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  • 1.
    Amcoff, Mirjam
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kolm, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Courtship signalling with a labile bilateral signal: males show their best side2009In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 12, p. 1717-1725Article in journal (Refereed)
    Abstract [en]

    Asymmetries in courtship signals can result from both developmental instability during ontogeny and from temporary or permanent damage following mating, fighting, or interactions with predators. These two types of asymmetries, which can be divided into fluctuating asymmetry (FA) and damage asymmetry (DA), have both been suggested to play an important role in mate choice as potential honest indicators of phenotypic and/or genetic quality, while at the same time, DA may affect ornament asymmetry in a random manner. Interestingly, despite the massive research effort that has been devoted to the study of asymmetry during the past decades, very little is known about how an individual's behaviour relates to asymmetry. Here, we measure and characterise asymmetry in morphological courtship signals in Corynopoma riisei, a fish where males carry elaborate paddle-like appendices on each side of the body that they display in front of females during courtship. Moreover, we investigate whether male courtship display, employing this bilateral morphological trait, reflects trait asymmetry. Finally, we assess whether males respond to phenotypic manipulations of DA with corresponding changes in courtship behaviour. We show that male display behaviour is asymmetric in a manner that reflects asymmetry of their morphological courtship trait and that male display behaviour responds to manipulations of asymmetry of these paddles. Our results thus suggest that males preferentially use their best side and, hence, that males respond adaptively to temporary changes in signal trait asymmetry.

  • 2. Arct, Aneta
    et al.
    Drobniak, Szymon M.
    Podmokla, Edyta
    Gustafson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Cichon, Mariusz
    Benefits of extra-pair mating may depend on environmental conditions-an experimental study in the blue tit (Cyanistes caeruleus)2013In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 67, no 11, p. 1809-1815Article in journal (Refereed)
    Abstract [en]

    Extra-pair mating constitutes a relatively common reproductive strategy in many socially monogamous bird species. This strategy may considerably improve reproductive success of males, but female benefits from extra-pair matings still remain unclear and empirical evidence is scarce. This may be because genetic benefits of extra-pair mating are not always revealed. It is possible that they are shown only in unfavourable environmental conditions and hence problems arise with detecting differences between within- and extra-pair offspring whose performance is measured under favourable conditions. In order to test this prediction, we manipulated environmental conditions by altering brood sizes of blue tits and compared phenotypic characteristics of within- and extra-pair offspring in mixed-paternity broods. We found that extra-pair young exhibited a higher response to phytohemagglutinin in comparison to within-pair young, but this was only observed among nestlings from experimentally enlarged broods. These results indicate that genetic benefits may interact with the environment, and thus benefits of extra-pair mating are likely to become visible only when conditions are relatively unfavourable.

  • 3.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Rosenqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Male limitation of female reproductive success in a pipefish  : effects of body-size differences1990In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 27, no 2, p. 129-133Article in journal (Refereed)
    Abstract [en]

     In the pipefish Syngnathus typhle, a species with exclusive male parental care, males limit female reproductive success because of their limited brood pouch space and long pregnancy. Sexual size dimorphism is absent in these 1-year-old animals but increases with age so that older females are larger than similarly aged males. Because fecundity is related to size in both sexes and increases more rapidly with body size in females than in males, the difference in growth increases female fecundity more, relative to male fecundity, as the fish get older. We therefore predicted that male limitation of female reproductive success is even more severe when all age classes are considered. To measure a female's maximum reproductive rate, she was provided with three males. Small 1-year-old females produced as many eggs, or produced eggs at the same rate, as a male of similar size could care for. Small females filled on average 1.06 males within the time span of one male pregnancy and actually produced on average 10 eggs fewer than needed to fill a similarly sized male. Large 2-year-old females, in contrast, produced on average a surplus of 149 eggs and filled 2.7 similarly sized males within the course of one pregnancy. The difference between females of the two size classes was highly significant. Males prefer to mate with larger females if given a choice. In nature sex ratios are equal, and males limit female reproductive success in the whole population. Therefore, small females are more severely constrained by mate availability than are larger females because males choose to mate with larger females.

  • 4.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Rosenqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Selective males and ardent females in pipefishes1993In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 32, no 5, p. 331-336Article in journal (Refereed)
    Abstract [en]

    In the pipefishes Syngnathus typhle and Nerophis ophidion, males have been shown to limit female reproductive rate, and females to compete for access to males. Hence, these species fit the criteria for sex-role reversal. Males brood the eggs and provide the offspring with nutrients, oxygen and an osmoregulated environment. Moreover, in S. typhle both sexes prefer a larger mate when given a choice. Sexual selection theory predicts that males should be more '' choosy '' than females, and that was experimentally demonstrated in this study. We predicted that S. typhle males should be less eager to copulate than S. typhle females with an unattractive (i.e. small) mate. We measured eagerness as the time from the start of the experiment until copulation occurred. Males with unattractive partners took significantly longer to copulate than females with unattractive partners. Moreover, females invariably initiated the courtship dance, and resumed it quicker after copulation than did the males, again suggesting ''reproductive hesitation'' in males. Neither male nor female size per se was correlated with time until copulation. In N. ophidion, where we have previously shown that males prefer larger to smaller females, we found that females did not select males with regard to size. Our results are consistent both with earlier findings (males limit female reproduction and females compete for males) and with operational sex ratios in nature: in seven annual field samples in June, the numbers of S. typhle females with ripe eggs always significantly exceeded numbers of receptive males. Hence, the potential cost of being choosy in terms of lost matings is much higher in females than in males. In conclusion, S. typhle females were somewhat choosy, but less so than males, whereas N. ophidion females were not choosy at all.

  • 5.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Rosenqvist, Gunilla
    Bernet, Patricia
    Ornamentation predicts reproductive success in female pipefish1997In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 40, no 3, p. 145-150Article in journal (Refereed)
    Abstract [en]

    In the sex-role reversed pipefish Syngnathus typhle females compete for access to males and males are choosy. Females develop a temporary ornament when competing over mates with other females and when performing nuptial dances with males. This ornament is an amplification of the normal striped pattern in these fishes. We here show experimentally that (1) the contrast of this normal pattern forecasts the extent to which the ornament is shown, (2) contrast and ornamentation honestly signal female quality (egg numbers), (3) contrast and ornamentation accurately predict female mating success, (4) contrast is a phenotypically plastic trait specifically exaggerated under situations of female - female competition, and (5) neither contrast nor ornament. are energetically expensive to the females (i.e., they are independent of short-term nutritional status). Hence, as predicted in sex-role reversed species, ornament design is constrained by costs to female fecundity: an energetically demanding ornament would impair on a female's ability to produce eggs. The type of ornament described here is the expected one, costly for reasons other than being energetically expensive to produce.

  • 6.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Rosenqvist, Gunilla
    Robinson-Wohlrath, Sarah
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Food or sex: males and females in a sex role reversed pipefish have different interests2006In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 60, no 2, p. 281-287Article in journal (Refereed)
    Abstract [en]

    In a sex role reversed pipefish, Syngnathus typhle, we found that basic life history allocations were directly influenced by sexual selection. We investigated time allocation to foraging and mating, respectively, in a choice experiment, giving males and females, of small or large body size, a choice between food and a potential partner. We found that males were more interested in foraging than mating, i.e., were more frequently observed in front of the food than in front of the partner, whereas females were more interested in the potential partner. This reflects sexual selection operating differently on the two sexes, as males and females are relatively similar in other life history traits, such as growth, mortality, age of maturity, dispersal, and parental expenditure. Moreover, large individuals allocated more time to mating activities, small to feeding. Individuals more interested in mating compared to food were subsequently more critical when given a choice between a large (high-quality) and a small (low-quality) partner, whereas individuals more interested in food were not selective. These findings are consistent with our predictions: sex-role reversed males can be relatively sure of achieving one or more matings, and should allocate more time to feeding and, hence, to parental investment, growth and/or future reproduction. Females, on the other hand, have more uncertain mating prospects and should allocate time to imminent reproductive activities, thereby foregoing other life history traits such as growth and future egg production. By this, they also sacrifice future fecundity and attractiveness.

