provides evidence of learning benefits to internally contrasting patterns as the striped prey stimuli were learned faster than the unstriped. Also, we found no beneficial effects of pattern regularity and symmetry. The birds generalized more between prey with different black patterns than to the profitable prey, suggesting that color is of foremost importance. The generalization test also showed a greater avoidance of striped than that of unstriped prey, suggesting some attention on patterns. Thus, internal patterning may affect signal salience and in some circumstances benefit prey due to both a faster avoidance learning and generalization behavior.

  • 10.
    Aronsson, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Why do aposematic prey often have contrasting internal patterns: Evidence of benefits through predator avoidance learning and generalization.Manuscript (preprint) (Other academic)
  • 11.
    Aronsson, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Colour and pattern similarity in mimicry - evidence for a hierarchical discriminative learning of warning colour pattern components.Manuscript (preprint) (Other academic)
  • 12. Barber, I.
    et al.
    Svensson, P. A.
    Effects of experimental Schistocephalus solidus infections on growth, morphology and sexual development of female three-spined sticklebacks, Gasterosteus aculeatus2003In: Parasitology, ISSN 0031-1820, E-ISSN 1469-8161, Vol. 126, 359-367 p.Article in journal (Refereed)
    Abstract [en]

    The use of naturally infected hosts in studies attempting to identify parasite-induced changes in host biology is problematical because it does not eliminate the possibility that infection may be a consequence, rather than a cause, of host trait variation. In addition, uncontrolled concomitant infections may confound results. In this study we experimentally infected individual laboratory-bred female three-spined sticklebacks Gasterosteus aculeatus L. with the pseudophyllidean cestode Schistocephalus solidus [Muller], and compared the morphology and growth patterns of infected females with sham-exposed controls over a 16-week period. Fish were fed a ration of 8% body weight per day. Non-invasive image analysis techniques allowed the growth of individual plerocercoids to be tracked in vivo throughout the course of infection, and patterns of host and parasite growth were determined. Females that developed infections diverged morphometrically from unexposed control females and exposed-uninfected females at 6 weeks post-infection, with the width of the body at the pectoral fins giving the earliest indication of infection success. When including the plerocercoid, infected females gained weight more quickly than controls, but when plerocercoid weight was removed this trend was reversed. There was no effect of infection on the increase in fish length. Plerocercoids grew at different rates in individual hosts, and exhibited measurable sustained weight increases of up to 10% per day. Final estimates of plerocercoid weight from morphometric analysis prior to autopsy were accurate to within +/-17% of actual plerocercoid weight. At autopsy, infected female sticklebacks had significantly lower perivisceral fat reserves but had developed significantly larger ovaries than controls. The results are discussed in relation to previous studies examining natural infections, and the value of utilizing experimental infections to examine ecological aspects of host-parasite interactions is discussed.

  • 13. Barber, I.
    et al.
    Svensson, P. Andreas
    Synchrony between parasite development and host behaviour change2003In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 63 Supp A, 246- p.Article in journal (Refereed)
  • 14. Barber, I.
    et al.
    Walker, P.
    Svensson, P. A.
    Behavioural responses to simulated avian predation in female three spined sticklebacks the effect of experimental Schistocephalus solidus infections2004In: Behaviour, ISSN 0005-7959, E-ISSN 1568-539X, Vol. 141, 1425-1440 p.Article in journal (Refereed)
    Abstract [en]

    Plerocercoid larvae of Schistocephalus solidus are common parasites of three-spined sticklebacks that require the ingestion of stickleback hosts by birds to complete their life cycle. Amongst wild-caught sticklebacks, infection is associated with a reduction in antipredator behaviour; however, to date no study has examined the escape responses of experimentally infected sticklebacks, and thus assigning causality remains difficult. Here, we compare aspects of the antipredator behaviour of five experimentally infected female sticklebacks with shamexposed controls over a 16 post-exposure week period. During weeks 1-7 post-exposure, the escape responses of infected fish did not differ significantly from those of sham-exposed fish. However, over weeks 9-15, when infected fish had developed plerocercoids of >50 mg—the size at which they become infective to birds —a lower proportion of infected fish performed directional responses and reached cover within 2 s of the strike. Infected fish also performed a lower frequency of ‘staggered dashes’, and a higher frequency of ‘slow swims’, than shamexposed fish over weeks 9-15. Amongst sham-exposed fish, re-emergence from cover was uncommon throughout the study, but infected fish regularly left cover during weeks 9-15. Our results support those of previous studies examining behavioural change in naturally infected fish and, although other explanations remain possible, our finding that behaviour change in experimentally-infected fish is limited to hosts harbouring single infective parasites provides further evidence that the behaviour changes may be parasite adaptations.

  • 15.
    Beltéky, Johan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Eklund, Beatrix
    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.
    Gene expression of behaviorally relevant genes in the cerebral hemisphere changes after selection for tameness in Red Junglefowl.2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 5, e0177004Article in journal (Refereed)
    Abstract [en]

    The process of domestication in animals has led to alterations in behavior, physiology and phenotypic traits, changes that may be driven by correlations with reduced fear of humans. We used Red Junglefowl, ancestors of all domesticated chickens selected for either high or low fear of humans for five generations to study the effects of selection on gene transcription in the cerebral hemisphere, which is heavily involved in behaviour control. A total of 24 individuals from the parental generation as well as from the fifth selected generation were used. Twenty-two genes were significantly differentially expressed at p < 0.05 after false discovery rate (FDR) correction. Those genes that were upregulated in the low fearful animals were found to be involved in neural functions. Gene ontology and pathway analysis revealed enrichment for terms associated with behavioural processes. We conclude that five generations of divergent selection for high or low tameness has significantly changed gene expression patterns in the cerebral hemisphere in the Red Junglefowl population used here, which could underlie a range of changes in the domestic phenotype.

  • 16.
    Bergvall, Caroline
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    The domestication effects on social support in chickens (Gallus gallus)2012Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    When animals are stressed they use a trait called social support to alleviate their stress responses. With domestication many traits from the ancestor red junglefowl have changed in the domesticated breed white leghorn. White leghorns are bred to be able to live in large groups where it becomes hard to recognize every chicken. They are therefore not as dependent of familiar stimuli birds for social support as red junglefowl. Our hypotheses were that red jungle males would be more interested in unfamiliar stimuli birds than white leghorn male before stress due to their territoriality. We tested total 56 chickens in an open field test. The test arena was divided in three zones and the time the focal birds spent in each zone was recorded. The focal bird was recorded in 300 seconds before being stressed by being suspended in a net and then recorded again in 300 seconds. The results showed that social support and social behaviour differs between females and males for both breeds. No significant differences were found between the breeds. There was a tendency for significant of breed (P=0.08) effects in the central zone unstressed. The two interactions before stressed between breed and sex, central zone (P<0.01) and unfamiliar zone (P<0.01) had significant effects. We observed fights between white leghorn males and familiar stimuli. Waltzing did also occur in red jungle males in front of unfamiliar. In conclusion, numeric differences can be seen but not large enough to be significant and our hypotheses are not confirmed.

