Search Results (200)

Vision is considered the most important of the five primary senses in birds, particularly in raptors, and the relatively large size of the avian eye reflects its importance. This study provides a morphological and histomorphometric characterisation of the eye and retina of the Common Kestrel (Falco tinnunculus), a diurnal raptor with bifoveate retinal organisation. Two adult Common Kestrels, obtained through a wildlife rehabilitation programme, were examined. Eye morphology was characterised using the ratio between corneal diameter and transverse eye diameter, while retinal morphology and layer thickness were evaluated using conventional histological procedures, and opsin expression was examined in both foveae. The eyes showed a globose morphology with a strongly protruding cornea and anterior segment, within the range reported for diurnal birds of prey. Marked regional variation in retinal morphology was observed, with the central retina displaying the greatest overall thickness (254.4 ± 27.04 µm), compared with 108.6 ± 15.58 µm in the peripheral retina. Two distinct foveae were identified: a deep convexiclivate fovea within the area centralis and a temporal fovea with a deep pit and steep walls. Both foveae showed displacement of the inner retinal layers and reduced thickness at the foveal pit. The central and temporal foveae exhibited depths of 217.66 µm and 106.38 µm, respectively. S- and L/M-opsin immunoreactivity was detected in both foveae, and the absence of rhodopsin immunoreactivity in the central foveal pit suggests that high-acuity vision in both foveae is predominantly mediated by cones. Full article

Birds actively modulate their wing and tail morphologies to achieve high aerodynamic efficiency and maneuverability, enabling long-duration gliding while retaining the ability to execute rapid maneuvers. Innovations in aircraft design and control are increasingly inspired by these avian flight characteristics through control surfaces that imitate the natural wing and tail movements of birds. This paper presents a non-flapping, unmanned aerial vehicle (UAV), called “SMART Hawk” (Shape-Morphing Artificial Red-Tailed Hawk), inspired by the flight and physical characteristics of Buteo jamaicensis, known as the Red-Tailed Hawk (RTH), which exhibits excellent soaring abilities and agility characteristic of birds of prey. To determine the design parameters required for flight, a mathematical model was developed in MachUpX, then validated and refined using Reynolds-averaged computational fluid dynamics (CFD) models in ANSYS Fluent. SMART Hawk incorporates biomimetic wing and tail morphing, including coordinated forward sweep of the mid-wing and aft sweep of the outer wing, as well as active tail pitch, roll, and feather tucking and expansion. The drone was manufactured from a combination of composite, wood, and 3D-printed components. Multiple flight tests were conducted with proof-of-concept prototypes to demonstrate the design’s effectiveness. Full article

Mycoplasmas are frequently recovered from the upper respiratory tract of birds of prey, yet many isolates remain taxonomically unresolved. In the present study, a collection of ten previously unclassified Mycoplasma strains, predominantly isolated from the trachea of the common buzzard (Buteo buteo), was subjected to comprehensive phenotypic and genomic characterization. All strains grew well in modified Hayflick’s medium and formed colonies with the characteristic fried-egg appearance. None of the strains produced acid from glucose or hydrolyzed arginine or urea. Phylogenetic analyses based on 16S rRNA gene, 16S–23S intergenic spacer, and partial rpoB gene sequences placed the strains within the Mycoplasma synoviae cluster, in close proximity to five recently described Mycoplasma species associated with raptors such as eagles and kites. Matrix-assisted laser desorption ionization–time of flight (MALDI-ToF) mass spectrometry enabled the clear discrimination of the investigated strains from closely related taxa. Whole-genome comparisons, together with phylogenomic analyses, supported the assignment of these strains to a novel species within the genus Mycoplasma. The name Mycoplasma tracheobuteonis sp. nov. is proposed, corresponding to its preference for colonizing the upper respiratory tract of the common buzzard, with strain 48589B^T (=DSM 115882^T = NCTC 14927^T) designated as the type strain. Full article

