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Becciu P, Séchaud R, Schalcher K, Plancherel C, Roulin A. Prospecting movements link phenotypic traits to female annual potential fitness in a nocturnal predator. Sci Rep 2023; 13:5071. [PMID: 36977731 PMCID: PMC10050157 DOI: 10.1038/s41598-023-32255-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Recent biologging technology reveals hidden life and breeding strategies of nocturnal animals. Combining animal movement patterns with individual characteristics and landscape features can uncover meaningful behaviours that directly influence fitness. Consequently, defining the proximate mechanisms and adaptive value of the identified behaviours is of paramount importance. Breeding female barn owls (Tyto alba), a colour-polymorphic species, recurrently visit other nest boxes at night. We described and quantified this behaviour for the first time, linking it with possible drivers, and individual fitness. We GPS-equipped 178 female barn owls and 122 male partners from 2016 to 2020 in western Switzerland during the chick rearing phase. We observed that 111 (65%) of the tracked breeding females were (re)visiting nest boxes while still carrying out their first brood. We modelled their prospecting parameters as a function of brood-, individual- and partner-related variables and found that female feather eumelanism predicted the emergence of prospecting behaviour (less melanic females are usually prospecting). More importantly we found that increasing male parental investment (e.g., feeding rate) increased female prospecting efforts. Ultimately, females would (re)visit a nest more often if they had used it in the past and were more likely to lay a second clutch afterwards, consequently having higher annual fecundity than non-prospecting females. Despite these apparent immediate benefits, they did not fledge more chicks. Through biologging and long-term field monitoring, we highlight how phenotypic traits (melanism and parental investment) can be related to movement patterns and the annual potential reproductive output (fecundity) of female barn owls.
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Affiliation(s)
- Paolo Becciu
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
| | - Robin Séchaud
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Agroecology and Environment, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Kim Schalcher
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Céline Plancherel
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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2
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Kvalnes T, Sæther BE, Engen S, Roulin A. Density-dependent selection and the maintenance of colour polymorphism in barn owls. Proc Biol Sci 2022; 289:20220296. [PMID: 35642371 PMCID: PMC9156910 DOI: 10.1098/rspb.2022.0296] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The capacity of natural selection to generate adaptive changes is (according to the fundamental theorem of natural selection) proportional to the additive genetic variance in fitness. In spite of its importance for development of new adaptations to a changing environment, processes affecting the magnitude of the genetic variance in fitness-related traits are poorly understood. Here, we show that the red-white colour polymorphism in female barn owls is subject to density-dependent selection at the phenotypic and genotypic level. The diallelic melanocortin-1 receptor gene explained a large amount of the phenotypic variance in reddish coloration in the females ([Formula: see text]). Red individuals (RR genotype) were selected for at low densities, while white individuals (WW genotype) were favoured at high densities and were less sensitive to changes in density. We show that this density-dependent selection favours white individuals and predicts fixation of the white allele in this population at longer time scales without immigration or other selective forces. Still, fluctuating population density will cause selection to fluctuate and periodically favour red individuals. These results suggest how balancing selection caused by fluctuations in population density can be a general mechanism affecting the level of additive genetic variance in natural populations.
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Affiliation(s)
- Thomas Kvalnes
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Bernt-Erik Sæther
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Steinar Engen
- Department of Mathematical Sciences, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne CH-1015, Switzerland
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3
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Exogenous corticosterone and melanin-based coloration explain variation in juvenile dispersal behaviour in the barn owl (Tyto alba). PLoS One 2021; 16:e0256038. [PMID: 34492014 PMCID: PMC8423310 DOI: 10.1371/journal.pone.0256038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/28/2021] [Indexed: 11/19/2022] Open
Abstract
Natal dispersal affects many processes such as population dynamics. So far, most studies have examined the intrinsic and extrinsic factors that determine the distance between the place of birth and of first breeding. In contrast, few researchers followed the first steps of dispersal soon after fledging. To study this gap, we radio-tracked 95 barn owl nestlings (Tyto alba) to locate their diurnal roost sites from the fledging stage until December. This was used to test whether the age of nest departure, post-fledging movements and dispersal distance were related to melanin-based coloration, which is correlated to fitness-related traits, as well as to corticosterone, a hormone that mediates a number of life history trade-offs and the physiological and behavioural responses to stressful situations. We found that the artificial administration of corticosterone delayed the age when juveniles left their parental home-range in females but not in males. During the first few months after fledging, longer dispersal distances were reached by females compared to males, by individuals marked with larger black feather spots compared to individuals with smaller spots, by larger individuals and by those experimentally treated with corticosterone. We conclude that the onset and magnitude of dispersal is sensitive to the stress hormone corticosterone, melanin-based coloration and body size.
