Occurrence and profiles of benzotriazole UV stabilizers in bird feathers from polar regions and China.

Bird feathers possess functions such as water resistance, thermal insulation, and air permeability, providing inspiration for the design of functional fabrics. Based on the functional differentiation of different feather regions and the structural constraints associated with these functions, this study selected down feathers, feather vanes, hooklets, and fluffy feather filament node structures as biomimetic prototypes. Four biomimetic knitted structures were designed for outdoor environments with significant temperature fluctuations and for the thermo-moisture comfort needs of older adults. Through macro- and micro-structural feature extraction, three-dimensional modeling, and experimental testing, a multi-parameter evaluation system covering water resistance, thermal resistance, thermal insulation rate, air permeability, moisture vapor transmission, and moisture management was established to systematically evaluate the thermo-moisture regulation performance of the fabrics. The results showed that each structure exhibited distinct performance advantages: Structure 1 demonstrated the best thermal insulation performance; Structure 2 showed relatively superior water resistance and outstanding air permeability; Structure 4 exhibited relatively superior moisture vapor transmission and moisture management performance; and Structure 3 achieved the highest gray relational optimality value, indicating a relatively balanced thermo-moisture regulation capability. Among all performance indicators, air permeability showed the highest correlation with the knitted structures. Based on these results, and considering regional differences in heat generation and sweating across different body parts of older adults, this study further explored zonal application strategies for elderly outdoor clothing to improve wearing comfort and functionality under environments with fluctuating thermal conditions.

Pesticides continue to be widely used despite the concerns about their negative impacts on non-target organisms. Birds are at risk from exposure to several classes of pesticides regardless of the habitats they are found in, since pesticides are applied in rural and urban areas. In some instances, the doses received have been found to cause lethal and/or sublethal effects. However, levels of pesticide exposure in wild birds remain largely unknown and this study aims to shed light on this matter. Feathers from five widespread bird species (blackbird Turdus merula, blue tit Cyanistes caeruleus, chaffinch Fringilla coelebs, dunnock Prunella modularis and goldfinch Carduelis carduelis) were collected from seven sites across the UK and Republic of Ireland from a variety of habitats. These were tested for the presence of 17 pesticides and 5 insecticide metabolites. All samples contained measurable levels of pesticides (> limit of quantification) and an average of four pesticides were present per sample. The most frequently occurring pesticides included the insecticides permethrin, chlorpyrifos, clothianidin and imidacloprid, and the herbicide pendimethalin. Permethrin was the most dominant pesticide present at all sites and in 98% of samples. These results highlight the prevalence of pesticide contamination using a non-intrusive method, which can be of value to monitor pesticide presence in the environment and flag up those of particular concern needing further investigation.

Light as a feather: A novel approach for whole- feather microstructure imaging through tissue clearing and autofluorescence imaging.

Aerial-aquatic robots can adapt to diverse environments and hold significant potential for applications, while most existing aerial-aquatic robots primarily utilize artificial propulsion, lacking bionic flapping-wing propulsion. Flapping-wing robots can exhibit high efficiency and maneuverability in aerial or aquatic environment, but in nature, aerial-aquatic flapping species possess distinct kinematics in two environments, making it challenging to balance lightweight and complex kinematics in robotics. This article draws inspiration from two different species, birds and manta rays, proposing a chordwise bimodal joint with a weight of 5 g for large-scale flapping-wing robots. The joint can mimic the asymmetric deformation of bird feathers and the symmetric deformation of manta ray fins. It has four torsion springs and a jagged plate, the torsion springs manage the dynamic response of the joint, while the jagged plate is used to switch between symmetrical and asymmetrical strokes. The effectiveness of mode switching and the optimal stiffness of torsion springs are verified through theoretical analysis and experiments. Compared to the traditional flapping wing, the proposed amphibious flapping wing based on bimodal joints can enhance <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {111.6 \%}$</tex-math></inline-formula> lift in the air, while improving <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {35.9 \%}$</tex-math></inline-formula> thrust efficiency in the water. An aerial-aquatic flapping-wing robot is developed, and its flight and swimming capabilities are validated by motion tests. This article provides a feasibility reference for amphibious motions of large-scale flapping-wing robots, thereby expanding their application prospects to aerial-aquatic amphibious scenarios.

