Search Results (439)

This study proposes a bio-inspired control framework for unmanned aerial vehicle (UAV) swarms, designed to emulate the collective motion phase transitions observed in the homing behavior of pigeon flocks. A second-order self-propelled particle model is established, integrating a self-propulsion term, an interaction potential term, and a key roosting force term inspired by the roosting behavior of pigeons. The framework enables the swarm to dynamically switch between a translational motion phase and a vortex motion phase based on the distance to a designated roost location. Based on the proposed swarm model, theoretical analysis proves the stability property of the specific two motion phases under specific conditions. Numerical simulations validate the stability of the two motion phases, demonstrating that UAV swarms can reliably maintain each phase and execute phase transitions triggered by the roosting force. The proposed framework is able to describe the phase transition behavior in the process of pigeons returning home. Full article

Estimating forest aboveground biomass (AGB) in mountainous forest ecosystems remains a significant challenge due to complex terrain, the high cost and limited applicability of traditional field-based methods. To address this issue, a remote sensing-based AGB estimation framework integrating intelligent optimization and machine learning was developed for Mount Tai in eastern China. Sentinel-2 multispectral data were selected to derive 105 candidate variables, including spectral bands, vegetation indices, texture features, and topographic factors, from which 17 key variables were selected using Pearson correlation analysis for model construction. A Support Vector Machine (SVM) optimized by the Pigeon-inspired optimization (PIO) algorithm was developed to adaptively determine optimal hyperparameters, and its performance was compared with that of Random Forest (RF) and standard SVM models. Among the three models, PIO-SVM produced the highest numerical accuracy. For the training dataset, it obtained an R² of 0.85 and an RMSE of 46.12 t/hm². For the testing dataset, it achieved an R² of 0.73 and an RMSE of 62.19 t/hm², compared with 0.72 and 66.25 t/hm² for the standard SVM model and 0.70 and 65.19 t/hm² for the RF model. The spatial distribution of AGB derived from the optimal model shows higher AGB values in the central and northern regions characterized by dense forest cover, in close agreement with field observations. Overall, the results suggest that PIO-based parameter optimization can improve SVM performance for AGB estimation in mountainous forests. This study provides a reliable and efficient framework for regional-scale monitoring of forest biomass and carbon sink dynamics. Full article

Intercropping systems involving sorghum, grasses, and legumes can enhance forage production and improve sustainability under no-tillage systems. In the context of agricultural systems, the effective selection of rotational species is essential, as they contribute to soil system dynamics and provide feed for livestock. In this study, the dry matter production of grain sorghum (GS: cultivar A 9902), forage sorghum (FS: cultivar Volumax), and dual-purpose sorghum (DPS: cultivar Rancheiro) intercropped with Urochloa brizantha and dwarf pigeon pea was evaluated at five sowing densities (0 to 24 seeds m⁻¹) over two growing seasons (2018 and 2019), conducted in a randomized complete block design under autumn growing conditions. Biometric and productive traits of sorghum were assessed, as well as the dry matter production of the companion species, in order to understand interspecific interactions within the system. Sorghum dry matter yield was not affected by pigeon pea density, indicating high stability of the main crop. Grain sorghum (GS) and forage sorghum (FS) showed higher production in the first season (20,428 and 18,210 kg ha⁻¹, respectively), whereas dual-purpose sorghum (DPS) performed best in the second season (25,388 kg ha⁻¹). GS exhibited the highest panicle production, exceeding the other cultivars by up to 55%. Increasing pigeon pea density enhanced its biomass production but reduced Urochloa production by up to 50%; however, Urochloa showed better performance when intercropped with GS and FS. Sorghum morphological traits were not affected, and overall, the intercropping system maintained sorghum productivity while increasing total biomass, demonstrating potential for silage production and pasture establishment. Full article

Plant polysaccharides, such as Astragalus polysaccharide (APS) and Glycyrrhiza polysaccharide (GPS), hold potential as feed additives, yet their individual and synergistic effects on squab meat quality remain unclear. In this study, 192 healthy, 15-day-old, early-weaned Silver King squabs were assigned to one of four dietary treatments for 28 days: a control group (CK), an APS group, a GPS group, and a combined APS + GPS group (AG). Slaughter traits, organ indices, liver antioxidant capacity, and meat quality were evaluated across the four groups. Results indicated that supplementation with APS, GPS, and AG enhanced several slaughter traits compared to CK, including live weight, carcass weight, full-eviscerated weight, half-eviscerated weight, and leg muscle weight. GPS and AG supplementation improved color parameters in both breast and leg muscles, with AG showing the most favorable tenderness-related outcomes. Additionally, AG supplementation enhanced liver antioxidant capacity, as evidenced by increased total antioxidant capacity and superoxide dismutase activity. Given AG’s superior overall performance, the ileal metabolomics analysis focused on comparing CK and AG. Metabolomics data revealed clear group separation and significant changes in amino acid-related pathways. In summary, while APS and GPS individually improved certain traits, their combined supplementation yielded the most favorable results, likely through enhanced antioxidant capacity and altered ileal amino acid metabolism. Full article

