Ornithology最新文献

{"title":"Barn Swallows in East Asia show strong tolerance against nest mites","authors":"Yu Liu, L. Tian, Zhuoya Zhou, K. Gao, De Chen, Donglai Li, Y. Wang, Zhengwang Zhang","doi":"10.1093/ornithology/ukad001","DOIUrl":"https://doi.org/10.1093/ornithology/ukad001","url":null,"abstract":"ABSTRACT Hosts defend against parasites through two main strategies: resistance and tolerance. These two strategies have different influences on the parasite load of the host and so have variable effects on the fitness of parasites. In this study, we investigated the strategy used by the Barn Swallow (Hirundo rustica) to defend against a hematophagous mite (Dermanyssus hirundinis) in East Asia. For the first time, we found Barn Swallows were parasitized by D. hirundinis in Asia and, in northeastern China, over 60% of broods were parasitized. We examined whether swallows with better body condition or the males with more extravagant sexually selected traits (longer tail streamers or redder ventral plumage) showed stronger resistance or tolerance to these parasites. The results showed that males with more extravagant sexual ornaments had weaker resistance (heavier brood mite load) than males with less extravagant traits; however, the heavier mite load was likely to be a byproduct of larger brood size. Moreover, the Barn Swallow population showed strong tolerance against the parasite (i.e. the brood mite load did not affect brood size or nestling body mass). It is worth noting that male swallows with redder breast plumage showed weaker tolerance (lower seasonal reproductive success) than other males. Further, we conducted experimental ectoparasite manipulations in 46 Barn Swallow nests to verify the potential effect of these parasites on the body condition of nestlings. Neither the body mass nor the hemoglobin concentration differed between the designed groups; however, the hemoglobin concentration of nestlings decreased with mite load. We concluded that the Barn Swallow population in East Asia used the tolerance strategy, rather than resistance to defend against nest mites, and the ectoparasitic mite did not appear to be a strong selective factor for reproductive success owing to the strong tolerance of the studied Barn Swallow population. LAY SUMMARY To defend against parasites, hosts either reduce parasite burden (resistance) or compensate for parasite damage (tolerance). In this study, we are the first to report the existence of a bloodsucking parasite species Dermanyssus hirundinis on Barn Swallow (Hirundo rustica) nestlings in Asia, and we investigated the swallows defense against this ectoparasite. Different from previous studies which showed that Barn Swallow males with longer tails or redder plumage coloring had stronger resistance against nest mites, our results showed that such males had weaker resistance to ectoparasites in northeastern China, which was likely to be a byproduct of a larger brood size. As heavier mite load did not appear to impair their reproductive success, the studied Barn Swallow population showed strong overall tolerance to these ectoparasites; however, the nest mite could still affect swallow nestling hemoglobin concentration. 摘要 宿主主要通过两种策略防御寄生虫：抵抗力和忍耐力。采取这两种策略对于宿主的寄生虫负载量有不同的影响，从而对于寄生虫的适合度产生不同 影响。在本项研究中，我们探讨了位于亚洲东部的一个","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"112 1","pages":"1 - 13"},"PeriodicalIF":0.0,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88071863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gradual transitions in genetics and songs between coastal and inland populations of Setophaga townsendi","authors":"Madelyn J Ore, Silu Wang, D. Irwin","doi":"10.1093/ornithology/ukac060","DOIUrl":"https://doi.org/10.1093/ornithology/ukac060","url":null,"abstract":"ABSTRACT Setophaga townsendi is a species of wood warbler (family Parulidae) in northwestern North America that has geographic structure in the mitochondrial and nuclear genomes: while interior populations have differentiated mitonuclear ancestry from the sister species S. occidentalis, coastal populations have a mix of inland and S. occidentalis mitonuclear ancestries. This coastal to inland transition in genomic ancestry raises the possibility of similar geographic structure in phenotypic traits, especially those involved in mate choice. Using qualitative and multivariate approaches, we investigated whether there is a sharp transition between coastal and inland populations in both song and in nuclear DNA. We find there is a shallow geographic cline in Type I song but not in Type II song. Nuclear DNA shows a gradient between coast and inland. There is little correlation between variation in song and the isolation-by-distance pattern in the nuclear DNA. Learned songbird song is shaped by both genetic and cultural processes. There has been a debate on whether song learning promotes or slows down population differentiation. By comparing the within-species variation in song and genetic structures, we can expand our understanding of the