Testosterone activates sexual dimorphism including male-typical carotenoid but not melanin plumage pigmentation in a female bird

Journal of Experimental Biology, Journal Year: 2016, Volume and Issue: 219(19), P. 3091 - 3099

Published: Oct. 1, 2016

ABSTRACT In males it is frequently testosterone (T) that activates the expression of sexually selected morphological and behavioral displays, but role T in regulating similar traits females less clear. Here, we combine correlational data with results from gonadotropin-releasing hormone (GnRH) manipulations both sexes to assess mediating dimorphic coloration morphology red-backed fairy-wren (Malurus melanocephalus). We show that: (1) natural variation female ornamental (darkened bills red back feathers) positively associated age circulating androgen titres, (2) have capacity express most male-typical response exogenous T, including carotenoid-pigmented body plumage, shorter feathers, darkened bill enlarged cloacal protuberance, (3) appear constrained production melanin-pigmented (4) low levels during pre-nuptial molt, probably because ovarian for steroid (or luteinizing sensitivity), prevent developing male-like ornamentation. Thus, retain molecular mechanisms hormonally regulated ornamentation, although these are rarely activated insufficient hormonal signal.

Language: Английский

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Conspicuous Plumage Does Not Increase Predation Risk: A Continent-Wide Test Using Model Songbirds

The American Naturalist, Journal Year: 2019, Volume and Issue: 193(3), P. 359 - 372

Published: Jan. 23, 2019

The forces shaping female plumage color have long been debated but remain unresolved. Females may benefit from conspicuous colors are also expected to suffer costs. Predation is one potential cost, few studies explicitly investigated the relationship between predation risk and coloration. fairy-wrens show pronounced variation in coloration reside a wide variety of habitats across Australasia. Species with more females found denser habitats, suggesting that conspicuousness open habitat increases vulnerability predators. To test this, we measured attack rates on 3-D-printed models mimicking conspicuously colored males dull eight different fairy-wren Australia. Attack were higher at latitudes. Contrary our predictions, attacked similar models. Further, probability increased for both types than male model. Across models, degree contrast (chromatic achromatic) environmental backgrounds was unrelated rate. These findings do not support long-standing hypothesis plumage, isolation, costly due attraction Our results indicate interacts other factors driving evolution

Language: Английский

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Sex differences in song and plumage color do not evolve through sexual selection alone: new insights from recent research

Journal of Ornithology, Journal Year: 2019, Volume and Issue: 160(4), P. 1213 - 1219

Published: June 15, 2019

Language: Английский

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The evolutionary history and mechanistic basis of female ornamentation in a tropical songbird

Evolution, Journal Year: 2022, Volume and Issue: 76(8), P. 1720 - 1736

Published: June 24, 2022

Ornamentation, such as the showy plumage of birds, is widespread among female vertebrates, yet evolutionary pressures shaping ornamentation remain uncertain. In part this due to a poor understanding mechanistic route in females. To address issue, we evaluated history ornament expression tropical passerine bird, White-shouldered Fairywren, whose females, but not males, strongly vary between populations occurrence ornamented black-and-white plumage. We first use phylogenomic analysis demonstrate that derived and evolves independently changes male then exogenous testosterone field experiment induce partial naturally unornamented By sequencing transcriptome experimentally induced natural feathers, identify genes expressed during production evaluate degree which system associated with elevated testosterone, common males. reveal some females linked sexes differ ornament-linked gene expression. Lastly, using genomic outlier candidate melanogenesis lies region high divergence also differentially feather follicles different plumages. Taken together, these findings are consistent sex-specific selection favoring evolution ornaments key role for generating population through regulation. More broadly, our work highlights similarities differences how sexes.

Language: Английский

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Rapid evolution of elaborate male coloration is driven by visual system in Australian fairy-wrens (Maluridae)

Journal of Evolutionary Biology, Journal Year: 2015, Volume and Issue: 28(12), P. 2125 - 2135

Published: Aug. 24, 2015

The interplay between colour vision and animal signalling is of keen interest to behavioural ecologists evolutionary biologists alike, but difficult address in terrestrial animals. Unlike most avian lineages, which relatively invariant among species, the fairy-wrens allies (Maluridae) show a recent gain ultraviolet sensitivity (UVS). Here, we compare rates evolution on 11 patches for males females across Maluridae context their visual system. We measured reflectance spectra 24 estimating five vision-independent metrics as well contrast sexual dichromatism receiver-neutral space. fit Brownian motion (BM) Ornstein-Uhlenbeck (OU) models estimate these test whether male coloration, female coloration or was driven by selective regimes defined system geography. found that general evolved rapidly comparison with females. Male strongly correlated expanded greatly UVS whereas weakly associated geography (Australia vs. Papua New Guinea). These results suggest has evolve at different rates, are selection pressures.