  • 17.
    Bergvall, Ulrika Alm
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Plant secondary compounds and the frequency of food types affect food choice by mammalian herbivores2005In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 86, no 9, 2450-2460 p.Article in journal (Refereed)
    Abstract [en]

    We have investigated food choice in individual fallow deer (Dama dama) encountering different relative frequencies of food types in the form of bowls containing pellets with either high or low concentrations of hydrolyzable tannin. We performed two similar experiments, one with large and one with small differences in tannic acid concentration. With small differences in tannic acid concentration, the ratio of the consumption per low- and high-tannin bowl was independent of frequency of occurrence, but with large differences in tannic acid concentration, we found frequency-dependent food choice. The deer ate proportionally less from high-tannin bowls if these occurred at low relative frequency. Variation between frequency treatments in the average order of encounter of bowl types might have produced this effect, because we found that the deer left a high-tannin bowl more quickly if they had switched to it from a low-tannin bowl. We argue that the perceived contrast between the tastes of different food types can play a role for food choice by mammalian herbivores.

  • 18.
    Bjällerhag, Nathalie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behaviours and experiences as indicators for the result in a behavioural test for dogs2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In 2005 Swedish Armed Forces (SAF) started a breeding program of military working dogs. The dogs leave SAF’s kennel at an age of 8 weeks and live with puppy raisers. To evaluate the suitability of dogs for military work the dogs conduct a behavioural test at an age of 15-18 months. An “Index value” is extracted from this behavioural test. The puppy raisers answered a modified version of Canine Behavioral Assessment and Research Questionnaire (C-BARQ) when the dogs were approximately 12 months old. Answered questionnaires and results from the behavioural test were obtained for 59 dogs. Dogs that had passed the behavioural test had tendency for higher scores for “Trainability” (p = 0.078) and “If lived with other animals” (p = 0.066). Failing dogs had significantly higher score for “Stranger Directed Fear” (p = 0.006), ”Non-Social Fear” (p = 0.005), “Dog Directed Fear” (p = 0.021), “Hours of daily activation” (p = 0.001), “Mounting objects” (p = 0.012), and a tendency for higher risk of “Urinating when home alone” (p = 0.058). In a regressions between the “Index value” and the values of the questions from C-BARQ, the “Index value” was negatively correlated to “Stranger Directed Fear” (p = 0.002), “Non-social Fear” (p = 0.003), and “Dog Directed Fear” (p = 0.006). The “Index value” was positively correlated to “Trainability” (p = 0.013), “Hours left home alone” (p=0.043), “Hyperactive” (p = 0.018), “Chases shadows/light spots” (p = 0.043), and a positive tendency for “Chewing on inappropriate objects” (p = 0.075). From a PCA at the categories in C-BARQ, 3 components were extracted. All three components had a correlation to the “Index value”. The results show that the use of C-BARQ can indicate whether the dog will pass the behavioural test or not.

  • 19.
    Björklund Aksoy, Simon
    Linköping University, Department of Physics, Chemistry and Biology. 2015.
    Effects of serotonin on personality in field crickets (Gryllus bimaculatus)2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Animal personality can be defined as a set of physiological and behavioral characteristics that differ between individuals, but are consistent over time and across situations. The evolution of individual differences in behavior that are consistent over time and situations is still not clear. Our understanding of why animals have personality can be improved by investigating the underlying physiological mechanisms of animal behavior. Serotonin is a key monoamine that serves as a physiological modulator of animal behavior. Selective serotonin reuptake inhibitors are a group of chemicals that increase levels of serotonin in the brain. Fluoxetine is one such chemical and is used to treat depression in humans. In the field cricket (Gryllus bimaculatus), increased levels of serotonin have been linked to higher activity and boldness, which are both personality traits. In the current study, the effects of induced serotonin on activity, exploration, boldness and aggression was investigated. My results show that injecting fluoxetine causes substantial changes in behavioral traits used to describe personality in field crickets. This result is opposite to previous studies, as serotonin induced individuals were less active, less explorative, and won less fights, compared to control individuals. This could be due to serotonin existing naturally within the circulatory system of the field cricket, whereas fluoxetine is a manufactured chemical intended for human receptors, or that fluoxetine has a similar effect in modulating personality in field crickets as in humans. Since fluoxetine acts similarly in field crickets as in humans, an increased understanding of the effects of induced serotonin on different behaviors in field crickets could be beneficial for treating psychological illnesses.

  • 20.
    Blixt, Torbjörn
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    The behavioural response of mice to predator odours2012Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The ability to detect and react to a predator odour is crucial for prey species. In the present study 10 mice (Mus musculus) were used to test the behavioural response of mice towards two predator odours (3-methyl-1-butanethiol and 3-mercapto-3-methyl-butan-1-ol) and one fruity odour (n-pentyl acetate). All three odours were tested against a near odourless blank stimulus (diethyl phthalate). The animals were individually placed in a test chamber of two equally sized compartments divided by a vertical Plexiglas wall with a semicircular opening. Their proximity to the odours, placed beneath the floor in petri dishes in each compartment, was measured continuously with stop watches. The mice spent less time in proximity to 3-methyl-1-butanethiol and n-pentyl acetate compared to diethyl phthalate (P<0,05). The mice did not prefer any specific compartment in the test with 3-mercapto-3-methyl-butan-1-ol compared to diethyl phthalate (P>0,05). The avoidance of 3-methyl-1-butanethiol and n-pentyl acetate can be explained either by neophobia, or in the case of 3-methyl-1-butanethiol that it contains sulphur. The lack of behavioural response towards 3-mercapto-3-methyl-butan-1-ol may be due to its loss of intensity over time. From this study it is not certain if mice have an innate fear of predator odours.

  • 21.
    Brodd, Louise
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    The help-seeking behaviour of dogs (Canis familiaris)2014Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    During domestication, the dog( Canis familiaris), have become skilful in understanding human communication and also in communicating with humans. The wolf ( Canis lupus), is not as skilled with this interspecific communication. When dogs are faced with an unsolvable problem, they seek help from human by e.g. gazing at them. This behaviour has been studied and both age and breed group differences have been showed. In this study, we presented dogs with a task that consisted of a solvable and unsolvable problem in order to see if they gazed at their owner and/or an unfamiliar person for help. Although we did not find any difference in breed groups regarding gazing at humans, we did find that adult dogs (dogs older than 2 years) gazed more frequently at their owner and for a longer duration than adolescent dogs (6 months to 2 years). This may be because the adult dogs have more experience of this communication with humans, as they have lived longer with them. These findings empathize the bond between a dog and its owner that seems to grow stronger during the dogs’ life.