  • 7.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Rosenqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Svensson, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Mate choice, fecundity and sexual dimorphism in two pipefish species (Syngnathidae)1986In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 19, no 4, p. 301-307Article in journal (Refereed)
    Abstract [en]

    In order to understand the causes of sexual dimorphism, mate choice and size-related fecundity were studied in two pipefish species, Syngnathus typhle and Nerophis ophidion. Sexual dimorphism is more pronounced in N. ophidion; females are larger, have sexual colourings, and are more active during courtship. In S. typhle the sexes are alike in all these respects. Males brood their offspring in both species. In N. ophidion fecundity was positively correlated with both body size and the amount of sexual colouring in females. In males no correlation between body size and fecundity, or between body size and embryo size existed. Predictably, in mate choice experiments with equal-sized females, males chose females with more extensive sexual colourings. We explain sexual dimorphism in this species as a consequence of both natural selection (fecundity increases with size in females but not in males) and sexual selection (males prefer larger females). We argue that sexual size dimorphism did not evolve by selection minimizing overlap in food niches between the sexes, because food production is high in the Zostera beds where the fishes live, and no size dimorphism was found in the sympatrically occurring S. typhle. Furthermore, in N. ophidion dimorphism is not greater in a particular mouth character than in overall body size. In S. typhle egg size and the average number of eggs transferred per spawning were positively correlated with female body size. Apparently more energy per offspring was provided by larger males than by smaller males, and larger males also carried more offspring. As predicted, large mates were preferred by both sexes in mate choice experiments. This is explicable in terms of both natural selection (fecundity increases with size in both sexes) and sexual selection (both sexes prefer large mates). As a consequence of selection acting in the same direction in both sexes, sexual dimorphism is absent in S. typhle.

  • 8.
    Björklund, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Male contests in the Scarlet rosefinch (Carpodacus erythrinus) in relation to asymmetries in resource holding power and pairing status1989In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 25, p. 137-140Article in journal (Refereed)
  • 9.
    Björklund, Mats
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Westman, Björn
    Extra-pair copulations in the pied flycatcher, Ficedula hypoleuca. A removal experiment1983In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 13, p. 271-275Article in journal (Refereed)
  • 10. Boström, Jannika E.
    et al.
    Fransson, Thord
    Henshaw, Ian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Materials Science.
    Jakobsson, Sven
    Kullberg, Cecilia
    Åkesson, Susanne
    Autumn migratory fuelling: a response to simulated magnetic displacements in juvenile wheatears, Oenanthe oenanthe2010In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 64, no 11, p. 1725-1732Article in journal (Refereed)
    Abstract [en]

    Recent experiments exposing migratory birds to altered magnetic fields simulating geographical displacements have shown that the geomagnetic field acts as an external cue affecting migratory fuelling behaviour. This is the first study investigating fuel deposition in relation to geomagnetic cues in long-distance migrants using the western passage of the Mediterranean region. Juvenile wheatears (Oenanthe oenanthe) were exposed to a magnetically simulated autumn migration from southern Sweden to West Africa. Birds displaced parallel to the west of their natural migration route, simulating an unnatural flight over the Atlantic Ocean, increased their fuel deposition compared to birds experiencing a simulated migration along the natural route. These birds, on the other hand, showed relatively low fuel loads in agreement with earlier data on wheatears trapped during stopover. The experimental displacement to the west, corresponding to novel sites in the Atlantic Ocean, led to a simulated longer distance to the wintering area, probably explaining the observed larger fuel loads. Our data verify previous results suggesting that migratory birds use geomagnetic cues for fuelling decisions and, for the first time, show that birds, on their first migration, can use geomagnetic cues to compensate for a displacement outside their normal migratory route, by adjusting fuel deposition.

  • 11. Brodin, Tomas
    et al.
    Lind, Martin I.
    Wiberg, Miria Kaltiala
    Johansson, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Personality trait differences between mainland and island populations in the common frog (Rana temporaria)2013In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 67, no 1, p. 135-143Article in journal (Refereed)
    Abstract [en]

    Understanding and predicting species range expansions is an important challenge in modern ecology because of rapidly changing environments. Recent studies have revealed that consistent within-species variation in behavior (i.e., animal personality) can be imperative for dispersal success, a key process in range expansion. Here we investigate how habitat isolation can mediate differentiation of personality traits between recently founded island populations and the main population. We performed laboratory studies of boldness and exploration across life stages (tadpoles and froglets) using four isolated island populations and four mainland populations of the common frog (Rana temporaria). Both tadpoles and froglets from isolated populations were bolder and more exploratory than conspecifics from the mainland. Although the pattern can be influenced by possible differences in predation pressure, we suggest that this behavioral differentiation might be the result of a disperser-dependent founder effect brought on by an isolation-driven environmental filtering of animal personalities. These findings can have important implications for both species persistence in the face of climate change (i.e., range expansions) and ecological invasions as well as for explaining rapid speciation in isolated patches.

  • 12. Buhl, Jerome
    et al.
    Hicks, Kerri
    Miller, Esther R.
    Persey, Sophie
    Alinvi, Ola
    Sumpter, David J. T.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Shape and efficiency of wood ant foraging networks2009In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 3, p. 451-460Article in journal (Refereed)
    Abstract [en]

    We measured the shape of the foraging trail networks of 11 colonies of the wood ant Formica aquilonia (Formica rufa group). We characterized these networks in terms of their degree of branching and the angles between branches, as well as in terms of their efficiency. The measured networks were compared with idealized model networks built to optimize one of two components of efficiency, total length (i.e., total amount of trail) and route factor (i.e., average distance between nest and foraging site). The analysis shows that the networks built by the ants obtain a compromise between the two modes of efficiency. These results are largely independent of the size of the network or colony size. The ants' efficiency is comparable to that of networks built by humans but achieved without the benefit of centralized control.

  • 13.
    Dijk, Ben
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Orizaola, German
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Johansson, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Is one defence enough?: Disentangling the relative importance of morphological and behavioural predator-induced defences2016In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 70, no 2, p. 237-246Article in journal (Refereed)
    Abstract [en]

    Many organisms show predator-induced behavioural and morphological phenotypic plasticity. These defence mechanisms are often expressed simultaneously. To estimate the relative importance of these two defences, we conducted a laboratory experiment using tadpoles of the common frog (Rana temporaria) as prey and Aeshna dragonfly larvae as predators. We first raised tadpoles in the presence and absence of caged predators to induce differences in defensive morphology, and then conducted free ranging predator trials in environments that were either with or without the presence of predation cues to induce differences in defensive behaviour. This 2 x 2 design allowed us to separate the effects of inducible morphology from inducible behaviour. Caged predators induced deeper bodies and tailfins and reduced activity levels in tadpoles. The time to first capture was shortest in tadpoles without morphological or behavioural defences. Tadpoles with a behavioural defence had a significantly longer time to first capture. Tadpoles with only antipredator morphology tended to have a longer time to first capture as compared to those without any induced defences. This treatment also had a higher number of injured tadpoles as compared to other treatments, suggesting that inducible morphology facilitates predator escape due to the 'lure effect'. However, tadpoles with both behavioural and morphological defences did not have a longer time to first capture as compared to tadpoles with only morphological or behavioural induced defences. Our results suggest that both behavioural and morphological antipredator responses contribute to reduced capture efficiency by predators, but their simultaneous expression did not have any additive effect to the time of first capture and survival, and that the morphology response is most effective when tadpoles are active.

