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  • 1.
    Acerbi, Alberto
    et al.
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Nunn, Charles
    Harvard University, Department of Human Evolutionary Biology.
    Predation and the phasing of sleep: an evolutionary individual-based model2011In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 81, no 4, p. 801-811Article in journal (Refereed)
    Abstract [en]

    All mammals thus far studied sleep, yet important questions remain concerning the ecological factors that influence sleep patterns. Here, we developed an evolutionary individual-based model to investigate the effect of predation pressure on prey sleep. We investigated three ecological conditions, including one that assumed a dynamic interaction between predator and prey behaviour. In condition 1, we found that monophasic predators (i.e. with one sleep bout per 24 h) select for monophasic prey that sleep perfectly out of phase with predators. In condition 2, predators were monophasic but the safety of prey varied as a function of their activity (sleeping versus awake). In this condition, the prey adjusted their sleeping behaviour to lower the risk of predation. Finally, in condition 3, we modelled a more dynamic interaction between predator and prey, with predator activity dependent on prey activity in the previous hour. In this scenario, the prey adjusted their behaviour relative to one another, resulting in either greater or lesser synchrony in prey as a function of predator searching behaviour. Collectively, our model demonstrates that predator behaviour can have a strong influence on prey sleep patterns, including whether prey are monophasic or polyphasic (i.e. with many sleep bouts per 24 h). The model further suggests that the timing of sleep relative to predator behaviour may depend strongly on how other potential prey partition the activity period.

  • 2.
    Amcoff, Mirjam
    et al.
    Uppsala universitet, Zooekologi.
    Lindqvist, Charlotte
    Uppsala universitet, Zooekologi.
    Kolm, Niclas
    Uppsala universitet, Zooekologi.
    Sensory exploitation and plasticity in female mate choice in the swordtail characin2013In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 85, no 5, p. 891-898Article in journal (Refereed)
    Abstract [en]

    Despite extensive research in the field of sexual selection, the evolutionary origin and maintenance of preferences for sexual ornaments are still debated. Recent studies have pointed out that plasticity in mate choice might be more common than previously thought, but little is still known about the factors that affect such plasticity. The swordtail characin, Corynopoma riisei, is a tropical fish species in which males use a food-mimicking ornament to attract females. We tested whether ecological factors, more specifically prior foraging experience, can affect female preference for male ornaments. For this, we habituated females on a diet consisting of either red-coloured food or standard-coloured green food items and then we tested whether female preferences for artificially red-coloured male ornaments matched their previous foraging experience. We found a strong effect of food treatment: females trained on red food showed a stronger response to males with red-coloured ornaments than females trained on green food. Our results show that ecological variation can generate divergence of female preferences for male ornaments and that the response in preference to environmental change can be rapid if the bias is partly learnt.

  • 3.
    Aronsson, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology.
    Colour and pattern similarity in mimicry: evidence for a hierarchical discriminative learning of different components2012In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 84, no 4, p. 881-887Article in journal (Refereed)
    Abstract [en]

    Many aposematic species combine their bright colours with a black pattern that produces internal contrasts. Studies have shown that birds often pay attention to some parts of a signalling pattern and disregard others, which could be of importance in Batesian mimicry, where a palatable species copies the visual appearance of a distasteful model in order to deceive predators. We used domestic chicks, Gallus gallus domesticus, and artificial prey signals to investigate whether predators use different warning colour components for discrimination depending on the degree of information about prey quality they convey. This study supports earlier findings of the importance of colour for discrimination among prey but also provides evidence that other less associable signal properties such as internal patterning, when holding valuable discriminatory information, can be used to assess prey quality in a hierarchical manner. The results also suggest that, in certain circumstances, the presence of a palatable mimic can have positive effects on learning, resulting in 'super-Mullerian' effects. We propose that the degree of selection for perfect mimicry may be dependent on the proportion of well-educated predators in the population.

  • 4.
    Aronsson, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Gamberale-Stille, Gabriella
    Stockholm University, Faculty of Science, Department of Zoology.
    Domestic chicks primarily attend to colour, not pattern, when learning an aposematic coloration2008In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 75, p. 417-423Article in journal (Refereed)
    Abstract [en]

    Aposematic conspicuous coloration consists of one or a few bright colours, often in combination with a black defined internal pattern. The function of conspicuousness in aposematism has been ascribed to signal efficacy, based on experimental evidence involving prey items with uniform colour that contrast with the background. Although there are several hypotheses about the existence of internal contrasts within warning coloration, little experimental evidence has been presented. Here we used domestic chicks, Gallus gallus domesticus, to investigate the relative importance of colour and pattern in avoidance learning. Birds in two groups were first trained to discriminate between a grey positive stimulus and a cyan negative stimulus with either black dots or stripes. Pieces of mealworms, untreated and palatable or made unpalatable by soaking in quinine were used as reinforcers. Secondly, to determine what birds had attended to when learning the discrimination, colour and/or pattern, we compared how they generalized their avoidance of the ‘training stimulus’ to either a ‘colour only’ or ‘pattern only’ stimulus. The chicks learned to avoid the unpalatable prey items but showed no difference in behaviour depending on the type of pattern presented. The generalization test showed that birds avoided the novel ‘colour only’ stimulus at least as much as the ‘training stimulus’, and did not generalize their avoidance to the ‘pattern only’ stimulus. We conclude that birds do not necessarily attend to complex patterns when learning a warning signal, and domestic chicks primarily learn a bright colour rather than an equally novel conspicuous black pattern.