dynamic interplay between mating signals and population differentiation. LAY SUMMARY Song and nuclear genomic data were collected across the entire range of Setophaga townsendi, a species known to have differences in genomic ancestry between coastal and inland populations. Type I song—song thought to be used in courtship—shows greater geographic gradient than Type II song—song thought to be used in male–male competition. Overall nuclear genomic variation follows an isolation-by-distance pattern between coastal and inland populations. Despite geographic gradient in Type I song, some variants are shared over broad geographic distances. RESUMEN Setophaga townsendi es una especie de Parulidae del noroeste de América del Norte con una estructura geográfica en los genomas mitocondrial y nuclear: mientras que las poblaciones del interior tienen ancestralidad mito-nuclear diferenciada de la especie hermana S. occidentalis, las poblaciones costeras tienen una mezcla de ancestralidades del interior y mito-nucleares de S. occidentalis. Esta transición de la costa al interior en la ancestralidad genómica plantea la posibilidad de una estructura geográfica similar en los rasgos fenotípicos, especialmente aquellos involucrados en la elección de pareja. Utilizando enfoques cualitativos y multivariados, investigamos si existe una transición brusca entre las poblaciones costeras y del interior tanto en el canto como en el ADN nuclear. Encontramos que hay una clina geográfica poco profunda en el canto Tipo I pero no en el canto Tipo II. El ADN nuclear muestra un gradiente entre la costa y el interior. Hay poca correlación entre la variación del canto y el patrón de aislamiento por distancia en el ADN nuclear. El canto aprendido de las ","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"58 1","pages":"1 - 14"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84325918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitochondrial DNA sequences and nuclear microsatellites reveal population genetic structure of the range-restricted hummingbird Phaeoptila sordida in the Balsas Basin","authors":"M. Hernández-Soto, Yuyini Licona-Vera, J. Ornelas","doi":"10.1093/ornithology/ukac059","DOIUrl":"https://doi.org/10.1093/ornithology/ukac059","url":null,"abstract":"ABSTRACT The Dusky Hummingbird Phaeoptila sordida (= Cynanthus sordidus), occurs in the Balsas Basin, a region with a complex biogeographical history, and in the Tehuacán-Cuicatlán Valley and Valles Centrales in Puebla and Oaxaca, Mexico. However, the biogeographical and evolutionary history of these two regions of Mexico is poorly understood. We aimed to understand the genetic structure and phylogeographic history of P. sordida, a range-restricted hummingbird to these two regions, as a proxy to study the evolutionary history of the Balsas Basin, by using mitochondrial DNA (mtDNA) sequences and nuclear microsatellites. Geographic structure was evident for both markers; however, some discordance was observed between the mitochondrial and nuclear markers. Based on mtDNA, samples from the Balsas Basin form one haplogroup, well separated from the Tehuacán-Cuicatlán Valley and Valles Centrales samples. In contrast to this, nuclear microsatellites uncovered two slightly different genetic clusters restricted to different habitats: samples from the Western Balsas restricted to the seasonally deciduous tropical dry forest, and samples from the Eastern Balsas-Tehuacán/Cuicatlán-Tehuantepec area in shrub and dry forested habitats. As expected by the interglacial refugia hypothesis, ENM predicted that the distribution of P. sordida was more contracted and fragmented during the Last Inter Glacial and more expanded at the Last Glacial Maximum. Consistent with that observed for other range-restricted hummingbird species, ENM predictions and a strong signal of population expansion indicate that the geographical range and population size are unstable over time, as compared to widespread hummingbird species, and that ecological and climatic factors possibly impacted its diversification. This study contributes to the debate that disputes the integrity of the Balsas Basin as a biogeographical unit and urges for the conservation of endemic species in the Balsas region and interior Oaxaca. LAY SUMMARY We conduct phylogeographic analyses to infer genetic relationships among Phaeoptila sordida (= Cynanthus sordidus) populations. Using mitochondrial DNA sequences and nuclear microsatellites, we consistently show the existence of two genetic clusters morphologically and ecologically differentiated: samples from the Western Balsas and from the Eastern Balsas-Tehuacán/Cuicatlán-Tehuantepec. Population fragmentation predicted by ecological niche modeling and population expansion suggest that the distribution of P. sordida was more contracted and fragmented during the Last Inter Glacial and more expanded at the Last Glacial Maximum, as expected by the interglacial refugia hypothesis. The study contributes to understanding the cryptic diversity of a species highly restricted in range. RESUMEN El Colibrí Oscuro, Phaeoptila sordida (= Cynanthus sordidus), se encuentra en la Depresión del Balsas, una región con una historia biogeográfica compleja, y en el Valle de Tehuacán-Cuicat","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"79 1","pages":"1 - 19"},"PeriodicalIF":0.