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Being Dark is Better: A Feral Pigeon Plumage Polymorphism as a Response to Urban Environments in Slovakia. EKOLÓGIA (BRATISLAVA) 2021. [DOI: 10.2478/eko-2021-0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Abstract
The purpose of this study was to determine the distribution and plumage phenotypes of the feral pigeon, Columba livia forma urbana (Gmelin, 1789), in Slovakia. Censuses carried out in the built-up areas of 16 towns and cities from November to February (2012–2018) counted and evaluated 3,123 individual birds. The most frequent were melanic colored birds (checker, T-pattern and spread phenotypes), which predominated in the population (51.6%, n = 1,613), followed by paler ones (42.1%, n = 1,316) and other types (6.2%, n = 194). A statistically significant difference was confirmed among the melanic and paler plumage phenotypes (χ2 = 81.49, df = 15, p < 0.0001). Correlation confirmed the different importance of city area and human density on the maintenance of dark and/or pale pigeons living in cities.
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5
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Pheomelanin-based coloration is related to individual quality and oxidative stress in blue petrels. Evol Ecol 2019. [DOI: 10.1007/s10682-019-10010-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Roulin A, Uva V, Romano A. A melanin-based trait is more strongly related to body size in the tropics than in temperate regions in the globally distributed barn owl family. J Evol Biol 2018; 31:1932-1944. [DOI: 10.1111/jeb.13386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 08/31/2018] [Accepted: 10/01/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Alexandre Roulin
- Department of Ecology and Evolution; University of Lausanne; Biophore, Lausanne Switzerland
- Wissenschaftskolleg zu Berlin; Berlin Germany
| | - Vera Uva
- Department of Ecology and Evolution; University of Lausanne; Biophore, Lausanne Switzerland
| | - Andrea Romano
- Department of Ecology and Evolution; University of Lausanne; Biophore, Lausanne Switzerland
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7
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Ducret V, Gaigher A, Simon C, Goudet J, Roulin A. Sex-specific allelic transmission bias suggests sexual conflict at MC1R. Mol Ecol 2016; 25:4551-63. [PMID: 27480981 DOI: 10.1111/mec.13781] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 02/03/2023]
Abstract
Sexual conflict arises when selection in one sex causes the displacement of the other sex from its phenotypic optimum, leading to an inevitable tension within the genome - called intralocus sexual conflict. Although the autosomal melanocortin-1-receptor gene (MC1R) can generate colour variation in sexually dichromatic species, most previous studies have not considered the possibility that MC1R may be subject to sexual conflict. In the barn owl (Tyto alba), the allele MC1RWHITE is associated with whitish plumage coloration, typical of males, and the allele MC1RRUFOUS is associated with dark rufous coloration, typical of females, although each sex can express any phenotype. Because each colour variant is adapted to specific environmental conditions, the allele MC1RWHITE may be more strongly selected in males and the allele MC1RRUFOUS in females. We therefore investigated whether MC1R genotypes are in excess or deficit in male and female fledglings compared with the expected Hardy-Weinberg proportions. Our results show an overall deficit of 7.5% in the proportion of heterozygotes in males and of 12.9% in females. In males, interannual variation in assortative pairing with respect to MC1R explained the year-specific deviations from Hardy-Weinberg proportions, whereas in females, the deficit was better explained by the interannual variation in the probability of inheriting the MC1RWHITE or MC1RRUFOUS allele. Additionally, we observed that sons inherit the MC1RRUFOUS allele from their fathers on average slightly less often than expected under the first Mendelian law. Transmission ratio distortion may be adaptive in this sexually dichromatic species if males and females are, respectively, selected to display white and rufous plumages.
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Affiliation(s)
- Valérie Ducret
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland.
| | - Arnaud Gaigher
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| | - Céline Simon
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| | - Jérôme Goudet
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Biophore Building, Lausanne, CH-1015, Switzerland
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8
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Roulin A. Evolutionary trade-off between naturally- and sexually-selected melanin-based colour traits in worldwide barn owls and allies. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12828] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Alexandre Roulin
- Department of Ecology and Evolution; University of Lausanne; Biophore Building CH-1015 Lausanne Switzerland
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9
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Bolton PE, Rollins LA, Griffith SC. Colour polymorphism is likely to be disadvantageous to some populations and species due to genetic architecture and morph interactions. Mol Ecol 2016; 25:2713-8. [PMID: 27178202 DOI: 10.1111/mec.13632] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 02/22/2016] [Accepted: 03/24/2016] [Indexed: 11/29/2022]
Abstract
Polymorphism describes two or more distinct, genetically determined, phenotypes that co-occur in the same population, where the rarest morph is maintained at a frequency above the mutation rate (Ford 1945; Huxley 1955). In a recent opinion piece, we explored a new idea regarding the role of genetic architectures and morph interactions in colour polymorphisms and how this can negatively affect population performance (Bolton et al. 2015). In this issue of Molecular Ecology, Forsman (2016) thoroughly discusses the current evidence for polymorphisms enhancing population performance and critiques the validity of the definitions of polymorphism we use in our original paper. We respond by clarifying that the negative consequences of polymorphisms that we discussed are likely to be most pertinent in species that have a particular set of characteristics, such as strong sexual or social interactions between morphs and discrete genetic architectures. Although it was not our intention to redefine polymorphism, we do believe that there should be further discussion about refining or characterizing balanced polymorphisms with respect to the degree of morph sympatry, discreteness of traits and their underlying genetic architecture, and the types of selection that drive and maintain the variation. The latter describes whether polymorphism is primarily maintained by external factors such as predation pressure or internal factors such as interactions with members of the same species. The contribution of Forsman (2016) is useful to this discussion, and we hope that our exchange of opinions will inspire new empirical and theoretical ideas on the origin and maintenance of colour polymorphisms.