  • 5. Belton, Lydia E.
    et al.
    Cameron, Elissa Z.
    Dalerum, Fredrik
    Stockholm University, Faculty of Science, Department of Zoology. University of Pretoria, South Africa; University of Oviedo, Spain.
    Social networks of spotted hyaenas in areas of contrasting human activity and infrastructure2018In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 135, p. 13-23Article in journal (Refereed)
    Abstract [en]

    In group-living animals, the structure of social interactions among group members can have important consequences for individual fitness. Changes in resource abundance can influence social interactions with an expected weakening of social ties during times of resource scarcity. Although human activity and infrastructure often impose a disturbance on animal populations, they can also be a source of reliable resources that are relatively easy to access. We evaluated whether the social networks differed between four spotted hyaena, Crocuta crocuta, clans experiencing contrasting levels of human activity and infrastructure in the Kruger National Park, South Africa. The clan living in an area of high human activity and infrastructure had a less dense social network than the other clans, and the clan living in an area with limited human activity and infrastructure had shorter path lengths than the other clans, suggesting that it had more closely associated individuals. Our results did not support substantial differences between clans in the relative social network positions of animals from different age and rank classes. Contrary to our expectations, we suggest that anthropogenic resources may have weakened the social cohesiveness within spotted hyaena clans. We also argue that our study supports previous suggestions that there may be individual variation within broader classes of rank, age and sex in the position of individual animals in social networks.

  • 6.
    Bergman, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Gotthard, Karl
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Mate acquisition by females in a butterfly: the effects of mating status and age on female mate-locating behaviour2011In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 81, no 1, p. 225-229Article in journal (Refereed)
    Abstract [en]

    In most species, female reproductive success is determined by realized fecundity, which depends on the amount of female reproductive reserves and the availability of time for oviposition. Consequently, selection is likely to favour behaviour in virgin females that increases the likelihood of encountering males and thereby minimizing time without sperm. We used the speckled wood butterfly, Pararge aegeria, to test the hypothesis that virgin females increase the probability of encountering males by behaving more conspicuously. We also tested for an effect of age on behaviour, with the prediction that females behave more conspicuously if they remain unmated for a longer period. To do this we conducted controlled behavioural studies in large outdoor cages, comparing the behaviour of young and old, virgin and mated, females. We also assessed the time it took for a male to discover virgin versus mated females. Our results show an effect of age and mating status: old virgin females behaved more conspicuously than young virgin females and mated females, and spent more time in flight and performed more individual flights. Males also discovered virgin females faster than mated females. Furthermore, virgin females did not specifically locate the large sunspot, where perching males are found. Hence, females of P. aegeria adjust their behaviour in accordance with mating status and age, making them more likely to encounter a male and thereby maximize their reproductive success. This study underlines the importance of taking the distribution and behaviour of receptive females into account when studying mate-locating behaviour.

  • 7.
    Bergman, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Differences in mate location behaviours between residents and nonresidents in a territorial butterfly2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, ISSN 0003-3472, Vol. 78, no 5, p. 1161-1167Article in journal (Refereed)
    Abstract [en]

    Mate location strategies vary between species. Among butterflies two strategies are recognized: 'patrolling' males spend their life on the wing searching for females and 'perching' males stay at a specific site waiting to intercept passing females. In the speckled wood butterfly, Pararge aegeria, two alternative male strategies have been described: dominant males adopt a perching strategy monopolizing large sunspots on the forest floor, and subdominant males adopt a patrolling strategy. However, comparative analyses have shown that body design differs between perching and patrolling species, hence constraining opportunity for within-species variation in mate location strategy. We tested whether males differ in their propensity to adopt perching or patrolling behaviour by recording time spent flying during 30 min when alone in a large cage with only one large sunspot and many smaller ones, and whether subdominant males adopt a patrolling strategy by allowing dyads of males to interact in the cage for 60 min and recording the same behaviours again. All males adopted perching behaviour when alone, and subdominant males in dyads spent only a short time in extended flights after losing contests over territory ownership, soon returning to a perching strategy and making the best of a bad job from the vantage point of a small sunspot. We argue that previous descriptions of subdominant male P. aegeria adopting a patrolling strategy are based on too short observation periods, and have mistaken males in temporary transit for males adopting patrolling behaviour.

