| 1. |
- Nilsson, Jan-Åke
(författare)
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Establishment of juvenile marsh tits in winter flocks: an experimental study : an experimental study
- 1989
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Ingår i: Animal Behaviour. - 0003-3472. ; 38:4, s. 586-595
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Tidskriftsartikel (refereegranskat)abstract
- Establishment in flocks by juvenile marsh tits, Parus palustris, was simulated in outdoor aviaries. Encounters between established and intruding juveniles were won by the established ones, irrespective of sex, size or age. As existing flock size increased, establishment became successively harder. Intruding females received less aggression from already established juveniles than did intruding males because: (1) established males largely ignored intruding females, whereas established females chased male and female intruders to the same degree and (2) the level of aggression from established males towards intruding males was higher than between established and intruding females. This sex difference among established individuals may be related both to future benefits in the form of availability of reserve breeding partners, and to costs in the form of future risks of becoming subdominant to the intruding individual. The difference between the sexes in the difficulty in becoming established was supported by field observations. Females seem more selective than males in their choice of flock or flock territory. Intruding juveniles, trying to become established, lost foraging time, which resulted in longer periods without food and lower intake rates than those of established juveniles.
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| 2. |
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| 3. |
- Alatalo, Rauno V, et al.
(författare)
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Can Female Preference Explain Sexual Dichromatism In The Pied Flycatcher, Ficedula-Hypoleuca
- 1990
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Ingår i: Animal Behaviour. - 0003-3472 .- 1095-8282. ; 39, s. 244-252
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Tidskriftsartikel (refereegranskat)abstract
- How important female choice is for the evolution of male secondary sexual characteristics is controversial. Two field and one laboratory experiment, using the pied flycatcher, were performed to test the female choice aspect of sexual selection. In addition, non-manipulative data from 5 years are presented. The observational data suggest a slight preference for dark males by females but in field experiments in which males had territories at random sites (i.e. they did not choose a territory) or the colour of concurrently arriving males was altered, there was no preference for darker ones. Similarly, oestradiol-treated females did not prefer black or brown males in the laboratory. Thus, there is little support for the idea that female choice has been an important mechanism in the evolution of sexual dichromatism in the pied flycatcher.
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| 4. |
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| 5. |
- Berglund, Anders
(författare)
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Sequential hermaphroditism and the size-advantage hypothesis: an experimental test
- 1990
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Ingår i: Animal Behaviour. - 0003-3472 .- 1095-8282. ; 39:3, s. 426-433
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Tidskriftsartikel (refereegranskat)abstract
- When members of one sex have a low reproductive success when small and a high reproductive success when large, while members of the opposite sex do relatively better when small and relatively worse when large, sequential hermaphroditism is commonly believed to be favoured by natural selection. This so-called size-advantage hypothesis has not been rigorously tested experimentally. For the hermaphrodite Ophryotrocha puerilis puerilis, a polychaete, in which small individuals are males and large ones females, the hypothesis predicts that reproductive success will increase less with body size for males than for females, eventually promoting sex change in males. Dry body weight of males was not correlated with reproductive rate, whereas there was a positive correlation for females in reproducing pairs. Furthermore, an increment in the size of females affected clutch size and reproductive rate more than did an equal increment in the size of males. Reproductive success of males decreased with size, because females preferred smaller males. At the same time, large males won contests for access to females, although female choice overrode this combat superiority. Therefore, after reaching a certain size a male would not benefit from staying male. Taking into account the relatively low cost of sex change in this species (about 5 days being lost, equivalent to one interbrood interval) sex reversal occurred as predicted by the size-advantage hypothesis.
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| 6. |
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| 7. |
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| 8. |
- Göransson, Görgen, et al.
(författare)
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Male characteristics, viability, and harem size in a wild population of pheasants.
