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Mark E. Hauber - One of the best experts on this subject based on the ideXlab platform.
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How to Make a Mimic? Brood Parasitic Striped Cuckoo Eggs Match Host Shell Color but Not Pigment Concentrations
Journal of Chemical Ecology, 2018Co-Authors: Miri Dainson, Mandë Holford, Melissa Mark, Marouf Hossain, Barney Yoo, Shannon E. Mcneil, Christina Riehl, Mark E. HauberAbstract:Hosts of avian brood parasites often use visual cues to reject foreign eggs, and several lineages of brood parasites have evolved mimetic Eggshell coloration and patterning to circumvent host recognition. What is the mechanism of parasitic egg color mimicry at the chemical level? Mimetic egg coloration by Common Cuckoos Cuculus canorus is achieved by depositing similar concentrations of colorful pigments into their shells as their hosts. The mechanism of parasitic egg color mimicry at the chemical level in other lineages of brood parasites remains unexplored. Here we report on the chemical basis of egg color mimicry in an evolutionarily independent, and poorly studied, host-parasite system: the Neotropical Striped Cuckoo Tapera naevia and one of its hosts, the Rufous-and-white Wren Thryophilus rufalbus . In most of South America, Striped Cuckoos lay white eggs that are identical to those of local host species. In Central America, however, Striped Cuckoos lay blue eggs that match those of the Rufous-and-white Wren, suggesting that blue egg color in these cuckoo populations is an adaptation to mimic host egg appearance. Here we confirm that Striped Cuckoo eggs are spectrally similar to those of their hosts and consistently contain the same major Eggshell pigment, biliverdin. However, wren Eggshells lacked protoporphyrin, which was present in the parasitic cuckoo Eggshells. Furthermore, biliverdin concentrations were significantly lower in cuckoo Eggshells than in host Eggshells. Similarity of host-parasite Eggshell appearance, therefore, need not always be paralleled by a quantitative chemical match to generate effective visual mimicry in birds.
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What Does the Eggshell Cuticle Do? A Functional Comparison of Avian Eggshell Cuticles.
Physiological and biochemical zoology : PBZ, 2017Co-Authors: Liliana D'alba, Geoffrey I. N. Waterhouse, Mark E. Hauber, Roxana Torres, Chad M. Eliason, Matthew D. ShawkeyAbstract:AbstractThe avian Eggshell is a highly ordered structure with several layers (mammillae, palisades, and vertical crystal layer) composed of calcium carbonate (∼96%) and minerals within an organic matrix. The cuticle is a noncalcified layer that covers the Eggshells of most bird species. Eggshells are multifunctional structures that have evolved in response to diverse embryonic requirements and challenges, including protection from microbial infection, nest flooding, and exposure to solar radiation. However, experimental evidence for these functions across diverse taxa is currently limited. Here we investigated the effects of nanosphere cuticles on (1) bacterial attachment and transshell penetration, (2) Eggshell wettability, (3) water vapor conductance, and (4) regulation of ultraviolet (UV) reflectance in seven ground-nesting bird species. We found considerable interspecific variation in ultrastructure and chemical composition of cuticles. Experimental removal of the cuticle confirmed that all nanosphere...