  • 8.
    Bergman, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Erratum to: Differences in mate location behaviours between residents and nonresidents in a territorial butterfly2010In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 80, p. 593-Article in journal (Other (popular science, discussion, etc.))
  • 9.
    Bergman, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Visual mate detection and mate flight pursuit in relation to sunspot size in a woodland territorial butterfly2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, ISSN 0003-3472, Vol. 78, no 1, p. 17-23Article in journal (Refereed)
    Abstract [en]

    Territory residency is associated with considerable benefits. In the speckled wood butterfly, Pararge aegeria, males fight over ownership of large sunspots in open forest habitats; winners become sunspot residents, and losers become nonterritorial and sit and wait for females in small sunspots. A previous study has shown that residents have higher mating success than nonterritorial males, although females are not more attracted to territorial males or sunspot territories per se. Here we tested the hypotheses (1) that the higher success of resident males is caused by visual mate detection being more efficient in a large than in a small sunspot, and (2) that only sunspots above a certain size are defended as territories. Field assessment of territorial sunspot size showed that defended sunspots were significantly larger than 'average sunspots' on the forest floor. Experimental tests of male ability to detect visually a model butterfly passing through a sunspot showed that males were more successful in pursuing and intercepting a passing model when. own a longer distance in the sunspot. Hence, we conclude that light conditions and associated visual mate detection and ability to complete mate flight pursuit can explain why P. aegeria males defend territories in large sunspots in forest habitats.

  • 10.
    Bergvall, Ulrika A
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Rautio, Pasi
    Luotola, Tuomas
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    A test of simultaneous and successive negative contrast in fallow deer foraging behaviour2007In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 74, no 3, p. 395-402Article in journal (Refereed)
    Abstract [en]

    The study of contrast investigates how rewards influence behaviour when animals are exposed to two or more levels of rewards compared to when they experience only a single level. The appearance of an exaggerated response to a shift in reward is referred to as a contrast effect and is an empirically well-established phenomenon. Although contrast effects could be important in foraging behaviour, no direct experimental tests of contrast effects in foraging by mammalian herbivores exist. During foraging, mammalian herbivores can encounter a range of plants that vary in the amount of nutrients and toxins. They may thus compare food items by taste, which in turn can give rise to contrast effects. In feeding experiments with fallow deer, Dama dama, we investigated the presence of simultaneous negative contrast. We found that the deer consumed less from a bowl of pellets containing 1% tannin when they shifted to it from a bowl with pellets containing only 0.25% tannin than when they shifted from another bowl with pellets containing 1% tannin. We estimated a fourfold difference between treatments in test food consumption at the highest levels of preloading, but none at the lowest levels. We found no support for successive negative contrast in experiments where the deer approached food in a runway, comparing a current reward with the memory of a previous reward. We suggest that simultaneous negative contrast can influence foraging decisions in mammalian herbivores.

  • 11.
    Bergvall, Ulrika A.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology. University of Edinburgh, U.K..
    Schäpers, Alexander
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Kjellander, Petter
    Weiss, Alexander
    Personality and foraging decisions in fallow deer, Dama dama2011In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 81, no 1, p. 101-112Article in journal (Refereed)
    Abstract [en]

    Recent studies have examined the ecological and evolutionary bases for variation in animal personality. However, only a few such studies have examined how foraging parameters are influenced by different personality domains. In wild ungulates, the trade-off between the time spent on food intake and antipredator behaviour differs between individuals, but the underlying reason for this is not yet well understood. One possibility is that this trade-off reflects personality dimensions such as boldness. To relate foraging decisions to personality we measured personality and performed feeding experiments with familiar and novel food in familiar and novel situations. We measured personality traits in 15 tame fallow deer, using novel object tests (NO), behavioural observations (BO) and personality ratings (PR). Boldness dimensions were found using PR and NO, dominance dimensions were found using BO and PR, and a flexibility dimension was found using BO. Multitrait–multimethod analysis showed that similar dimensions were significantly correlated across different methods and that different dimensions were not significantly correlated, even if measured using the same method. We also found that novel food eaten in familiar situations and familiar food eaten in novel situations were strongly related to boldness but not dominance, flexibility or age. Thus the trade-off between the benefits of gaining more food and the costs of reduced vigilance or increased toxin ingestion reflect boldness. These findings highlight the nature of personality dimensions in ungulates and how boldness impacts foraging behaviour.

  • 12. Cresswell, Will
    et al.
    Lind, Johan
    Stockholm University, Faculty of Science, Department of Zoology.
    Kaby, Ulrika
    Stockholm University, Faculty of Science, Department of Zoology.
    Quinn, John
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology.
    Does an opportunistic predator preferentially attack nonvigilant prey?2003In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 66, no 4, p. 643-648Article in journal (Refereed)
    Abstract [en]

    The dilution effect as an antipredation behaviour is the main theoretical reason for grouping in animals and states that all individuals in a group have an equal risk of being predated if equally spaced from each other and the predator. Stalking predators, however, increase their chance of attack success by preferentially targeting nonvigilant individuals, potentially making relative vigilance rates in a group relatively important in determining predation compared with the dilution effect. Many predators, however, attack opportunistically without stalking, when targeting of nonvigilant individuals may be less likely, so that the dilution effect will then be a relatively more important antipredation reason for grouping. We tested whether an opportunistically hunting predator, the sparrowhawk, Accipiter nisus, preferentially attacked vigilant or feeding prey models presented in pairs. We found that sparrowhawks attacked vigilant and feeding mounts at similar frequencies. Our results suggest that individuals should prioritize maximizing group size or individual vigilance dependent on the type of predator from which they are at risk. When the most likely predator is a stalker, individuals should aim to have the highest vigilance levels in a group, and there may be relatively little selective advantage to being in the largest group. In contrast, if the most likely predator is an opportunist, then individuals should simply aim to be in the largest group and can also spend more time foraging without compromising predation risk. For most natural systems this will mean a trade-off between the two strategies dependent on the frequency of attack of each predator type.