- 1990
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Ingår i: Animal Behaviour. - 0003-3472 .- 1095-8282. ; 40:1, s. 89-104
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Tidskriftsartikel (refereegranskat)abstract
- A population of pheasants was studied for 4 years in southern Sweden to determine how sexual selection operates among males. Morphological characters, viability, dominance, territory quality, date of territorial establishment, harem size and reproductive success of males were measured; 81 males and 101 females were radio-tracked. The spur length of males was the most important predictor of harem size. Phenotypic condition and viability were significantly related to spur length, the best single predictor of the reproductive success of males. These are the first data to show that a sexually selected male character correlates significantly with male viability. The results support models suggesting that viability-based processes can contribute to the evolution of mate choice and secondary sexual characters.
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| 9. |
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| 10. |
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| 11. |
- HOGLUND, J, et al.
(författare)
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MATE-CHOICE COPYING IN BLACK GROUSE
- 1995
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 49:6, s. 1627-1633
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Tidskriftsartikel (refereegranskat)
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| 12. |
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| 13. |
- Larsson, Kjell, et al.
(författare)
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Intraspecific nest parasitism and adoption of young in the barnacle goose : effects on survival and reproductive performance
- 1995
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Ingår i: Animal Behaviour. - : Elsevier. - 0003-3472 .- 1095-8282. ; 50:5, s. 1349-1360
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Tidskriftsartikel (refereegranskat)abstract
- DNA fingerprinting was used to determine the proportion of extra-pair young in a population of barnacle geese, Branta leticopsis, breeding in the Baltic area, Sweden. Of 137 analysed fledged young 17% were found to be extra-pair young. One or more extra-pair young were found in 27% of the 63 analysed families. The proportion of extra-pair young differed between years. No case of extra-pair fertilization was detected. All extra-pair young at fledgling originated either from intraspecific nest parasitism or from adoptions of foreign hatched young. Broods with extra-pair young at fledgling were significantly larger than broods without extra-pair young. However, the number of within-pair young did not differ significantly in broods with and without extra-pair young. Body mass, survival or subsequent reproductive performance did not differ between parents with and without extra-pair fledged young. Post-fledgling survival and age at first breeding were not significantly different between the three analysed classes of fledged young, i.e., within-pair young in families without extra-pair young, within-pair young in families with at least one extra-pair young, and extra-pair young. It is concluded that possible costs or benefits associated with caring for extra-pair fledged young are small or absent in this population.
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| 14. |
- Aastrup, Christian, et al.
(författare)
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Size and immune function as predictors of predation risk in nestling and newly fledged jackdaws
- 2023
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472. ; 198, s. 73-84
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Tidskriftsartikel (refereegranskat)abstract
- Prey choice by predators may be based on the potential prey's condition, for example resulting in substandard individuals running a higher risk of being predated. Over 5 years, we studied young jackdaws, Corvus monedula, to determine whether size and innate baseline immune function may predict predation risk by goshawks, Accipiter gentilis, during the nestling and early fledging phases. We measured body mass, wing length, tarsus length and four innate immune indices two to four times when nestlings were 12–29 days old. To determine which individuals had been predated during the nestling phase and shortly after fledging, we searched for metal rings of the jackdaws in the only goshawk territory close to the jackdaw colony. Nestling mortality before 12 days of age was entirely due to starvation, whereas between 12 days of age and fledging, mortality was mainly due to predation. Nestlings with smaller size (mass, wing, tarsus) and low lysis titre and haptoglobin concentrations were at a higher risk of being predated before fledging. Directly after fledging, individuals with short wings were preferentially predated, with no effects of body mass, tarsus length or any of the four immune indices measured at day 29 (i.e. shortly before fledging). That lower immune function and smaller size predict predation risk in nestlings may reflect that these individuals are of poor quality and/or lag behind in development. We hypothesize that hunger makes these nestlings sit closest to the entrance hole and hence become the first to be predated. For fledglings, our results suggest that poor flight ability makes individuals with short wings the easiest targets for avian predators.
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| 15. |
- Acerbi, Alberto, et al.
(författare)
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Predation and the phasing of sleep : an evolutionary individual-based model
- 2011
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 81:4, s. 801-811
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 16. |
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| 17. |
- Alerstam, Thomas, et al.