ABSTRACT Synthetic composite materials such as aramid, carbon, and glass fibers are extensively used in engineering applications; however, their non-biodegradability, high cost, and environmental impact have led to increased interest in sustainable alternatives. The present study aims to develop an eco-friendly natural fiber reinforced composite using sisal fiber mat, seashell powder, and bird feather quill in an epoxy matrix. The primary objective is to utilize waste and natural materials to produce lightweight composites with improved mechanical properties. The composites were fabricated using epoxy resin (Araldite AW106) and hardener (HV953 IN) through a compression moulding process. A systematic experimental approach was adopted to study the influence of reinforcement composition on mechanical properties. Tensile, flexural, and hardness tests were conducted to evaluate the performance of the fabricated specimens. The results indicate that the addition of seashell powder enhances stiffness and hardness, while bird feather quill contributes to weight reduction with acceptable strength. An optimal combination of materials exhibited improved tensile and flexural properties compared to other compositions. The study concludes that the developed natural fiber composite can serve as a cost-effective, lightweight, and sustainable alternative to conventional synthetic composites for engineering applications. Keywords: Epoxy resin (Araldite AW106), Hardener (HV953 IN), Sisal fiber mat, Seashell powder, Bird feather quill.

Purpose This paper seeks to examine the application of active flow control using a valve system in a new hole-down-array (HDA-2p) wing design. Design/methodology/approach The active valve system functions by opening and closing various apertures to regulate airflow around the wing. A range of valve configurations, both open and closed, were examined and assessed alongside factors such as airspeed. The primary goal was to maximize efficiency. The aerodynamic characteristics of different wing setups were evaluated and enhanced. Findings The study demonstrates that using active flow control through valves on an innovative HDA wing design can potentially enhance the aerodynamic characteristics, notably improving aerodynamic efficiency. Practical implications The research carried out will lead to a deeper understanding of innovative wing designs along with the crucial topic of flow control, both passive and notably active. The data gathered from these studies will aid in the advancement of future wing designs, specifically regarding the application of flow control techniques. Originality/value The groundbreaking wing designs, featuring a HDA combined with active valve control, exhibit distinctive characteristics due to their nontraditional geometry and aerodynamic features. Inspired by natural elements such as the gaps between bird feathers, these vertical holes equipped with adjustable valves demonstrate significant potential for future advancements.

Structural colouration arises from the interaction of light with nanoscale structures and offers sustainable alternatives to pigment-based colours. However, current structural colour patterning methods rely on multi-step lithographic processes or multiple ink formulations, limiting scalability and spatial resolution. Inspired by melanosome self-assembly in bird feathers, we develop a one-step, mask-free strategy to generate high-resolution structural colour patterns via tunable nanoparticle segregation. During photocuring, silica nanoparticles dispersed in acrylic resin migrate toward oxygen-permeable substrates, forming a nanoparticle-enriched disordered layer. Such segregation is driven by interfacial oxygen inhibition and kinetically governed by the photocuring rate. Using grayscale digital light processing printing, we programmably control the local segregation thickness to create high-resolution structural colour patterns for visual display and information encryption. The segregation structure also affects mid-infrared reflectivity, allowing for infrared camouflage. This scalable approach establishes a mechanistically guided route to multifunctional photonic materials.

One well-known family of water birds is the Anhingidae. The feathers of large Anhingidae birds are sexually dimorphic. They are between 80 and 100 centimeters (2.6 and 3.3 feet) long, weigh between 1,050 and 1,350 grams (37 and 48 ounces), and have a wingspan of around 120 centimeters (3.9 feet). The males have a larger beak than the females, dark-brown and black feathers, and a little erectile crest on the neck. The females have significantly darker plumage, especially on the neck and underparts, and are a little larger. Both feature gray stippling on their upper wing coverts and long scapulars. The bill lacks an external nose and has serrated edges and a desmognathous palate. Its legs are small and webbed. (Brodkorb, et.al,1982) [13].This research article focuses on habits and habitat ecology of near threatened Oriental darter and practices of their conservation for future.