  • 13. 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, p. 53-63Article 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.

  • 14.
    Enquist, Magnus
    et al.
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Strimling, Pontus
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Eriksson, Kimmo
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    Laland, Kevin
    School of Biology, University of St Andrews.
    Sjöstrand, Jonas
    Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution.
    One cultural parent makes no culture2010In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 79, no 6, p. 1135-1162Article in journal (Refereed)
    Abstract [en]

    The ability to acquire knowledge and skills from others is widespread in animals and is commonly thought to be responsible for the behavioural traditions observed in many species. However, in spite of the extensive literature on theoretical analyses and empirical studies of social learning, little attention has been given to whether individuals acquire knowledge from a single individual or multiple models. Researchers commonly refer to instances of sons learning from fathers, or daughters from mothers, while theoreticians have constructed models of uniparental transmission, with little consideration of whether such restricted modes of transmission are actually feasible. We used mathematical models to demonstrate that the conditions under which learning from a single cultural parent can lead to stable culture are surprisingly restricted (the same reasoning applies to a single social-learning event). Conversely, we demonstrate how learning from more than one cultural parent can establish culture, and find that cultural traits will reach a nonzero equilibrium in the population provided the product of the fidelity of social learning and the number of cultural parents exceeds 1. We discuss the implications of the analysis for interpreting various findings in the animal social-learning literature, as well as the unique features of human culture.

  • 15.
    Gamberale-Stille, Gabriella
    et al.
    Stockholm University, Faculty of Science, Department of Zoology, Ethology.
    Bragée, Carolina
    Stockholm University, Faculty of Science, Department of Zoology.
    Tullberg, Birgitta S.
    Stockholm University, Faculty of Science, Department of Zoology, Animal Ecology.
    Higher survival of aposematic prey in close encounters with predators – an experimental study of detection distance.2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 78, p. 111-116Article in journal (Refereed)
    Abstract [en]

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

  • 16.
    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, p. 239-247Article 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.

  • 17.
    Hagman, Mattias
    et al.
    Univ Sydney, Sch Biol Sci, Sydney, NSW 2006, Australia.
    Shine, Rick
    Univ Sydney, Sch Biol Sci, Sydney, NSW 2006, Australia.
    Deceptive digits: the functional significance of toe waving by cannibalistic cane toads (Bufo marinus)2008In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 75, p. 123-131Article in journal (Refereed)
    Abstract [en]

    Many ambush foraging predators possess specialized structures and behaviours that plausibly function to attract prey, but this hypothesis has rarely been subject to direct empirical tests. If luring evolved to attract specific prey types then we predict that it will be manifested only if that prey type is present, and only by predators of the size class that feed on that prey type. Also, luring should induce closer approach by prey; and aspects of the behaviour (e. g. frequency of movement of the lure) should have been. ne tuned by selection to induce maximal response from prey. We describe a novel luring system: small- and medium-sized ( but not metamorph and large) cane toads, Chaunus marinus, wave the long middle toe of the hind-foot up and down in an obvious display. In keeping with the functional hypothesis, toe waving is elicited by moving edible-sized objects such as crickets or metamorphic toads. Metamorphic toads are attracted to this stimulus, and trials with a mechanical model show that both the colour and the vibrational frequency of the toe correspond closely with those most effective at attracting smaller conspecifics towards the lure. The independent evolution of visual luring systems in many animal lineages provides a powerful opportunity for robust empirical tests of adaptive hypotheses about signal design.

  • 18.
    Kodandaramaiah, Ullasa
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Vallin, Adrian
    Stockholm University, Faculty of Science, Department of Zoology.
    Fixed eyespot display in a butterfly thwarts attacking birds2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 77, no 6, p. 1415-1419Article in journal (Refereed)
    Abstract [en]

    Eyespots have evolved in many lepidopteran insects, which suggests their adaptive value. One of their hypothesized functions is that predators are intimidated by prey with large and conspicuous eyespots and hence refrain from attacking them. Recent experiments have shown that a combination of eyespots and intimidating behaviour can increase survival. We tested whether the mere presence of conspicuous eyespots can thwart attacking birds, that is, when the eyespots are displayed constantly, without any intimidating behaviour. We used prey that consisted of wings of the peacock pansy butterfly, Junonia almana, glued onto a piece of cardboard so as to resemble a butterfly with its wings open. A mealworm was placed between the wings in place of the body. Great tits, Parus major, were used as the predator in the study and were offered a choice between two model prey, one with intact eyespots and one without. Prey with eyespots were attacked significantly fewer times than those without. The time between the first and second attack was longer when the prey without eyespots was attacked first. These results support the hypothesis that naturally occuring butterfly eyespots can increase survival even when they are constantly displayed and motionless.