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Affiliation(s)
- Peri E Bolton
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Lee A Rollins
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, 75 Pigdons Road, Locked Bag 20000, Geelong, Vic., 3220, Australia
| | - Simon C Griffith
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
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10
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Sumasgutner P, Tate GJ, Koeslag A, Amar A. Family morph matters: factors determining survival and recruitment in a long-lived polymorphic raptor. J Anim Ecol 2016; 85:1043-55. [PMID: 26990283 DOI: 10.1111/1365-2656.12518] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 03/04/2016] [Indexed: 01/02/2023]
Abstract
From an evolutionary perspective, recruitment into the breeding population represents one of the most important life-history stages and ultimately determines the effective population size. In order to contribute to the next generation, offspring must survive to sexual maturity, secure a territory and find a mate. In this study, we explore factors influencing both offspring survival and their subsequent recruitment into the local breeding population in a long-lived urban raptor, the black sparrowhawk (Accipiter melanoleucus). Adult black sparrowhawks show discrete colour polymorphism (dark and light morphs), and in South Africa, morphs are distributed clinally with the highest proportion of dark morphs (c.75%) present in our study population on the Cape Peninsula. Parental morph was associated with both survival and recruitment. For survival, parental morph combination was important - with young produced by pairs of contrasting morphs having higher survival rates than young fledged from like-pairs. The association between recruitment and morph was more complex; with an interaction between male morph and breeding time, whereby recruitment of offspring from dark morph fathers was more likely when fledging earlier in the season. The opposite relationship was found for light morph fathers, with their offspring more likely to be recruited if fledged later in the season. This interaction may be due to differential morph-specific hunting success of fathers (males contribute most food provisioning), linked to background matching and crypsis in different weather conditions. Dark morph males may hunt more successfully in rainier and cloudier conditions, which occur more frequently earlier in the breeding season, and light morph males may be more successful later on, when weather conditions become increasingly brighter and drier. Our results reveal a complex situation whereby the family morph combination influences survival, and the father morphs specifically recruitment, revealing morph-specific benefits dependent on the timing of breeding. These empirical data are among the first to support the idea that differential fitness consequence of morph combination may explain balanced polymorphism in a vertebrate population.
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Affiliation(s)
- Petra Sumasgutner
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Cape Town, South Africa.,Centre for Statistics in Ecology, Environment and Conservation, University of Cape Town, Cape Town, South Africa
| | - Gareth J Tate
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Cape Town, South Africa
| | - Ann Koeslag
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Cape Town, South Africa
| | - Arjun Amar
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Cape Town, South Africa
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11
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Acker P, Grégoire A, Rat M, Spottiswoode CN, van Dijk RE, Paquet M, Kaden JC, Pradel R, Hatchwell BJ, Covas R, Doutrelant C. Disruptive viability selection on a black plumage trait associated with dominance. J Evol Biol 2015; 28:2027-41. [PMID: 26249359 PMCID: PMC4949555 DOI: 10.1111/jeb.12717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 07/26/2015] [Accepted: 08/01/2015] [Indexed: 11/30/2022]
Abstract
Traits used in communication, such as colour signals, are expected to have positive consequences for reproductive success, but their associations with survival are little understood. Previous studies have mainly investigated linear relationships between signals and survival, but both hump-shaped and U-shaped relationships can also be predicted, depending on the main costs involved in trait expression. Furthermore, few studies have taken the plasticity of signals into account in viability selection analyses. The relationship between signal expression and survival is of particular interest in melanin-based traits, because their main costs are still debated. Here, we first determined the main factors explaining variability in a melanin-based trait linked to dominance: the bib size of a colonial bird, the sociable weaver Philetairus socius. We then used these analyses to obtain a measure representative of the individual mean expression of bib size. Finally, we used capture-recapture models to study how survival varied in relation to bib size. Variation in bib size was strongly affected by year and moderately affected by age, body condition and colony size. In addition, individuals bearing small and large bibs had higher survival than those with intermediate bibs, and this U-shaped relationship between survival and bib size appeared to be more pronounced in some years than others. These results constitute a rare example of disruptive viability selection, and point towards the potential importance of social costs incurred by the dominance signalling function of badges of status.