(författare)
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Temporal and spatial patterns of repeated migratory journeys by ospreys
- 2006
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Ingår i: Animal Behaviour. - : Elsevier BV. - 1095-8282 .- 0003-3472. ; 71:3, s. 555-566
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Tidskriftsartikel (refereegranskat)abstract
- We used satellite-tracking data from repeated journeys between Europe and West Africa by the same osprey, Pandion haliaetus, individuals to test whether the timing of migration differs between spring and autumn and whether landmarks and stopover goal areas are important for navigation. The timing of migration varied more in autumn than in spring, owing to significant differences between individuals (related to sex) in autumn migration dates. Autumn journeys were significantly slower than spring journeys because they included more stopover days. The difference may be explained by environmental conditions restricting the timing of migration in spring, by differences in opportunities to deposit fuel prior to departure, and by differences in expected changes in foraging/fuelling conditions along the route. Flight paths from repeated journeys by the same individual were often 120-405 km apart (maximum east-west separation 1400 km). These distances exceed the expected normal range of vision, suggesting that the ospreys did not find their way by following familiar landmarks. Flight paths converged in some regions, indicating the existence of up to three intermediary goal areas along the route of individual birds. Between these goal regions route fidelity was low, and the ospreys could find the next goal region after extensive deviation, presumably by map-based navigation and possibly in combination with path integration. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All tights reserved.
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| 18. |
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| 19. |
- Amcoff, Mirjam, et al.
(författare)
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Sensory exploitation and plasticity in female mate choice in the swordtail characin
- 2013
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 85:5, s. 891-898
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 20. |
- Anderson, Peter, et al.
(författare)
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Larval host plant experience modulates both mate finding and oviposition choice in a moth
- 2013
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 85, s. 1169-1175
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Tidskriftsartikel (refereegranskat)abstract
- Host plant choice in polyphagous insects can be connected with costs of being naive when confronted with several potential host plants, for example through slower decision making. Utilization of earlier experience could be one way to overcome some of these limitations. We studied whether larval feeding experience influences mate finding by males and female choice of oviposition site in the moth Spodoptera littoralis. Larvae were reared on either artificial diet or the host plants, cotton, clover or alfalfa, and we recorded the behaviour of adults from each diet. In two sets of experiments, in both the laboratory and the field, we investigated the female's oviposition choice and the male's response to female pheromone with different plant odour backgrounds. We found that experience with cotton, clover or alfalfa during the larval period induced female oviposition on the corresponding plant both in the laboratory and in the field. Furthermore, males were more attracted to female sex pheromone combined with odour from a host plant species that they had experienced as larvae than to sex pheromone combined with odour from host plant species they had not experienced. The results show convergent modulation of male and female responses to plant odour depending on their larval food plant. The influence of larval experience during the first-to-fifth instars on host preference was also stronger than the influence of experience acquired in the late larval, pupal and early adult stages. Consequences for host plant choice efficiency and fitness effects for males and females are discussed. (C) 2013 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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| 21. |
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| 22. |
- Aplin, L. M., et al.
(författare)
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Consistent individual differences in the social phenotypes of wild great tits, Parus major
- 2015
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 108, s. 117-127
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 23. |
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| 24. |
- Aronsson, Marianne, 1978-, et al.
(författare)
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Colour and pattern similarity in mimicry : evidence for a hierarchical discriminative learning of different components
- 2012
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 84:4, s. 881-887
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 25. |
- Aronsson, Marianne, et al.
(författare)
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Domestic chicks primarily attend to colour, not pattern, when learning an aposematic coloration
- 2008
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 75, s. 417-423
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 26. |
- Balogh, Alexandra C.V., et al.
