scholarly journals Morphological and plumage colour variation in the Réunion grey white-eye (Aves:Zosterops borbonicus): assessing the role of selection

2014 ◽  
Vol 114 (2) ◽  
pp. 459-473 ◽  
Author(s):  
Josselin Cornuault ◽  
Boris Delahaie ◽  
Joris A. M. Bertrand ◽  
Yann X. C. Bourgeois ◽  
Borja Milá ◽  
...  
2020 ◽  
Author(s):  
ANGEL CRUZ MIRALLES ◽  
Jesús M. Avilés ◽  
Olivier Chastel ◽  
Mónica Expósito-Granados ◽  
Deseada Parejo

Abstract Background: Individuals within populations often show consistent variation in behavioural and physiological traits, which are frequently inter-correlated, potentially leading to phenotypic integration. Understanding the mechanisms behind such integration is a key task in evolutionary ecology, and melanism has been suggested to play a pivotal role. In birds, most of plumage colour variation is determined by two types of melanin, eumelanin and phaeomelanin, but the role of melanin in avian phenotype integration has mostly been analysed in relation to eumelanin. Here we test for covariation between phaeo-melanin-based coloration, behavioural traits (i.e. nest territoriality, response against researchers, breath rate and parental behaviour) and corticosterone profiles in the polymorphic scops owl Otus scops , a bird species in which more phaeomelanic individuals display reddish colorations. Results: In males, we observed differences between red and grey individuals in latency to return to the nest after being disturbed and in feather CORT. Reddish males took longer to return to their nests and showed higher levels of feather CORT than grey ones. Behaviour and CORT profiles did not differ between red and grey females. Conclusions: The found associations between redness, behaviour and CORT in males, but not in females, might suggest the existence of a sex-specific integrated phaeomelanic phenotype, likely due to pleiotropy, in scops owls.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241380
Author(s):  
Ángel Cruz-Miralles ◽  
Jesús M. Avilés ◽  
Olivier Chastel ◽  
Mónica Expósito-Granados ◽  
Deseada Parejo

Individuals within populations often show consistent variation in behavioural and physiological traits which are frequently inter-correlated, potentially leading to phenotypic integration. Understanding the mechanisms behind such integration is a key task in evolutionary ecology, and melanin based colouration has been suggested to play a pivotal role. In birds, most of plumage colour variation is determined by two types of melanin, eumelanin and phaeomelanin, but the role of phaeomelanin in avian phenotype integration has been barely investigated. Here, we test for covariation between phaeomelanin-based colouration, behavioural traits (i.e. nest territoriality, aggressiveness, breath rate and parental behaviour) and corticosterone in feathers in the polymorphic scops owl Otus scops, a bird species in which more phaeomelanic individuals display reddish colourations. In males, we observed that reddish males took longer to return to their nests and showed higher levels of feather CORT than more greyish ones. Behaviour and feather CORT were not associated to plumage colour in females. The found associations between redness, behaviour and feather CORT in males, but not in females, might suggest the existence of a sex-specific integrated phaeomelanic phenotype in scops owls.


2019 ◽  
Vol 128 (3) ◽  
pp. 550-568 ◽  
Author(s):  
Marie Fan ◽  
Liliana D’alba ◽  
Matthew D Shawkey ◽  
Anne Peters ◽  
Kaspar Delhey

AbstractClosely related species often differ in coloration. Understanding the mechanistic bases of such differences can reveal whether evolutionary changes in colour are driven by single key mechanisms or changes in multiple pathways. Non-iridescent structural plumage colours in birds are a good model in which to test these questions. These colours result from light absorption by pigments, light scattering by the medullary spongy layer (a nanostructure found within barbs) and contributions from other structural elements. Fairy-wrens (Malurus spp.) are a small clade of closely related birds that display a large diversity of ornamental structural colours. Using spectrometry, electron microscopy and Fourier analysis, we show that 30 structural colours, varying from ultraviolet to blue and purple, share a similar barb morphology. Despite this similarity, we find that at the microscopic scale, variation across multiple structural elements, including the size and density of the keratin cortex, spongy layer and melanin, explains colour diversity. These independent axes of morphological variation together account for sizeable amounts of structural colour variability (R2 = 0.21–0.65). The coexistence of many independent, evolutionarily labile mechanisms that generate colour variation suggests that the diversity of structural colours in this clade could be mediated by many independent genetic and environmental factors.