Staphylococcus aureus is a globally distributed bacterium that spans interconnected human, animal, and environmental niches and is a major driver of antimicrobial resistance. Environmental and wildlife-associated isolates from hospital-surrounding settings remain underrepresented in comparative genomic studies. To address this gap, we integrated a newly sequenced environmental isolate recovered from pigeon fecal samples collected around a hospital into a standardized pangenome framework composed of 99 reproducibly selected RefSeq genomes plus the environmental isolate S_S3. Using uniform genome annotation and orthologous gene family clustering, we identified an open pangenome of 8366 gene families (Heaps’ law γ = 0.275), consistent with the high genomic plasticity previously reported for S. aureus. The core genome stabilized at approximately 1757 genes, including 1651 genes conserved across all genomes. Gene frequency spectra showed a dominant cloud genome and a structured shell fraction contributing to interstrain differentiation. Jaccard-based gene content similarity resolved clusters shaped mainly by accessory gene composition. The environmental isolate retained the complete core genome, carried only 15 isolate-specific gene families (0.18% of the pangenome), and clustered within an established lineage. Its unique content included a lincosamide resistance-associated locus and efeB, a gene potentially related to heme or iron metabolism and oxidative stress response. These findings highlight a conserved genomic backbone over a dynamic accessory reservoir and support One Health genomic surveillance that includes wildlife-associated niches, while indicating that the environmental isolate fits within the broader gene content diversity observed in the analyzed dataset. Full article

Cajanus cajan (L.) Huth (Fabaceae) is a food legume of considerable nutritional and functional significance. This study examined the comparative effects of salt stress on seed germination, hydroponic growth, and phytochemical accumulation across two developmental stages: 10-day-old germinated seeds and 45-day-old hydroponically grown plants, using NaCl solutions at concentrations of 0, 25, 50, 75, 100, and 150 mM. Both germination rate and growth were greatest at 0–25 mM NaCl, with performance declining at higher concentrations. LC–MS/MS analysis of free amino acids in 10-day-germinated seeds revealed a salt-induced metabolic shift. Proline, leucine, and phenylalanine were the dominant free amino acids and increased progressively with rising NaCl concentrations. Phytochemical profiling by HPLC identified gallic acid, catechin, and genistin as the major compounds, with increased levels under salinity stress. Germinated seeds at 150 mM NaCl, germinated seeds exhibited the highest phytochemical accumulation, with total phenolic content (TPC), total flavonoid content (TFC), and DPPH activity reaching 18.192 ± 0.020 mg GAE/g extract, 8.519 ± 0.026 mg QE/g extract, and 11.623 ± 0.284 mg AAE/g extract, respectively. Phytochemical responses in 45-day hydroponic plants varied by tissue type. Leaves exhibited declining TPC and TFC with increasing NaCl (from 29 to 16 mg GAE/g and 41 mg QE/g extract), while stems showed the opposite trend, reaching 18 mg GAE/g and 21 mg QE/g extract at 50 mM. Root tissues maintained comparatively low phytochemical levels throughout. Notably, DPPH scavenging capacity increased across all tissues under salt stress, with peak values of 12–13 µg AAE/g extract recorded at 50 mM NaCl. These results indicate that salt stress exerts stage- and organ-dependent effects on phytochemical accumulation in C. cajan. High salinity during germination stimulates bioactive compound production, whereas moderate salinity appears to be the threshold at which antioxidant capacity is maximized in hydroponic systems. These observations point to the practical utility of controlled salt elicitation as a strategy for enriching pigeon pea with health-promoting phytochemicals, reinforcing its potential as a functional food crop. Full article