  • 14.
    Eklöv, Peter
    et al.
    Umeå University, Department of Animal Ecology.
    Persson, Lennart
    Umeå University, Department of Animal Ecology.
    SPECIES-SPECIFIC ANTIPREDATOR CAPACITIES AND PREY REFUGES - INTERACTIONS BETWEEN PISCIVOROUS PERCH (PERCA-FLUVIATILIS) AND JUVENILE PERCH AND ROACH (RUTILUS-RUTILUS)1995In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 37, no 3, p. 169-178Article in journal (Refereed)
    Abstract [en]

    The outcome of predator-prey interactions depends on the characteristics of predators and prey as well as the structure of the environment. In a replicated field enclosure experiment, we tested the effects of quantity and quality of different prey refuges (no structure, structure forming a partial refuge, and structure forming a complete refuge) on the interaction between piscivorous perch (Perca fluviatilis) and juvenile perch and roach (Rutilus rutilus). We quantified the behaviour of the predators and the prey and predator-induced prey mortality. The piscivores stayed in or close to the prey refuge and were more dispersed in the presence than in the absence of prey refuges. Survival of juvenile perch and roach decreased in the presence of predators and was higher for juvenile roach than for juvenile perch. In addition, juvenile perch survival increased with refuge efficiency. Roach formed schools which were denser in the presence of predators, had a higher swimming speed (both in the open water and in the refuge) and used a larger area than juvenile perch. Both prey species decreased their distance to the prey refuge and increased the proportion of their time spent in the refuge in the presence of predators. The number of switches between the open-water habitat and the prey refuge was higher for juvenile roach than for juvenile perch. Juvenile perch used different parts of the prey refuge in a flexible way depending both on presence of predators and refuge type whereas juvenile roach used the different parts of the prey refuge in fixed proportions over all refuge treatments. Our results suggest that juvenile roach had a overall higher capacity to avoid predation than juvenile perch. However, in the presence of qualitatively different prey refuges juvenile perch responded to predators with more flexible refuge use than juvenile roach. The differences in antipredator capacities of juvenile perch and roach when subjected to piscivorous perch predation may depend on differences in life history patterns of the two species.

  • 15.
    Esteban, R.
    et al.
    CIRCE Conservat Informat & Res Cetaceans, Cadiz 11390, Spain..
    Verborgh, P.
    CIRCE Conservat Informat & Res Cetaceans, Cadiz 11390, Spain..
    Gauffier, P.
    CIRCE Conservat Informat & Res Cetaceans, Cadiz 11390, Spain..
    Gimenez, J.
    GEMA, Estn Biol Donana CSIC, Seville 41092, Spain..
    Foote, Andrew D.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology. Nat Hist Museum Denmark, Ctr GeoGenet, DK-1350 Copenhagen K, Denmark..
    de Stephanis, R.
    CIRCE Conservat Informat & Res Cetaceans, Cadiz 11390, Spain..
    Maternal kinship and fisheries interaction influence killer whale social structure2016In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 70, no 1, p. 111-122Article in journal (Refereed)
    Abstract [en]

    The primary prey of killer whales (Orcinus orca) in the Strait of Gibraltar is the bluefin tuna (Thunnus thynnus). All killer whales observed in this area hunt tuna by chasing individual fish until they become exhausted and can be overcome. However, a subset of pods also interact with a dropline tuna fishery which has developed since 1995. Here, we investigated the social structure within and among social units (pods). Our data suggested that social structure was shaped by maternal kinship, which appears to be a species-specific trait, but also by foraging behavior, which is less common at the intra-population level. At the start of the study, only one cohesive pod interacted with the fishery, which during the course of the study underwent fission into two socially differentiated pods. Social structure within these two fishery-interacting pods was more compact and homogenous with stronger associations between individuals than in the rest of the population. Three other pods were never seen interacting with the fishery, despite one of these pods being regularly sighted in the area of the fishery during the summer. Sociality can influence the spread of the novel foraging behaviors and may drive population fragmentation, which, in this example, is already a critically small community. Observations of social changes in relation to changes in foraging at the earliest stages of diversification in foraging behavior and social segregation may provide insights into the processes that ultimately result in the formation of socially isolated discrete ecotypes in killer whales.

  • 16.
    Flanagan, Sarah P.
    et al.
    Texas A&M Univ, Dept Biol, College Stn, TX 77843 USA.;Univ Tennessee, Natl Inst Math & Biol Synth, Knoxville, TN 37996 USA..
    Rosenqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Biology. Norwegian Univ Sci & Technol, Dept Biol, Ctr Biodivers Dynam, N-7491 Trondheim, Norway..
    Jones, Adam G.
    Texas A&M Univ, Dept Biol, College Stn, TX 77843 USA..
    Mate quality and the temporal dynamics of breeding in a sex-role-reversed pipefish, S. typhle2017In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 71, no 1, article id UNSP 28Article in journal (Refereed)
    Abstract [en]

    The spatiotemporal dynamics of receptivity and breeding date, coupled with individual-level quality and attractiveness, are centrally important to mating system dynamics. These topics have been investigated in some detail in birds, but much less work has been devoted to other taxonomic groups, and almost no work has addressed spatiotemporal factors and individual quality in sex-role-reversed taxa. The broad-nosed pipefish, Syngnathus typhle, provides an excellent opportunity to investigate these ideas in a sex-role-reversed fish. Here, we addressed three questions related to mating dynamics in S. typhle: (1) Do higher-quality males arrive earlier on the breeding grounds and mate first? (2) Are early-breeding males in better condition than later-breeding males? And (3) do mating events involving higher-quality males produce better clutches than mating events involving lower-quality males? We collected data from a field study and a laboratory breeding experiment to address our hypotheses. Our results show that larger males mate earlier than smaller males and that pregnant males have higher measures of condition compared to non-pregnant males. Moreover, our laboratory results demonstrate that pairings between larger males and preferred females yielded more offspring than pairings involving smaller males. In summary, the spatiotemporal dynamics of S. typhle breeding patterns, combined with variation in individual quality, play an important role in shaping mating systems and should be incorporated in future analyses of mating behavior and sexual selection in this interesting sex-role-reversed pipefish. Significance statement The breeding patterns of a species can fluctuate over time due to a number of factors, one of which is individual quality. Although the effects of both the timing of reproduction and female quality on mating systems have been studied in some species, they have been investigated primarily in isolation. Here, we demonstrate that individual quality and the timing of reproduction interact to affect reproductive success in a wild population of sex-role-reversed fish.

  • 17.
    Griesser, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Anthropological Institute and Museum, University of Zurich, Switzerland .
    Halvarsson, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sahlman, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Ekman, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    What are the strengths and limitations of direct and indirect assessment of dispersal?: Insights from a long-term field study in a group-living bird species2014In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 68, no 3, p. 485-497Article in journal (Refereed)
    Abstract [en]

    Molecular methods of assessing dispersal have become increasingly powerful and have superseded direct methods of studying dispersal. Although now less popular, direct methods of studying dispersal remain important tools for understanding the evolution of dispersal. Here, we use data from Siberian jays Perisoreus infaustus, a group-living bird species, to compare natal dispersal distances and rates using visual mark-recapture, radio-tracking and microsatellite data. Siberian jays have bimodal natal dispersal timing; socially dominant offspring remain with their parents for up to 5 years (delayed dispersers), while they force their subordinate brood mates to leave the parental territory at independence (early dispersers). Early dispersers moved about 9,000 m (visual mark-recapture, radio-tracking) before settling in a group as a non-breeder. In contrast, delayed dispersers moved about 1,250 m (visual mark-recapture only) and mainly moved to a breeding opening. Dispersal distances were greater in managed habitat compared to natural habitat for both early and delayed dispersers. Molecular estimates based on 23 microsatellite loci and geographical locations supported distance estimates from the direct methods. Our study shows that molecular methods are at least 22 times cheaper than direct methods and match estimates of dispersal distance from direct methods. However, molecular estimates do not give insight into the behavioural mechanisms behind dispersal decisions. Thus, to understand the evolution of dispersal, it is important to combine direct and indirect methods, which will give insights into the behavioural processes affecting dispersal decisions, allowing proximate dispersal decisions to be linked to the ultimate consequences thereof.

  • 18. Helfenstein, Fabrice
    et al.
    Podevin, Murielle
    Universität Bern.
    Richner, Heinz
    Sperm morphology, swimming velocity, and longevity in the house sparrow Passer domesticus2010In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 64, no 4, p. 557-565Article in journal (Refereed)
    Abstract [en]

    Sperm competition exerts strong selection on males to produce spermatozoa with an optimal morphology that maximizes their fertilization success. Long sperm were first suggested to be favored because they should swim faster. However, studies that investigated the relationship between spermlength and sperm competitive ability or sperm swimming velocity yielded contradictory results. More recently, ratios of the different sections of a spermatozoon (the head,midpiece, and flagellum)were suggested to bemore crucial in determining swimming velocity. Additionally, sperm ability to remain and survive in the female storage organs may also influence fertilization success, so that optimal sperm morphology may rather maximize sperm longevity than velocity. In this study, we investigated how sperm morphology is related to sperm velocity and sperm longevity in the house sparrow Passer domesticus. Sperm velocity was found to be correlated with head/flagellum ratio. Sperm with small heads relative to their flagellum showed higher swimming velocity. Additionally, shorter sperm were found to live longer. Finally, we found sperm morphological traits to vary substantially within males and the head/flagellum ratio to be unrelated to total sperm length. We discuss the hypothesis that the substantial within-male variation in sperm morphology reflects a male strategy to produce a diversity of sperm from long, fast-swimming to short, long-living sperm to maximize their fertilization success in a context of sperm competition.