2020 ◽  
Vol 130 (2) ◽  
pp. 239-246
Author(s):  
Rafael S Marcondes ◽  
Robb T Brumfield

Abstract Intraspecific geographic phenotypic variation is a crucial theme in evolutionary biology. Comparing its magnitude across species can provide insights into its ecological and genetic correlates. Here, we developed an index, which we dub the V index, to quantify intraspecific plumage colour variation in typical antbirds (Thamnophilidae), a family which has long interested ornithologists due to a high prevalence of intraspecific variation. The V index is based on a bivariate colour space defined by brightness and redness. Its value for each species equals the mean area occupied by each of its subspecies in that colour space, divided by the area of the species. Lower values indicate greater intraspecific geographic variation. Based on this index, Thamnophilus caerulescens (Variable Antshrike) was exceptionally geographically variable compared to other thamnophilids, as previously suggested based on qualitative evidence. In general, we found that the most variable species had disjunct distributions and deep phylogeographic structure, suggesting an effect of historical population dynamics in producing geographic variation. The V index can be adapted for use with other taxa, traits, and taxonomic levels, and we expect it will instigate novel ways of thinking about phenotypic variation in birds and other animals.


2013 ◽  
Vol 100 (10) ◽  
pp. 983-991 ◽  
Author(s):  
Miklós Laczi ◽  
Gergely Hegyi ◽  
Márton Herényi ◽  
Dorottya Kiss ◽  
Gábor Markó ◽  
...  

2013 ◽  
Vol 26 (11) ◽  
pp. 2415-2427 ◽  
Author(s):  
J. P. Renoult ◽  
M. Thomann ◽  
H. M. Schaefer ◽  
P.-O. Cheptou

2016 ◽  
Vol 118 (3) ◽  
pp. 551-568 ◽  
Author(s):  
Georgia V. McNeil ◽  
Caitlin N. Friesen ◽  
Suzanne M. Gray ◽  
Amalia Aldredge ◽  
Lauren J. Chapman

2012 ◽  
Vol 279 (1742) ◽  
pp. 3401-3408 ◽  
Author(s):  
María C. De Mársico ◽  
Mariela G. Gantchoff ◽  
Juan C. Reboreda

Egg mimicry by obligate avian brood parasites and host rejection of non-mimetic eggs are well-known textbook examples of host–parasite coevolution. By contrast, reciprocal adaptations and counteradaptations beyond the egg stage in brood parasites and their hosts have received less attention. The screaming cowbird ( Molothrus rufoaxillaris ) is a specialist obligate brood parasite whose fledglings look identical to those of its primary host, the baywing ( Agelaioides badius ). Such a resemblance has been proposed as an adaptation in response to host discrimination against odd-looking young, but evidence supporting this idea is scarce. Here, we examined this hypothesis by comparing the survival rates of young screaming cowbirds and non-mimetic shiny cowbirds ( Molothrus bonariensis ) cross-fostered to baywing nests and quantifying the similarity in plumage colour and begging calls between host and cowbird fledglings. Shiny cowbirds suffered higher post-fledging mortality rates (83%) than screaming cowbirds (0%) owing to host rejection. Visual modelling revealed that screaming cowbirds, but not shiny cowbirds, were indistinguishable from host young in plumage colour. Similarly, screaming cowbirds matched baywings' begging calls more closely than shiny cowbirds. Our results strongly support the occurrence of host fledgling mimicry in screaming cowbirds and suggest a role of visual and vocal cues in fledgling discrimination by baywings.


Sign in / Sign up

Export Citation Format

Share Document