Autonomous traversal flight in unknown 3D environments remains challenging due to mapping bottlenecks and computational latency. Inspired by pigeons navigating cluttered forests through instantaneous visual perception rather than constructing global metric maps, this paper presents a pigeon-inspired depth-reasoning-driven decision framework for agile quadrotor traversal in unmapped spaces without explicit map construction. To ensure feasibility, we leverage a robust state estimation backbone enhanced by deep-learning-based feature matching, providing stable pose feedback under aggressive maneuvers. The core contribution is a pigeon-inspired depth-reasoning framework that translates raw sensory depth data into a hybrid optimization framework, integrating both hard safety constraints and soft geometric smoothness constraints, directly emulating the three avian mechanisms: gap selection via instantaneous depth gradients, path selection that minimizes posture changes, and a safety field driven by the looming effect. By bypassing time-consuming mapping and spatial discretization processes, the framework significantly reduces perception-to-control latency. Finally, validated via simulations and real-world experiments on a resource-constrained quadrotor platform, our map-less approach achieves superior decision frequencies and comparable safety margins to those of state-of-the-art map-based planners. This framework offers a practical, high-frequency solution for autonomous flight where computational resources and environmental knowledge are strictly limited. Full article

Pigeonpox is a significant infectious disease caused by Pigeonpox virus (PPV), which severely impacts the pigeon industry. Current control methods primarily rely on heterologous vaccines, such as those derived from avian poxviruses, but their protection is limited, creating an urgent need for the development of a specific vaccine. In this study, 720 samples collected from several regions of China between 2022 and 2023 were tested for PPV, followed by virus isolation, identification, and genetic evolutionary analysis. Based on these findings, complete genome sequencing and attenuation of the representative BJ-02 isolate were conducted, and the potential of this strain as a candidate for an attenuated vaccine was preliminarily evaluated. The survey showed PCR positive rates of 9.05%, 16.11%, and 12.50% in samples from Beijing, Guangdong, and Hainan, respectively. Six viral strains were isolated, all of which produced typical lesions on chorioallantoic membranes (CAM) and chicken embryo fibroblasts (CEF). Phylogenetic analysis based on the P4b gene revealed that the six viruses clustered within the same evolutionary branch, closely related to PPV and penguinpox virus strains from South Africa, India, and Taiwan, China. Complete genome sequencing of the BJ-02 strain showed its genomic structure to be similar to that of other fowlpox viruses, with some differences. After serial passage in CAM, PEF and CEF, the BJ-02 SD55 high-passage strain adapted well to in vitro culture, exhibited significantly reduced pathogenicity in chicken embryos and pigeons, and showed no reversion to virulence after five consecutive back-passages. Animal immunization tests demonstrated that the BJ-02 SD55 suspected attenuated strain induced specific antibodies and provided 100% protection against challenge with the virulent strain. In conclusion, PPV is widely prevalent in China. The BJ-02 strain, successfully isolated and attenuated through serial passage, demonstrates excellent immunogenicity and high safety, making it a promising candidate for a specific pigeonpox vaccine. Additionally, the complete genome characterization of BJ-02 contributes to the avian poxvirus genome database and provides critical data to support research on viral pathogenesis and the development of viral vector vaccines for avian and potentially mammalian species. Full article

Avian trichomonosis is caused by protozoa of the genus Trichomonas, mainly Trichomonas gallinae, which infects the upper digestive tract of birds and is commonly associated with Columbiformes, the main reservoirs of the parasite. This study aimed to investigate the occurrence and genetic diversity of Trichomonas spp. in captive synanthropic birds from southeastern Brazil. Oropharyngeal swabs were collected from 281 birds belonging to 13 avian orders and analyzed using Diamond medium culture, Giemsa-stained smears, and molecular assays. Of the 262 samples submitted to culture analysis, 72 (27.48%) showed trophozoite-like structures under light microscopy. Molecular screening based on the ITS1–5.8S–ITS2 region detected Trichomonas DNA in 76 out of 267 samples with successful DNA extraction (28.46%), including 72 Columba livia domestica from Franca, one Coragyps atratus from Ribeirão Preto, and three rock doves from Jaboticabal. Among the ITS-positive samples, 67 (88.15%) amplified the Fe-hydrogenase gene, and 65 (85.5%) were also positive for the 18S rRNA gene. Only six samples (2.29%) exhibited structures compatible with Trichomonas spp. in Giemsa-stained smears. Phylogenetic analyses based on ITS sequences grouped the isolates into two clades within the Trichomonas gallinae complex. Greater genetic diversity was observed using Fe-hydrogenase and 18S rRNA markers, revealing multiple haplotypes and clades. Molecular assays, particularly PCR applied directly to oropharyngeal swabs, showed higher sensitivity for detecting and characterizing Trichomonas gallinae compared to culture and cytology. These findings highlight the high occurrence and genetic diversity of T. gallinae in captive synanthropic pigeons and reinforce the importance of molecular tools for epidemiological surveillance in wildlife facilities. Full article