  • 19.
    Kolm, Niclas
    Uppsala universitet, Zooekologi.
    Male size determines reproductive output in a paternal mouthbrooding fish2002In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 63, no 4, p. 727-733Article in journal (Refereed)
    Abstract [en]

    Size can have strong effects on reproductive success in both males and females, and in many species large individuals are preferred as mates. To estimate the potential benefits from mate choice for size in both sexes, I studied the effects of the size of each sex on the reproductive output of pairs of Banggai cardinalfish, Pterapogon kauderni, a sexually monomorphic obligate paternal mouthbrooder. When pairs were allowed to form freely, a size-assortative mating pattern was observed and larger pairs had a higher reproductive output as determined by total clutch weight and egg size. To separate the potential benefits from mate choice for size for each sex, I subsequently used these pairs to form reversed size-assortative pairs, that is, the largest male paired to the smallest female and vice versa. I found a positive correlation between male size and clutch size: relatively heavier clutches were found in pairs where females were given a larger male. This suggests that the size of the male influences clutch weight. For egg size, however, the size of both sexes seemed important. The study reveals the benefits of mutual mate choice on size in this species: larger females provide larger eggs and larger males can brood heavier clutches. Furthermore, these results suggest that females differentially allocate resources into the eggs according to the size of the mate.

  • 20. Kotrschal, Alexander
    et al.
    Rogell, Björn
    Uppsala universitet, Zooekologi.
    Bundsen, Andreas
    Svensson, Beatrice
    Zajitschek, Susanne
    Brännström, Ioana
    Immler, Simone
    Maklakov, Alexei A.
    Kolm, Niclas
    Uppsala universitet, Zooekologi.
    The benefit of evolving a larger brain: big-brained guppies perform better in a cognitive task2013In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 86, no 4, p. e4-e6Article in journal (Refereed)
    Abstract [en]

    We previously selected for large and small brain size in guppies. Large-brained females outperformed small-brained females in a learning task. Healy and Rowe challenged our interpretations of larger brains = better learning. Here we argue why we think they are mistaken.

  • 21.
    Larsdotter Mellström, Helena
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    What affects mating rate?: Polyandry is higher in the directly developing generation of the butterfly Pieris napi2010In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 80, p. 413-418Article in journal (Refereed)
    Abstract [en]

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

  • 22.
    Liljestrand Rönn, Johanna
    et al.
    Uppsala universitet.
    Katvala, Mari
    Arnqvist, Göran
    The costs of mating and egg production in Callosobruchus seed beetles2006In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 72, no 2, p. 335-342Article in journal (Refereed)
    Abstract [en]

    The net cost of reproduction, as well as the trade-off between reproduction and lifespan, is affected by many male and female adaptations. Because several of these are sexually selected, we expect the cost of reproduction to be affected by sexual selection. For example, traits favoured in males by sexual selection may cause elevated costs of mating for females. We conducted a series of experiments where we independently varied female exposure to males and access to oviposition substrates in six congeneric seed beetle species (Callosobruchus spp.). These experiments allowed us to partition the cost of reproduction for females into the cost of mating and the cost of egg production. The results show that there is dramatic variation across species in the costs and benefits of a single mating in terms of effects on female lifespan. In some species, females lived for longer after mating once while others showed a net cost of mating expressed as a reduction in lifespan. Lifelong cohabitation with males resulted in a shortened lifespan for females of all species but the extent to which cohabitation reduced female lifespan varied across species. We also found partial support for a depressed lifetime egg production as a result of cohabitation with males. Collectively, our results reveal a remarkable variation across species in the costs and benefits of mating within this clade of closely related and ecologically uniform species. We conclude that key traits, which influence the economics of sexual interactions and reproduction, have evolved rapidly in this model system.

  • 23.
    Liljestrand Rönn, Johanna L.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Hotzy, Cosima
    Do longer genital spines in male seed beetles function as better anchors during mating?2012In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 83, no 1, p. 75-79Article in journal (Refereed)
    Abstract [en]

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

  • 24.
    Løvlie, Hanne
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Linkoping University, Sweden.
    Zidar, Josefina
    Stockholm University, Faculty of Science, Department of Zoology. Linkoping University, Sweden.
    Berneheim, Christina
    A cry for help: Female distress calling during copulation is context-dependent2014In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 92, p. 151-157Article in journal (Refereed)
    Abstract [en]

    Owing to selection for increased mating propensity, males often expose females to sexual harassment. Consequently, females may evolve counterstrategies to retain control of mating. Females can do this directly by resisting copulations, or indirectly by manipulating other males to intervene and prevent the copulation. Uttering copulation calls may be one indirect method for females to trigger male intervention. Copulation calls are commonly observed in mammals, primarily in primates, and also in some birds. Female fowl, Gallus gallus, sometimes utter calls during copulation, particularly in forced copulations with low-ranking males. These loud calls, called distress calls, attract other males and can result in disruption of the copulation, and subsequent mating with the intervening male if he is high ranking. Consequently, uttering such calls can act both to abort a coerced copulation and to generate novel opportunities for females to copulate with higher-ranking males. Nevertheless, uttering loud calls can carry costs, such as attracting predators. Females are therefore predicted to utter copulation calls primarily when doing so offers benefits, which for female fowl requires the presence of another high-ranking male. We tested this prediction by altering the social environment of female domestic fowl, G. g. domesticus. We found that females uttered copulation calls more frequently during copulations in the presence of dominant 'observer' males than in their absence. Thus, we provide evidence of context-dependent utterance of female calls during copulations in a bird. This type of female vocalization is rarely investigated in nonprimate vertebrates, but increased research in this field offers potential to improve understanding of female mate choice strategies and the dynamics of sexual selection.