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The cuticle modulates ultraviolet reflectance of avian Eggshells
Biology open, 2015Co-Authors: Daphne Fecheyr-lippens, Branislav Igic, Liliana D'alba, Daniel Hanley, Aida Verdes, Mandë Holford, Geoffrey I. N. Waterhouse, Tomáš Grim, Mark E. Hauber, Matthew D. ShawkeyAbstract:Avian Eggshells are variedly coloured, yet only two pigments, biliverdin and protoporphyrin IX, are known to contribute to the dramatic diversity of their colours. By contrast, the contributions of structural or other chemical components of the Eggshell are poorly understood. For example, unpigmented Eggshells, which appear white to the human eye, vary in their ultraviolet (UV) reflectance, which may be detectable by birds. We investigated the proximate mechanisms for the variation in UV-reflectance of unpigmented bird Eggshells using spectrophotometry, electron microscopy, chemical analyses, and experimental manipulations. We specifically tested how UV-reflectance is affected by the Eggshell cuticle, the outermost layer of most avian Eggshells. The chemical dissolution of the outer Eggshell layers, including the cuticle, increased UV-reflectance for only Eggshells that contained a cuticle. Our findings demonstrate that the outer Eggshell layers, including the cuticle, absorb UV-light, probably because they contain higher levels of organic components and other chemicals, such as calcium phosphates, compared to the predominantly calcite-based Eggshell matrix. These data highlight the need to examine factors other than the known pigments in studies of avian Eggshell colour.
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Not so colourful after all: Eggshell pigments constrain avian Eggshell colour space
Biology letters, 2015Co-Authors: Daniel Hanley, Tomáš Grim, Phillip Cassey, Mark E. HauberAbstract:Birds' Eggshells are renowned for their striking colours and varied patterns. Although often considered exceptionally diverse, we report that avian Eggshell coloration, sampled here across the full phylogenetic diversity of birds, occupies only 0.08–0.10% of the avian perceivable colour space. The concentrations of the two known tetrapyrrole Eggshell pigments (protoporphyrin and biliverdin) are generally poor predictors of colour, both intra- and interspecifically. Here, we show that the constrained diversity of Eggshell coloration can be accurately predicted by colour mixing models based on the relative contribution of both pigments and we demonstrate that the models' predictions can be improved by accounting for the reflectance of the Eggshell's calcium carbonate matrix. The establishment of these proximate links between pigmentation and colour will enable future tests of hypotheses on the functions of perceived avian Eggshell colours that depend on Eggshell chemistry. More generally, colour mixing models are not limited to avian Eggshell colours but apply to any natural colour. Our approach illustrates how modelling can aid the understanding of constraints on phenotypic diversity.
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Impact of time since collection on avian Eggshell color: a comparison of museum and fresh egg specimens
Behavioral Ecology and Sociobiology, 2010Co-Authors: Phillip Cassey, Camille Duval, Golo Maurer, John G. Ewen, Mark E. HauberAbstract:Studies of avian Eggshell coloration have been a long-standing research focus in behavioral evolutionary ecology. Museum collections have provided a widely used resource because they allow efficient sampling across broad temporal, geographical, and taxonomic ranges, even for species that are rare and for which sampling in the wild is ethically or practically unwarranted. We used reflectance spectrophotometry across the avian visual spectrum to compare Eggshell color of specimens of the song thrush ( Turdus philomelos ) in two museums (Natural History Museum, UK and Auckland Museum, New Zealand) with each other and with Eggshells collected fresh in New Zealand. These data enabled us to test the effects of source and storage in different museums, as well as time since collection, across four metrics of Eggshell coloration: blue-green and ultraviolet chroma, overall brightness, and the spectral coefficient of variation. Variation within an egg, within a clutch, and among clutches, was similar between the two museum datasets but different from those of fresh eggs. We found significant differences in all four metrics between the collections, and that fresh Eggshells reflected stronger in the blue-green wavelength than in museum eggs. This difference is most likely due to different preservation techniques and storage histories. Furthermore, an effect of time since collection was only apparent in the blue-green chroma and was higher in more recent museum Eggshell samples. Our results support the use of historic museum samples in intraspecific studies of shell coloration providing that efforts are made to compare specimens, which were collected during similar periods.
Juan Jose Soler - One of the best experts on this subject based on the ideXlab platform.