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83802133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of differing staging strategies between adult and juvenile Semipalmated Sandpipers highlights the importance of small staging sites in Atlantic Canada","authors":"Rebeca C. Linhart, D. Hamilton, J. Paquet, C. Gratto-Trevor","doi":"10.1093/ornithology/ukac056","DOIUrl":"https://doi.org/10.1093/ornithology/ukac056","url":null,"abstract":"ABSTRACT Semipalmated Sandpipers (Calidris pusilla) are Arctic-breeding shorebirds that use staging sites in Atlantic Canada during their southbound migration to South America. The upper Bay of Fundy is recognized as a critical staging area, but hundreds of smaller sites outside the Bay of Fundy also host staging Semipalmated Sandpipers and have received comparatively little attention. Using the Motus Wildlife Tracking System, we tracked adult and juvenile Semipalmated Sandpipers and identified different staging strategies used by sandpipers tagged inside and outside the Bay of Fundy. Birds tagged in the Bay of Fundy remained there, while birds tagged along the Northumberland Strait, a tidal water body along the eastern coast of New Brunswick and northern Nova Scotia displayed multiple strategies. Most birds tagged along the Northumberland Strait used sites outside the Bay of Fundy exclusively, while a smaller proportion moved to the Bay of Fundy. Length of stay was shorter for birds using only sites outside the Bay of Fundy compared to birds using Bay sites or transferring between them. Choice of departure conditions also varied; birds using the Bay were more selective of specific wind conditions, favoring north and northwesterly winds. We found juvenile Semipalmated Sandpipers stayed 3 days longer in the region than adults and appeared to use a broader variety of sites. Our results highlight the importance of implementing conservation measures for smaller, lesser-known staging sites in Atlantic Canada, many of which are at an increased risk of loss and degradation due to climate change, coastal development, pollution, and human disturbance. LAY SUMMARY Nanotags and the Motus Wildlife Tracking System were used to track the movements of staging adult and juvenile Semipalmated Sandpipers tagged at two locations in Atlantic Canada-one within the Bay of Fundy and the other along the Northumberland Strait. Adults and juveniles tagged at both locations differed in site use, with juveniles using a broader variety of sites than adults. Most adults and juveniles tagged along the Northumberland Strait did not move into the Bay of Fundy, and exclusively used sites outside the Bay of Fundy during staging. Juveniles stayed in the region ∼3 days longer than adults. Adults and juveniles used similar departure cues, but Semipalmated Sandpipers using sites outside the Bay were less selective of wind conditions and may take a different departure route than those using sites within the Bay. RÉSUMÉ Calidris pusilla sont un limicole nichant dans l'Arctique qui utilise des sites de halte migratoire dans le Canada atlantique au cours de sa migration vers l'Amérique du Sud. La partie supérieure de la baie de Fundy est reconnue comme une halte migratoire importante, mais des centaines de sites plus petits à l'extérieur de la baie de Fundy accueillent également C. pusilla et ont reçu relativement peu d'attention. À l'aide du système de suivi de la faune Motus, nous avons","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"5 1","pages":"1 - 14"},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75595536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric song recognition does not influence gene flow in an emergent songbird hybrid zone","authors":"W. E. Brooks, P. Wimberger","doi":"10.1093/ornithology/ukac055","DOIUrl":"https://doi.org/10.1093/ornithology/ukac055","url":null,"abstract":"ABSTRACT Hybrid zones can be used to examine the mechanisms, like song recognition, that affect reproductive isolation and speciation. Song has mixed support as a driver of speciation; we did not find song to be associated with reproductive isolation in White-crowned Sparrow subspecies (Zonotrichia leucophrys pugetensis and Z. l. gambelii). We examined an emerging secondary contact zone in these subspecies by measuring song variation, song recognition, plumage, morphology, and mitochondrial DNA (mtDNA). Plumage and morphological characters provided evidence of hybridization in the contact zone, with some birds possessing intermediate phenotype and song characteristics, and some possessing discordant phenotype and mitochondrial haplotype. Playback experiments revealed asymmetric song recognition: male