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Affiliation(s)
- P Acker
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France.,Laboratoire Évolution & Diversité Biologique (UMR 5174 EDB), Université Toulouse 3 Paul Sabatier - CNRS - ENFA, Toulouse, France
| | - A Grégoire
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France
| | - M Rat
- Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - C N Spottiswoode
- Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa.,Department of Zoology, University of Cambridge, Cambridge, UK
| | - R E van Dijk
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - M Paquet
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France.,Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - J C Kaden
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,The Royal Zoological Society of Scotland, Edinburgh Zoo, Edinburgh, UK
| | - R Pradel
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France
| | - B J Hatchwell
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - R Covas
- Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa.,CIBIO, University of Porto, Vairão, Portugal.,Biology Department, Science Faculty, University of Porto, Porto, Portugal
| | - C Doutrelant
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France.,Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
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12
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Almasi B, Roulin A. Signalling value of maternal and paternal melanism in the barn owl: implication for the resolution of the lek paradox. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Bettina Almasi
- Swiss Ornithological Institute; CH-6204 Sempach Switzerland
| | - Alexandre Roulin
- Department of Ecology and Evolution; University of Lausanne; Biophore Building CH-1015 Lausanne Switzerland
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13
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Roulin A. Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration. Biol Rev Camb Philos Soc 2015; 91:328-48. [PMID: 25631160 DOI: 10.1111/brv.12171] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 11/30/2014] [Accepted: 12/11/2014] [Indexed: 02/03/2023]
Abstract
The signalling function of melanin-based colouration is debated. Sexual selection theory states that ornaments should be costly to produce, maintain, wear or display to signal quality honestly to potential mates or competitors. An increasing number of studies supports the hypothesis that the degree of melanism covaries with aspects of body condition (e.g. body mass or immunity), which has contributed to change the initial perception that melanin-based colour ornaments entail no costs. Indeed, the expression of many (but not all) melanin-based colour traits is weakly sensitive to the environment but strongly heritable suggesting that these colour traits are relatively cheap to produce and maintain, thus raising the question of how such colour traits could signal quality honestly. Here I review the production, maintenance and wearing/displaying costs that can generate a correlation between melanin-based colouration and body condition, and consider other evolutionary mechanisms that can also lead to covariation between colour and body condition. Because genes controlling melanic traits can affect numerous phenotypic traits, pleiotropy could also explain a linkage between body condition and colouration. Pleiotropy may result in differently coloured individuals signalling different aspects of quality that are maintained by frequency-dependent selection or local adaptation. Colouration may therefore not signal absolute quality to potential mates or competitors (e.g. dark males may not achieve a higher fitness than pale males); otherwise genetic variation would be rapidly depleted by directional selection. As a consequence, selection on heritable melanin-based colouration may not always be directional, but mate choice may be conditional to environmental conditions (i.e. context-dependent sexual selection). Despite the interest of evolutionary biologists in the adaptive value of melanin-based colouration, its actual role in sexual selection is still poorly understood.
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Affiliation(s)
- Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Building Biophore, 1015 Lausanne, Switzerland
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14
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Dreiss AN, Roulin A. Divorce in the barn owl: securing a compatible or better mate entails the cost of re-pairing with a less ornamented female mate. J Evol Biol 2014; 27:1114-24. [DOI: 10.1111/jeb.12402] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 03/25/2014] [Accepted: 03/26/2014] [Indexed: 11/30/2022]
Affiliation(s)
- A. N. Dreiss
- Department of Ecology and Evolution; University of Lausanne; Lausanne Switzerland
| | - A. Roulin
- Department of Ecology and Evolution; University of Lausanne; Lausanne Switzerland
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15
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Steinsland I, Larsen CT, Roulin A, Jensen H. Quantitative genetic modeling and inference in the presence of nonignorable missing data. Evolution 2014; 68:1735-47. [PMID: 24673414 DOI: 10.1111/evo.12380] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 01/21/2014] [Indexed: 11/28/2022]
Abstract
Natural selection is typically exerted at some specific life stages. If natural selection takes place before a trait can be measured, using conventional models can cause wrong inference about population parameters. When the missing data process relates to the trait of interest, a valid inference requires explicit modeling of the missing process. We propose a joint modeling approach, a shared parameter model, to account for nonrandom missing data. It consists of an animal model for the phenotypic data and a logistic model for the missing process, linked by the additive genetic effects. A Bayesian approach is taken and inference is made using integrated nested Laplace approximations. From a simulation study we find that wrongly assuming that missing data are missing at random can result in severely biased estimates of additive genetic variance. Using real data from a wild population of Swiss barn owls Tyto alba, our model indicates that the missing individuals would display large black spots; and we conclude that genes affecting this trait are already under selection before it is expressed. Our model is a tool to correctly estimate the magnitude of both natural selection and additive genetic variance.