  • 19.
    Henshaw, Ian
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Fransson, Thord
    Jakobsson, Sven
    Kullberg, Cecilia
    Geomagnetic field affects spring migratory direction in a long distance migrant2010In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 64, no 8, p. 1317-1323Article in journal (Refereed)
    Abstract [en]

    Night-migrating song birds travel to and from their wintering and breeding areas often separated thousands of kilometers apart and are clearly capable of finding intended goal areas from a distant location. Displacement experiments provide a useful way to highlight orientation and navigational skills in migrants. To investigate which cues birds actually use to compensate for displacement and the exact mechanism of each cue, experiments with manipulation of single cues are required. We conducted a simulated displacement of lesser whitethroats Sylvia curruca on spring migration. Birds were displaced not geographically but in geomagnetic space only, north and south of their breeding area to test whether they incorporate information from the geomagnetic field to find their breeding area. Lesser whitethroats held in southeast Sweden but experiencing a simulated displacement north of their breeding area (Norway) failed to show a consistent direction of orientation, whereas birds displaced south of their breeding area (Czech Republic) exhibited consistent northerly orientation, close to the expected seasonally appropriate direction, after displacement toward the trapping location. The absence of a clear compensatory direction in birds displaced north might be due to unfamiliar magnetic information or lack of sufficient information such as a magnetic gradient when moving around. By isolating one orientation cue, the geomagnetic field, we have been able to show that lesser whitethroats might incorporate geomagnetic field information to determine latitude during spring migration.

  • 20. HOGLUND, J
    et al.
    ALATALO, RV
    LUNDBERG, A
    THE EFFECTS OF PARASITES ON MALE ORNAMENTS AND FEMALE CHOICE IN THE LEK-BREEDING BLACK GROUSE (TETRAO-TETRIX)1992In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 30, no 2, p. 71-76Article in journal (Refereed)
  • 21. HOGLUND, J
    et al.
    KALAS, JA
    FISKE, P
    THE COSTS OF SECONDARY SEXUAL CHARACTERS IN THE LEKKING GREAT SNIPE (GALLINAGO-MEDIA)1992In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 30, no 5, p. 309-315Article in journal (Refereed)
  • 22. HOGLUND, J
    et al.
    LUNDBERG, A
    SEXUAL SELECTION IN A MONOMORPHIC LEK-BREEDING BIRD - CORRELATES OF MALE MATING SUCCESS IN THE GREAT SNIPE GALLINAGO-MEDIA1987In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 21, no 4, p. 211-216Article in journal (Refereed)
  • 23. HOGLUND, J
    et al.
    MONTGOMERIE, R
    WIDEMO, F
    COSTS AND CONSEQUENCES OF VARIATION IN THE SIZE OF RUFF LEKS1993In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 32, no 1, p. 31-39Article in journal (Refereed)
  • 24. HOGLUND, J
    et al.
    ROBERTSON, JGM
    SPACING OF LEKS IN RELATION TO FEMALE HOME RANGES, HABITAT REQUIREMENTS AND MALE ATTRACTIVENESS IN THE GREAT SNIPE (GALLINAGO-MEDIA)1990In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 26, no 3, p. 173-180Article in journal (Refereed)
  • 25.
    Hämäläinen, Anni
    et al.
    Univ Alberta, Dept Biol Sci, Edmonton, Canada.
    Immonen, Elina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Tarka, Maja
    Norwegian Univ Sci & Technol NTNU, Ctr Biodivers Dynam, Dept Biol, Trondheim, Norway.
    Schuett, Wiebke
    Univ Hamburg, Inst Zool, Hamburg, Germany.
    Evolution of sex-specific pace-of-life syndromes: causes and consequences2018In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 72, no 3, article id UNSP 50Article, review/survey (Refereed)
    Abstract [en]

    Males and females commonly differ in their life history optima and, consequently, in the optimal expression of life history, behavioral and physiological traits involved in pace-of-life syndromes (POLS). Sex differences in mean trait expression typically result if males and females exhibit different fitness optima along the same pace-of-life continuum, but the syndrome structure may also differ for the sexes. Due to sex-specific selective pressures imposed by reproductive roles and breeding strategies, the sexes may come to differ in the strength of correlation among traits, or different traits may covary in males and females. Ignorance of these selective forces operating between and within the sexes may lead to flawed conclusions about POLS manifestation in the species, and stand in the way of understanding the evolution, maintenance, and variability of POLS. We outline ways in which natural and sexual selection influence sex-specific trait evolution, and describe potential ultimate mechanisms underlying sex-specific POLS. We make predictions on how reproductive roles and the underlying sexual conflict lead to sex-specific trait covariances. These predictions lead us to conclude that sexual dimorphism in POLS is expected to be highly prevalent, allow us to assess possible consequences for POLS evolution, and provide guidelines for future studies.

  • 26.
    Immler, Simone
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Taborsky, Michael
    Sequential polyandry affords post-mating sexual selection in the mouths of cichlid females2009In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 8, p. 1219-1230Article, review/survey (Refereed)
    Abstract [en]

    Females mating with multiple males may obtain direct benefits such as nuptial gifts or paternal care or indirect (i.e. genetic) benefits resulting in higher-quality offspring. While direct benefits are easily identified, it is difficult to determine indirect benefits, and it is hence largely unclear how they are obtained. This is particularly true in species with external fertilisation, where females seem to have little control over fertilisation. In cichlids, most maternal mouthbrooders show sequential multiple mating, where females visit several males for egg deposition. Genetic data revealed that multiple paternity of eggs and young in the mouth of females is common, but behavioural data of female spawning decisions are missing. Here, we test four hypotheses to explain female multiple mating in the maternally mouthbrooding cichlid, Ophthalmotilapia ventralis: (1) fertilisation insurance, (2) genetic bet-hedging, (3) female choice and (4) 'sperm shopping' (i.e. induction of sperm competition resulting in sexually selected sperm). Detailed observations of spawning behaviour in the field combined with histological analyses of the male reproductive organs suggest that fertilisation insurance, genetic bet-hedging and pre-mating female choice are unlikely to explain the sequential female multiple mating in O. ventralis. Instead, cryptic female choice by sperm shopping, i.e. post-mating sexual selection, is most compatible with our data and might be the major ultimate cause of multiple mating in females of this species and of mouthbrooding cichlids with maternal care in general. Our study provides new insight into ultimate causes of sequential polyandry in species with external fertilisation, as hitherto post-mating sexual selection by cryptic female choice has been assumed to be incompatible with external fertilisation mechanisms except by components of the ovarian fluid.

  • 27.
    Immonen, Elina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Hämäläinen, Anni
    Univ Alberta, Dept Biol Sci, Edmonton, Canada.
    Schuett, Wiebke
    Univ Hamburg, Inst Zool, Hamburg, Germany.
    Tarka, Maja
    Norwegian Univ Sci & Technol NTNU, Ctr Biodivers Dynam, Dept Biol, Trondheim, Norway.
    Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms2018In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 72, no 3, article id UNSP 60Article, review/survey (Refereed)
    Abstract [en]

    Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS. Here, we outline mechanisms for how males and females can evolve differences in POLS traits and in how such traits can covary differently despite constraints resulting from a shared genome. We review the current knowledge of the genetic basis of POLS traits and suggest candidate genes and pathways for future studies. Pleiotropic effects may govern many of the genetic correlations, but little is still known about the mechanisms involved in trade-offs between current and future reproduction and their integration with behavioral variation. We highlight the importance of metabolic and hormonal pathways in mediating sex differences in POLS traits; however, there is still a shortage of studies that test for sex specificity in molecular effects and their evolutionary causes. Considering whether and how sexual dimorphism evolves in POLS traits provides a more holistic framework to understand how behavioral variation is integrated with life histories and physiology, and we call for studies that focus on examining the sex-specific genetic architecture of this integration.