(författare)
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Learning and the mimicry spectrum: from quasi-Bates to super-Müller
- 2008
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472. ; 76:5, s. 1591-1599
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Tidskriftsartikel (refereegranskat)abstract
- Müllerian mimicry is the mutualistic resemblance between two defended species, while Batesian mimicry is the parasitic resemblance between a palatable species (the mimic) and an unpalatable one (the model). These two kinds of mimicry are traditionally seen as extreme ends of a mimicry spectrum. For the range in between, it has been suggested that mimetic relations between unequally defended species could be parasitic, and this phenomenon has been referred to as quasi-Batesian mimicry. Where a mimetic relation is placed along the mimicry spectrum depends on the assumptions made about predator learning. In this work, we use a variant of the Rescorla-Wagner learning model for virtual predators to analyse the different possible components of the mimicry spectrum. Our model entails that the rate of associative learning is influenced by variation in the stimuli to be learned. Variable stimuli, i.e. unequal defences, can increase the predator learning rate and thus lead to an increased level of mutualism in a mimetic relation. In our analysis, we make use of the concepts of super-Müllerian mimicry, where the benefit of mimicry is even greater than in traditional Müllerian mimicry, and quasi-Müllerian mimicry, where mimicry by a palatable mimic is mutualistic. We suggest that these types of mimicry should be included in the mimicry spectrum along with Müllerian, Batesian and quasi-Batesian mimicry.
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| 27. |
- Belton, Lydia E., et al.
(författare)
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Social networks of spotted hyaenas in areas of contrasting human activity and infrastructure
- 2018
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 135, s. 13-23
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 28. |
- Berglund, Anders, et al.
(författare)
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Male pipefish prefer ornamented females
- 2001
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 61:2, s. 345-350
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Tidskriftsartikel (refereegranskat)abstract
- In the sex-role reversed pipefish Syngnathus typhle females compete for access to males and males are choosy. Females display a temporary ornament, a striped pattern. We show here for the first time in a sex role-reversed species that ornament display predicts how much time a female will devote to competitive behaviours, that males prefer ornamented females over nonornamented ones, and that the ornament is attractive even when female behaviour is held constant. This was demonstrated in an experiment with a male choosing between two females, first with the females separated and then with interactions allowed between the females as well as with the male. Females displaying the ornament for a longer time enjoyed a higher mating success then those displaying the ornament more briefly. Ornament display in the absence of intrasexual competition also predicted the amount of time that females subsequently spent competing. Thus, females initially displaying an attractive trait were also subsequently competing for longer. Furthermore, we manipulated the ornament by painting females and controlled their behaviour by sedating them and moving them in a dance-like fashion by a motor. This experiment showed that males preferred ornamented females, even when female behaviour was standardized. Thus, ornament display accurately predicted the duration of female–female competition and mating success, and was used as a signal by males in their choice of mates.
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| 29. |
- Berglund, Anders
(författare)
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Risky sex: male pipefishes mate at random in the presence of a predator
- 1993
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 46:1, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- Whether the presence of a predator alters courtship behaviour and mating in male pipefish, Syngnathus typhle, was studied experimentally by first allowing a male to choose between a large and a small female in an enclosure. The females were subsequently released to establish with which the male mated. In the presence of an enclosed predator, males were not more active in front of or danced more with larger than smaller females, but in the absence of a predator the larger females received more activity and dancing. Moreover, control males (without a predator) copulated more often with large than with small females, whereas predator-exposed males copulated infrequently and indiscriminately. These differences are most likely to be due to a decrease in male choosiness when a predator is present, as treatment, size and time of the day did not influence the activity of enclosed females. Predator-exposed males courted and copulated less, but each copulation transferred more eggs, compared with the control males. There was no significant difference in total number of eggs transferred to the males' brood pouches between treatments. Thus, the presence of a predator made mating random and minimized conspicuous mating behaviour, thereby decreasing the potential for sexual selection to act under high predation regimes in this pipefish.
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| 30. |
- Bergman, Martin, et al.
(författare)
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Differences in mate location behaviours between residents and nonresidents in a territorial butterfly
- 2009
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Ingår i: Animal Behaviour. - London, England : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0003-3472 .- 1095-8282. ; 78:5, s. 1161-1167
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 31. |
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| 32. |
- Bergman, Martin, 1981-, et al.
(författare)
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Mate acquisition by females in a butterfly : the effects of mating status and age on female mate-locating behaviour
- 2011
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 81:1, s. 225-229
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 33. |
- Bergman, Martin, et al.
(författare)
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Visual mate detection and mate flight pursuit in relation to sunspot size in a woodland territorial butterfly
- 2009
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Ingår i: Animal Behaviour. - London, England : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LT. - 0003-3472 .- 1095-8282. ; 78:1, s. 17-23
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 34. |
- Bergvall, Ulrika A, et al.