The increasing integration of renewable energy resources into modern microgrids requires reliable scheduling methods capable of managing uncertainty, seasonal variability, operating cost, and environmental impact. This study proposes a stochastic day-ahead scheduling approach for a representative grid-connected multi-energy microgrid comprising photovoltaic generation, wind generation, a microturbine, a fuel cell, an energy storage system, and utility-grid exchange. The proposed model was implemented and simulated in a MATLAB (2024b) environment. The Birds of Prey-Based Optimization algorithm is applied to determine the optimal 24 h dispatch schedule by minimizing a weighted objective function that combines operating and emission costs. Uncertainties in solar irradiance, wind speed, electrical load, ambient temperature, and electricity prices are modeled using probabilistic distributions and Monte Carlo simulations. To improve computational efficiency, 1000 generated scenarios are reduced to 10 representative scenarios using Fast Forward Selection based on Kantorovich distance. Seasonal case studies for winter, spring, summer, and autumn are used to evaluate the proposed method. Compared with five metaheuristic algorithms, the proposed approach achieves the lowest fitness value in all seasons, with reductions of 15.2%, 26.5%, 6.8%, and 23.9%, respectively. The results confirm improved economic and environmental microgrid operation under seasonal renewable uncertainty. Full article

Wild birds are increasingly exposed to anthropogenic threats that compromise population viability. Wildlife rehabilitation centers provide valuable data to monitor these pressures and their conservation implications. This retrospective study analyzed wild bird admissions to the Wildlife Recovery Center of the University of Trás-os-Montes and Alto Douro (CRAS-UTAD) in northern Portugal between January 2007 and October 2025. A total of 5090 birds from 135 species and 44 families were admitted. Causes of admission were grouped into 11 categories, and outcomes into 7. Admissions increased over time, rising from approximately 160 birds in 2007 to more than 430 in 2025, although the overall temporal trend was not statistically significant. Birds of prey were the most frequently admitted group, particularly Strix aluco (9.16%) and Buteo buteo (8.00%). The most common causes of admission were orphaned birds (26.2%), followed by seizures from illegal captivity (12.2%) and collisions (5.0%). Overall, 43.2% of birds were released, while 29.4% died and 18.3% were euthanized. Admission cause was strongly associated with outcome, with electrocution showing the poorest prognosis and seizure from illegal captivity the highest probability of release. These findings highlight the major impact of human activities on wild bird morbidity and mortality and reinforce the importance of rehabilitation centers as sentinels for conservation and mitigation strategies. Full article

As one of the busiest airports in East China, effective bird-strike prevention is of paramount importance for Hangzhou Xiaoshan International Airport. Ground-dwelling insects in airport grasslands serve as a critical food source for insectivorous birds, making the study of insect communities essential for understanding bird activity patterns and mitigating bird-strike risks from a food chain perspective. This study investigates the communities of insects, birds, and vegetation in the flight zone and clear zone of Hangzhou Xiaoshan International Airport. Based on monthly surveys conducted from January to December 2024, we analyzed insect community composition and diversity, assessed bird-strike risks, and examined correlations between insect and bird communities. The results recorded a total of 7744 birds belonging to 107 species, 43 families, and 15 orders in the flight zone and clear zone. Passeriformes was the most species-rich order, and resident birds dominated the avian community. Bird species richness and abundance peaked in spring and autumn. In the flight zone, 18 bird species (e.g., Hirundo rustica) were classified as highly hazardous (R ≥ 15, where R is the calculated risk index) or above. The vegetation survey identified Cynodon dactylon as the dominant plant species in the flight zone. Importantly, positive trends were observed between insectivorous birds and insect abundance, though correlations did not reach statistical significance. To reduce food availability for birds, we recommend stringent management of the grassland habitat in the flight zone, including targeted insect control measures. Given the airport’s location along the East Asian-Australasian Flyway, enhanced bird dispersal efforts should be implemented during peak migration seasons. This study provides a crucial ecological foundation for developing an integrated “vegetation–insect–bird” management strategy for bird-strike prevention at Hangzhou Xiaoshan International Airport and similar aviation hubs. Full article