  • 28. Jones, Adam G.
    et al.
    Rosenqvist, Gunilla
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Avise, John C.
    The genetic mating system of a sex-role-reversed pipefish (Syngnathus typhle): a molecular inquiry1999In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 46, no 5, p. 357-365Article in journal (Refereed)
    Abstract [en]

    In the pipefish Syngnathus typhle as in other species of Syngnathidae, developing embryos are reared on the male's ventral surface. Although much laboratory research has been directed toward understanding sexual selection in this sex-role-reversed species, few studies have addressed the mating behavior of S. typhle in the wild, and none has capitalized upon the power of molecular genetic assays. Here we present the first direct assessment of the genetic mating system of S. typhle in nature. Novel microsatellite loci were cloned and characterized from this species, and employed to assay entire broods from 30 pregnant, field-captured males. Genetic analysis of 1340 embryos revealed that 1-6 females (mean = 3.1) contributed to each brooded clutch, the highest rate of multiple maternity yet documented in any pipefish. Evidence of multiple mating by females was also detected. Thus, this population of S. typhle displays a polygynandrous mating system, a finding consistent with previous field and laboratory observations. Our results, considered together with similar studies of other syngnathid species, provide preliminary support for the hypothesis that the genetic mating system is related to the evolution of sexual dimorphism in the fish family Syngnathidae.

  • 29. Jones, Theresa M.
    et al.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    McNamara, Kathryn B.
    Elgar, Mark A.
    Size-assortative pairing across three developmental stages in the Zeus bug, Phoreticovelia disparata2012In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 66, no 7, p. 995-1003Article in journal (Refereed)
    Abstract [en]

    The mechanisms underlying size-assortative pairing have received considerable attention. Typically, pairing is assumed to occur at, or just prior to, the adult phase of the life cycle. However, in many invertebrates, males commence associations with juvenile females who are more than a single moult away from sexual maturity. These species are ideal to explore the importance of reproductive and survival benefits as mechanisms driving size-assortative pairing. In the Zeus bug, Phoreticovelia disparata, adult males are found riding on juvenile (fourth and fifth instar) and adult females-a behaviour that is costly for females but has survival benefits for males. Using a combination of field collections and laboratory manipulations, we show that pairing is size-assortative both within and between female age classes and that riding males are smaller than non-riding males. In a series of mating trials, we revealed that males attempt to ride any female but that their riding success is dependent on female age. We also provide the first direct evidence of female resistance to male riding attempts in P. disparata. We propose that size-assortative pairing arises through adaptations that have evolved to minimise the potential costs of sexual conflict. We suggest that the selective pressure on males to maximise survival benefits is sufficiently high that it outweighs the reproductive benefits of discriminating against fourth instar females. Finally, given that female resistance is under direct selection in juvenile females, it is likely to be the main form of selective pressure for adult females.

  • 30.
    Kolm, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Female courtship in the Banggai cardinalfish: honest signals of egg maturity and reproductive output?2004In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 56, no 1, p. 59-64Article in journal (Refereed)
    Abstract [en]

    Despite the vast literature on male courtship behaviour, little is known about the function and information content of female courtship behaviour. Female courtship behaviour may be important in many species, particularly where both sexes invest heavily in the offspring, and if such behaviours contain honest information regarding a female’s potential reproductive investment, they may be particularly important in male mate choice. Using observations of two female courtship behaviours (the “rush” and the “twitch”) from experimental pairings in the Banggai cardinalfish (Pterapogon kauderni), I addressed the question of whether these courtship behaviours contained information on female reproductive output (clutch weight) and egg maturity (proximity to spawning), traits commonly associated with male mate choice. I especially focused on the importance of these courtship behaviours in relation to other female characters, such as size and condition, using multiple regression. I found that one of these behaviours, the rush, was strongly associated with fecundity, whereas size, condition and the twitch were not. Further, I found that the “twitch” behaviour was associated with how close to actual spawning a female was. The results suggest that female courtship behaviour may convey highly important information in a mate choice context. I discuss the adaptive value of honest information in female courtship behaviour in light of these results.

  • 31.
    Kotrschal, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Rogell, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Maklakov, Alexei A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Kolm, Nichlas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Sex-specific plasticity in brain morphology depends on social environment of the guppy, Poecilia reticulata2012In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 66, no 11, p. 1485-1492Article in journal (Refereed)
    Abstract [en]

    The vertebrate brain is a remarkably plastic organ, which responds quickly to environmental changes. However, to date, studies investigating plasticity in brain morphology have focused mostly on the physical properties of the surrounding environment, and little is known about brain plasticity in response to the social environment. Moreover, sex differences in brain plasticity remain virtually unexplored. Here, we tested how the social environment influenced brain morphology in adult males and females using experimental manipulation of the sex composition of social pairs (same sex vs. mixed sex) in the guppy (Poecilia reticulata). We detected substantial sex-specific plasticity in both the overall brain size (controlling for body size) and separate brain structures. The brain size was larger in males that interacted with females, and female optic tectum was larger in female-only groups. Overall, females had larger olfactory bulbs and cerebellum in comparison to males. While net sexual dimorphism in the brain structure can be explained in light of the known differences in boldness and foraging behaviour between the sexes, our results also support that cognitive demands associated with courtship behaviour can lead to plastic changes in the brain size. Our findings demonstrate that not only social environment can generate rapid, plastic responses in the vertebrate brain but also that such responses can depend strongly on sex.

  • 32.
    Landis, Susanne H.
    et al.
    Helmholtz Ctr Ocean Res Kiel GEOMAR, Evolutionary Ecol Marine Fishes, D-24105 Kiel, Germany..
    Sundin, Josefin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Rosenqvist, Gunilla
    Norwegian Univ Sci & Technol, Dept Biol, Ctr Biodivers Dynam, N-7491 Trondheim, Norway..
    Poirier, Maude
    Helmholtz Ctr Ocean Res Kiel GEOMAR, Evolutionary Ecol Marine Fishes, D-24105 Kiel, Germany..
    Jorgensen, Guro Oistensen
    Norwegian Univ Sci & Technol, Dept Biol, Ctr Biodivers Dynam, N-7491 Trondheim, Norway..
    Roth, Olivia
    Helmholtz Ctr Ocean Res Kiel GEOMAR, Evolutionary Ecol Marine Fishes, D-24105 Kiel, Germany..
    Female pipefish can detect the immune status of their mates2015In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 69, no 12, p. 1917-1923Article in journal (Refereed)
    Abstract [en]

    Given the ubiquity of the parasites and their important fitness consequences on mate and offspring condition, selection for the ability to distinguish healthy from parasitized potential mates is a key process to enhance Darwinian fitness. In this study, we experimentally evaluated how the immunological experience of two potential partners influences mate choice, using the sex-role-reversed pipefish Syngnathus typhle. We exposed S. typhle to immune challenges with heat-killed Vibrio bacteria and investigated whether the activation of the immune system determined mate preferences. Our results demonstrate that the immune status of the potential partners influenced female mate preference, such that females that were exposed to an immune challenge became choosy and favored unchallenged males. Males, however, did not show any preferences for female immune status. In this context, we discuss mate choice decisions and behavioral plasticity as a complex result of immune challenge, severity of infection, as well as trans-generational effects.

  • 33. Landis, Susanne H.
    et al.
    Sundin, Josefin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Rosenqvist, Gunilla
    Roth, Olivia
    Behavioral adjustments of a pipefish to bacterial Vibrio challenge2012In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 66, no 10, p. 1399-1405Article in journal (Refereed)
    Abstract [en]

    Animals can profit from increasing temperatures by prolonged breeding seasons and faster growth rates. However, these fitness benefits are traded off against higher parasite load and increased virulence of temperature-sensitive pathogens. In thermally stratified habitats, behavioral plasticity can allow hosts to choose the optimal temperature to enhance individual fitness and to escape parasite pressure. To test this idea, we performed a temperature choice experiment with the host-parasite system of the sex-role reversed broad-nosed pipefish (Syngnathus typhle) and its bacterial pathogen Vibrio spp. In this species, pregnant males are expected to face a trade-off between shortening their brooding period in warm water and decreasing the effect of the infection in cold water. We found that exposure to Vibrio changed the temperature preference for both pregnant and nonpregnant males, as well as females compared to nonchallenged fish that tended to prefer warm water. This study shows that behavioral plasticity is one option for avoidance of higher bacterial prevalence, as expected due to rising ocean temperatures.