pugetensis displayed greater response to their own song than gambelii song, whereas gambelii did not discriminate significantly. If female choice operates similarly to male song discrimination, we predicted asymmetric gene flow, resulting in a greater number of hybrids with gambelii mtDNA. Contrary to our prediction, more gambelii and putative hybrids in the contact zone possessed pugetensis mtDNA haplotypes, possibly due to greater pugetensis abundance and female-biased dispersal. LAY SUMMARY Hybrid zones, or boundaries where closely related populations or species interbreed, provide an opportunity to study factors affecting reproductive isolation and speciation. Many songbirds exhibit preference for local song types which may facilitate reproductive isolation. Recent contact between White-crowned Sparrows (Zonotrichia leucophrys pugetensis and Z. l. gambelii) appears to have resulted in hybridization in the Washington Cascade mountains. We investigated the role that song recognition may play in determining whether the two subspecies interbreed in the new contact zone. In playback experiments, male pugetensis recognized their own subspecies song more than that of gambelii, whereas gambelii did not discriminate. This difference in song discrimination correlates with the presence of geographic song variation. Pugetensis has regional dialects, distinguishes among different dialects, and is exposed to less song variation, thus may be less likely to recognize foreign songs. Gambelii is exposed to more song variation, and thus may be more likely to recognize foreign songs. Genetic results indicated greater movement of pugetensis mitochondrial DNA into gambelii-like individuals, suggesting that female pugetensis hybridized more frequently than female gambelii. This result was contrary to what we expected from the playback experiment results (if female choice mirrored male discrimination behavior). Asymmetric hybridization may be explained by some combination of differences in relative population growth/size, female dispersal, or female choice. Our results underscore the complexity of hybrid zones and the importance of investigating multiple possible mechan","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"16 1","pages":"1 - 11"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75665746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A rallid ballad: Communal signaling is correlated with year-round territoriality in the most duet-rich family of birds (Gruiformes: Rallidae)","authors":"Daniel L Goldberg, B. Sadd, A. Capparella","doi":"10.1093/ornithology/ukac054","DOIUrl":"https://doi.org/10.1093/ornithology/ukac054","url":null,"abstract":"ABSTRACT Duetting, in which 2 or more individuals call in coordinated unison, is common in birds, yet most research investigating the function of avian duets has focused only on oscine passerines. However, we have discovered that duetting occurs in 61 species (59%) in the family Rallidae (rails), one of the highest known rates in any bird clade, and that rail duets are also significantly associated with year-round territoriality and habitat type. We applied a comparative approach to study the occurrence of duetting relative to socio-ecological traits and call properties in 103 rail species, with the prediction that duetting rails produce low-frequency calls that spread well over short distances in densely vegetated habitats. Using a model correcting for phylogenetic signal, we found that duetting is the ancestral state in Rallidae, and that duetting rails show a trending effect for being sedentary and nonmigratory. Contrary to our predictions, there was no significant correlation between rail duetting and social bond length, breeding system, breeding latitude from the equator, or sexual dimorphism, as year-round territoriality and forest or heterogeneous habitats were the strongest predictors of duets. Despite the prevalence of duetting in Rallidae, few studies have tested duet functions such as territory defense in this family, and our comparative phylogenetic study lays the groundwork for future research, as little remains known about the behavioral ecology and vocal interactions of many rails. Lay Summary Many birds duet, but most research into avian duetting has focused on songbirds. Rails include a high percentage of duetting species but are not well-studied. Using a published phylogeny, call recordings, and life history traits, we compared 103 rail species and measured their call properties to determine what behaviors and environments are associated with duetting in rails. Duetting is most common in rails that defend territories year-round, but it is not strongly associated with other life history traits or call properties. Future studies of rails will increase our understanding of duet evolution in birds. RESUMEN Hacer un dueto, en el que 2 o más individuos realizan llamadas coordinadas al unísono, es común en las aves, pero la mayoría de los trabajos que investigan la función de los duetos de aves se