  • 22.
    Brodd, Louise
    Linköping University, Department of Physics, Chemistry and Biology, Biology.
    Behavioural differences between and within retriever breeds2016Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    The retriever breeds have the same origin and have long been used as a gundog for hunting of game, mostly birds. However, recently the retriever breeds have become a popular pet and show dog. This have affected the breeding of the dogs as the same traits are not bred for a gundog and a pet or show dog. Breeds as the Labrador retriever consists of a field- and common-type. The aim of this study is to investigate any differences between and within five of the retriever breeds in behaviours as retrieving, search and game reaction. 64 dogs undergoing the field trial Description of Function- Retriever was video recorded and scores from 430 dogs that have undergone field trials was obtained. Both differences between and within breeds were found when analysing both the videos and scores. In the video analysis, the Flatcoated retriever showed the most retrieving behaviours and was the most passive. The Nova scotia duck tolling retriever was in both the video and score analyses the most active breed. The Labrador retriever scored high in game reaction. The field- and mixed-types had almost always higher scores in behaviours linked to hunting, compared to the common-type. This supports findings that recent selection in breeding have a larger effect on behaviour than the origin uses of the dogs.

  • 23. Bäckman, Lars
    et al.
    Lindenberger, Ulman
    Li, Shu-Chen
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Linking cognitive aging to alterations in dopamine neurotransmitter functioning: Recent data and future avenues2010In: Neuroscience and Biobehavioral Reviews, ISSN 0149-7634, E-ISSN 1873-7528, Vol. 34, no 5, 670-677 p.Article, review/survey (Refereed)
    Abstract [en]

    Molecular-imaging studies of dopaminergic neurotransmission measure biomarkers of dopamine (DA), such as the DA transporter and D(1) and D(2) receptor densities in the living brain. These studies indicate that individual differences in DA functions are linked to cognitive performance irrespective of age, and serve as powerful mediators of age-related decline in executive functioning, episodic memory, and perceptual speed. This focused review targets several recent findings pertaining to these relationships. Specifically, we discuss novel evidence concerning (a) the role of DA in within-person cognitive variability; (b) age-related differences in DA release during cognitive processing; (c) DA release following cognitive training in younger and older adults; and (d) the relationship between DA and task-induced functional brain activity. Based on these lines of empirical inquiry, we outline a series of avenues for future research on aging, DA, and cognition.

  • 24.
    Calais, Andreas
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Is personality dependent of growth rate in red junglefowl (Gallus gallus)?2013Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Personality has been reported in a large variety of animal species, but it is not obvious why animals have personality. Variation in physiological traits, such as growth rate, should theoretically affect variation in behaviours and thus can explain why we observe variation in personalities. Growth rate is, theoretically, positively correlated with active personality types. Empirical studies have reported this pattern in different fish species, but there are not yet many studies on endothermic animals. I have therefore scored behaviours of 100 red junglefowl (Gallus gallus) chicks in four personality assays; novel arena, novel object, tonic immobility, and a proactive-reactive test, together with recording variation in growth rate of these individuals. The chicks individual growth rate (% day-1) were calculated and the relationship between personality and growth rate investigated. There was significant difference in growth rate between the sexes, where males grew faster than females, detected already at one week of age. However, no significant correlations between behavioural traits and growth rate were observed, indicating that personality seem to be independent of growth rate. Further studies should therefore investigate the generality of this finding, and alternative underlying mechanisms for variation in personality should be explored.

  • 25.
    Cederlund, Joakim
    Linköping University, Department of Physics, Chemistry and Biology, Biology.
    Eye preference in humans and its correlation with eye dominance, visual acuity and handedness2016Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Handedness is the most obvious expression of lateralized behaviour in humans. However, there is only limited knowledge about other forms of lateralized behaviour, e.g. preferential use of an eye and whether these may correlate with handedness. Thus to investigate this, 100 subjects (50 males and 50 females) between 11 and 80 years of age were assessed for their eye preference, eye dominance, visual acuity, and handedness. Eye preference was assessed by performing four different monocular tasks, eye dominance by performing the binocular Dolman test, visual acuity was assessed with a Snellen chart and handedness was surveyed using the Edinburgh Handedness Inventory. Regarding eye preference, the right eye was preferred by 69% of the subjects. 90 % of the subjects were consistent for their preferred eye across all four tasks. 66% of the subjects had a dominant right eye, 33% had left eye dominance and 1% could not be assessed using the Dolman test. 56% of the subjects differed in their visual acuity between both eyes, while 43% had the same visual acuity in both of their eyes. 86% of the subjects were right-handed while 4% were left handed and 10% were ambidextrous. Significant correlations were found between visual acuity and eye preference and between visual acuity and eye dominance. The study also found a positive correlation between handedness and eye preference. These results support the notion that there is a weak correlation between the different aspects of lateralized behaviour in humans. 

  • 26. Chiarle, Alberto
    et al.
    Kronestedt, Torbjörn
    Swedish Museum of Natural History, Department of Zoology.
    Isaia, Marco
    Courtship behavior in European species of the genus Pardosa (Araneae, Lycosidae)2013In: Journal of Arachnology, ISSN 0161-8202, Vol. 41, no 2, 108-125 p.Article in journal (Refereed)
  • 27. Collis, Ken
    et al.
    Roby, Daniel D.
    Larson, Keith W.
    Department of Fisheries and Wildlife, 104 Nash Hall, Oregon State University, Corvallis, OR, 97331, USA; Evolutionary Ecology, Lund University, Sølvegatan 37, 223 62 Lund, Sweden.
    Adrean, Lindsay J.
    Nelson, S. Kim
    Evans, Allen F.
    Hostetter, Nathan
    Battaglia, Dan
    Lyons, Donald E.
    Marcella, Tim
    Patterson, Allison
    Trends in Caspian Tern Nesting and Diet in San Francisco Bay: Conservation Implications for Terns and Salmonids2012In: Waterbirds (De Leon Springs, Fla.), ISSN 1524-4695, E-ISSN 1938-5390, Vol. 35, no 1, 25-34 p.Article in journal (Refereed)
    Abstract [en]

    Colony size, nesting ecology and diet of Caspian Terns (Hydroprogne caspia) were investigated in the San Francisco Bay area (SFBA) during 2003-2009 to assess the potential for conservation of the tern breeding population and possible negative effects of predation on survival of juvenile salmonids (Oncorhyn-chusspp.). Numbers of breeding Caspian Terns declined 36% from 2003 to 2009, mostly due to abandonment of the Knight Island colony and decline of the Brooks Island colony, the two largest colonies in the SFBA. Concurrently, nesting success declined 69% associated with colony site characteristics such as (a) quality and quantity of nesting substrate, (b) vulnerability to nest predators, (c) displacement by other colonial waterbirds and (d) human disturbance. Marine fishes were the predominant prey in tern diets from the SFBA; however, diet composition varied among colonies. Juvenile salmonids comprised 22.9% of the diet of terns nesting in the North Bay, 5.3% of diet of terns nesting in the Central Bay, and 0.1% in the South Bay. Construction or restoration of nesting islands in the South Bay may help maintain and restore breeding Caspian Terns without enhancing mortality of salmonid stocks of conservation concern.