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16
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Männiste M, Hõrak P. Emerging infectious disease selects for darker plumage coloration in greenfinches. Front Ecol Evol 2014. [DOI: 10.3389/fevo.2014.00004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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17
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Scriba MF, Ducrest AL, Henry I, Vyssotski AL, Rattenborg NC, Roulin A. Linking melanism to brain development: expression of a melanism-related gene in barn owl feather follicles covaries with sleep ontogeny. Front Zool 2013; 10:42. [PMID: 23886007 PMCID: PMC3734112 DOI: 10.1186/1742-9994-10-42] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 07/24/2013] [Indexed: 11/10/2022] Open
Abstract
Background Intra-specific variation in melanocyte pigmentation, common in the animal kingdom, has caught the eye of naturalists and biologists for centuries. In vertebrates, dark, eumelanin pigmentation is often genetically determined and associated with various behavioral and physiological traits, suggesting that the genes involved in melanism have far reaching pleiotropic effects. The mechanisms linking these traits remain poorly understood, and the potential involvement of developmental processes occurring in the brain early in life has not been investigated. We examined the ontogeny of rapid eye movement (REM) sleep, a state involved in brain development, in a wild population of barn owls (Tyto alba) exhibiting inter-individual variation in melanism and covarying traits. In addition to sleep, we measured melanistic feather spots and the expression of a gene in the feather follicles implicated in melanism (PCSK2). Results As in mammals, REM sleep declined with age across a period of brain development in owlets. In addition, inter-individual variation in REM sleep around this developmental trajectory was predicted by variation in PCSK2 expression in the feather follicles, with individuals expressing higher levels exhibiting a more precocial pattern characterized by less REM sleep. Finally, PCSK2 expression was positively correlated with feather spotting. Conclusions We demonstrate that the pace of brain development, as reflected in age-related changes in REM sleep, covaries with the peripheral activation of the melanocortin system. Given its role in brain development, variation in nestling REM sleep may lead to variation in adult brain organization, and thereby contribute to the behavioral and physiological differences observed between adults expressing different degrees of melanism.
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Affiliation(s)
- Madeleine F Scriba
- Avian Sleep Group, Max Planck Institute for Ornithology, Eberhard-Gwinner-str.11, Seewiesen 82319, Germany.,Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
| | - Anne-Lyse Ducrest
- Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
| | - Isabelle Henry
- Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zürich and ETH Zürich, Zürich 8057, Switzerland
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Eberhard-Gwinner-str.11, Seewiesen 82319, Germany
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Lausanne 1015, Switzerland
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Almasi B, Roulin A, Jenni L. Corticosterone shifts reproductive behaviour towards self-maintenance in the barn owl and is linked to melanin-based coloration in females. Horm Behav 2013; 64:161-71. [PMID: 23583559 DOI: 10.1016/j.yhbeh.2013.03.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 02/06/2013] [Accepted: 03/08/2013] [Indexed: 11/21/2022]
Abstract
Trade-offs between the benefits of current reproduction and the costs to future reproduction and survival are widely recognized. However, such trade-offs might only be detected when resources become limited to the point where investment in one activity jeopardizes investment in others. The resolution of the trade-off between reproduction and self-maintenance is mediated by hormones such as glucocorticoids which direct behaviour and physiology towards self-maintenance under stressful situations. We investigated this trade-off in male and female barn owls in relation to the degree of heritable melanin-based coloration, a trait that reflects the ability to cope with various sources of stress in nestlings. We increased circulating corticosterone in breeding adults by implanting a corticosterone-releasing-pellet, using birds implanted with a placebo-pellet as controls. In males, elevated corticosterone reduced the activity (i.e. reduced home-range size and distance covered within the home-range) independently of coloration, while we could not detect any effect on hunting efficiency. The effect of experimentally elevated corticosterone on female behaviour was correlated with their melanin-based coloration. Corticosterone (cort-) induced an increase in brooding behaviour in small-spotted females, while this hormone had no detectable effect in large-spotted females. Cort-females with small eumelanic spots showed the normal body-mass loss during the early nestling period, while large spotted cort-females did not lose body mass. This indicates that corticosterone induced a shift towards self-maintenance in males independently on their plumage, whereas in females this shift was observed only in large-spotted females.
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Viability is associated with melanin-based coloration in the barn swallow (Hirundo rustica). PLoS One 2013; 8:e60426. [PMID: 23573254 PMCID: PMC3616026 DOI: 10.1371/journal.pone.0060426] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Accepted: 02/26/2013] [Indexed: 01/13/2023] Open
Abstract
Pigmentation of body surface in animals can have multiple determinants and accomplish diverse functions. Eumelanin and pheomelanin are the main animal pigments, being responsible of yellow, brownish-red and black hues, and have partly common biosynthetic pathways. Many populations of vertebrates show individual variation in melanism, putatively with large heritable component. Genes responsible for eu- or pheomelanogenesis have pleiotropic but contrasting effects on life-history traits, explaining the patterns of covariation observed between melanization and physiology (e.g. immunity and stress response), sexual behavior and other characters in diverse taxa. Yet, very few studies in the wild have investigated if eu- and pheomelanization predict major fitness traits like viability or fecundity. In this correlative study, by contrasting adult barn swallows (Hirundo rustica) matched for age, sex, breeding site, and year and date of sampling, we show that males but not females that survived until the next year had paler, relatively more eu- than pheomelanic pigmentation of ventral body feathers. Better performance of individuals that allocate relatively more to eumelanogenesis was expected based on previous evidence on covariation between eumelanic pigmentation and specific traits related to immunity and susceptibility to stress. However, together with the evidence of no covariation between viability and melanization among females, this finding raises the question of the mechanisms that maintain variation in genes for melanogenesis. We discuss the possibility that eu- and pheomelanization are under contrasting viability and sexual selection, as suggested by larger breeding and sperm competition success of darker males from other barn swallow subspecies.