han centrado solo en los paseriformes oscinos. Sin embargo, hemos descubierto que el dueto ocurre en 61 especies (59%) en la familia Rallidae (rálidos), una de las tasas más altas conocidas en cualquier clado de aves, y que los duetos de los rálidos también están significativamente asociados con la territorialidad durante todo el año y el tipo de hábitat. Aplicamos un enfoque comparativo para estudiar la aparición de duetos en relación con rasgos socio-ecológicos y las propiedades de las llamadas en 103 especies de rálidos, con la predicción de que los duetos producen llamadas de baja frecuencia que se propagan bien a distancias cortas en háb","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"56 1","pages":"1 - 11"},"PeriodicalIF":0.0,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73115973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Professional ethics survey identifies strengths and areas for improvement in the American Ornithological Society","authors":"Jennifer Walsh, R. Bowman, J. Brawn, Kristen M. Covino, Katie M. Dugger, R. Fleischer, Jennifer L. Houtz, Sean M. Mahoney, M. Pruett-Jones, C. Tarwater, J. Fair","doi":"10.1093/ornithology/ukac053","DOIUrl":"https://doi.org/10.1093/ornithology/ukac053","url":null,"abstract":"ABSTRACT In response to a growing need to foster ethical behavior within scientific societies, the American Ornithological Society's (AOS) professional ethics committee conducted a survey of members in spring 2021 to identify the primary challenges and ethical conduct concerns. The survey indicated that the AOS has a strong culture of professional ethics and highlighted areas needing improvement. Participants identified discrimination and lack of inclusivity (44%), scientific fraud and abuse in data and publications (35%), and sexual harassment (31%) as the highest potential risks for unethical behavior in our organization. Moreover, approximately one-third of respondents (34%) had personally witnessed or experienced unethical behavior as an AOS member. A smaller proportion (16%) felt pressure to compromise their work standards in ornithology. These findings are likely representative of broader patterns that professional, scientific societies face as they seek to provide safe, welcoming, and thoughtful environments for researchers to share their work, gain valuable feedback, and develop collaborations. The survey results also create a framework for workshops, training opportunities, and disseminating information within the AOS and, ideally, with the broader, international community of ornithologists. LAY SUMMARY Scientific societies have an obligation to foster ethical behavior of their membership. The American Ornithological Society (AOS) has conducted a survey to help identify the primary challenges and ethical conduct concerns that face the ornithological community. We disseminate the major findings of the survey here and discuss implications and future steps the AOS to address member concerns. Overall, AOS ranked admirably regarding the overall ethical culture of our professional society, but the survey also identified room for improvement. RESUMEN En respuesta a la creciente necesidad de fomentar el comportamiento ético dentro de las sociedades científicas, el comité de ética profesional de la Sociedad Ornitológica Estadounidense (AOS, por sus siglas en inglés) realizó una encuesta entre los miembros en la primavera de 2021 para identificar los principales desafíos y preocupaciones de conducta ética. La encuesta indicó que la AOS tiene una sólida cultura de ética profesional y destacó las áreas que necesitan mejorarse. Los participantes identificaron la discriminación y la falta de inclusión (44%), el fraude científico y el abuso en datos y publicaciones (35%) y el acoso sexual (31%) como los mayores riesgos potenciales de comportamiento no ético en nuestra organización. Además, aproximadamente un tercio de los encuestados (34%) había presenciado o experimentado personalmente un comportamiento no ético como miembro de la AOS. Una proporción menor (16%) sintió presión para transigir sus estándares de trabajo en ornitología. Es probable que estos hallazgos sean representativos de patrones más amplios a los que se enfrentan las sociedades cient","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"38 1","pages":"1 - 7"},"PeriodicalIF":0.0,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76324646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Painting the Bunting: Carotenoids and structural elements combine to produce the feather coloration of the male Painted Bunting","authors":"Nicholas M. Justyn, R. Weaver","doi":"10.1093/ornithology/ukac052","DOIUrl":"https://doi.org/10.1093/ornithology/ukac052","url":null,"abstract":"ABSTRACT Male Painted Buntings (Passerina ciris) display at least 6 distinct plumage colors that encapsulate much of the visible light spectrum, yet the specific mechanisms responsible for generating this diversity of color have not been identified. Here, we show that metabolically