  • 28.
    Crespo Mingueza, Laia
    Linköping University, Department of Physics, Chemistry and Biology, Biology.
    Assessment of lateralized behaviour in free-ranging Mexican mantled howler monkeys (Alouatta palliata mexicana)2015Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    The evolutionary origins of human handedness are still unknown. The study of lateralized behaviour in our closest relatives, the nonhuman primates, is useful to clarify how this trait appeared and evolved in our species. In the present study, lateralized behaviour was assessed in a population of 32 free-ranging Mexican mantled howler monkeys (Alouatta palliata mexicana) for thirteen spontaneous motor patterns, at individual and group levels, as well as the effect that age, sex and posture have on its strength and direction. The studied population of howler monkeys displayed only few significant lateral biases at the individual level with single motor patterns (Binomial tests, p≤0.05). No biases towards the use of a particular limb or side of the body were found at a population level. Therefore, even though some individuals showed significant limb/side preference with single motor patterns, no signs of task specialization, side specialization, or true handedness were found. Similarly, no effects of sex, age or posture were found on the direction or strength of lateralized behaviour. The general absence of limb/side preferences found in this population may be due to the constraints imposed by the arboreal life and/or the type of diet. Possible causal agents of the few significant individual biases found here may be the presence of handicaps and/or experience. Further research is needed in order to assess whether the lack of human-like handedness reported in this study is only specific to the studied population, a general phenomenon of the genus Alouatta or perhaps of all the Platyrrhini.

  • 29. Cunha, Mário
    et al.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Alves, T
    Monteiro, Nuno
    Reduced cannibalism during male pregnancy2016In: Behaviour, ISSN 0005-7959, E-ISSN 1568-539X, Vol. 153, no 1, 91-106 p.Article in journal (Refereed)
    Abstract [en]

    Cannibalism provides energetic benefits but is also potentially costly, especially when directed towards kin. Since fitness costs increase with time and energy invested in offspring, cannibalism should be infrequent when parental investment is high. Thus, filial cannibalism in male syngnathids, a group known for the occurrence of male pregnancy, should be rare. Using the pipefish (Syngnathus abaster) we aimed to investigate whether cannibalism does occur in both sexes and how it is affected by reproductive and nutritional states. Although rare, we witnessed cannibalism both in the wild and in the laboratory. Unlike non-pregnant males and females, pregnant and postpartum males largely refrained from cannibalising juveniles. Reproducing males decreased their feeding activity, thus rendering cannibalism, towards kin or non-kin, less likely to occur. However, if not continuously fed, all pipefish adopted a cannibal strategy, revealing that sex and life history stages influenced the ratio between the benefits and costs of cannibalism.

  • 30. Debeffe, L.
    et al.
    Lemaitre, J. F.
    Bergvall, Ulrika A.
    Stockholm University, Faculty of Science, Department of Zoology. Swedish University of Agricultural Science, Sweden.
    Hewison, A. J. M.
    Gaillard, J. M.
    Morellet, N.
    Goulard, M.
    Monestier, C.
    David, M.
    Verheyden-Tixier, H.
    Jäderberg, L.
    Vanpe, C.
    Kjellander, P.
    Short- and long-term repeatability of docility in the roe deer: sex and age matter2015In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 109, 53-63 p.Article in journal (Refereed)
    Abstract [en]

    Behavioural consistency is a key assumption when evaluating how between-individual differences in behaviour influence life history tactics. Hence, understanding how and why variation in behavioural repeatability occurs is crucial. While analyses of behavioural repeatability are common, few studies of wild populations have investigated variation in repeatability in relation to individual status (e.g. sex, age, condition) and over different timescales. Here, we aimed to fill this gap by assessing within-population variation in the repeatability of docility, as assessed by the individual’s response to human handling, in a free-ranging population of European roe deer, Capreolus capreolus. Docility was an equally repeatable behaviour at both short- and long-term timescales, suggesting that this behavioural trait is stable across time. Repeatability did not differ markedly between age and sex categories but tended to be higher in juvenile males than in juvenile females. Finally, contrary to expectation, individual variation in the repeatability of docility was not correlated with individual body mass. Further studies are required to assess the life history consequences of the individual variation in docility we report here.

  • 31.
    Domeij Hilliges, Isak
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Stendahl, Cecilia
    Halmstad University, School of Business and Engineering (SET).
    Ocean acidification effects on marine organisms: a study of Littorina littorea and Balanus improvisus 2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The world’s oceans are becoming more acid in a process called ocean acidification. The pH of the ocean have already decreased by 0.1 units from pre-industrial time until today. Scientists predict that by the year of 2100 the pH will decrease by as much as 0.4 units. This is a big potential problem to many marine species, because they have developed in such a stable environment that has not changed for millions of years. It is difficult to predict how they might be affected by such a decrease in pH during a relatively short time period. Several studies have been made on marine species exposed to decreased pH-levels, the results showed changes in their physiology but it is hard to predict how these changes will affect the organism in a long-term scale and if this might change ecosystem dynamics. Our study measured the activity of Littorina littorea and Balanus improvisus when exposed to lower pH, the results of our study showed an increase in activity for the lower pH (pH 6.0-7.5) when compared to the control (~pH8). The area of ocean acidification is a field that requires further studies to fully understand its effects on the marine ecosystems and the species within it.