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preening as a vehicle for key bacteria in hoopoes
Microbial Ecology, 2015Co-Authors: Angela Martinezgarcia, Juan Jose Soler, Antonio M Martinplatero, Manuel Martinezbueno, Sonia M Rodriguezruano, Natalia Juarezgarcia, Manuel MartinvivaldiAbstract:Oily secretions produced in the uropygial gland of incubating female hoopoes contain antimicrobial-producing bacteria that prevent feathers from degradation and eggs from pathogenic infection. Using the beak, females collect the uropygial gland secretion and smear it directly on the Eggshells and brood patch. Thus, some bacterial strains detected in the secretion should also be present on the Eggshell, beak, and brood patch. To characterize these bacterial communities, we used Automatic Ribosomal Intergenic Spacer Analysis (ARISA), which distinguishes between taxonomically different bacterial strains (i.e. different operational taxonomic units [OTUs]) by the size of the sequence amplified. We identified a total of 146 different OTUs with sizes between 139 and 999 bp. Of these OTUs, 124 were detected in the uropygial oil, 106 on the beak surface, 97 on the brood patch, and 98 on the Eggshell. The highest richness of OTUs appeared in the uropygial oil samples. Moreover, the detection of some OTUs on the beak, brood patch, and Eggshells of particular nests depended on these OTUs being present in the uropygial oil of the female. These results agree with the hypothesis that symbiotic bacteria are transmitted from the uropygial gland to beak, brood patch, and Eggshell surfaces, opening the possibility that the bacterial community of the secretion plays a central role in determining the communities of special hoopoe Eggshell structures (i.e., crypts) that, soon after hatching, are filled with uropygial oil, thereby protecting embryos from pathogens.
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the evolution of size of the uropygial gland mutualistic feather mites and uropygial secretion reduce bacterial loads of Eggshells and hatching failures of european birds
Journal of Evolutionary Biology, 2012Co-Authors: Juan Jose Soler, Juan Manuel Peraltasanchez, Antonio M Martinplatero, Manuel Martinvivaldi, Manuel MartinezbuenoAbstract:Potentially, pathogenic bacteria are one of the main infective agents against which a battery of chemical and physical barriers has evolved in animals. Among these are the secretions by the exocrine uropygial gland in birds. The antimicrobial properties of uropygial secretions may prevent colonization and growth of microorganisms on feathers, skin and Eggshells. However, uropygial gland secretions also favour the proliferation of feather mites that feed on secretions and microorganisms living on feathers that would otherwise reach Eggshells during incubation if not consumed by feather mites. Therefore, at the interspecific level, uropygial gland size (as an index of volume of uropygial secretion) should be positively related to Eggshell bacterial load (i.e. the risk of egg infection), whereas Eggshell bacterial loads may be negatively related to abundance of feather mites eating bacteria. Here, we explore these previously untested predictions in a comparative framework using information on Eggshell bacterial loads, uropygial gland size, diversity and abundance of feather mites and hatching success of 22 species of birds. The size of the uropygial gland was positively related to Eggshell bacterial loads (mesophilic bacteria and Enterobacteriaceae), and bird species with higher diversity and abundance of feather mites harboured lower bacterial density on their Eggshells (Enterococcus and Staphylococcus), in accordance with the hypothesis. Importantly, Eggshell bacterial loads of mesophilic bacteria, Enterococcus and Enterobacteriaceae were negatively associated with hatching success, allowing us to interpret these interspecific relationships in a functional scenario, where both uropygial glands and mutualistic feather mites independently reduce the negative effects of pathogenic bacteria on avian fitness.
Manuel Martinezbueno - One of the best experts on this subject based on the ideXlab platform.