  • 25. Magris, Martina
    et al.
    Cardozo, Gabriela
    Santi, Francesco
    Devigili, Alessandro
    Stockholm University, Faculty of Science, Department of Zoology. University of Padova, Italy.
    Pilastro, Andrea
    Artificial insemination unveils a first-male fertilization advantage in the guppy2017In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 131, p. 45-55Article in journal (Refereed)
    Abstract [en]

    Several factors are involved in determining the outcome of sperm competition. In addition to sperm number, sperm quality and male phenotype, insemination order is often associated with skewed paternity share. Patterns of sperm precedence can be produced by the mechanics of sperm storage and fertilization, or by active processes under male or female control. However, as males and females always interact during copulation, it is difficult to identify the mechanism responsible. The Trinidadian guppy, Poecilia reticulata, is a polyandric species characterized by last-male sperm precedence in natural matings. During such matings, females allow attractive males to inseminate more sperm by controlling copulation duration. We used artificial insemination to clarify the extent to which female control of sperm transfer influences the observed pattern of sperm precedence in this species. This technique allowed us to experimentally manipulate the number of sperm transferred and the timing of insemination. We found a significant first-male fertilization advantage. This advantage, however, declined as the time between insemination and parturition increased. Presumably, the anatomy and the physiology of the female genital tract favour egg fertilization by the first ejaculate inseminated, whereas sperm mixing is likely to be responsible for the reduction in first-male advantage associated with longer insemination-parturition intervals. Our results suggest that the last-male precedence detected after two consecutive natural matings is caused by cryptic female preference for attractive males associated with a female trading-up strategy (i.e. the second male is more frequently more attractive than the first male), rather than by insemination order per se. As the pattern of sperm precedence has important consequences for male reproductive strategies (for example mate guarding and male mate choice copying), unravelling its dynamic represents an important contribution to understanding the sexual behaviour of this model species.

  • 26.
    Merilaita, Sami
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Ruxton, Graeme
    Optimal apostatic selection: how should predators adjust to variation in prey frequencies?2009In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 77, no 1, p. 239-245Article in journal (Refereed)
    Abstract [en]

    Although frequency-dependent predation or apostatic selection has been established as one of the phenomena that may promote prey diversity, little is known about its selection. We studied such selection with a model with two prey types, treating frequency-dependent predator behaviour as an evolving trait determined by two parameters. One parameter controlled change in both prey type detection probabilities as a consequence of detecting a prey individual of a given type, and the other controlled the maximal amount of bias in detection probabilities of the two prey types. We let frequency-dependent behaviour evolve under different conditions of prey frequency variation. We found that frequency-dependent predator behaviour was most beneficial when deviations from equal prey type frequencies were large. Furthermore, different patterns of prey type variation selected for different types of frequency-dependent predator behaviour. We conclude that optimal frequency-dependent predator behaviour is likely to vary with ecological conditions.

  • 27.
    Olofsson, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Dimitrova, Marina
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    The white 'comma' as a distractive mark on the wings of comma butterflies2013In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 86, no 6, p. 1325-1331Article in journal (Refereed)
    Abstract [en]

    Distractive marks have been suggested to prevent predator detection or recognition of a prey, by drawing the attention away from recognizable traits of the bearer. The white 'comma' on the wings of comma butterflies, Polygonia c-album, has been suggested to represent such a distractive mark. In a laboratory experiment using blue tits, Cyanistes caeruleus, as predators, we show that the comma increased survival, since the blue tits attacked butterflies with overpainted commas more often than sham-painted butterflies with intact commas. In a field experiment we placed hibernating, similarly manipulated, comma butterflies on tree trunks of two different species and noted their survival. Although survival was higher on birch trees than on oak trees, there was no effect of treatment, probably because the butterflies were preyed on by both diurnal and nocturnal predators and the latter are unlikely to attend to small conspicuous markings.

  • 28.
    Olofsson, Martin
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Vallin, Adrian
    Stockholm University, Faculty of Science, Department of Zoology.
    Jakobsson, Sven
    Stockholm University, Faculty of Science, Department of Zoology.
    Wiklund, Christer
    Stockholm University, Faculty of Science, Department of Zoology.
    Winter predation on two species of hibernating butterflies: monitoring rodent attacks with infrared cameras2011In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 81, no 3, p. 529-534Article in journal (Refereed)
    Abstract [en]