  • 32.
    Dussutour, Audrey
    et al.
    Centre National de la Recherche Scientifique, Université Toulouse III.
    Ma, Qi
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Analysis and Applied Mathematics.
    Vogel, David
    Department of Chemistry and of Animal Biology, Université libre de Bruxelles.
    Sumpter, David
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Analysis and Applied Mathematics.
    Speed-accuracy tradeoffs and the construction of transport netowrksManuscript (preprint) (Other academic)
    Abstract [en]

    One of the key challenges in the study of networks is linking structure to function. For example, how do design requirements about the speed and accuracy with which information is transferred through a network determine its form?  We show that different strains of the slime mould Physarum polycephalum form different network structures, ranging from a diffuse network of thin links to a tree-like branching structure.  Using a current-reinforced random walk model, we explain these different structures in terms of two model parameters: the strength and the degree of non-linearity in the reinforcement. These parameters are further shown to tune the speed and accuracy with which the network can detect resource gradients. We use a battery of experimental tests to show that Physarum strains with diffuse networks make more accurate but slower decisions and those with thick, trunk branches make faster less accurate decisions. Intermediate structures can also be found which are relatively fast and accurate. The current reinforced random walk employed by the slime mould provides a tunable algorithm for decision-making, which may also apply in other systems where transport networks are constructed.

  • 33.
    Elebring, Viktoria
    Linköping University, Department of Physics, Chemistry and Biology.
    Vad skiljer domesticerade värphöns från de röda djungelhönsen (Gallus gallus) i återhämtningsprocessen efter en standardiserad stressupplevelse?: En studie med ett didaktiskt perspektiv2011Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Tidigare studier har visat att domesticerade höns påvisar en lägre nivå av rädsla jämfört med förfadern, de röda djungelhönsen. I denna studie testades 18 domesticerade White Leghorn (WL) och 18 röda djungelhöns (RJF). Målet med studien var att studera återhämtningen för de båda raserna vid en standardiserad stressupplevelse. Försöket gick ut på att hönsen vistades i enskilda burar och blev efter ett dygn utsatta av en akut stress. Därefter startades observationerna omedelbart för att se när hönsen återhämtade sig och återigen började visa naturliga beteenden. Utifrån alla hönsens resultat beräknades medelvärde och standardfel för varje ras och kön, som sedan jämfördes med variansanalys (repeated measures ANOVA). Beteenden som visade signifikanta resultat över tiden analyseras och visade i några fall tyda på en återhämtningsprocess. Överlag visade White Leghorn på en snabbare och effektivare återhämtning jämfört med de röda djungelhönsen. Resultatet tyder även på att honor har en snabbare återhämtning jämfört med hanar. Studien innehåller även ett didaktiskt moment då etologi studerades utifrån skolverkets föreskrifter om vad biologiundervisning ska innehålla för grundskolans senare år. Läroplanen och kursplaner studerades därefter och jämfördes med läroböcker.

  • 34.
    Elmberg, Johan
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Dessborn, Lisa
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Arzel, Céline
    Andungar har bra koll när faran hotar2014In: Vår fågelvärld, ISSN 0042-2649, Vol. 73, no 3, 34-35 p.Article in journal (Other (popular science, discussion, etc.))
  • 35.
    Elmberg, Johan
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Dessborn, Lisa
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Arzel, Céline
    Så undviker andungarna rovdjuren2015In: Svensk jakt, ISSN 0039-6583, Vol. 153, no 6, 38-40 p.Article in journal (Other (popular science, discussion, etc.))
  • 36. Engkvist, R.
    et al.
    Malm, T.
    Svensson, A.
    Asplund, L.
    Isaeus, M.
    Kautsky, L.
    Greger, M.
    Lanberg, T.
    Makroalgsblomningar längs Ölands kuster, effekter på det lokala näringslivet och det marina ekosystemet. (English title: Macro algal blooms in the central Baltic proper, effects on the economy and the marine ecosystem.)2001Report (Refereed)
  • 37.
    Enquist, Magnus
    et al.
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Centre for the Study of Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology.
    Lind, Johan
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Centre for the Study of Cultural Evolution.
    Ghirlanda, Stefano
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies, Centre for the Study of Cultural Evolution. Brooklyn College, USA; Graduate Center of the City University of New York, USA.
    The power of associative learning and the ontogeny of optimal behaviour2016In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 3, no 11, 160734Article in journal (Refereed)
    Abstract [en]

    Behaving efficiently (optimally or near-optimally) is central to animals' adaptation to their environment. Much evolutionary biology assumes, implicitly or explicitly, that optimal behavioural strategies are genetically inherited, yet the behaviour of many animals depends crucially on learning. The question of how learning contributes to optimal behaviour is largely open. Here we propose an associative learning model that can learn optimal behaviour in a wide variety of ecologically relevant circumstances. The model learns through chaining, a term introduced by Skinner to indicate learning of behaviour sequences by linking together shorter sequences or single behaviours. Our model formalizes the concept of conditioned reinforcement (the learning process that underlies chaining) and is closely related to optimization algorithms from machine learning. Our analysis dispels the common belief that associative learning is too limited to produce ‘intelligent’ behaviour such as tool use, social learning, self-control or expectations of the future. Furthermore, the model readily accounts for both instinctual and learned aspects of behaviour, clarifying how genetic evolution and individual learning complement each other, and bridging a long-standing divide between ethology and psychology. We conclude that associative learning, supported by genetic predispositions and including the oft-neglected phenomenon of conditioned reinforcement, may suffice to explain the ontogeny of optimal behaviour in most, if not all, non-human animals. Our results establish associative learning as a more powerful optimizing mechanism than acknowledged by current opinion.

  • 38.
    Ericsson, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Stress in chickens: Effects of domestication and early experience on behaviour and welfare2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    I denna avhandling presenteras resultat från fyra studier där alla har effekter av stress hos höns som gemensam nämnare. Vi har främst tittat på hur stress tidigt i livet påverkar beteendet och mängden stresshormoner i blodet på kort och lång sikt, men även hur den tidiga stressen kan påverka avkomman. I två av studierna undersöks också effekterna av domesticering.

    Domesticeringen, processen där vi avlat djur på tamhet och andra önskvärda anlag, har anpassat djuren till våra mänskliga förhållanden. Förfadern till alla våra domesticerade raser, det Röda djungelhönset, finns fortfarande kvar i vida populationer i Sydostasien där de lever i skogar. Detta är en stor fördel då man vill studera domesticeringsprocessen och vilka förändringar som uppkommit, eftersom man kan göra studier mellan raser och sedan direkt jämföra skillnader och likheter. Domesticeringen av höns inleddes för ca 8000 år sedan. Man tror att högre tolerans mot stress kan vara en bidragande faktor i domesticeringsprocessen eftersom tamhönsen har fått anpassa sig till miljöer och förhållanden som egentligen är kan betraktas som onaturliga för en höna, till exempel mycket stora flockar, trånga utrymmen och inomhusvistelse.