(författare)
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A test of simultaneous and successive negative contrast in fallow deer foraging behaviour
- 2007
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 74:3, s. 395-402
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 35. |
- Bergvall, Ulrika A., et al.
(författare)
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Personality and foraging decisions in fallow deer, Dama dama
- 2011
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 81:1, s. 101-112
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 36. |
- Björk, Johannes R., et al.
(författare)
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Mechanisms behind size-assortative nest choice by sand goby males in absence of intrasexual competition
- 2012
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 83:1, s. 55-62
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Tidskriftsartikel (refereegranskat)abstract
- Among nest-holding !sh, males often choose nest sites according to their own body size (i.e. size-assortative nest choice). In most cases, this can be explained by intrasexual competition. However, a few studies, for example on a marine population of the sand goby, Pomatoschistus minutus, have found a size-assortative nest preference, even when intrasexual competition is excluded. We conducted three aquarium experiments, using small sand goby males (47e54 mm) that were given either small (size-matched) or large (size-mismatched) nest sites, to test for potential mechanisms underlying this size-assortative nest choice in the absence of intrasexual competition. The three mechanisms investigated were (1) female preference, (2) paternal expenditure and (3) nest take-over. We did not, however, !nd any !tness advantages for sizematched males in any of the three experiments, suggesting that some other mechanism, such as defence against egg predators, is underlying this particular behaviour. Thus, further studies are needed to explain size-assortative nest choice behaviour in the sand goby.
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| 37. |
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| 38. |
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| 39. |
- Björklund, Mats, et al.
(författare)
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Mate Guarding In The Great Tit - A Reply
- 1994
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 47:5, s. 1230-1231
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Tidskriftsartikel (refereegranskat)
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| 40. |
- Blanckenhorn, Wolf U., et al.
(författare)
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Comparative sexual selection in field and laboratory in a guild of sepsid dung flies
- 2021
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Ingår i: Animal Behaviour. - : Elsevier. - 0003-3472 .- 1095-8282. ; 175, s. 219-230
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Tidskriftsartikel (refereegranskat)abstract
- Phenomenological and behavioural studies have greatly advanced the study of natural selection. Field studies of selection well appraise the natural situation, but is this also true for laboratory studies, which are typically more mechanistic? We compared precopulatory sexual selection (mating differential based on pairing success) in field and laboratory of several closely related, ecologically similar black scavenger dung flies (Diptera: Sepsidae). Selection on fore femur (sexual trait) and wing size (nonsexual trait) and shape varied considerably among seven species and continental populations in agreement with variation in their mating system and sexual size dimorphism. Selection on trait size was mostly positive or nil, but never significantly negative, implying mating advantages of large males in most species. Strongest selection was found in species/populations with male-biased size dimorphism, associating evolutionary shifts from female- to male-biased dimorphism with intensified sexual selection for large male size by adding male -male competition to a mating system previously driven primarily by female choice. Although sexual selection on shape was closely aligned with allometric shape variation, selection on fore femur shape was more consistent than selection on wing shape, which was absent in most species. Sexual selection intensities, but not necessarily the underlying behavioural mechanisms, were overall similar in field and laboratory, suggesting that laboratory assessments well represent the natural situation. If this conclusion can be generalized, it would lend credence to the strategy of using controlled laboratory mating studies to better understand natural selection, behaviour and ecology, at least for smaller animals that can be held in captivity. ? 2021 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.
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| 41. |
- Bliard, Louis, et al.