Abstract Colour produced via melanin pigments is widespread in extant bird feathers and has been inferred in many fossil birds, feathered dinosaurs and pterosaurs. Current models of fossil feather colour are based on the geometry of feather melanosomes in extant birds, but to date, feather colour has been assigned on a purely visual basis. Here, we assess statistical support for visually assigned categories of melanin-based colour. We performed quantitative analysis of spectral reflectance data from black, brown, grey and rufous feathers, using both raw reflectance spectra and spectrally derived parameters. Only rufous feathers show a systematic division into distinct light and dark subcategories, whereas brown, grey and black categories are better treated as discrete groups. Analysis of spectral data demonstrates that colour categories are distinct. Predictive models for feather colour using linear discriminant analysis yield predicted accuracies of over 80% using parameter data and over 90% using raw spectral data. Results confirm the validity of these visually assigned colour categories. Future studies of feather colour should use spectral analysis to test whether visually assigned colour categories are statistically supported. This will provide a robust foundation for future efforts to investigate the evolution of feather colour in the fossil record.

Abstract Collecting GPS positions on bird movements requires secure and efficient attachment methods that maintain animal welfare. For seabirds, one of the most threatened bird groups globally, non-permanent attachment methods are often preferred in short-term studies due to their lower risk of injury, feather damage, or long-term behavioral disruption. However, most available non-permanent solutions, such as tape or temporary adhesives, fail to stay attached for extended periods, often resulting in device loss within days or weeks. Here, we present a novel 3D-printed clamp design for attaching small solar-powered GPS devices to seabirds. The clamp and device were attached to the bird's feathers using only glue, with the clamp specifically designed to interlock with the device. This interlocking mechanism effectively sandwiches the feathers between the clamp and the device, ensuring a secure connection through the use of glue. The clamps were designed to maximize solar panel exposure and minimize premature detachment. We deployed 86 GPS devices on six seabird species across seven locations in Norway from 2023 to 2024, using device-specific clamp variants for attachment to mantle or tail feathers. Devices remained attached for an average of 39 days on mantle feathers (77 birds) and 77 days on tail feathers (four birds), providing sufficient deployment durations to monitor key life stages, such as incubation and chick-rearing. The weight of the clamp structure ranged from 0.5 to 3.2 g, depending on the variant, and emphasis was placed on keeping the total attachment weight as low as possible. The clamps were low-cost, easy to produce using standard 3D printers, and allowed adjustments during application. Our method offers a practical alternative to conventional glue or tape mounts, enabling longer device retention, optimal solar charging, and improved data recovery without resorting to permanent attachment methods such as harnesses. It is particularly well suited for short-term tracking applications over a few weeks to months, such as studying foraging behavior, molt timing, or seasonal movements. Overall, the clamp-based attachment system offers a practical and reliable method for short-term seabird tracking, improving data quality while minimizing impact on the birds.

Phase separation of a liquid mixture embedded within an elastic network is relevant to a wide range of natural and industrial systems, including biomolecular condensates interacting with the cytoskeleton, structural colouring in bird feathers, and gas bubbles forming within soft sediments. Recent experiments in synthetic polymer gels have demonstrated that when the size of phase-separated domains is comparable to the characteristic pore size of the network, a patterned phase with a well-defined length scale may emerge. Theoretical works based on an equilibrium approach have attributed this pattern formation to non-local elastic effects arising from heterogeneity of the underlying network. Here, we extend these ideas by developing a dynamic theory in which phase separation is coupled to non-local elasticity via the framework of large-deformation poroelasticity. We study our model via both linear stability analysis and numerical simulation, identifying the parameter space in which phase separation occurs, and investigating the impact of different elasticity models. We find that although local elasticity can inhibit phase separation and affect domain count, it is unable to completely suppress coarsening. In contrast, non-local elasticity arrests coarsening to form patterned domains with a well-defined length scale that decreases with increasing stiffness. Our modelling framework thus paves the way for quantitative comparisons between simulations and experiments, for example by considering a strain-stiffening network rheology.