Brain-Derived Neurotrophic Factor (BDNF), a key member of the neurotrophin family, is critically involved in neuronal survival, synaptic plasticity, learning, and memory. While its roles in mammals have been extensively documented, the molecular regulatory mechanisms governing BDNF expression and its causal contributions to complex cognitive behaviors remain poorly understood in non-mammalian vertebrates—particularly for the domestic pigeon (Columba livia domestica), a species distinguished by its remarkable spatial navigation and homing capabilities. This review synthesizes the current evidence on BDNF in the pigeon central nervous system across five thematic domains: molecular structure and isoform diversity, transcriptional and epigenetic regulatory networks, involvement in neural development, associations with cognitive and navigational behaviors, and potential translational applications. A particular emphasis is placed on the region-specific and activity-dependent expression patterns of BDNF in brain structures such as the hippocampal formation (HF), optic tectum, and striatum, and their functional relevance to visual processing, homing behavior, and stress adaptation. To date, most findings remain correlational; therefore, establishing a mechanistic understanding necessitates the integration of advanced methodologies—including single-cell omics, CRISPR-based gene editing, and high-resolution behavioral phenotyping—to causally link BDNF dynamics, neural circuit modulation, and spatial cognition. This synthesis aims to bridge gaps in comparative neurobiology, inform molecular approaches to avian cognitive enhancement, and support evidence-based strategies for racing pigeon breeding and welfare assessment. Full article

Antimicrobial resistance (AMR) is a silently escalating global crisis, presenting a specific challenge for the One Health approach. Landscapes can serve as reservoirs of AMR bacteria and genes, while synurban wildlife may act as vectors of bidirectional exchange. However, these species can also be utilised as sentinels of landscape AMR load. Herbivorous avian bioindicators, such as the Common Wood Pigeon (Columba palumbus), continuously sample the landscape during foraging and drinking, providing a homogenous spatial overview on the state of AMR. This study aimed to investigate the potential of this species for assessing the impact of landscape diversity on bacterial communities and their AMR patterns. Toward this objective, two spatial units of 4 km in diameter located at an upstream and a downstream section of a river, relative to a provincial town, were compared using 16 cloacal samples per site. Heterotrophic plate count techniques resulted in 60 isolates, of which 48 were identified, and 35 were tested for AMR using the VITEK 2 Compact system. The association between bacteriological findings and landscape diversity was analysed using Rényi diversity profiles. The Gram-positive/Gram-negative ratio was the only parameter that proved to be significantly different between the two study sites. The investigation detected six MDR isolates, with two methicillin-resistant phenotypes (Staphylococcus gallinarum, Mammaliicoccus lentus) and two carbapenem-resistant Pseudomonas fluorescens isolates. We established that the small sample size limits drawing definitive conclusions. However, exploring the link between landscape diversity and the cultivable faecal microbiota of herbivorous birds is a promising approach for more extensive research. Full article

Both breed and plumage color are considered potential genetic factors influencing meat quality in pigeons, yet their independent effects remain poorly distinguished. This study aimed to disentangle the regulatory roles of breed and plumage color on meat quality, nutritional composition, and flavor-related metabolites in meat pigeons. White-feathered (SQB) and grey-feathered (SQH) Shiqi pigeons were compared with European Mimas white pigeons (MMS) under identical rearing conditions. Slaughter performance, meat quality traits, and flavor profiles were assessed, followed by untargeted metabolomics and transcriptomics sequencing of pectoral muscle tissues. The results demonstrated that breed exerted a significant influence on carcass traits, water-holding capacity, collagen content, as well as the composition of fatty acids and free amino acids. In contrast, no notable disparity in meat quality was observed between the white- and gray-feathered varieties within the same Shiqi pigeon breed. A total of 114 and 205 differentially expressed metabolites (DEMs), and 11 and 327 differentially expressed genes (DEGs) were identified in plumage color and breed comparisons, respectively. Key flavor-associated metabolites, including glutathione, L-histidine, L-carnosine, and cytidine-5′-monophosphate, were identified as candidate biomarkers for breed-specific flavor differentiation. Breed is the dominant genetic factor determining meat quality and flavor in meat pigeons, while plumage color variation within breed has a limited impact. The identified pathways and regulatory networks provide actionable targets for the precision breeding and flavor enhancement of local pigeon breeds. Full article