(författare)
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The role of introductory alarm calls for song discrimination in Ficedula flycatchers
- 2021
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Ingår i: Animal Behaviour. - : Elsevier. - 0003-3472 .- 1095-8282. ; 177, s. 241-251
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Tidskriftsartikel (refereegranskat)abstract
- Assortative mating depends on species distinctiveness in mating traits and preferences, which can be challenging to maintain when traits and/or preferences are learned. This is because learning may cause individuals to copy heterospecific signals. Juvenile songbirds possess innate sensory biases favouring them to learn and to prefer conspecific songs, but the effectiveness of these biases relies on consistent and sufficient differences between the songs produced by different species. However, mating signals, including learned songs, sometimes converge in sympatry, and the species-specific cues that individuals use to shape their preferences are often unknown. In Ficedula flycatchers, a stereotyped and highly species-specific alarm call is often incorporated as the first syllable of their songs. However, where the two species co-occur, pied flycatchers, Ficedula hypoleuca, learn to incorporate the introductory calls of the closely related collared flycatcher, Ficedula albicollis, into their songs. In this study, we investigated the role of introductory alarm calls for song discrimination in collared flycatchers, using playback experiments of both manipulated and unmanipulated songs on adults and nestlings within the hybrid zone of Oland, Sweden. We predicted that the introductory alarm call would be sufficient to trigger song responses, such that adults and nestlings would respond similarly to song phrases including the call, whether it is followed by conspecific or heterospecific notes. Our results provide evidence that the introductory alarm call is sufficient to trigger song discrimination in nestlings, but not in adult males, potentially due to their greater experience with songs and, therefore, subtler discrimination. Altogether, this study highlights the often-overlooked importance of calls within or associated with songs.
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| 42. |
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| 43. |
- Bohlin, Titti, et al.
(författare)
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The effect of signal appearance and distance on detection risk in an aposematic butterfly larva (Parnassius apollo)
- 2008
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472. ; 76, s. 577-584
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Tidskriftsartikel (refereegranskat)abstract
- Aposematic coloration commonly involves patterns with contrasting colours. The early larva of Parnassius apollo is uniformly black, but the later instars develop two rows of dorsal orange spots. We tested the effect of these orange markings on the conspicuousness of the last-instar larva, by manipulating larval coloration in photographs from a natural habitat and measuring how fast human subjects could discover the larva on a touch screen. In the first experiment we compared the detectability of the natural phenotype with that of manipulated uniformly black and uniformly orange variants at different distances. In the second experiment with another set of photographs we added manipulations involving enlarged and reduced spot sizes. Generally, detection time increased with distance, and decreased with the proportion of orange in the coloration. The uniformly black larvae were surprisingly hard to detect even at the closest distances, suggesting that the young black instar has an efficient camouflage. Furthermore, even a small amount of orange colour increased the conspicuousness of the larva considerably, indicating that the orange markings are costly in terms of detectability. Importantly, as the increase in detection time over distances was larger for the natural coloration than for the orange coloration, we suggest that the natural coloration may involve a distance-dependent switch from conspicuousness to camouflage with increasing distance. Thus, even though the orange markings most probably have a signalling function, the coloration is not maximized for either crypsis or conspicuousness.
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| 44. |
- Bonato, Maud, et al.
(författare)
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Male coloration reveals different components of immunocompetence in ostriches, Struthio camelus
- 2009
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Ingår i: Animal Behaviour. - : Elsevier BV. - 1095-8282 .- 0003-3472. ; 77:5, s. 1033-1039
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that secondary sexual ornamentation signals male ability to resist infections, as only high-quality individuals are able to invest both in high immune defence and elaborate ornament expression. Such ornaments could thus serve as indicators of male quality and could be used by females in choosing mates. Ostriches are sexually dimorphic with regard to coloration of their feathers, bill, neck and legs, and have a promiscuous mating system, with a high degree of reproductive skew, particularly in males. We investigated the relationship between the coloration of the feathers, bill, neck and legs of 15 male ostriches, maintained in a breeding flock, and the cell-mediated (measured using a phytohaemagglutinin (PHA) injection) and humoral components of their immune systems, as well as their heterophil: lymphocyte ratio. We found that male responses to PHA injection and humoral responses to tetanus were predicted by leg coloration, humoral responses to diphtheria were predicted by white feather coloration, and the heterophil: lymphocyte ratio was related to bill coloration. These traits, which relate to male immune capacity, are exposed during male-male interactions and courtship display, so we suggest that these visual cues could provide valuable information on male quality to females (as well as rival males), forming the basis of mate choice in this species. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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| 45. |