Bird diversity is reflected in the abundance and variety of extraordinary plumages. Some of these include elongate, ornamental tail feathers that are typically attributed to either intraspecific communication in monomorphic species or sexual selection in sexually-dimorphic ones. Enantiornithines (Aves: Ornithothoraces) were the most diverse group of birds during the Cretaceous. Importantly, some enantiornithine fossils preserve soft tissues, most often in the form of feathers surrounding the body. Unlike any living bird, many enantiornithine specimens lack tail feathers (rectrices) all together, with the tail region consisting entirely of contour feathers. However, when present, enantiornithine rectrices typically consist of a pair of elongate, ornamental feathers with unusually wide rachises, referred to as rachis-dominated feathers. Here we describe Plumadraco bankoorum gen. et sp. nov., a new bohaiornithid enantiornithine with a pair of exceptionally long rectrices. These tail feathers measure twice the individual's body length, ending in proportionally small pennaceous rackets, thus adding to the growing diversity of these unusual feathers. The fine preservation of these tail feathers, in comparison to other enantiornithine rectrices, reveals previously unrecognized structural variation that hints at their potential function in courtship displays. Although ornamental feathers in enantiornithines are widely considered sexually dimorphic, determining the selection pressures that shaped them is difficult due primarily to limited soft tissue data. Enantiornithine rectrices are likely the result of an interplay between both sexual and naturally selective pressures, similar to the processes which produce analogous structures in birds today.

ABSTRACTIntroductionDuring the 2021 COVID‐19 pandemic, Ghana experienced outbreaks of high pathogenic avian influenza virus (HPAIV) H5N1 among poultry.ObjectivesHere, we describe the distribution and genetic characterisation of clade 2.3.4.4b HPAIV H5N1 isolated among poultry.MethodsWe conducted active surveillance for influenza viruses among animals (poultry and swine) and environmental samples across Ghana from 2021 to 2022. Tracheal/cloacal swabs were collected from poultry while nasal/anal swabs were collected from swine. Environmental samples (bird droppings, feathers, and water) were collected from Ramsar sites. We detected the presence of influenza viruses using specific primers and probes and reverse transcription polymerase chain reactions previously described by the US‐CDC. We sequenced and detected viruses using Oxford Nanopore Technologies.ResultsA total of 2847 samples were collected: 2640 from birds, 207 from swine, and 186 from the environment. Out of 2847, 2.2% (63/2847) were positive for HPAIV H5N1. All the H5N1 viruses were detected in poultry populations and none in swine. Again, environmental samples tested negative for influenza. Greater Accra (35), Central (10), and Upper East (7) regions recorded the highest number of H5N1 infections. Phylogenetic analysis of H5N1 showed that these viruses belonged to the clade 2.3.4.4b, which is currently circulating worldwide. Genetic analysis of the HA revealed some mammalian adaptive motifs.ConclusionThese findings highlight the importance of continuous genomic surveillance for these zoonotic pathogens in‐country and further analyses to determine their zoonotic potential. Early detection and local containment are critical for mitigating the threat posed by zoonotic influenza.

ABSTRACTFungi play critical roles in ecosystem functioning, yet the mechanisms underlying their spore dispersal, especially via animal vectors, remain underexplored. We investigated the potential of birds and insects as fungal spore vectors in Japanese temperate forests by analysing fungal communities on the feathers of 14 bird species and within 158 insects collected from fungal fruiting bodies. Comparisons were also made with air samples collected from the surrounding forest (n = 124). Microscopy and next generation sequencing (NGS) revealed fungal spores on all bird feather samples, with Cladosporium and Penicillium most abundant when analysed microscopically, and identified 39 assigned fungal species across 381 operational taxonomic units (OTUs), with genera including both common environmental fungi and taxa that contain members with pathogenic potential. Fungal assemblages differed markedly between air and feather samples. Insects, particularly Drosophilidae and Phoridae, carried spores both externally and internally, with notable detection of mycorrhizal Thelephora aurantiotincta spores in Blattodea digestive tracts. Our findings highlight the significant and distinct roles of both birds and insects in dispersing a diverse array of fungi, with potentially important implications for ecosystem processes, public health and forestry.