derived carotenoids and nanostructures capable of producing structural color were ubiquitous across feather patches. We used digital photography, light microscopy, spectrophotometry, carotenoid extraction, and high-performance liquid chromatography to show that the resulting color of each feather patch depended on the concentration of carotenoids, melanins, and underlying feather nanostructures. For example, we found that the blue-violet head feathers contained low concentrations of ketolated carotenoids, which is not typical of blue-violet structurally colored feathers. Additionally, the red breast and orange belly feathers contained a green-tuned structural color visible after carotenoid extraction, which is not typical of feathers that contain ketolated carotenoids. Although, none of these abnormal combinations of carotenoids and structural coloration appeared to significantly impact feather color. Conversely, we found the purple rump, dark green greater coverts, and bright yellow-green mantle feather coloration resulted from the combination of high concentrations of carotenoids and the presence of structural color. For the first time, we identify the combination of red ketolated carotenoids and blue structural color as a mechanism to produce purple feather coloration. Identifying the specific mechanisms that give rise to the diversity of colors within this species will facilitate the study of the—to date—unknown signaling functions of colors produced through the combination of carotenoids and nanostructures in Painted Buntings and other songbirds. LAY SUMMARY Some of the most spectacular feather colors result from 2 distinct processes: light interacting with specific pigments or from the reflection of light by microscopic feather components. Red Northern Cardinal feathers are colored by only red pigments called carotenoids, whereas only feather nanostructures create the blue color of Blue Jay feathers. We demonstrate that all the different colored feather patches on male Painted Bunting contain both carotenoid pigments and structures capable of producing color. For the first time, we also detail how red carotenoid pigments and blue structural color are combined to create a purple-colored rump feather in the male Painted Bunting. These findings will inform future studies on the physiology, ecology, and evolution of bird coloration and provide insight into which genes underly color variation among individuals and species. RESUMEN Los machos de Passerina ciris muestran al menos seis colores de plumaje distintos que encapsulan gran parte del espectro de luz visible, pero no se han identificado los mecanismos específicos responsables de generar esta diversidad de colore","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"18 1","pages":"1 - 8"},"PeriodicalIF":0.0,"publicationDate":"2022-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72976628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term winter food supplementation shows no significant impact on reproductive performance in Mountain Chickadees in the Sierra Nevada Mountains","authors":"B. R. Sonnenberg, Joseph F. Welklin, C. Branch, A. Pitera, L. M. Benedict, V. Heinen, D. Kozlovsky, E. Bridge, V. Pravosudov","doi":"10.1093/ornithology/ukac051","DOIUrl":"https://doi.org/10.1093/ornithology/ukac051","url":null,"abstract":"ABSTRACT Supplemental feeding of wild animal populations is popular across many areas of the world and has long been considered beneficial, especially to avian taxa. Over 4 billion dollars are spent by hobby bird feeders in the United States each year alone. However, there is mixed evidence whether wildlife feeding is beneficial, including when it is implemented as a conservation management tool, a targeted experimental design, or an avocation. Much of the current evidence suggests that providing supplemental food is advantageous to the reproductive output and general survival of focal taxa. However, many of these studies are limited in scope and duration, leaving possible negative impacts unaddressed. This is particularly true regarding passive backyard feeding, which describes the majority of supplemental feeding, including the immense effort of millions of public enthusiasts. Here we show that winter supplemental feeding prior to reproduction had no significant impact on a range of reproductive parameters in a resident, montane passerine species, the Mountain Chickadee (Poecile gambeli). This population resides in an intact natural environment with no exposure to supplemental food beyond our experimental treatments, and individual birds were tracked across six years using radio frequency identification technology. Our results add to the growing evidence that supplemental feeding alone, isolated from the effects of urban environments, may have little to no impact on the population dynamics of some avian taxa. LAY SUMMARY Supplemental feeding of avian species has been linked to beneficial, negative and neutral outcomes. Understanding the drivers behind these