    Ägg och kyckling är viktiga livsmedel i stora delar av världen och bara i Sverige kläcks många miljoner höns till kött- och äggproduktion varje år. På kläckerier utsätts kycklingar för en rad av potentiellt stressande situationer och behandlingar och man har varit osäker på om detta påverkar kycklingarna negativt. Forskning visar att stress tidigt i livet kan störa utvecklingen av bl.a. hjärnan och stressystemet, som kontrollerar utsöndringen av stresshormoner. Negativa erfarenheter tidigt i livet kan ge upphov till bl.a. beteendestörningar, sänkt immunförsvar och påverka kognitiva beteenden på senare i livet. Det innebär att det kan vara mer allvarligt att utsättas för stress när man är liten jämfört med när man är äldre. Vid stress ökar mängden stresshormoner i blodet. Detta leder till att beteendet förändras och vissa kroppsfunktioner minskar i aktivitet för att energin istället behövs i musklerna. Kroppen förbereder sig på att försvara sig mot det potentiella hotet genom kamp eller flykt. Genom att ta blodprov kan man mäta mängden stresshormoner.

    I ett projekt undersöktes välfärd hos nykläckta kycklingar och huruvida hanteringen på kläckerier kan bidra till fysiologiska och beteendemässiga förändringar hos djuren. Vidare har vi undersökt hur stressystemet utvecklas tidigt i livet, om det finns skillnader i hur Röda djungelhöns och domesticerade värphöns reagerar. Vi har också undersökt om stress vid olika åldrar under kycklingstadie och pubertet kan ge effekter i vuxen ålder och slutligen har vi undersökt hur akut stress hos vuxna djur påverkar beteende och en rad olika hormoner.

    Resultaten visar att kycklingstadiet och puberteten kan anses som stresskänsliga perioder och ge upphov till kort- och långsiktiga effekter på beteende, genexpression och stressfysiologi. Även avkomman kan i vissa avseenden påverkas. Vi har också kunnat bekräfta att kycklingar har en fullt fungerande stressrespons redan från dag ett efter kläckning. De potentiellt stressande upplevelserna på kläckerier har en påverkan på hur vissa gener kopplade till stress uttrycks i hjärnan. Hanar i vuxen ålder verkar påverkas mer av den tidiga hanteringen än vad honor gör. Vidare visar vi att domesticeringen har påverkat hur höns reagerar på stress både tidigt i livet och i vuxen ålder.

  • 39.
    Favati, Anna
    Stockholm University, Faculty of Science, Department of Zoology.
    Social dominance and personality in male fowl (Gallus gallus domesticus)2013Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Individuals in social species commonly form dominance relationships among each other, and

    are often observed to differ in behaviour depending on their social status. However, whether

    such behavioural differences are a consequence of dominance position, or also a cause to it,

    remains unclear. In this thesis I therefore investigated two perspectives of the relationship

    between social dominance and personality in the domestic fowl (Gallus gallus domesticus), a

    social species that forms relatively stable dominance hierarchies. In paper I I investigated the

    influence of social status on the expression and consistency of behaviours by experimentally

    changing status between repeated personality assays. The level of vigilance, activity and

    exploration changed with social status, while boldness and territorial crows appeared as

    stable individual properties, independent of status. These results showed that social status

    contribute to both variation and consistency in behavioural responses. Social status should

    therefore be taken into account when investigating and interpreting variation in personality.

    In paper II I showed that behaviour in a novel arena test and during encounter with an

    opponent can predict social status, more specifically that fast exploration and aggressiveness

    predicted a dominant social position. Together, these results highlight the dynamics of the

    two-way relationship between social position and individual behaviour and indicate that

    individual behaviour can both be a cause and a consequence of social status.

  • 40.
    Favati, Anna
    Stockholm University, Faculty of Science, Department of Zoology.
    The relationship between personality and social dominance in the domestic fowl – a critical perspective2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Social dominance relationships are formed within numerous animal species and reduce costly fights over resources. Dominant individuals often enjoy greater access to important resources such as food and mating partners, and are generally more aggressive, bold, active and explorative compared to subdominant individuals. These behavioural traits can differ among individuals, but they can also be consistent within the individual, thereby describing the individual’s personality type. However, the causal direction of the observed correlation between dominance and personality is not well studied. One possibility is that some personality types have higher chances of obtaining a dominant social position. This would suggest that personality has consequences for fitness. Another possible explanation is that possessing different social positions gives rise to consistent behavioural differences among individuals on various timescales. If social status has a lasting effect on behaviour, social status would constitute a ‘stable state’ that explains some of the diversity of personality types that has been observed in a multitude of animal species. Dominance and personality may also share underlying proximate factors. In this thesis, I investigate the relationship between social dominance and personality using male domestic fowl, Gallus gallus domesticus. The species is group-living with pronounced dominance hierarchies, and dominance increases male access to mating partners. I show that some aspects of personality, exploration, vigilance and in particular aggressiveness, increased a male’s chances of obtaining dominance (paper III, IV, V), and that aggressiveness can be even more important than body weight and ornament size (comb size, paper V) or recent experience of winning or losing (paper IV). Winning a social interaction resulted in an increase in aggressiveness, while a decrease was seen in males that experienced a loss (paper IV). By observing behaviour before and after changes in male dominance relationships, I further show that a recent (2 days earlier) change in social status induced behavioural adjustments to the new social status in activity, exploration and vigilance (paper I). By extending the time of the new social relationship to 3 weeks, I show that such behavioural changes did not continue (paper II). Finally, I show that the social environment during juvenile development had little impact on adult male competitiveness (paper V). Social interactions appear to have several short-term effects on behaviour, but did not contribute significantly to variation and long-term consistency of personality in male fowl. Instead, a male's personality, and in particular his aggressiveness, affected the outcome of dominance interactions. Overall, my studies reveal important consequences of individual differences in behaviour, and contribute to the highly sought-after empirical testing of hypotheses explaining variation in animal personality.

  • 41.
    Favati, Anna
    et al.
    Stockholm University, Sweden.
    Leimar, Olof
    Stockholm University, Sweden.
    Radesäter, Tommy
    Stockholm University, Sweden.
    Løvlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology. Stockholm University, Sweden.
    Social status and personality: stability in social state can promote consistency of behavioural responses2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1774, 20132531- p.Article in journal (Refereed)
    Abstract [en]

    Stability of ‘state’ has been suggested as an underlying factor explainingbehavioural stability and animal personality (i.e. variation among, andconsistency within individuals in behavioural responses), but the possibilitythat stable social relationships represent such states remains unexplored.Here, we investigated the influence of social status on the expression andconsistency of behaviours by experimentally changing social status betweenrepeated personality assays. We used male domestic fowl (Gallus gallusdomesticus), a social species that forms relatively stable dominance hierarchies,and showed that behavioural responses were strongly affected bysocial status, but also by individual characteristics. The level of vigilance,activity and exploration changed with social status, whereas boldnessappeared as a stable individual property, independent of status. Furthermore,variation in vocalization predicted future social status, indicatingthat individual behaviours can both be a predictor and a consequence ofsocial status, depending on the aspect in focus. Our results illustrate thatsocial states contribute to both variation and stability in behaviouralresponses, and should therefore be taken into account when investigatingand interpreting variation in personality.