Aiming at diverse urban tree structures and difficulties in vegetation point cloud extraction and utilization, this study proposed single-tree-scale biological parameter estimation methods for urban scenarios to enhance point cloud’s application value in urban greening management. For single-tree segmentation, it constructed a method based on the constraints of the trees’ geometric features and combined the gravitational modeling characteristics, called the CGF-CG single-tree segmentation method. This method (i) combines clustering and principal direction analysis to extract trunk points, (ii) introduces canopy segmentation based on trunk positions, (iii) optimizes edge point attributes via a gravitational model. Based on CGF-CG’s accurate results, an improved random forest method for single-tree biological parameter (IRF-BP) estimation (aboveground biomass, carbon storage, leaf area index, living vegetation volume) was proposed: (i) correlation analysis with variable screening, (ii) adaptive feature selection and pigeon-inspired optimization to enhance model generalization, (iii) adopting Shapley Additive Explanations (SHAP) to improve interpretability. Based on these, a complete model for different tree species was constructed. Validation showed that CGF-CG exhibited negligible over-segmentation and under-segmentation in the selected study areas, with overall average precision, recall, and F1-score over 98.5%. Additionally, on the selected overall region, the overall mF1 score, mPTP, and mPTR of our method are 99.13%, 99.15%, and 99.12%, respectively, which are superior to Forestmetrics, lidR, PyCrown, and DBSCAN methods. IRF-BP performed well, with a highest R² of 0.81 and a lowest mean absolute percentage error of 7.5%, effectively surpassing the performance of traditional models such as RFR, GBR, KNN, and XGB. In summary, results provided theoretical and technical support for urban green resource management and evaluation. Full article

In recent years, pigeon rotavirus A (PiRVA) infection, an important emerging disease, has posed a major threat to the healthy development of the pigeon industry and public health. Therefore, developing an accurate, rapid and convenient detection method for this virus is vital for monitoring and early diagnosis of the disease. In this study, on the basis of the ORF sequence characteristics of the PiRVA VP6 gene, crRNA and reverse transcription recombinase-aided amplification (RT-RAA) primers were designed. On the basis of the CRISPR/Cas12a system, for the first time, the RT-RAA-CRISPR/Cas12a rapid detection method of PiRVA was established by combining RT-RAA and lateral flow strips. This method could specifically detect PiRVA, and there was no cross-reaction with other common viruses originating from pigeons. The minimum detection limit was 16.8 copies/μL, and the results of the intrabatch and interbatch repeated tests were consistent. Moreover, the method established in this study and the previously established common PCR method were used to analyse 56 clinical tissue samples from racing pigeons and domestic pigeons collected in 2025. The positive rates of racing pigeon and domestic pigeon samples detected by PCR were 17.6% and 12.8%, respectively, and the positive rates of racing pigeon and meat pigeon samples detected by the RT-RAA-CRISPR/Cas12a method were 23.5% and 17.9%, respectively, indicating that PiRVA infection occurs in both racing pigeon and domestic pigeon populations in China. In summary, the PiRVA RT-RAA-CRISPR/Cas12a detection method established in this study has good specificity, sensitivity, and reproducibility, and allows visualization of the results, which can be used for field applications. This study provides technical support for epidemiological surveillance and etiological research on PiRVA. Full article

In order to investigate the prevalence of duck Tembusu virus (DTMUV) in several regions of China, this study conducted an epidemiological survey on 2674 avian throat swab samples (including chickens, ducks, geese, and pigeons) collected from seven provincial-level administrative regions in China in 2024. Following RT-qPCR testing, 198 positive samples were identified, demonstrating an overall positivity rate of 7.40% (198/2674) across the seven provinces included in the study. Subsequent virus isolation using BHK-21 cells led to successful isolation in 17 cases. Additionally, genetic evolution analysis of the partial NS5 gene was carried out on these 17 isolates through RT-PCR amplification and sequencing. The data analysis indicated that Guangdong Province had the highest positive detection rate, reaching 22.40% (86/384), followed by Henan at 12.24% (47/384). Among infected hosts, geese were primarily affected by DTMUV, with a positivity rate of 40.76% (97/238). The prevailing subgroup of DTMUV in circulation in China is subgroup 3.2. Farmer’s markets, wholesale markets, slaughterhouses, and poultry farms all showed evidence of DTMUV presence, indicating widespread contamination across diverse locations. This study examines the distribution, genetics, and phylogenetic features of DTMUV in China, which will enhance our comprehension of the epidemiological landscape of DTMUV in China. Full article