  • 34.
    Landis, Susanne H.
    et al.
    Evolutionary Ecology of Marine Fishes, Helmholtz Centre of Ocean Research Kiel (GEOMAR).
    Sundin, Josefin
    Department of Animal Ecology, Evolutionary Biology Centre (EBC), Uppsala University.
    Rosenqvist, Gunilla
    Gotland University, School of Culture, Energy and Environment.
    Roth, Olivia
    Evolutionary Ecology of Marine Fishes, Helmholtz Centre of Ocean Research Kiel (GEOMAR).
    Behavioral adjustments of a pipefish to bacterial Vibrio challenge2012In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 66, no 10, p. 1399-1405Article in journal (Refereed)
    Abstract [en]

    Animals can profit from increasing temperatures by prolonged breeding seasons and faster growth rates. However, these fitness benefits are traded off against higher parasite load and increased virulence of temperature-sensitive pathogens. In thermally stratified habitats, behavioral plasticity can allow hosts to choose the optimal temperature to enhance individual fitness and to escape parasite pressure. To test this idea, we performed a temperature choice experiment with the host–parasite system of the sex-role reversed broad-nosed pipefish (Syngnathus typhle) and its bacterial pathogen Vibrio spp. In this species, pregnant males are expected to face a trade-off between shortening their brooding period in warm water and decreasing the effect of the infection in cold water. We found that exposure to Vibrio changed the temperature preference for both pregnant and nonpregnant males, as well as females compared to nonchallenged fish that tended to prefer warm water. This study shows that behavioral plasticity is one option for avoidance of higher bacterial prevalence, as expected due to rising ocean temperatures.

  • 35.
    Maklakov, Alexei A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Lubin, Yael
    Indirect genetic benefits of polyandry in a spider with direct costs of mating2006In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 61, no 1, p. 31-38Article in journal (Refereed)
    Abstract [en]

    The search for the evolutionary explanation of polyandry is increasingly focused on direct and indirect selection on female resistance. In a polyandrous spider Stegodyphus lineatus, males do not provide material benefits and females are resistant to remating. Nevertheless, polyandrous females may obtain indirect genetic benefits that offset the costs associated with multiple mating. We manipulated the opportunity for females to select between different partners and examined the effect of female mating history (mated once, mated twice, or rejected the second male) on offspring body mass, size, condition, and survival under high- and low-food rearing regimens. We found that multiple mating, not female choice, results in increased female offspring body mass and condition. However, these effects were present only in low-food regimen. We did not find any effects of female mating history on male offspring variables. Thus, the benefits of polyandry depend not only on sex, but also on offspring environment. Furthermore, the observed patterns suggest that indirect genetic benefits cannot explain the evolution of female resistance in this system.

  • 36. Merilä, Juha
    et al.
    Sheldon, Ben C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Zoology.
    Testis size variation in the greenfinch Carduelis chloris: relevance for some recent models of sexual selection1999In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 45, no 2, p. 115-123Article in journal (Refereed)
    Abstract [en]

    Interspecific evidence that testis size responds to selection caused by sperm competition has been obtained from many taxa. However, little is known about the sources of intraspecific variation in testis size, although such variation may have functional significance. Variation in testis size and asymmetry was studied within and between eight geographically separated (and genetically differentiated) populations of greenfinches Carduelis chloris. The relationships between testis size and plumage brightness (degree of yellowness) and the prevalence of haematozoan infections were also investigated in three of these populations, as they related to the predictions of the immunocompetence handicap hypothesis, and Møller's hypothesis relating directional testis asymmetry to phenotypic quality. There were large differences between populations in testis size, with males from northern populations having larger testes than those from southern populations. Within populations, large testes were associated with larger body size and greater age. When the influence of these factors was removed statistically, males with large testes were more likely to be infected with haematozoan parasites, and had brighter yellow plumage. No evidence was found that directional asymmetry in testis size was related to either of these measures of phenotypic quality. These results are consistent with the hypothesis that males with large testes, while signalling higher phenotypic quality as revealed by increased plumage brightness, also pay a cost in terms of reduced immunocompetence, revealed by the increased probability of infection in these males. That these patterns were similar in three different populations adds further strength to these conclusions. Our results suggest that studying the sources of variation in testis size among individuals can reveal interesting processes in sexual selection.

  • 37. Meunier, Joël
    et al.
    Pinto, Susana Figueiredo
    Burri, Reto
    Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland .
    Roulin, Alexandre
    Eumelanin-based coloration and fitness parameters in birds: a meta-analysis2011In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 65, no 4, p. 559-567Article in journal (Refereed)
    Abstract [en]

    Although melanin is the most common pigment in animal integuments, the adaptive function of variation in melanin-based coloration remains poorly understood. The individual fitness returns associated with melanin pigments can be variable across species as these pigments can have physical and biological protective properties and genes involved in melanogenesis may vary in the intensity of pleiotropic effects. Moreover, dark and pale coloration can also enhance camouflage in alternative habitats and melanin-based coloration can be involved in social interactions. We investigated whether darker or paler individuals achieve a higher fitness in birds, a taxon wherein associations between melanin-based coloration and fitness parameters have been studied in a large number of species. A meta-analysis showed that the degree of melanin-based coloration was not significantly associated with laying date, clutch size, brood size, and survival across 26 species. Similar results were found when restricting the analyses to non-sexually dimorphic birds, colour polymorphic and monomorphic species, in passerines and non-passerines and in species for which inter-individual variation in melanism is due to colour intensity. However, eumelanic coloration was positively associated with clutch and brood size in sexually dimorphic species and those that vary in the size of black patches, respectively. Given that greater extent of melanin-based coloration was positively associated with reproductive parameters and survival in some species but negatively in other species, we conclude that in birds the sign and magnitude of selection exerted on melanin-based coloration is species- or trait-specific.

  • 38.
    Mobley, Kenyon
    et al.
    Department of Ecology and Environmental Science, Umeå university.
    Kvarnemo, Charlotta
    Department of Zoology, Göteborg University.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Partridge, Charlyn
    Department of Biology, Texas A&M University, USA.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Jones, Adam G.
    Department of Biology, Texas A&M University, USA.
    The effect of maternal body size on embryo survivorship in the broods of pregnant male pipefish2011In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 65, no 6, p. 1169-1177Article in journal (Refereed)
    Abstract [en]

    The occurrence of male pregnancy in the family Syngnathidae (seahorses, pipefishes, and sea dragons) provides an exceptionally fertile system in which to investigate issues related to the evolution of parental care. Here, we take advantage of this unique reproductive system to study the influence of maternal body size on embryo survivorship in the brood pouches of pregnant males of the broad-nosed pipefish, Syngnathus typhle. Males were mated with either two large females, two small females, a large then a small female, or a small then a large female. Our results show that offspring survivorship depends on an interaction between female body size and the number of eggs transferred by the female. Eggs of larger females deposited in large numbers are more likely to result in viable offspring than eggs of smaller females laid in large numbers. However, when females deposited smaller numbers of eggs, the eggs from smaller females were more likely to produce viable offspring compared to those from larger females. We found no evidence that this result was based on mating order, the relative sizes of competing females, or egg characteristics such as dry weight of eggs. Additionally, male body size did not significantly influence the survivorship of offspring during brooding. Our results suggest that the factors underlying offspring survivorship in pipefish may be more complex than previously believed, with multiple factors interacting to determine the fitness of individual offspring within the broods of pregnant males.

  • 39. Nilsson, T
    et al.
    Fricke, C
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    The effects of male and female genotype on variance in male fertilization success in the red flour beetle (Tribolium castaneum)2003In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 53, no 4, p. 227-233Article in journal (Refereed)
  • 40. Partridge, Charlyn
    et al.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Kvarnemo, Charlotta
    Mobley, B
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Jones, G
    The effect of perceived female parasite load on post-copulatory male choice in a sex-role-reversed pipefish2009In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 3, p. 345-354Article in journal (Refereed)
    Abstract [en]

    The last several decades of research in behavioral ecology have resulted in a deeper appreciation of post-mating processes and sexual conflict in sexual selection. One of the most controversial aspects of sexual selection is cryptic mate choice. Here, we take advantage of male pregnancy in a sex-role-reversed pipefish (Syngnathus typhle) to quantify cryptic choice based on perceived parasite load and other sources of variance in female fitness. Studies have shown that S. typhle males preferentially mate with females with lower parasite loads and that a male's perception of female parasite load can be altered by tattooing females. We manipulated the apparent parasite load of females in controlled mating experiments to test the hypothesis that post-copulatory sexual selection is dependent on a male's perception of female parasite load in pipefish. Our results provided no evidence for cryptic male choice based on perceived female parasite load. However, we found evidence that eggs from larger females were more likely to result in viable offspring than eggs from smaller females and that the first female to mate with a male transferred more eggs per copulation on average. Overall, our results show that potential for post-copulatory sexual selection does exist in pipefish, but the male's perception of female parasite load does not play a major role in this process.