    Documentation of predator attacks in nature is important for understanding how specific antipredator defences have evolved, but previous accounts have been mostly anecdotal. Therefore, we monitored predation on two closely related butterfly species, Aglais urticae and Inachis io, during winter hibernation. Butterflies were placed singly close to the floor on walls in dark, seminatural hibernation sites (e.g. unheated outhouses). We used motion-initiated infrared-sensitive cameras to record predator attacks on the butterflies. The antipredator attributes of the two species have two characteristics: during rest the butterflies reduce predators’ attention by mimicking leaves but they can suddenly change their guise by repeatedly flicking their wings. The wing flicking also produces hissing sounds and ultrasonic clicks and, furthermore, I. io, but not A. urticae, have large eyespots on the dorsal wing surface. The two butterfly species suffer from mouse predation during the winter and mice have been suggested as potential targets for the butterflies’ sound production. Results showed that (1) mice (Apodemus spp.) were important predators on butterflies, (2) I. io often survived attacks by wing-flicking behaviour, and (3) both species moved to less accessible positions after interactions with mice and other small mammalian predators, but I. io more often so. The successful predator evasion in darkness by I. io suggests a multimodal defence; in addition to the large eyespots, which intimidate birds, we suggest that the hissing and/or click sounds produced during wing flicking may have evolved as defence against rodent attacks

  • 29.
    Sansom, Alex
    et al.
    School of Biology, University of St. Andrews.
    Cresswell, Will
    School of Biology, University of St. Andrews.
    Minderman, Joroen
    School of Biology & Psychology, Newcastle University.
    Lind, Johan
    Stockholm University. Stockholm University, Faculty of Humanities, Centre for the Study of Cultural Evolution. Stockholm University, Faculty of Science, Department of Zoology, Department of Ethology.
    Vigilance benefits and competition costs in groups:: do individual redshanks gain an overall foraging benefit?2008In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 75, p. 1869-1875Article in journal (Refereed)
    Abstract [en]

    Animals gain antipredation benefits from being in larger groups through increased probability of predator detection, dilution of individual risk of being attacked and confusion of predators during attack. A further benefit is that individuals in larger groups can decrease the amount of time they spend being vigilant, while maintaining a high probability of predator detection. They may then gain extra time to forage, so increasing overall intake rate. Increasing group size, however, can also increase competition so that intake rates decrease. We investigated whether there was a foraging benefit in redshanks, Tringa totanus, that show the group size decrease in individual vigilance. Intake rates did not change with group size, despite an increase in time spent foraging. Interference competition increased with group size because individuals travelled more to find prey. Redshanks used the extra time available to forage to maintain intake rates under increased competition. Although the group size effect on vigilance did not accrue direct foraging benefits, larger groups formed, conferring other antipredation benefits. Intake rates were maintained because the interference competition was compensated by the benefits of reduced individual vigilance.

  • 30.
    Stutz, Rebecca S.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Bergvall, Ulrika A.
    Stockholm University, Faculty of Science, Department of Zoology.
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Tuomi, Juha
    Rautio, Pasi
    Cohesiveness reduces foraging efficiency in a social herbivore2018In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 135, p. 57-68Article in journal (Refereed)
    Abstract [en]

    For social foragers, movement as a group could increase foraging efficiency through collective discovery of high-quality food sources. This would require an efficient mechanism for transferring information about food quality between individuals. Conversely, the constraints of foraging as a cohesive group could decrease efficiency; grouping may persist to serve other functions such as protection from predators. To test what drives cohesion in herbivores, we manipulated patch shape and within-patch pattern of food quality and quantified the effects on group level diet selection by a social herbivore, the fallow deer, Dama dama. We arranged feeders containing fodder in lines or blocks, and manipulated the pattern of food quality within patches by adding tannin, a plant secondary compound that decreases palatability. We quantified the relative consumption of low- and high-tannin food to compare diet selectivity at the group level between patch treatments. If group foraging evolved to increase foraging efficiency, altering the spatial arrangement of food should not affect diet selectivity because information about food location and quality is shared. We found, however, that the herd expressed different levels of selectivity between both patch shapes and food quality patterns. Deer selected better diets in blocks than lines. In lines, the herd selected better diets when quality varied between alternate feeders rather than between the two halves of the patch, suggesting a reliance on personal rather than group information. Deer consumed the most at patch centres in all treatments except in blocks with high-tannin centres, but diet selection was poorer in the latter compared to blocks with low-tannin centres. Aggregation at the centre of patches appears to have restricted exploitation of the best food. Predation pressure and/or resource variability may have favoured the evolution of a foraging strategy that prioritizes social cohesion over effective diet selection.

  • 31.
    Svartberg, Kenth
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Tapper, Ingrid
    Stockholm University, Faculty of Science, Department of Zoology.
    Temrin, Hans
    Stockholm University, Faculty of Science, Department of Zoology.
    Radesäter, Tommy
    Stockholm University, Faculty of Science, Department of Zoology.
    Thorman, Staffan
    Consistency of personality traits in dogs2005In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 69, no 2, p. 283-291Article in journal (Refereed)
    Abstract [en]

    We investigated the consistency of behaviour over repeated tests in dogs, Canis familiaris. Dogs were tested three times, with an average of 30 and 35 days between tests. The behavioural test used in the study included 10 subtests that exposed dogs to various situations, such as the appearance of an unfamiliar person, play, preylike objects, metallic noise and a suddenly appearing dummy. Studies using the same test with many dogs have revealed five specific personality traits, labelled Playfulness, Chase-proneness, Curiosity/Fearlessness, Sociability and Aggressiveness, and one higher-order, broader dimension, interpreted as a shyness–boldness continuum. We used these traits in the present study. We found significant correlations over the test series in all the specific traits as well as in the Boldness dimension. The magnitude of trait scores for Playfulness, Chase-proneness and Sociability, as well as for the Boldness dimension, was stable between tests. The scores for Aggressiveness and Curiosity/Fearlessness, however, differed between the first two tests: the intensity of behaviour related to fear and aggression decreased from test 1 to test 2, but the intensity of exploratory behaviour increased. This result indicates that these two traits in dogs are sensitive to novelty, although individual differences are also maintained in nonnovel situations. The results suggest that playful, social, exploratory, avoidant and aggressive behaviour in dogs is influenced by stable dispositions; i.e. personality traits, that seem to have been important during the evolution of the domestic dog