In healthy ecosystems, large raptors such as the White-tailed Eagle perform the essential roles of predators, bioindicators, and umbrella species. Despite their importance, many species of raptors are globally endangered, and similarly, in the Republic of Moldova, 13 species of diurnal birds of prey went extinct in the last 7 decades. The White-tailed Eagle (Haliaeetus albicilla) is the only example of a raptor that has regionally made a demographic and distributional comeback after decades of absence. Following this comeback, a national monitoring scheme during 2014–2025, including a nest counting survey in 2022–2024, has been implemented to understand what the current national situation of the species is and its ecological preferences and threats, together with the fundamental ecological context that allowed the breeding population to adapt to an ever-changing landscape. Field research conducted over 12 years confirmed the breeding of eight pairs, with data indicating a minimum of 19–23 nesting pairs. Pairs generally avoid human-dominated landscapes, preferring higher coverage of wetlands and forests, but current data suggests frequent occupancy of suboptimal territories and increasing tolerance towards human activity and infrastructure. Although currently small, the breeding population experiences high breeding success with no negative outcomes recorded. However, droughts and forestry activities in the proximity of the nests potentially reduced and delayed breeding success. Current forestry and fish farming practices increase the vulnerability of the few known breeding pairs to habitat degradation, poaching, and deforestation. To improve the conservation status of this endangered raptor in the Republic of Moldova, as close as possible to Least Concern status, it is crucial to implement multi-purpose buffer zones around active nests during the breeding season and to further survey the breeding population and assess any demographic trends. Full article

(1) The bird colouration is the result of adaptation to environmental conditions, predator–prey relationships, and sexual selection (intraspecific competition and signalling of quality). Only a few studies have explicitly explored the plumage colouration of birds at the level of species communities. (2) Methods: We combined data with bird plumage colours and their spatial distribution at a large spatial scale in Italy, exploring the relationship between community colours and different types of habitats and landscape heterogeneity. (3) Results: Overall, we found that the more representative colours of avian communities were grey, white, black, and brown. The percentage of black colour in the community was smaller in close habitats (e.g., forests). A high percentage of brown was observed in forests and shrublands, whereas a high percentage of white was found in wetlands, water bodies, and urban areas. The percentage of yellow was relatively low overall, but it was slightly higher in deciduous forests. Land use richness increased the percentage of brown, green, rufous, and yellow, while negatively affecting other pigments (black and grey = melanins, purple = structural, and red = carotenes). The community colour inequality decreased when the species and land use richness increased, while it increased when the weighted edge density of surrounding landscapes increased. Finally, we found that bird communities that are made up of closely related species show a wider variety of colours (e.g., lower colour inequality). This supports the idea that closely related species that live together develop different features to improve species recognition. (4) Conclusions: We found that the colours of bird communities are related to the type of environment. Full article

Diurnal birds of prey (Falconiformes and Accipitriformes) often display karyotypes that diverge markedly from the putative ancestral avian condition (2n = 80), with reduced diploid numbers and fewer microchromosome pairs driven by extensive chromosomal rearrangements. The harpy eagle (Harpia harpyja) was the first raptor analyzed by chromosome painting, revealing a karyotype (2n = 58) shaped by both microchromosome fusions and macrochromosome fissions followed by secondary fusions. However, these earlier analyses were limited in probe coverage. Here, we present a comprehensive chromosomal map of H. harpyja using multidirectional chromosome painting combined with chromosome-level genome assembly data. We integrated cross-species probes from Gallus gallus and Leucopternis albicollis with high-resolution genomic data to refine syntenic relationships and identify fission–fusion hotspots. G. gallus probes confirmed most previously described and genomically inferred associations but revealed novel features, including a new GGA1/GGA3 association and an increased number of GGA1-derived segments (five to six). Genomic data did not support previously suggested fusions involving GGA20–HHA1 or GGA12–Z. Dual-probe FISH further uncovered lineage-specific rearrangements, indicating rapid chromosomal evolution within Accipitriformes. This integrative approach clarifies harpy eagle genome organization and highlights dynamic evolutionary restructuring in raptor chromosomes. Full article