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20
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Vroonen J, Vervust B, Van Damme R. Melanin-based colouration as a potential indicator of male quality in the lizard Zootoca vivipara (Squamata: Lacertidae). AMPHIBIA-REPTILIA 2013. [DOI: 10.1163/15685381-00002916] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In many animals, aspects of colouration are hypothesized to convey information on the body condition or quality of individuals. This idea has been tested primarily for the carotenoid-based component of body colouration. The significance of other pigments in this context has received far less attention. In the common lizard, Zootoca vivipara, the degree of black patterning on the ventrum and throats is sexually dimorphic and varies considerably among individuals. In this study, we examine whether this melanin-based component of body colouration may reflect individual differences in quality (SVL, condition, immune response). We find that males (but not females) with a higher degree of ventral patterning mount a stronger phytohemagglutinin-induced immune response. The amount of black patterning does not correlate with body size, body condition, aspects of dorsal colouration or parasite load. We conclude that in male Zootoca vivipara, melanin-based ventral colouration may signal an aspect of immune capacity to sexual rivals or potential partners.
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Affiliation(s)
- Jessica Vroonen
- 1Functional Morphology, Department of Biology, University of Antwerp, Universiteitsplein 1, BE-2610 Wilrijk, Belgium
| | - Bart Vervust
- 2Institute of Biology, Department of Integrative Zoology, University of Leiden, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Raoul Van Damme
- 1Functional Morphology, Department of Biology, University of Antwerp, Universiteitsplein 1, BE-2610 Wilrijk, Belgium
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van den Brink V, Dreiss AN, Roulin A. Melanin-based coloration predicts natal dispersal in the barn owl, Tyto alba. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.07.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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22
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Schmidt KL, Furlonger AA, Lapierre JM, MacDougall-Shackleton EA, MacDougall-Shackleton SA. Regulation of the HPA axis is related to song complexity and measures of phenotypic quality in song sparrows. Horm Behav 2012; 61:652-9. [PMID: 22418051 DOI: 10.1016/j.yhbeh.2012.02.027] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 02/29/2012] [Accepted: 02/29/2012] [Indexed: 11/18/2022]
Abstract
Regulation of the hypothalamic-pituitary-adrenal (HPA) axis is a key component of the vertebrate stress response. Prior studies have found that variation in HPA responses were correlated to measures of fitness and physiological condition. In addition, sexually-selected traits have also been found to correlate to measures of condition. The proximate mechanisms responsible for such covariation between sexually selected traits and measures of quality are unclear, but could involve variation in HPA regulation. We investigated whether HPA activity is related to song complexity, body size/condition and leukocyte profiles in wild male song sparrows (Melospiza melodia). We characterized three aspects of HPA activity: 1) response to restraint stress; 2) negative feedback, assessed by the ability of exogenous dexamethasone to suppress corticosterone levels; and 3) adrenal sensitivity to exogenous adrenocorticotropic hormone (ACTH). Birds with lower responses to restraint stress had more complex song and more heterophils and higher heterophil to lymphocyte (H:L) ratios. Birds with more effective negative feedback were larger and had fewer heterophils and lower H:L ratios, suggesting lower levels of physiological stress or infection. We observed no relationship between adrenal sensitivity to exogenous ACTH and any of the factors. These findings illustrate important relationships between HPA activity, song complexity, and morphological and physiological traits. Song complexity may thus provide receivers with information about the ability of the singer to cope with stressors.
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Affiliation(s)
- Kim L Schmidt
- Department of Biology, University of Western Ontario, London, Ontario, Canada.
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23
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van den Brink V, Dolivo V, Falourd X, Dreiss AN, Roulin A. Melanic color-dependent antipredator behavior strategies in barn owl nestlings. Behav Ecol 2011. [DOI: 10.1093/beheco/arr213] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Roulin A, Ducrest AL. Association between melanism, physiology and behaviour: A role for the melanocortin system. Eur J Pharmacol 2011; 660:226-33. [DOI: 10.1016/j.ejphar.2011.01.036] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/22/2010] [Accepted: 01/13/2011] [Indexed: 11/26/2022]
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25
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26
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DREISS AMELIEN, ROULIN ALEXANDRE. Age-related change in melanin-based coloration of Barn owls (Tyto alba): females that become more female-like and males that become more male-like perform better. Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01503.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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27
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ROULIN A, ALMASI B, JENNI L. Temporal variation in glucocorticoid levels during the resting phase is associated in opposite way with maternal and paternal melanic coloration. J Evol Biol 2010; 23:2046-2053. [DOI: 10.1111/j.1420-9101.2010.02086.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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28
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ROULIN A, SALAMIN N. Insularity and the evolution of melanism, sexual dichromatism and body size in the worldwide-distributed barn owl. J Evol Biol 2010; 23:925-34. [DOI: 10.1111/j.1420-9101.2010.01961.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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29
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Butler MW, Leppert LL, Dufty AM. Effects of small increases in corticosterone levels on morphology, immune function, and feather development. Physiol Biochem Zool 2010; 83:78-86. [PMID: 19929638 DOI: 10.1086/648483] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Stressors encountered during avian development may affect an individual's phenotype, including immunocompetence, growth, and feather quality. We examined effects of simulated chronic low-level stress on American kestrel (Falco sparverius) nestlings. Continuous release of corticosterone, a hormone involved in the stress response, can model chronic stress in birds. We implanted 13-d-old males with either corticosterone-filled implants or shams and measured their growth, immune function, and feather coloration. We found no significant differences between groups at the end of the weeklong exposure period in morphometrics (mass, tarsus, wing length, and asymmetry), immunocompetence (cutaneous immunity, heterophil/lymphocyte ratio, and humoral immunity), or feather coloration. One week subsequent to implant removal, however, differences were detected. Sham-implanted birds had significantly longer wings and a reduced level of cutaneous immune function compared with those of birds given corticosterone-filled implants. Therefore, increases of only 2 ng/mL in basal corticosterone titer can have small but measurable effects on subsequent avian development.