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preening as a vehicle for key bacteria in hoopoes
Microbial Ecology, 2015Co-Authors: Angela Martinezgarcia, Juan Jose Soler, Antonio M Martinplatero, Manuel Martinezbueno, Sonia M Rodriguezruano, Natalia Juarezgarcia, Manuel MartinvivaldiAbstract:Oily secretions produced in the uropygial gland of incubating female hoopoes contain antimicrobial-producing bacteria that prevent feathers from degradation and eggs from pathogenic infection. Using the beak, females collect the uropygial gland secretion and smear it directly on the Eggshells and brood patch. Thus, some bacterial strains detected in the secretion should also be present on the Eggshell, beak, and brood patch. To characterize these bacterial communities, we used Automatic Ribosomal Intergenic Spacer Analysis (ARISA), which distinguishes between taxonomically different bacterial strains (i.e. different operational taxonomic units [OTUs]) by the size of the sequence amplified. We identified a total of 146 different OTUs with sizes between 139 and 999 bp. Of these OTUs, 124 were detected in the uropygial oil, 106 on the beak surface, 97 on the brood patch, and 98 on the Eggshell. The highest richness of OTUs appeared in the uropygial oil samples. Moreover, the detection of some OTUs on the beak, brood patch, and Eggshells of particular nests depended on these OTUs being present in the uropygial oil of the female. These results agree with the hypothesis that symbiotic bacteria are transmitted from the uropygial gland to beak, brood patch, and Eggshell surfaces, opening the possibility that the bacterial community of the secretion plays a central role in determining the communities of special hoopoe Eggshell structures (i.e., crypts) that, soon after hatching, are filled with uropygial oil, thereby protecting embryos from pathogens.
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the evolution of size of the uropygial gland mutualistic feather mites and uropygial secretion reduce bacterial loads of Eggshells and hatching failures of european birds
Journal of Evolutionary Biology, 2012Co-Authors: Juan Jose Soler, Juan Manuel Peraltasanchez, Antonio M Martinplatero, Manuel Martinvivaldi, Manuel MartinezbuenoAbstract:Potentially, pathogenic bacteria are one of the main infective agents against which a battery of chemical and physical barriers has evolved in animals. Among these are the secretions by the exocrine uropygial gland in birds. The antimicrobial properties of uropygial secretions may prevent colonization and growth of microorganisms on feathers, skin and Eggshells. However, uropygial gland secretions also favour the proliferation of feather mites that feed on secretions and microorganisms living on feathers that would otherwise reach Eggshells during incubation if not consumed by feather mites. Therefore, at the interspecific level, uropygial gland size (as an index of volume of uropygial secretion) should be positively related to Eggshell bacterial load (i.e. the risk of egg infection), whereas Eggshell bacterial loads may be negatively related to abundance of feather mites eating bacteria. Here, we explore these previously untested predictions in a comparative framework using information on Eggshell bacterial loads, uropygial gland size, diversity and abundance of feather mites and hatching success of 22 species of birds. The size of the uropygial gland was positively related to Eggshell bacterial loads (mesophilic bacteria and Enterobacteriaceae), and bird species with higher diversity and abundance of feather mites harboured lower bacterial density on their Eggshells (Enterococcus and Staphylococcus), in accordance with the hypothesis. Importantly, Eggshell bacterial loads of mesophilic bacteria, Enterococcus and Enterobacteriaceae were negatively associated with hatching success, allowing us to interpret these interspecific relationships in a functional scenario, where both uropygial glands and mutualistic feather mites independently reduce the negative effects of pathogenic bacteria on avian fitness.
Manuel Martinvivaldi - One of the best experts on this subject based on the ideXlab platform.