  • 32. Szorkovszky, Alex
    et al.
    Kotrschal, Alexander
    Stockholm University, Faculty of Science, Department of Zoology. Stockholm Univ, Zool Dept, Stockholm, Sweden.
    Herbert-Read, James E.
    Stockholm University, Faculty of Science, Department of Zoology. University of Bristol, U.K..
    Buechel, Severine D.
    Stockholm University, Faculty of Science, Department of Zoology.
    Romenskyy, Maksym
    Rosen, Emil
    van der Bijl, Wouter
    Stockholm University, Faculty of Science, Department of Zoology.
    Pelckmans, Kristiaan
    Kolm, Niclas
    Stockholm University, Faculty of Science, Department of Zoology.
    Sumpter, David J. T.
    Assortative interactions revealed by sorting of animal groups2018In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 142, p. 165-179Article in journal (Refereed)
    Abstract [en]

    Animals living in groups can show substantial variation in social traits and this affects their social organization. However, as the specific mechanisms driving this organization are difficult to identify in already organized groups typically found in the wild, the contribution of interindividual variation to group level behaviour remains enigmatic. Here, we present results of an experiment to create and compare groups that vary in social organization, and study how individual behaviour varies between these groups. We iteratively sorted individuals between groups of guppies, Poecilia reticulata, by ranking the groups according to their directional alignment and then mixing similar groups. Over the rounds of sorting the consistency of the group rankings increased, producing groups that varied significantly in key social behaviours such as collective activity and group cohesion. The repeatability of the underlying individual behaviour was then estimated by comparing the experimental data to simulations. At the level of basic locomotion, individuals in more coordinated groups displayed stronger interactions with the centre of the group, and weaker interactions with their nearest neighbours. We propose that this provides the basis for a passive phenotypic assortment mechanism that may explain the structures of social networks in the wild.

  • 33.
    Zidar, J.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Lovlie, H.
    Stockholm University, Faculty of Science, Department of Zoology.
    Scent of the enemy: behavioural responses to predator faecal odour in the fowl2012In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 84, no 3, p. 547-554Article in journal (Refereed)
    Abstract [en]

    Chemical communication is used by diverse organisms in a variety of contexts and can have strong fitness consequences for the individuals involved. However, despite the extensive use of birds as models for many research areas in biology, avian olfaction has been poorly investigated. Studies on bird species that lack well-developed olfactory organs and those investigating responses to predator odours are particularly scarce. We investigated behavioural responses of the domestic fowl, Gallus gallus domesticus, a ground-living species with intermediate olfactory bulb size, to several predator and nonpredator faecal odours. We found that the birds spent less time foraging and were more vigilant when exposed to predator faecal odour compared with nonpredator faecal odour. Individuals showed a similar response when exposed to increased amounts of faeces. Taken together, our results demonstrate that domestic fowl can distinguish between herbivore and predator faecal odour, and respond to predator olfactory cues alone, without prior experience. Our results have implications for the understanding of predator-prey interactions and responses to olfactory cues in general, and for chemical communication in avian species more specifically. (C) 2012 The Association for the Study of Animal Behaviour.

  • 34. Zidar, Josefina
    et al.
    Balogh, Alexandra
    Favati, Anna
    Stockholm University, Faculty of Science, Department of Zoology.
    Jensen, Per
    Leimar, Olof
    Stockholm University, Faculty of Science, Department of Zoology.
    Løvlie, Hanne
    A comparison of animal personality and coping styles in the red junglefowl2017In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 130, p. 209-220Article in journal (Refereed)
    Abstract [en]

    There is an increased focus in biology on consistent behavioural variation. Several terms are used to describe this variation, including animal personality and coping style. Both terms describe between individual consistency in behavioural variation; however, they differ in the behavioural assays typically used, the expected distribution of response variables, and whether they incorporate variation in behavioural flexibility. Despite these differences, the terms are often used interchangeably. We conducted experiments using juvenile and adult red junglefowl, Gallus gallus, as subjects to explore the degree to which animal personality and coping styles overlap. We demonstrate that animal personality and coping styles can be described in this species, and that shyer individuals had more flexible responses, as expected for coping styles. Behavioural responses from both personality and coping style assays had continuous distributions, and were not clearly separated into two types. Behavioural traits were not correlated and, hence, there was no evidence of a behavioural syndrome. Further, behavioural responses obtained in personality assays did not correlate with those from coping style tests. Animal personality and coping styles are therefore not synonymous in the red junglefowl. We suggest that the terms animal personality and coping style are not equivalent and should not be used interchangeably.

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