- Bonnot, Nadège
(författare)
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Boldness-mediated habitat use tactics and reproductive success in a wild large herbivore
- 2018
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 145, s. 107-115
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Tidskriftsartikel (refereegranskat)abstract
- The balance between resource acquisition and risk avoidance should vary according to personality type, with potential knock-on effects for fitness. Although previous studies have suggested a link between boldness and fitness components, little evidence is available on the behavioural mechanisms mediating this relationship in the wild. Because habitat use is the outcome of the trade-off between the costs and benefits associated with using each habitat type, we evaluated between-individual differences in habitat use of 64 GPS-collared female roe deer, Capreolus capreolus, using multinomial logit mixed models. To investigate whether deer differed in their habitat use tactics in relation to their personality type and their annual reproductive success, we assessed the link between individual habitat use patterns, boldness (measured as the strength of behavioural responsiveness to handling) and annual reproductive success (measured by the presence/absence of fawns at heel during autumn). Although daily and seasonal variations in the risk-resource landscapes clearly drove patterns of habitat use, individuals adopted contrasting habitat use tactics depending on their position along the shy-bold gradient and their reproductive status. Shy individuals occupied safer woodland more frequently, even at night when risk is lower. In contrast, bold individuals were better able to exploit rich open habitats. When this included mature autumn crops, these females weaned more offspring. Finally, irrespective of personality type, females that used meadows more often also achieved higher annual reproductive success. Overall, we demonstrate that individuals express divergent habitat use tactics as a function of their ability to avoid exposure to risk and their annual reproductive success. (C) 2018 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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| 46. |
- Bonnot, Nadège, et al.
(författare)
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Stick or twist: roe deer adjust their flight behaviour to the perceived trade-off between risk and reward
- 2017
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 124, s. 35-46
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Tidskriftsartikel (refereegranskat)abstract
- Because avoiding predation is crucial for fitness, foraging animals must trade acquisition of high-quality resources against risk avoidance when the best resources occur in locations with high predation risk. Although optimality models predict the distance at which an animal should initiate vigilance and flight, many studies have shown that animals generally flee soon after detecting an approaching threat, supporting the 'flush early and avoid the risk' (FEAR) hypothesis. Despite this, flight behaviour varies markedly depending on context, suggesting some behavioural plasticity in the response of prey to a given threat. We evaluated the degree of plasticity in the flight responses of roe deer, Capreolus capreolus, a highly flexible species which thrives in human-dominated landscapes. Based on individually identifiable animals and a standardized flight initiation protocol, we measured the distance at which a deer detected an approaching threat, and the distance at which it subsequently initiated flight. Our results provide strong support for the FEAR hypothesis, suggesting that alert and flight responses are strongly coupled in roe deer. However, the perceived level of both risk (in terms of landscape openness and proximity to human infrastructure) and reward (in terms of habitat quality) influenced the time it took for a deer to detect an approaching threat, and the subsequent time for which the threat was tolerated prior to flight. Overall, our findings indicate that although roe deer minimize monitoring costs when assessing risk by fleeing early, they also adjust their monitoring and flight responses to the local risk-resource trade-off. (C) 2016 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.
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| 47. |
- Booksmythe, Isobel, et al.
(författare)
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Competitor size, male mating success and mate choice in eastern mosquitofish, Gambusia holbrooki
- 2013
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 85:2, s. 371-375
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Tidskriftsartikel (refereegranskat)abstract
- Males usually compete for mates but, by choosing a favourable social environment (e.g. avoiding stronger competitors), males might increase their reproductive success. We first tested whether the mate choice of male eastern mosquitofish depended on the size of potential competitors. In two-choice trials, focal males preferred to associate with a group of large males over a group of small males. However, when both stimulus groups also contained females, focal males associated equally often with the group with large males and the group with small males. We then quantified the effect of competitor size on the relative mating success (proportion of all mating attempts) of males competing for access to a female. In mating trials, the relative mating success of focal males increased with focal male size. In addition, focal males had higher mating success when competing in a group of small males than a group of large males. We suggest that the benefits of associating with small male competitors in a mating context (greater mating success) are balanced by other benefits that have led to a general preference for associating with larger males.
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| 48. |
- Borg, Åsa A., et al.