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preening as a vehicle for key bacteria in hoopoes
Microbial Ecology, 2015Co-Authors: Angela Martinezgarcia, Juan Jose Soler, Antonio M Martinplatero, Manuel Martinezbueno, Sonia M Rodriguezruano, Natalia Juarezgarcia, Manuel MartinvivaldiAbstract:Oily secretions produced in the uropygial gland of incubating female hoopoes contain antimicrobial-producing bacteria that prevent feathers from degradation and eggs from pathogenic infection. Using the beak, females collect the uropygial gland secretion and smear it directly on the Eggshells and brood patch. Thus, some bacterial strains detected in the secretion should also be present on the Eggshell, beak, and brood patch. To characterize these bacterial communities, we used Automatic Ribosomal Intergenic Spacer Analysis (ARISA), which distinguishes between taxonomically different bacterial strains (i.e. different operational taxonomic units [OTUs]) by the size of the sequence amplified. We identified a total of 146 different OTUs with sizes between 139 and 999 bp. Of these OTUs, 124 were detected in the uropygial oil, 106 on the beak surface, 97 on the brood patch, and 98 on the Eggshell. The highest richness of OTUs appeared in the uropygial oil samples. Moreover, the detection of some OTUs on the beak, brood patch, and Eggshells of particular nests depended on these OTUs being present in the uropygial oil of the female. These results agree with the hypothesis that symbiotic bacteria are transmitted from the uropygial gland to beak, brood patch, and Eggshell surfaces, opening the possibility that the bacterial community of the secretion plays a central role in determining the communities of special hoopoe Eggshell structures (i.e., crypts) that, soon after hatching, are filled with uropygial oil, thereby protecting embryos from pathogens.
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the evolution of size of the uropygial gland mutualistic feather mites and uropygial secretion reduce bacterial loads of Eggshells and hatching failures of european birds
Journal of Evolutionary Biology, 2012Co-Authors: Juan Jose Soler, Juan Manuel Peraltasanchez, Antonio M Martinplatero, Manuel Martinvivaldi, Manuel MartinezbuenoAbstract:Potentially, pathogenic bacteria are one of the main infective agents against which a battery of chemical and physical barriers has evolved in animals. Among these are the secretions by the exocrine uropygial gland in birds. The antimicrobial properties of uropygial secretions may prevent colonization and growth of microorganisms on feathers, skin and Eggshells. However, uropygial gland secretions also favour the proliferation of feather mites that feed on secretions and microorganisms living on feathers that would otherwise reach Eggshells during incubation if not consumed by feather mites. Therefore, at the interspecific level, uropygial gland size (as an index of volume of uropygial secretion) should be positively related to Eggshell bacterial load (i.e. the risk of egg infection), whereas Eggshell bacterial loads may be negatively related to abundance of feather mites eating bacteria. Here, we explore these previously untested predictions in a comparative framework using information on Eggshell bacterial loads, uropygial gland size, diversity and abundance of feather mites and hatching success of 22 species of birds. The size of the uropygial gland was positively related to Eggshell bacterial loads (mesophilic bacteria and Enterobacteriaceae), and bird species with higher diversity and abundance of feather mites harboured lower bacterial density on their Eggshells (Enterococcus and Staphylococcus), in accordance with the hypothesis. Importantly, Eggshell bacterial loads of mesophilic bacteria, Enterococcus and Enterobacteriaceae were negatively associated with hatching success, allowing us to interpret these interspecific relationships in a functional scenario, where both uropygial glands and mutualistic feather mites independently reduce the negative effects of pathogenic bacteria on avian fitness.
Emily Holt - One of the best experts on this subject based on the ideXlab platform.
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The effects of cooking on avian Eggshell microstructure
Journal of Archaeological Science: Reports, 2016Co-Authors: Ariel Taivalkoski, Emily HoltAbstract:Abstract Although avian Eggshell is a common component of the faunal assemblages at archeological sites, attempts to identify it taxonomically and use it to construct complex economic arguments have been limited. One method of identifying avian Eggshell, using a scanning electron microscope (SEM) to examine characteristic microstructures, can provide more specific taxonomic identifications. This study sought to test whether cross-culturally common egg preparation methods were likely to damage Eggshell in ways that would make it difficult to identify taxonomically under a SEM. We found that most food preparation practices caused minimal or no damage. Only cooking eggs in hot coals caused significant damage to Eggshell microstructures, making it impossible to identify these Eggshells taxonomically. With the exception of fire-cooked eggs, the lack of damage to Eggshell microstructures meant that SEM analysis was sufficient to identify cooked Eggshells taxonomically but insufficient to differentiate most cooking techniques.