  • 42.
    Favati, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Løvlie, Hanne
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Effects of social experience during development on competitive ability and personality traits in male domestic fowlManuscript (preprint) (Other academic)
    Abstract [en]

    The ability to dominate conspecifics and thereby gain access to important resources depends on a number of traits and skills that may be both heritable and influenced by the environment. Experience of dominance relationships during development is a potential source of learning such skills. We here study the relative importance of social experience, personality, and morphological traits on competitive ability in male domestic fowl (Gallus gallus domesticus). By letting males grow up as either a single (dominant) male, as the dominant male of a pair, or as an intermediate ranked male in a group of males, we investigate if competitiveness in social interactions (winning duels) is mainly due to individual qualities or also influenced by social experience. We found that males were consistent over time in their competitive ability. Single raised males were inferior to pair dominant males and group-raised males in competitive ability, while pair dominant and group males did not differ significantly. This indicates that social training is important for future fighting success, but that the social position during development does not have a decisive influence on male fighting success in adulthood. Aggression and comb size, the latter possibly being a proxy for testosterone levels, had a marked effect on competitive ability. Together, our results indicate that certain behavioural and morphological traits are more important than experience of a social position in shaping competitive ability. These findings elucidate the relationship between social dominance and personality.

  • 43.
    Favati, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Løvlie, Hanne
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Individual aggression, but not winner–loser effects, predicts social rank in male domestic fowl2017In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 28, no 3, 874-882 p.Article in journal (Refereed)
    Abstract [en]

    Many factors can affect the probability for an individual to obtain a high social rank, including size, weaponry, and behavioral attributes such as aggression. Recent experiences of winning or losing can also affect the chances of winning future contests, commonly referred to as “winner–loser effects”. Individuals often differ in behavior in a consistent way, including in aggression, thereby showing differences in personality. However, the relative importance of recent experience and aspects of personality in determining rank, as well as the extent to which winning or losing affects aggression, has rarely been studied. Here, we investigate these questions using male domestic fowl. We matched males for body size, comb size, and aggression in pair-wise duels to: 1) study the effect of contest outcome on aggression and 2) compare the effect of individual aggression and contest experience on future social status in small groups. We found that aggression was a highly repeatable personality trait and that aggression increased after winning and decreased after losing. Nevertheless, such winner–loser effects were not enough to increase the odds of becoming dominant in a small group. Instead, aggressiveness measured prior to a contest experience best predicted future rank. Boldness and exploration did not predict rank and of the 2, only boldness was positively correlated with aggressiveness. We conclude that for male domestic fowl in contests among phenotypically matched contestants, aggressiveness is more important for obtaining high rank than winner–loser effects, or other aspects of personality.

  • 44.
    Favati, Anna
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Udén, Eva
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Løvlie, Hanne
    Personality remains: no effect of three-week social status experience on personality in male fowlManuscript (preprint) (Other academic)
    Abstract [en]

    Individuals often differ in behavior in a consistent way, i.e. show variation in personality. Understanding the processes explaining the emergence and maintenance of this variation is a major topic in the field of animal behavioral research. Recent theoretical models predict that differences in various 'states' can generate individual variation in behavior. Previous studies have mainly focused on endogenous states like metabolic rate or energy reserves, but theory also suggests that more complex states based on social interactions could play important roles in shaping personality. We have earlier demonstrated short-term status-dependent variation in behavior in the domestic fowl (Gallus gallus domesticus), but whether such behavioral variation remains also after a longer period of time, is unknown. Therefore, we examine the influence of social status on variation in behavior, using experimental manipulation of social status in pairs of male domestic fowl. We scored males in three personality assays (aggression test, novel arena test, novel object test) before and after three weeks in pairs as either dominant or subdominant. We found no support for social status acting as a state that generates variation in personality over this time interval: social status had no significant effect on behavioral responses in personality tests. Instead, we observed individual consistency of behavior despite alteration of social status. Our results suggest that the effect of social environment on behavior is dependent on context and time, and that personality is more important than current social situation for describing individual behavior in stable groups.

  • 45. Fleischer, Siegfried
    et al.
    Bauhn, Lovisa
    Fors, Patrik
    En kolsänka med syrebildning på köpet2014In: Kemivärlden Biotech med Kemisk Tidskrift, ISSN 1650-0725, no 4, 24-24 p.Article in journal (Other academic)
  • 46.
    Foyer, Pernilla
    et al.
    Swedish National Defence College, Department of Military Studies. Linköpings universitet, Biologi.
    Svedberg, Anna-Maria
    Linköpings universitet, Biologi.
    Nilsson, Emma
    Linköpings universitet, Biologi.
    Wilsson, Erik
    Swedish Armed Forces Dog Training Unit, Märsta, Sweden.
    Olsen Faresjö, Åshild
    Linköpings universitet, Avdelningen för samhällsmedicin.
    Jensen, Per
    Linköpings universitet, Biologi.
    Behavior and cortisol responses of dogs evaluated in a standardized temperament test for military working dogs2016In: Journal of Veterinary Behavior: Clinical Applications and Research, ISSN 1558-7878, E-ISSN 1878-7517, Vol. 11, 7-12 p.Article in journal (Refereed)
    Abstract [en]

    Military and police working dogs are often exposed to stressful or threatening events, and an improper response, e.g., fear, may implicate both reduced working efficiency and welfare. Therefore, identifying individuals that display a favorable response to potentially threatening situations is of great interest. In the present study, we investigated behavior responses of 85 prospective military working dogs in 4 subtests in a standardized temperament test used to select working dogs for the Swedish Armed Forces. Our goal was to evaluate behavioral responses in specific subtests and cortisol responses of candidate dogs. After dogs were rated as approved or nonapproved based on the test leader’s assessment of the full test result, we independently analyzed video recordings of 4 subtests. In addition, for 37 dogs, we analyzed pretest and posttest salivary cortisol levels. Dogs which were approved by the test leader for further training scored higher in the video recordings on emotionality and, in particular, fear-related behavior during a subset of the test and had higher levels of cortisol both before and after the test, than nonapproved dogs. Although this may actually reflect the desired traits, it could also indicate a bias in the selection procedure, which may pose limitations on the attempts to recruit the most suitable working dogs.