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Affiliation(s)
- Michael W Butler
- Department of Biological Sciences, Boise State University, Boise, Idaho 83725, USA.
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30
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Almasi B, Jenni L, Jenni-Eiermann S, Roulin A. Regulation of stress response is heritable and functionally linked to melanin-based coloration. J Evol Biol 2010; 23:987-96. [PMID: 20345817 DOI: 10.1111/j.1420-9101.2010.01969.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sexual selection theory posits that ornaments can signal the genetic quality of an individual. Eumelanin-based coloration is such an ornament and can signal the ability to cope with a physiological stress response because the melanocortin system regulates eumelanogenesis as well as physiological stress responses. In the present article, we experimentally investigated whether the stronger stress sensitivity of light than dark eumelanic individuals stems from differential regulation of stress hormones. Our study shows that darker eumelanic barn owl nestlings have a lower corticosterone release after a stressful event, an association, which was also inherited from the mother (but not the father) to the offspring. Additionally, nestlings sired by darker eumelanic mothers more quickly reduced experimentally elevated corticosterone levels. This provides a solution as to how ornamented individuals can be more resistant to various sources of stress than drab conspecifics. Our study suggests that eumelanin-based coloration can be a sexually selected signal of resistance to stressful events.
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Affiliation(s)
- B Almasi
- Swiss Ornithological Institute, Sempach, Switzerland.
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31
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Roulin A, Altwegg R, Jensen H, Steinsland I, Schaub M. Sex-dependent selection on an autosomal melanic female ornament promotes the evolution of sex ratio bias. Ecol Lett 2010; 13:616-26. [PMID: 20337696 DOI: 10.1111/j.1461-0248.2010.01459.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Sex-dependent selection often leads to spectacularly different phenotypes in males and females. In species in which sexual dimorphism is not complete, it is unclear which benefits females and males derive from displaying a trait that is typical of the other sex. In barn owls (Tyto alba), females exhibit on average larger black eumelanic spots than males but members of the two sexes display this trait in the same range of possible values. In a 12-year study, we show that selection exerted on spot size directly or on genetically correlated traits strongly favoured females with large spots and weakly favoured males with small spots. Intense directional selection on females caused an increase in spot diameter in the population over the study period. This increase is due to a change in the autosomal genes underlying the expression of eumelanic spots but not of sex-linked genes. Female-like males produced more daughters than sons, while male-like females produced more sons than daughters when mated to a small-spotted male. These sex ratio biases appear adaptive because sons of male-like females and daughters of female-like males had above-average survival. This demonstrates that selection exerted against individuals displaying a trait that is typical of the other sex promoted the evolution of specific life history strategies that enhance their fitness. This may explain why in many organisms sexual dimorphism is often not complete.
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Affiliation(s)
- Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Biophore 1015 Lausanne, Switzerland.
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32
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Antoniazza S, Burri R, Fumagalli L, Goudet J, Roulin A. Local adaptation maintains clinal variation in melanin-based coloration of European barn owls (Tyto alba). Evolution 2010; 64:1944-54. [PMID: 20148951 DOI: 10.1111/j.1558-5646.2010.00969.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ecological parameters vary in space, and the resulting heterogeneity of selective forces can drive adaptive population divergence. Clinal variation represents a classical model to study the interplay of gene flow and selection in the dynamics of this local adaptation process. Although geographic variation in phenotypic traits in discrete populations could be remainders of past adaptation, maintenance of adaptive clinal variation requires recurrent selection. Clinal variation in genetically determined traits is generally attributed to adaptation of different genotypes to local conditions along an environmental gradient, although it can as well arise from neutral processes. Here, we investigated whether selection accounts for the strong clinal variation observed in a highly heritable pheomelanin-based color trait in the European barn owl by comparing spatial differentiation of color and of neutral genes among populations. Barn owl's coloration varies continuously from white in southwestern Europe to reddish-brown in northeastern Europe. A very low differentiation at neutral genetic markers suggests that substantial gene flow occurs among populations. The persistence of pronounced color differentiation despite this strong gene flow is consistent with the hypothesis that selection is the primary force maintaining color variation among European populations. Therefore, the color cline is most likely the result of local adaptation.