  • 41. Riesch, Rüdiger
    et al.
    Duwe, Virginia
    Herrmann, Nina
    Padur, Lisa
    Ramm, Annemarie
    Scharnweber, Kristin
    Unit of Animal Ecology, University of Potsdam.
    Schulte, Matthias
    Schulz-Mirbach, Tanja
    Ziege, Madlen
    Plath, Martin
    Variation along the shy-bold continuum in extremophile fishes (Poecilia mexicana, Poecilia sulphuraria)2009In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 10, p. 1515-1526Article in journal (Refereed)
    Abstract [en]

    One potential trade-off that bold individuals face is between increased predation risks and gains in resources. Individuals experiencing high predation and hungry individuals (or individuals with low body condition) are predicted to show increased boldness. We examined one behavioral trait previously reported to be associated with boldness (the time individual fish needed to emerge from shelter) in various populations of mollies (Poecilia spp.). Our study system included several southern Mexican surface streams with high piscine predation and high food availability, sulfidic surface streams with high avian predation, in which the inhabiting fish show reduced body condition, and a sulfidic cave, where predation and body condition are low. Our comparison revealed very short times to emerge from the start box in populations from non-sulfidic streams. In sulfidic habitats (whether surface or cave), it took individual Poecilia mexicana considerably longer to emerge from the start box, and the same difference was also found in an independent comparison between P. mexicana and the closely related, highly sulfide-adapted Poecilia sulphuraria. Fish reared under common garden conditions (in the absence of predators and hydrogen sulfide) showed intermediate boldness scores to the extremes observed in the field. Our data thus indicate that (a) boldness is shaped by environmental conditions/experiential effects, but is not heritable, (b) predation affects boldness in the predicted direction, but (c) low body condition leads to reduced boldness. Extremophile Poecilia spp. spend most of their time surfacing to survive under sulfidic and hypoxic conditions, which exposes them to increased levels of predations, but the fish forage on the bottom. Hence, in this system, increased boldness does not increase foraging success. We argue that energy limitation favors reducing energetically costly behaviors, and exploring novel environments may be just one of them.

  • 42. RINTAMAKI, PT
    et al.
    ALATALO, RV
    HOGLUND, J
    LUNDBERG, A
    MATE SAMPLING BEHAVIOR OF BLACK GROUSE FEMALES (TETRAO TETRIX)1995In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 37, no 3, p. 209-215Article in journal (Refereed)
  • 43. Ruuskanen, Suvi
    et al.
    Doligez, Blandine
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Laaksonen, Toni
    Long-term effects of yolk androgens on phenotype and parental feeding behavior in a wild passerine2012In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 66, no 9, p. 1201-1211Article in journal (Refereed)
    Abstract [en]

    Early growth conditions, such as exposure to maternally derived androgens in bird eggs, have been shown to shape offspring in ways that may have important long-term consequences for phenotype and behavior. Using an experimental approach, we studied the long-term effects of yolk androgens on several phenotypic traits and parental behavior in adult and female collared flycatchers (Ficedula albicollis). We elevated yolk androgen levels and monitored the experimental recruits the following breeding seasons. Androgen treatment had a sex-dependent effect on adult body condition, yolk androgen-treated males being heavier than control males when controlling for size, a result which may be caused potentially by selective mortality, physiological differences, or different life-history strategies. Androgen treatment did not however affect the expression of sexually selected plumage ornaments (forehead and wing patch size), UV coloration, or parental feeding rate in either sex. Our results suggest that yolk androgens are unlikely to affect sexual selection via plumage characteristics or contribute to breeding success via altered parental care. Yolk androgens do not seem to act as a means for female collared flycatchers to enhance the attractiveness of their sons. The lower return rate previously observed for androgen-treated male offspring compared to controls may therefore not be due to lower mating or breeding success, but may rather reflect lower survival or higher dispersal propensity of yolk androgen-treated males.

  • 44.
    Seppa, Perttu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Evolutionary Functional Genomics.
    Fernandez-Escudero, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Evolutionary Functional Genomics.
    Gyllenstrand, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Evolutionary Functional Genomics.
    Pamilo, Pekka
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Evolutionary Functional Genomics.
    Colony fission affects kinship in a social insect2008In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 62, no 4, p. 589-597Article in journal (Refereed)
    Abstract [en]

    Establishment of new groups is an important step in the life history of a social species. Fissioning is a common mode not only in group proliferation, for instance, as a regular part of the life cycle in the honey bee, but also when multiple females reproduce in the same group, as in multiple-queen ant societies. We studied the genetic consequences of fissioning in the ant Proformica longiseta, based on DNA microsatellites. In P. longiseta, new nests arise by fissioning from the old ones when they grow large, and the daughter nests consist of workers and queens or queen pupae but never both. Our results show that fissioning is not entirely random with respect to kinship. Workers tend to segregate along kin lines, but only when the initial relatedness in the parental nests is low. Workers in a daughter nest also tend to be associated with closely related adult queens, whereas such an association is not detected between workers and queen pupae. Most queens and workers are carried to the daughter nest by a specialized group of transporting workers, suggesting active kin discrimination by them. Fissioning pattern in P. longiseta is different from that found in other social insects with regular fission (e.g., the honey bee, swarm-founding wasps), where no fissioning along kin lines has been found. It does, however, resemble fissioning in another group of social animals: primates.

  • 45.
    Sundberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Female Yellowhammers (Emberiza-Citrinella) Prefer Yellower Males - A Laboratory Experiment1995In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 37, no 4, p. 275-282Article in journal (Refereed)
    Abstract [en]

    The importance of male plumage coloration as a signal of male dominance and a cue for female choice in the monogamous yellowhammer, Emberiza citrinella, was tested in two sets of experiments in an indoor aviary. Dominance was tested by introducing two individuals, with no previous experience of each other, in an aviary with food and water. Aggression occurred more often between two males than between a male and a female and more frequently between pairs of males including at least one old male than between two young males. Dominance was not related to male colour in trials between males of the same age class, but it was in trials between an old and a young male, often differing in colour. Thus, age may be a more important determinant of dominance than colour. Female preference for more colourful males was tested by allowing hormone-induced females to choose between a more and a less colourful dummy male. Females spent more time in front of more colourful than drabber males and also more often perched beside colourful males than duller individuals. Although male colour cannot be ruled out as a dominance signal, the results suggest that male colour is primarily used as a signal in mate choice. Female choice may hence be responsible for maintenance of bright plumage in the male yellowhammer.