(författare)
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Seasonal change in female choice for male size in the two-spotted goby
- 2006
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472. ; 72, s. 763-771
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Tidskriftsartikel (refereegranskat)abstract
- Mate choice may vary according to various factors, such as mate availability and variation in mate quality. We tested seasonal changes in female choice regarding male size in a marine fish, the two-spotted goby, Gobiusculus flavescens. In this species, males occupy nests in which females lay their eggs and males thereafter provide exclusive parental care of the eggs until hatching. Females are predicted to prefer large males if, for example, they are better at competing for and defending nests. In this species, the opportunity for females to be selective should decline over the breeding season as the availability of males decreases. We therefore predicted a reduction in female choosiness with season. We conducted mate choice tests, during the early (May) and later (June) part of the breeding season, in which females were allowed to choose between males differing in body length. Females chose large males early in the season, but became unselective with respect to male size later on. This change in mate choice may be caused by a reduction in overall choosiness as a result of the decline in male availability with season. Alternatively, the change could be caused by a switch in choice cues used by females if factors other than male size become more important for female reproductive success later in the breeding season. Further studies are needed to test between these alternative explanations. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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| 49. |
- Brattström, Oskar, et al.
(författare)
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Effects of wind and weather on red admiral, Vanessa atalanta, migration at a coastal site in southern Sweden
- 2008
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Ingår i: Animal Behaviour. - : Elsevier BV. - 1095-8282 .- 0003-3472. ; 76, s. 335-344
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Tidskriftsartikel (refereegranskat)abstract
- Each autumn, large numbers of red admirals migrate throughout northern Europe,flying south, to reach areas with conditions suitable for surviving the winter. We observed the visible butterfly migration at Falsterbo peninsula, the southwesternmost point in Sweden, where red admirals are seen most autumns. ying towards the Danish coast on their way to more southern parts of Europe. Weather parameters from a local weather station were used to analyse what factors are important for red admiral migration across the sea. Wind direction was among the important weather variables affecting the initiation of the migratory departure; most other studies of butterfly migration reported no large effect of wind direction. This difference is probably because the butterflies in our study were about to cross open sea for more than 20 km, whereas most previous studies were from inland locations where butterflies could avoid wind effects by. ying close to the ground or on the lee side of topographical features. Other important weather variables affecting red admiral migration at Falsterbo were low wind speed and clear skies. The flight direction at Falsterbo was towards the west, which is in contrast to the southward direction generally reported during autumn migration in this species. This is probably because the red admirals followed both the local topography and the closest route to land on the other side and therefore deviated from the normally preferred direction to minimize flight over open water. (c) 2008 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.
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| 50. |
- Brodin, Anders
(författare)
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Mass-dependent predation and metabolic expenditure in wintering birds: is there a trade-off between different forms of predation?
- 2001
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Ingår i: Animal Behaviour. - : Elsevier BV. - 1095-8282 .- 0003-3472. ; 62:5, s. 993-999
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Tidskriftsartikel (refereegranskat)abstract
- Passerines maintain low levels of fat in winter even though larger fat reserves would provide better insurance against starvation. This is believed to be a result of predation risk and/or metabolic expenditure increasing with the amount of fat carried. Recent empirical studies indicate that the effect of increased mass on predation risk is small, but the effect on metabolic expenditure is large. Using dynamic modelling, I investigated how mass-dependent costs affect the pattern of fat gain. I found that increases in metabolic expenditure were sufficient to explain strong regulation of the level of fat, but that increases in direct predation risk cannot be excluded. A plausible explanation for the increase in metabolic expenditure is if the extra weight is compensated for by a parallel gain in flight muscle. Such compensation means that an increase in instantaneous predation risk can be avoided, but that costs depending on an increase in energy intake may occur instead. For example more time spent foraging increases exposure to predators, Hence, one form of predation risk (impaired ability to escape from an attacking predator) may be traded for another (more time spent foraging). This will be beneficial if this extended foraging is not risky, whereas failure to compensate for the extra mass would mean the risk of being caught by a predator increasing considerably. Besides the widely recognized trade-off between starvation and predation, this means that there may also be a trade-off between different forms of predation in wintering birds. (C) 2001 The Association for the Study of Animal Behaviour.
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