A group of avian species, mostly small passerines, allows us to reconstruct the landscape and general climate of an area of Fuerteventura prior to the arrival of the first humans. Many of the bird species are typical of forest environments and the edges of bodies of water, conditions incompatible with the current hot and arid climate. The record of a high number of quail as well as small flying passerines surely implies the concurrence of two types of diurnal birds of prey, hunters on the ground and in flight, respectively. No trace of the abundant Puffinus holeae has been found, which evidently occupied a habitat very different from those in the north and interior of the island. Full article

Climate change in Europe can influence the predator–prey interactions, a scarcely studied topic in birds. We examined relationships between the spring passage timing of the Eurasian Sparrowhawk, a generalist peak predator, and its main bird prey species (Song Thrush, Eurasian Blackbird, Common Chaffinch, Great Tit, European Robin). All species were ringed daily (26 March–15 May) in 1982–2021 at Hel Peninsula (N Poland). In 2024, we collected pluckings to identify Sparrowhawks’ prey. Sparrowhawks’ daily migration dynamics and those for the Song Thrush, Robin and Chaffinch were correlated. Sparrowhawks’ median dates of passage showed no multi-year trend, but large variation, correlated with those of its prey and with temperatures. Adult females and males migrated through Hel early after warm February and March at wintering grounds. Young males migrated early during warm Aprils at Hel. Medians were correlated between adult males and Robins, adult females and Blackbirds, and young females and Song Thrush. This suggests that Sparrowhawks adjust their migration timing each spring to the availability of these three prey species, with some sex differences, as males are smaller than females. Identifying changes in predator–prey dynamics in response to climate change helps us understand its effect on forest ecosystems. Full article

Named entity recognition (NER) is a fundamental task in natural language processing. Recently, non-traditional nouns (known as complex NER) have increasingly emerged, including long noun phrases and ambiguous names, for example, Birds of Prey (and the Fantabulous Emancipation of One Harley Quinn), Among Us, and Chicago, which may refer to a city or a novel. Such rapidly growing entity names pose significant challenges for NER. Arabic NER research is usually limited to flat and nested entities, overlooking complex entities due to limited resources, the language’s rich morphology, and context ambiguity. Such tasks require high-quality annotated data, yet most existing approaches rely heavily on supervised learning, which depends on large amounts of labeled data. However, acquiring large annotated datasets is costly and labor-intensive. We construct our corpus by leveraging the superior performance of large language models (LLMs), which have driven recent advances in dataset generation. We propose an Arabic complex NER (AraCoNER) dataset with semantically ambiguous and complex named entities, using both gold and silver labels. We investigate several agent-based annotation frameworks in addition to the plain LLM to determine the most efficient annotator for our task. Then, we introduce LLMAAA+, an LLM-agent-based framework that integrates an LLM-powered agent as an annotator into an active learning loop to efficiently select what should be labeled. Instead of solely synthesizing the training data from LLMs, we enhance both the annotation and training phases to generate pseudo-labels using k-NN sampling for in-context examples. Such an approach ensures both efficiency and quality, with cost-effective and minimal human involvement. Our results show that combining an LLM (GPT-4) with a structured agent framework (Google ADK) yields the highest annotation accuracy, even with a limited number of annotated examples, supporting the proposed LLM-agent-based active learning framework. Full article

Sarcocystis is a genus of heteroxenous, globally distributed apicomplexan parasites found in reptiles, birds, and mammals. Typically, sarcocysts develop in muscles of intermediate hosts, and oocysts sporulate in intestines of definitive hosts. The parasite’s life cycle is based on prey–predator relationships and usually involves two distinct host species. However, some Sarcocystis spp. can complete their full development within a single host species. Brown rats (Rattus norvegicus) are invasive, synanthropic, highly adaptable rodents that are true omnivores and opportunistic feeders. Therefore, it is possible that they can act as definitive hosts of Sarcocystis parasites. This study provides the first comprehensive assessment of Sarcocystis protists in brown rat intestinal samples under natural conditions, combining microscopy and molecular analyses. Of 27 brown rats investigated, 25.9% (7/27) of animals harbored oocysts/sporocysts of Sarcocystis spp. Based on nested PCR and sequencing of four genetic loci (18S rRNA, 28S rRNA, ITS1, and cox1), 59.3% of samples were positive for Sarcocystis spp. Parasites identified were genetically similar to Sarcocystis spp. using bird–bird, bird–Carnivora, rodent–Carnivora, or ungulate–Carnivora as their intermediate–definitive hosts. The present study suggests that synanthropic rodents may facilitate cross-ecosystem transmission of these parasites, increasing infection pressure on livestock, companion animals, and wildlife in human-dominated environments. Future molecular and dietary ecological studies are needed to assess the role of synanthropic and opportunistic hosts, such as the brown rat, in the transmission of Sarcocystis spp. Full article