  • 46.
    Sundin, Josefin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Amcoff, Mirjam
    Stockholm Univ, Dept Zool Funct Zoomorphol, Stockholm, Sweden.;Univ Texas Austin, Sect Integrat Biol, Austin, TX 78712 USA..
    Mateos-Gonzalez, Fernando
    Univ Texas Austin, Sect Integrat Biol, Austin, TX 78712 USA.;Univ Konstanz, Max Planck Inst Ornithol, Dept Collect Behav, Constance, Germany..
    Raby, Graham D.
    Australian Inst Marine Sci, Townsville, Qld, Australia.;Univ Windsor, Great Lakes Inst Environm Res, Windsor, ON, Canada..
    Jutfelt, Fredrik
    Norwegian Univ Sci & Technol, Dept Biol, Trondheim, Norway..
    Clark, Timothy D.
    Australian Inst Marine Sci, Townsville, Qld, Australia.;Univ Tasmania, Hobart, Tas, Australia.;CSIRO Agr & Food, Hobart, Tas, Australia..
    Long-term exposure to elevated carbon dioxide does not alter activity levels of a coral reef fish in response to predator chemical cues2017In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 71, no 8, article id 108Article in journal (Refereed)
    Abstract [en]

    Levels of dissolved carbon dioxide (CO2) projected to occur in the world's oceans in the near future have been reported to increase swimming activity and impair predator recognition in coral reef fishes. These behavioral alterations would be expected to have dramatic effects on survival and community dynamics in marine ecosystems in the future. To investigate the universality and replicability of these observations, we used juvenile spiny chromis damselfish (Acanthochromis polyacanthus) to examine the effects of long-term CO 2 exposure on routine activity and the behavioral response to the chemical cues of a predator (Cephalopholis urodeta). Commencing at similar to 3-20 days post-hatch, juvenile damselfish were exposed to presentday CO2 levels (similar to 420 mu atm) or to levels forecasted for the year 2100 (similar to 1000 mu atm) for 3 months of their development. Thereafter, we assessed routine activity before and after injections of seawater (sham injection, control) or seawater-containing predator chemical cues. There was no effect of CO2 treatment on routine activity levels before or after the injections. All fish decreased their swimming activity following the predator cue injection but not following the sham injection, regardless of CO2 treatment. Our results corroborate findings from a growing number of studies reporting limited or no behavioral responses of fishes to elevated CO2. Significance statement Alarmingly, it has been reported that levels of dissolved carbon dioxide (CO2) forecasted for the year 2100 cause coral reef fishes to be attracted to the chemical cues of predators. However, most studies have exposed the fish to CO2 for very short periods before behavioral testing. Using long-term acclimation to elevated CO2 and automated tracking software, we found that fish exposed to elevated CO2 showed the same behavioral patterns as control fish exposed to present-day CO2 levels. Specifically, activity levels were the same between groups, and fish acclimated to elevated CO2 decreased their swimming activity to the same degree as control fish when presented with cues from a predator. These findings indicate that behavioral impacts of elevated CO2 levels are not universal in coral reef fishes.

  • 47.
    Sundin, Josefin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Aronsen, Tonje
    Norwegian Univ Sci & Technol, Dept Biol, Ctr Biodivers Dynam, Trondheim, Norway.; Norwegian Inst Nat Res NINA, Trondheim, Norway.
    Rosenqvist, Gunilla
    Norwegian Univ Sci & Technol, Dept Biol, Ctr Biodivers Dynam, Trondheim, Norway.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sex in murky waters: algal induced turbidity increases sexual selection in pipefish2017In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 71, no 5, article id 78Article in journal (Refereed)
    Abstract [en]

    Algal induced turbidity has been shown to alter several important aspects of reproduction and sexual selection. However, while turbidity has been shown to negatively affect reproduction and sexually selected traits in some species, it may instead enhance reproductive success in others, implying that the impact of eutrophication is far more complex than originally believed. In this study, we aimed to provide more insight into these inconsistent findings. We used molecular tools to investigate the impact of algal turbidity on reproductive success and sexual selection on males in controlled laboratory experiments, allowing mate choice, mating competition and mate encounter rates to affect reproduction. As study species we used the broad-nosed pipefish, Syngnathus typhle, a species practicing male pregnancy and where we have previously shown that male mate choice is impaired by turbidity. Here, turbidity instead enhanced sexual selection on male size and mating success as well as reproductive success. Effects from mating competition and mate encounter rates may thus override effects from mate choice based on visual cues, producing an overall stronger sexual selection in turbid waters. Hence, seemingly inconsistent effects of turbidity on sexual selection may depend on which mechanisms of sexual selection that have been under study.

  • 48.
    Veen, Thor
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Träff, Johan
    Weissing, J
    Sheldon, Ben C.
    Reduced costs of mixed-species pairings in flycatchers: by-product or female strategy?2009In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 3, p. 329-337Article in journal (Refereed)
    Abstract [en]

    Heterospecific matings are generally assumed to be unconditionally disadvantageous due to reduced viability or fertility of hybrid offspring. For female collared flycatchers (Ficedula albicollis) mated to male pied flycatchers (Ficedula hypoleuca), the cost of heterospecific pair formation is reduced due to high levels of conspecific extra-pair paternity and a male-biased offspring sex ratio. In order to investigate whether these cost-reducing mechanisms are the result of female mating strategies, rather than being a by-product of species incompatibilities, we manipulated the plumage of male collared flycatchers before pair formation to make them resemble male pied flycatchers. Since species incompatibilities are absent in this design, any systematic effect of manipulation on sex ratio or paternity would indicate a role of female mating strategy. Paternity was determined by means of a likelihood approach that controls the errors made in assigning a chick to be 'within-pair' or 'extra-pair'. Neither the sex ratio nor the male share of paternity was affected by the manipulation in a systematic manner. We therefore conclude that our experimental data provide no support for the suggestion that female behavioural strategies are markedly adjusted in response to formation of mixed-species pairs.

  • 49.
    Vincent, Amanda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Zoology.
    Ahnesjö, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Zoology.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Zoology.
    Operational sex ratios and behavioral sex differences in a pipefish population1994In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 34, p. 435-442Article in journal (Refereed)
    Abstract [en]

    In the pipefish Syngnathus typhle, only males brood embryos in specially developed brood pouches, supplying oxygen and nutrients. Laboratory studies have shown that this elaborate paternal care has led to sex-role reversal in this species: males limit female reproductive rate, females are the primary competitors for mates and males exercise greater selectivity in accepting mates. In the first field study of this pipefish, we describe mating behaviour in the wild and test the hypothesis that temporal variations in the operational sex ratio (OSR) determine sex differences in mating behaviour. Our study comprised two reproductive seasons of two sequential mating periods each, the latter separated by a lengthy interval of male brooding. During mating periods, females displayed to all males without wandering and males moved about searching for females, without reacting to all females. The OSR was least female-biased (or even male-biased) at the onset of the breeding season, when most pipefish were simultaneously available to mate, but became strikingly female-biased as males' pouches were filled. The OSR remained substantially female-biased during the second mating period, because few males became available to remate at any one time. As hypothesised, female-biased OSRs resulted in more female-female meetings. As well, females were above the eelgrass more often than brooding males, thus exposing themselves to conspecifics and/or predators. In the second year, males arrived earlier than females on the breeding site and male pregnancies were shorter, because of higher water temperatures, so rematings occurred earlier. Males met more often during that year than the previous one, but male competitive interactions were still not observed. The field results support laboratory studies and demonstrate that behaviours associated with female-female competition are more prominent when the OSR is more female-biased.

  • 50. Winternitz, J. C.
    et al.
    Promerova, M.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Polakova, R.
    Vinker, M.
    Schnitzer, J.
    Munclinger, P.
    Babik, W.
    Radwan, J.
    Bryja, J.
    Albrecht, T.
    Effects of heterozygosity and MHC diversity on patterns of extra-pair paternity in the socially monogamous scarlet rosefinch2015In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 69, no 3, p. 459-469Article in journal (Refereed)
    Abstract [en]

    Extra-pair copulation without apparent direct benefits is an evolutionary puzzle that requires indirect fitness benefits to females to explain its ubiquity in socially monogamous mating systems. Using wild scarlet rosefinches (Carpodacus erythrinus), we tested if genetic benefits in the form of global (microsatellite) heterozygote advantage, adaptive genes (major histocompatibility complex), or complementary genes (using both markers) were responsible for female extra-pair mate choice, while considering that the benefits of mate choice may be conditional on female genotype. We found no evidence for assortative or relatedness-based mating (complementary genes), but higher MHC diversity, microsatellite heterozygosity, and condition were significantly related to male extra-pair paternity (EPP) success. In contrast, female probability of having extra-pair offspring decreased with increasing heterozygosity. Interestingly, extra-pair and within-pair males had higher heterozygosity than their female mates and extra-pair males had higher MHC supertype diversity. The only genetic difference between extra-pair and within-pair offspring was lower variance in MHC allelic diversity within extra-pair offspring, providing limited support for indirect genetic fitness benefits for the markers tested. Offspring had both higher neutral heterozygosity and number of MHC supertypes than adults, as well as significant identity disequilibrium, potentially suggesting that mates are chosen to increase offspring diversity in the period of the present study. Overall, our results point to an EPP heterozygote advantage for males, especially when involving less heterozygous females, and suggest that heterozygosity effects on reproduction may differ between the sexes.

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