During the 18th and 19th centuries, bird feathers (class: Aves) were harvested from wild populations and sold globally in enormous quantities to meet the rising demand of the fashion industry. Although many laws now prevent similar widescale harvest, there is a paucity of studies on the trade that has continued to occur since the 20th century. Using data from the Convention on the International Trade of Endangered Species of Wild Fauna and Flora (CITES) and the United States Fish and Wildlife Service (USFWS) Law Enforcement Management Information System (LEMIS), we synthesised the first modern analysis of the global feather trade. We discovered over 1800 bird species being traded for their feathers since the 1980s, with 18 of 41 orders found to be overrepresented in trade. Shipments ranged from occurrences of single species to large‐scale trade involving multiple species. Traded species were more likely to have plumage that deviated from brown‐ and/or grey tones compared to non‐traded species. Feathers from the culturally significant bald eagle Haliaeetus leucocephalus and golden eagle Aquila chrysaetos were the most commonly traded of all species. We determined that overall, the modern feather trade does not appear to operate on the scale of historic harvests, and our findings indicate that modern trade poses a lower risk to the majority of wild bird populations globally. However, the endangered green peafowl Pavo muticus warrants closer examination to establish whether wild populations are directly affected by current demand in both domestic and international markets. Lastly, we suggest that the feather types (i.e. wing feathers, tail feathers) should be recorded on import and/or export to improve monitoring capabilities, and we propose that conservation managers are mindful of this poorly studied trade in future species assessments.

On the partial TLR21 gene from the feathers of birds, a chicken, and a duck

Abstract British people's relationships with birds changed at the turn of the 20th century. Killing birds for food, feathers, collections and sports started to give way to seeing birds as creatures that deserved the right to live their own lives in nature. Studying the historical campaign against using birds in fashion offers insights into present discussions on the value of nature and how to leverage values for broader sustainability transformation. The wearing of bird feathers by women was debated in the media, on the streets, in shopping environments and on many other occasions. The campaign against feather fashions was instrumental in creating the (Royal) Society for the Protection of Birds [(R)SPB] and an important issue for other conservation organisations. This study is based on an analysis of around 200 leaflets, reports, academic and popular science articles, letters and other documents, mostly associated with the (R)SPB, covering three decades from 1889 to 1921. The (R)SPB campaign and the broader debate on feather fashions exemplify early attempts to shape people's relationship with birds. The campaign focused on moving from the consumptive use of birds towards the appreciation of the birds' rights to live in the wild and for people to develop meaningful relationships with them. It emphasised relational values on top of intrinsic and instrumental ones. The campaign illustrates how clashing values led to a broader transformative change. It involved working with worldviews, in particular, reinterpreting the Christian foundation as a sense of responsibility for other God's creatures and avoiding cruelty and harm to them. It also involved other strategies for transformative change, notably arguing for a systemic change in the sector specifically responsible for bird loss and promoting the legal protection of nature. It featured arguments that were used in many other campaigns for nature conservation, most notably those recently framed as relational values. Policy implications . This case study shows that conservation is not a linear story of continuous improvement or refinement of ideas but rather a cyclical one, with the same arguments reappearing in new contexts, fitting into the broader system of socio‐economic priorities. Read the free Plain Language Summary for this article on the Journal blog.

Microplastic contamination in waterbirds and their habitats: evidence from little egrets (Egretta garzetta) in tropical rice fields.

Global pollution from urbanization and technology exerts pressure on ecosystems through xenobiotics, especially heavy metals, which bioaccumulate and biomagnifies across food chains and trophic levels. In Nigeria, poorly managed landfills remain critical pollution hotspots, contributing to biodiversity loss and necessitating non-invasive ecotoxicological assessments. This study analyzed 13 metals (Fe, Mn, Zn, Cu, Co, Cr, Cd, Pb, Ni, Al, B, Se, Hg) in feathers of four bird species: Hirundo aethiopica and Anthus leucophrys (insectivores), Streptopelia senegalensis (granivore), and Turdus pelios (omnivore) using FAAS. Diversity indices and abundance were estimated via point counts, while ANOVA tested inter-trophic variation. Results showed elevated iron levels in insectivores (2.6985 ± 0.1975 ppm) compared to granivores (2.0100 ± 0.3172 ppm). Insectivores also accumulated higher levels of Cd, Co, Cr, Ni, Se, and Hg, whereas granivores consistently had lower concentrations. Significant differences were detected across trophic levels (p &lt; 0.05). Findings indicate landfills serve as reservoirs of heavy metal pollution, with resident birds acting as effective sentinels of bioaccumulation, asymmetry, and ecosystem stress. Feather-based monitoring offers a reliable tool for tracking contaminant fate and predicting ecological risk.