  • 47.
    Foyer, Pernilla
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Department of Military Studies, Military-Technology Division, Swedish Defence University, Stockholm, Sweden.
    Svedberg, Anna-Maria
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Nilsson, Emma
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wilsson, Erik
    Swedish Armed Forces Dog Training Unit, Märsta, Sweden.
    Olsen Faresjö, Åshild
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behavior and cortisol responses of dogs evaluated in a standardized temperament test for military working dogs2016In: Journal of Veterinary Behavior: Clinical Applications and Research, ISSN 1558-7878, E-ISSN 1878-7517, Vol. 11, 7-12 p.Article in journal (Refereed)
    Abstract [en]

    Military and police working dogs are often exposed to stressful or threatening events, and an improper response, e.g., fear, may implicate both reduced working efficiency and welfare. Therefore, identifying individuals that display a favorable response to potentially threatening situations is of great interest. In the present study, we investigated behavior responses of 85 prospective military working dogs in 4 subtests in a standardized temperament test used to select working dogs for the Swedish Armed Forces. Our goal was to evaluate behavioral responses in specific subtests and cortisol responses of candidate dogs. After dogs were rated as approved or nonapproved based on the test leader’s assessment of the full test result, we independently analyzed video recordings of 4 subtests. In addition, for 37 dogs, we analyzed pretest and posttest salivary cortisol levels. Dogs which were approved by the test leader for further training scored higher in the video recordings on emotionality and, in particular, fear-related behavior during a subset of the test and had higher levels of cortisol both before and after the test, than nonapproved dogs. Although this may actually reflect the desired traits, it could also indicate a bias in the selection procedure, which may pose limitations on the attempts to recruit the most suitable working dogs.

  • 48. Fransson, Thord
    et al.
    Kullberg, Cecilia
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Stach, Robert
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Barboutis, Christos
    Extensive fuelling in great reed warblers following the trans-Sahara crossing in springManuscript (preprint) (Other academic)
    Abstract [en]

    Migratory birds wintering in Africa face the challenge of passing the Sahara desert with little opportunities to forage. During spring migration birds thus arrive in the Mediterranean area after crossing the desert with very low energy reserves. Since early arrival to the breeding grounds often is of importance to maximize reproductive success, finding stopover sites with good refuelling possibilities after the Saharan passage is of utmost importance. Here we report on extensive fuelling in the great reed warbler, Acrocephalus arundinaceus, on the south coast of Crete in spring, the first land that they encounter after crossing the Sahara desert and the Mediterranean Sea in this area. Birds were trapped with mist nets at a river mouth, individually ringed and information about body mass, wing length, muscle score and fat score were recorded. Due to an exceptional high recapture rate at the trapping site (45%), we were able to calculate minimum stopover time and fuel deposition rates in 25 individual great reed warblers during one spring season. The large proportion of trapped great reed warbler compared to other species and the large number of recaptures suggests that great reed warbler actively choose this area for stopover. The relatively long stopover period at the site, the high fuel deposition rate (1 g day-1) and the large body mass increase show that great reed warblers at this site regularly deposit a much larger fuel load than needed for one continued flight stage to the north. It was also shown that birds with lower body mass at first capture had a higher fuel deposition rate than birds with higher body mass. This indicates that individuals are able to adjust their food intake in relation to energy reserves.

  • 49.
    Gamberale-Stille, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Johansen, Aleksandra I.
    Stockholm University, Faculty of Science, Department of Zoology.
    Tullberg, Birgitta S.
    Stockholm University, Faculty of Science, Department of Zoology.
    Change in protective coloration in the striated shieldbug Graphosoma lineatum (Heteroptera: Pentatomidae): predator avoidance and generalization among different  life stages2010In: Evolutionary Ecology, ISSN 0269-7653, E-ISSN 1573-8477, Vol. 24, no 2, 423-432 p.Article in journal (Refereed)
    Abstract [en]

    There are two major forms of protective coloration, camouflage and warning coloration, which often entail different colour pattern characteristics. Some species change strategy between or within life stages and one such example is the striated shieldbug, Graphosoma lineatum. The larvae and the pale brownish-and-black striated pre-diapause adults are more cryptic in the late summer environment than is the red-and black striation that the adults change to after diapause in spring. Here we investigate if the more cryptic pre-diapause adult and larval coloration may affect the aposematic function of the coloration as compared to the red adult form. In a series of trials we presented fifth instar larvae, pale or red adults to shieldbug-naïve domestic chicks, Gallus gallus domesticus, to investigate the birds’ initial wariness, avoidance learning, and generalization between the three prey types. The naïve chicks found the red adults most aversive followed by pale adults, and they found the larvae the least aversive. The birds did not find the larvae unpalatable and did not learn to avoid them, while they learned to avoid the two adult forms and then to a similar degree. Birds generalized asymmetrically between life stages, positively from larvae to adults and negatively from adults to larvae. We conclude that the lower conspicuousness in the pale forms of G. lineatum may entail a reduced aposematic function, namely a reduced initial wariness in inexperienced birds. The maintenance of the colour polymorphism is discussed

  • 50.
    Ghirlanda, Stefano
    et al.
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution. Brooklyn College, USA; CUNY Graduate Center, USA.
    Lind, Johan
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    ‘Aesop's fable’ experiments demonstrate trial-and-error learning in birds, but no causal understanding2017In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 123, 239-247 p.Article in journal (Refereed)
    Abstract [en]

    Experiments inspired by Aesop's fable The crow and the pitcher have been suggested to show that some birds (rooks, Corvus frugilegus, New Caledonian crows, Corvus moneduloides, and Eurasian jays, Garrulus glandarius) understand cause–effect relationships pertaining to water displacement. For example, the birds may prefer to drop stones in water rather than in sand in order to retrieve a floating food morsel, suggesting that they understand that only the level of water can be so raised. Here we re-evaluate the evidence for causal understanding in all published experiments (23 928 choices by 36 individuals). We first show that commonly employed statistical methods cannot disentangle the birds' initial performance on a task (which is taken as an indicator of causal understanding) from trial-and-error learning that may occur during the course of the experiment. We overcome this shortcoming with a new statistical analysis that quantifies initial performance and learning effects separately. We present robust evidence of trial-and-error learning in many tasks, and of an initial preference in a few. We also show that both seeming demonstrations of causal understanding and of lack of it can be understood based on established properties of instrumental learning. We conclude that Aesop's fable experiments have not yet produced evidence of causal understanding, and we suggest how the experimental designs can be modified to yield better tests of causal cognition.

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