During a late-winter field survey in Baihuashan National Nature Reserve, Beijing, several noctuid moths were observed flying during the daytime at low temperatures and being actively preyed upon by Marsh tits, which removed the heads and wings of captured individuals. These observations indicate that adults of this noctuid lineage are active in late winter, providing a critical nutritional resource for insectivorous birds during the ecologically constrained, food-limited winter period. Here, we formally describe this lineage as a new genus, Shoudus gen. nov., based on a new species, S. baihuashanus sp. nov., collected from Baihuashan reserve, including three specimens retrieved during active interception of tit predation, along with detached wings and heads recovered from the snow. The new genus is placed in the tribe Orthosiini Guenée, 1837, primarily based on adult external morphology, including large compound eyes with long interfacetal hairs and bipectinate male antennae, as well as forewing patterning similar to certain orthosiine genera such as Perigrapha and Clavipalpula. Notably, the dark reddish-brown forewings with sharply contrasting pale markings, as seen in the new genus and these related genera, appear well adapted for camouflage against bark, leaf litter, and exposed soil in their habitats—potentially functioning as both background matching and disruptive coloration. To further assess its phylogenetic placement, we conducted a molecular analysis based on mitochondrial COI sequences (13 newly generated and 6 retrieved from BOLD/NCBI). The resulting maximum likelihood and Bayesian trees consistently support the monophyly of the new genus and reveal a close phylogenetic relationship with Orthosia, the type genus of Orthosiini. This integrative evidence strongly supports the recognition of Shoudus as a distinct lineage within Orthosiini. Full article

Freshwater availability is one of the most pressing environmental concerns in arid ecosystems. The use of free-standing water by raptors has been little studied, and in the context of climate change has become increasingly important as extended droughts are expected to become more frequent. We analyzed digital images from camera traps captured in the freshwater springs of Sierra El Mechudo, during summer to early autumn of 2023 and 2024 in Baja California Sur, Mexico. We recorded 165 detections of four raptor species. The Turkey Vulture (Cathartes aura) was the most frequently detected (n = 55), followed by the Great Horned Owl (Bubo virginianus) (n = 50), the Red-tailed Hawk (Buteo jamaicensis) (n = 45), and the Cooper’s Hawk (Astur cooperii), which was observed only in early autumn 2024 (n = 15). The Great Horned Owl exhibited a distinct detection pattern (mainly crepuscular, with the highest peak at 6 a.m.), in contrast with the other three species, which were detected mainly at midday and in the afternoon, during the hottest hours of the day. All raptors were recorded drinking water; however, species differed in the proportion of behaviors they exhibited at the freshwater springs. The Turkey Vulture showed the highest drinking activity (76.3%), whereas both hawks exhibited the same lowest proportions (26.6%) among all species detected. The proportion of behaviors remained constant across years. The time spent at the freshwater springs did not differ across species or years. The Red-tailed Hawk, the Great Horned Owl, and the Turkey Vulture increased their detections at the springs in 2024, when a severe and prolonged drought affected the southern peninsula. The results showed that the importance of freshwater springs for raptors extends beyond their use for drinking only; the surrounding habitat as a refuge and availability of prey in the area are evidently essential for these birds of prey. Further studies should extend research into the diverse use of springs and home ranges of raptors in the southern Baja California peninsula. Full article