Language: Английский

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Habitat structure is linked to the evolution of plumage colour in female, but not male, fairy-wrens

BMC Evolutionary Biology, Journal Year: 2017, Volume and Issue: 17(1)

Published: Jan. 26, 2017

Both natural and sexual selection may drive the evolution of plumage colouration in birds. This can lead to great variation not only across species, but also between sexes within species. Australasian fairy-wrens are famous for their brightly coloured males, which exhibit colours ranging from bright blue red black. Female fairy wrens (and general) has been rarely studied, it be highly variable, including both cryptic plumages. We use a comparative framework explore basis this variation, test possibility that female experience when they occupy more exposed habitats offer little concealment predators. spectral measurements species subspecies fairy-wrens.We show (contrast against background) is strongly correlated with vegetation cover: females open less contrast background than closed habitats, while male associated habitat type.Female appears under stronger fairy-wrens, providing an example how act differently on males same

Language: Английский

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Shaping communicative colour signals over evolutionary time

Royal Society Open Science, Journal Year: 2016, Volume and Issue: 3(11), P. 160728 - 160728

Published: Nov. 1, 2016

Many evolutionary forces can shape the evolution of communicative signals, and long-term impact each force may depend on relative timing magnitude. We use a phylogenetic analysis to infer history blue belly patches

Language: Английский

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Butterfly dichromatism primarily evolved via Darwin's, not Wallace's, model

Evolution Letters, Journal Year: 2020, Volume and Issue: 4(6), P. 545 - 555

Published: Oct. 24, 2020

Abstract Sexual dimorphism is typically thought to result from sexual selection for elaborated male traits, as proposed by Darwin. However, natural could reduce expression of traits in females, Wallace. Darwin and Wallace debated the origins dichromatism birds butterflies, although evidence roughly equal, if not favor Wallace's model, butterflies lack a similar scale study. Here, we present large-scale comparative phylogenetic analysis evolution butterfly coloration, using all European non-hesperiid species (n = 369). We modeled evolutionary changes coloration each sex along their phylogeny, thereby estimating rate direction three-dimensional color space novel implementation ridge regression. show that evolved faster than female especially strongly dichromatic clades, with contribution twice females. These patterns are consistent classic Darwinian model via on suggesting this was dominant driver butterflies.

Language: Английский

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Testosterone induces plumage ornamentation followed by enhanced territoriality in a female songbird

Behavioral Ecology, Journal Year: 2020, Volume and Issue: 31(5), P. 1233 - 1241

Published: Aug. 4, 2020

Abstract We know little of the proximate mechanisms underlying expression signaling traits in female vertebrates. Across males, sexual and competitive traits, including ornamentation aggressive behavior, is often mediated by testosterone. In white-shouldered fairywren (Malurus alboscapulatus) New Guinea, females different subspecies differ presence or absence white shoulder patches melanic plumage, whereas males are uniformly ornamented. Previous work has shown that ornamented circulate more testosterone exhibit territorial aggression than do unornamented females. investigated degree to which regulates ornamental plumage behavior implanting free-living with Every testosterone-treated produced a male-like cloacal protuberance, 15 20 replaced experimentally plucked brown patch feathers but did not typically produce characteristic Testosterone treatment elevate prior production ornament during active life implant. However, induced ornamentation, exhausted implants, increased vocal components territory defense relative pretreatment period also testosterone-implanted ornamentation. Our results suggest induces partial acquisition phenotype expression, rather alone, elevations some behaviors.

Language: Английский

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Production of plumage ornaments among males and females of two closely related tropical passerine bird species

Ecology and Evolution, Journal Year: 2017, Volume and Issue: 7(11), P. 4024 - 4034

Published: April 25, 2017

Abstract The evolution of elaborate secondary sexual traits (i.e., ornaments) is well‐studied in males but less so females. Similarity the appearance ornaments between and females supports view that female arise as a neutral byproduct selection on male due to genetic correlation sexes, recent research suggests an adaptive function at least some contexts. Information degree which production differs sexes can shed light these alternative perspectives. We therefore characterized structural underpinnings melanin‐based plumage two closely related passerine bird species (genus Malurus ). Importantly, both ornamented unornamented phenotypes each sex are present species, providing opportunity test null expectation equivalent modes phenotypes. In alboscapulatus , qualitatively similar males, we describe distinctive phenotype from lacking blue sheen lower feather barbule density. M. melanocephalus also appearance, similarity color underlying structure pigment composition. Unornamented flexibly transition weeks, found extreme differences These results contradict idea have evolved this system following simple switch male‐like by demonstrating greater complexity than

Language: Английский

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