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Affiliation(s)
- Sylvain Antoniazza
- Department of Ecology and Evolution, University of Lausanne, Switzerland.
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33
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VERGARA PABLO, FARGALLO JUANA, MARTÍNEZ-PADILLA JESÚS, LEMUS JESÚSA. Inter-annual variation and information content of melanin-based coloration in female Eurasian kestrels. Biol J Linn Soc Lond 2009. [DOI: 10.1111/j.1095-8312.2009.01263.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Murphy TG, Hernández-Muciño D, Osorio-Beristain M, Montgomerie R, Omland KE. Carotenoid-based status signaling by females in the tropical streak-backed oriole. Behav Ecol 2009. [DOI: 10.1093/beheco/arp089] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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35
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Roulin A. Melanin-based coloration covaries with ovary size in an age-specific manner in the barn owl. Naturwissenschaften 2009; 96:1177-84. [PMID: 19575175 DOI: 10.1007/s00114-009-0579-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 05/18/2009] [Accepted: 05/20/2009] [Indexed: 11/28/2022]
Abstract
While the adaptive function of black eumelanin-based coloration is relatively well known, the function of reddish-brown pheomelanin-based coloration is still unclear. Only a few studies have shown or suggested that the degree of reddish-brownness is associated with predator-prey relationships, reproductive parameters, growth rate and immunity. To gain insight into the physiological correlates of melanin-based coloration, I collected barn owl (Tyto alba) cadavers and examined the covariation between this colour trait and ovary size, an organ that increases in size before reproduction. A relationship is expected because melanin-based coloration often co-varies with sexual activity. The results showed that reddish-brown juveniles had larger ovaries than whiter juveniles particularly in individuals in poor condition and outside the breeding season, while in birds older than 2 years lightly coloured females had larger ovaries than reddish-brown conspecifics. As barn owls become less reddish-brown between the first and second year of age, the present study suggests that reddish-brown pheomelanic and whitish colorations are associated with juvenile- and adult-specific adaptations, respectively.
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Affiliation(s)
- Alexandre Roulin
- Department of Ecology and Evolution, Biophore, University of Lausanne, Lausanne, Switzerland.
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36
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Covariation between eumelanic pigmentation and body mass only under specific conditions. Naturwissenschaften 2009; 96:375-82. [PMID: 19122994 DOI: 10.1007/s00114-008-0489-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2008] [Revised: 11/17/2008] [Accepted: 11/24/2008] [Indexed: 02/06/2023]
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37
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ROULIN A, WINK M, SALAMIN N. Selection on a eumelanic ornament is stronger in the tropics than in temperate zones in the worldwide-distributed barn owl. J Evol Biol 2008; 22:345-54. [DOI: 10.1111/j.1420-9101.2008.01651.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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38
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Almasi B, Roulin A, Jenni-Eiermann S, Jenni L. Parental investment and its sensitivity to corticosterone is linked to melanin-based coloration in barn owls. Horm Behav 2008; 54:217-23. [PMID: 18413149 DOI: 10.1016/j.yhbeh.2008.02.021] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/26/2008] [Accepted: 02/27/2008] [Indexed: 12/15/2022]
Abstract
Behavioral and physiological responses to unpredictable changes in environmental conditions are, in part, mediated by glucocorticoids (corticosterone in birds). In polymorphic species, individuals of the same sex and age display different heritable melanin-based color morphs, associated with physiological and reproductive parameters and possibly alternative strategies to cope with variation in environmental conditions. We examined whether the role of corticosterone in resolving the trade-off between self-maintenance and reproductive activities covaries with the size of melanin-based spots displayed on the ventral body side of male barn owls. Administration of corticosterone to simulate physiological stress in males revealed pronounced changes in their food-provisioning rates to nestlings compared to control males. Corticosterone-treated males with small eumelanic spots reduced nestling provisioning rates as compared to controls, and also to a greater degree than did corticosterone-treated males with large spots. Large-spotted males generally exhibited lower parental provisioning and appear insensitive to exogenous corticosterone suggesting that the size of the black spots on the breast feathers predicts the ability to cope with stressful situations. The reduced provisioning rate of corticosterone-treated males caused a temporary reduction in nestling growth rates but, did not affect fledgling success. This suggests that moderately elevated corticosterone levels are not inhibitory to current reproduction but rather trigger behavioral responses to maximize lifetime reproductive success.
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Affiliation(s)
- Bettina Almasi
- Swiss Ornithological Institute, 6204 Sempach, Switzerland.
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39
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Affiliation(s)
- Kevin J McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA.
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40
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41
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Melanin-based colorations signal strategies to cope with poor and rich environments. Behav Ecol Sociobiol 2007. [DOI: 10.1007/s00265-007-0475-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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