differences are important for understanding human impacts on avian populations as well as developing future conservation management plans. We tracked a population of Mountain Chickadees from two elevations in the Sierra Nevada, USA for nine years and compared the breeding performance of pairs that used versus those that did not use feeders available throughout the winter. The provisioning we provided is likely similar to the passive backyard feeding observed by many across the world but was conducted in an isolated natural coniferous forest environment. Despite the robust long-term dataset and intensive reproductive monitoring, we found no significant differences in the reproductive performance of chickadees that accessed feeders and those that did not. Our results add to the evidence that the effects of passive or targeted supplemental feeding are context and species dependent. RESUMEN La alimentación suplementaria de las poblaciones de animales silvestres es popular en muchas áreas del mundo y durante mucho tiempo se ha considerado beneficiosa, especialmente para los taxones de aves. Cada año se gastan más de cuatro mil millones de dólares en comederos para aves por parte de aficionados en los Estados Unidos. Sin embargo, existe evidencia contradictoria sobre si la alimentación de la vida ","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"144 1","pages":"1 - 12"},"PeriodicalIF":0.0,"publicationDate":"2022-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77562078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early nest initiation and vegetation density enhance nest survival in Wild Turkeys","authors":"Allison C. Keever, B. A. Collier, Michael J. Chamberlain, Bradley S. Cohen","doi":"10.1093/ornithology/ukac050","DOIUrl":"https://doi.org/10.1093/ornithology/ukac050","url":null,"abstract":"ABSTRACT The theory of adaptive habitat selection suggests resource selection by animals should reflect underlying quality, such that individual selection confers an adaptive advantage via increased fitness. Using resource selection functions and nest survival models, we demonstrated that visual obstruction at the nest site was adaptively significant but timing of nest initiation had the greatest effect on nest survival for eastern Wild Turkeys (Meleagris gallopavo silvestris). Predation risk is a selective pressure, and if individuals can perceive predation risk, they may respond by altering the selection of nest site characteristics based on prior experience. We evaluated patterns in nest site selection of 387 Wild Turkeys and the consequences of selection on reproductive success across the southeastern United States from 2014 to 2019. We monitored 549 nest sites and found that nest initiation date had the strongest effect on daily nest survival rates, wherein adult females at our earliest nest initiation date were ∼4 times more likely to successfully nest than females at our latest nest initiation date. Selection of nest sites with greater visual obstruction also increased daily nest survival rates, and females were 1.17 (95% CI: 1.100–1.234) and 1.37 (95% CI: 1.258–1.486) times more likely to select sites for every 10-cm increase in visual obstruction and maximum vegetation height, respectively. Collectively, our results indicate that nest initiation date is likely the critical parameter driving Wild Turkey nest success, whereas vegetative conditions play a lesser role in influencing nest success. Females nesting earlier may be in better body condition and show increased nest attentiveness, which may mediate nest success more than vegetation conditions around nest sites. Our work indicates that increasing the reproductive success of Wild Turkeys may hinge on females being able to nest as early as possible within the reproductive season. LAY SUMMARY For ground-nesting birds, selection of nest sites can have important consequences on nest survival and success which ultimately influence population trajectories. Therefore, effective management requires understanding drivers of nest site selection that impact nest success, particularly for ground-nesting species like eastern Wild Turkeys. We monitored nest site selection and consequences of selection on nest survival and success in turkeys across the southeastern United States. Although vegetation cover at the nest influenced selection and nest survival, timing of nest initiation had the greatest effect on nest survival. Increasing the reproductive success of Wild Turkeys may hinge on females being able to nest as early as possible within the reproductive season. RESUMEN La teoría de la selección adaptativa del hábitat sugiere que la selección de recursos por parte de los animales debería reflejar la calidad subyacente, de modo que la selección individual confiera una ventaja adaptativa a través d","PeriodicalId":19617,"journal":{"name":"Ornithology","volume":"24 4","pages":"1 - 14"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91424513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}