Search Results (250)

Understanding the mechanisms underlying seasonal community dynamics is important for predicting biodiversity responses to environmental fluctuations, enhancing ecological forecasting, and informing conservation strategies. In this study, we use standard transect and mist netting methods investigated seasonal altitudinal migration patterns of montane bird species in the Gyirong Valley, Central Himalayas. Our results showed four distinct altitudinal migration patterns among montane bird species: no shift, downslope shift, upslope shift, and contraction to mid-elevation zones. Species with smaller body weight and higher ratios of wing length, tail length, and tarsus length to body weight tended to migrate to lower elevations. Insectivorous birds exhibited a collective downslope shift, while omnivorous birds showed a wider range of migratory responses to seasonal variation. Migratory behavior was found to dynamically modulate the association between phenotypic traits and habitat preferences. During the breeding season, species (70.44%) and functional turnover (80.02%) dominated, while in the non-breeding season, nestedness significantly contributed to species (49.37%) and functional diversity (38.09%). In addition, migration can disrupt the direct influence of environmental variables on biodiversity patterns, providing important insights for montane biodiversity conservation under climate change. Our results highlight the critical need to safeguard low-elevation winter habitats and create dynamic protected areas to aid bird conservation amidst climate change. Full article

Hemibagrus guttatus is a large omnivorous fish of significant economic value, listed as a Class II protected species in the National Key Protected Wildlife List in 2021 in China. To provide a theoretical foundation for the artificial breeding of H. guttatus, this study employs high-throughput transcriptome sequencing of testes and ovaries to elucidate the molecular regulatory pathways involved in sex differentiation. Because H. guttatus exhibits no obvious sexual dimorphism even during the breeding season, the distinctive contribution of this study compared with previous gonadal-transcriptomic investigations in other Siluriformes lies not only in documenting sex-biased genes but also in providing a molecular foundation for developing non-lethal sex-identification methods for this morphologically indistinguishable species. A total of 303,192,896 raw reads were obtained, with an effective data rate of 98.4%, indicating high sequencing quality. Differential expression analysis identified 8694 genes, including 6369 upregulated in testes and 2325 upregulated in ovaries. Among these, 88 genes were functionally annotated as sex-related, with 62 testis-biased genes such as spata17, sox9, and dmrt1, and 26 ovary-biased genes including cyp19a, wnt8, and sox12. KEGG pathway enrichment analysis revealed that the TGF-β signaling pathway, insulin secretion, and steroid hormone biosynthesis may play crucial roles in gonadal development and differentiation in H. guttatus. The expression patterns of key genes such as hsd11b1, amh, and insl3 were validated by quantitative real-time PCR, showing consistency with the transcriptome results. These findings lay a molecular foundation for understanding the regulatory mechanisms of sex differentiation in H. guttatus, and provide candidate genes for further investigation into the genetic basis of gonadal development, which is essential for improving artificial reproduction and selective breeding practices. Full article

Nest architecture and surrounding habitat features can strongly influence the reproductive success of cavity-nesting birds; however, quantitative data from natural environments remain limited. We examined how nest structure and surrounding habitat features correlate with reproduction in the small bee-eater (Merops orientalis). A total of 38 natural nests were monitored during the breeding season. The Conway–Maxwell–Poisson model showed that cavity depth was a significant positive predictor of clutch size (β = 0.46 ± 0.22 SE, p = 0.036), whereas entrance diameter and nest height were not significantly related. Principal component analysis (PCA) of standardized cavity dimensions (cavity depth, entrance diameter, and nest height) showed that nest height (captured by PC2) was strongly associated with higher breeding success (OR = 0.002, p = 0.021), whereas overall cavity size (PC1) had a weaker, marginally positive correlation (OR = 3.87, p = 0.09). Habitat distance variables showed only weak, non-significant trends after accounting for multicollinearity. Nest structural traits explained more variation in reproductive performance than landscape variables (pseudo-R² = 0.80 for clutch size; 0.59 for breeding success). Field monitoring of 38 nests showed a mean clutch size of 3.9 eggs, an overall hatching success of 77.5%, and a fledging success of 51.2%, yielding a 37.1% breeding success. Our results highlight the importance of conserving sandy streambanks and mitigating human disturbance in proximity to active nests to conserve breeding success in small bee-eaters. As these findings were based on one site and a single breeding season, broader generalizations will require replication across additional years and locations. Full article

The global decline in biodiversity, mainly caused by human activities such as land use change, agricultural intensification, habitat degradation, and climate change, is impacting many species, including raptors. The lesser kestrel (Falco naumanni), a threatened colonial raptor strongly associated with traditional agricultural landscapes, has experienced marked distributional and demographic changes across Spain. Understanding the environmental and anthropogenic factors shaping its occurrence is essential for guiding effective conservation actions. In this study, we combined national-scale presence data with local breeding information to identify the main drivers influencing the species’ spatial patterns and potential causes of local population change. Nationally, the lesser kestrel showed positive associations with prey availability, grasslands, and non-irrigated croplands, while urban areas, water bodies, and higher altitudes negatively affected its occurrence. Climatic variables, particularly precipitation during the warmest quarter and temperature seasonality, were also significant predictors. At the local scale (Córdoba province), colony abundance increased in non-irrigated agricultural areas and certain human-modified habitats, but declined in woodlands, open natural areas, and landscapes characterised by larger patch sizes. Overall, our findings highlight the relevance of preserving heterogeneous, traditional agricultural mosaics and maintaining prey-rich open habitats. By integrating national and local perspectives, this study identifies priority areas for conservation and provides actionable insights to support efforts aimed at halting the decline of the lesser kestrel in Spain. Full article

The Military Macaw is a Neotropical psittacid that is endangered in Mexico. It faces significant threats due to habitat loss and the illegal pet trade. However, little is known about the nutritional characteristics of the plant resources available to this species throughout its annual cycle. This study aimed to characterize the nutritional profile of the fruits consumed by macaws in the Alto Balsas Basin, Mexico, and to infer potential seasonal patterns in the availability of the fruits they feed on in relation to the Macaws’ reproductive phenology. We identified 13 plant species that have been consistently reported as components of the diet of the macaws within the Alto Balsas Basin using a literature review, field observations, and local interviews. We conducted bromatological analyses to assess the content of moisture, protein, lipids, carbohydrates, and fiber for the pulp and seeds of all 13 identified plant species. Although we did not measure quantitative food intake, we integrated these data with reproductive phenology and resource availability to infer potential patterns of nutritional use. The results revealed significant differences in nutritional content among the different species, as well as seasonal variation in the nutritional profiles of available resources that coincide with the physiological demands of the macaw life cycle. During the non-breeding season, the availability of species whose fruits have high lipid and carbohydrate contents, such as Bursera spp., hackberry and madras thorn, may provide essential energy. Conversely, during the breeding season, resources with higher lipid and protein content (such as Mexican kapok tree and red mombin) could support the increased energetic investment associated with courtship, egg production, and chick provisioning. Although our study did not directly quantify the amount of each food item consumed, the integration of nutritional and ecological data provides a preliminary view of how resource quality may influence seasonal foraging patterns, offering valuable insights for the conservation and management of this species. Full article

Alfalfa (Medicago sativa) is a globally important forage crop; however, improvements in its biomass yield have stagnated due to its complex genetic architecture and the costly, labor-intensive phenotyping. This study evaluated the potential of the normalized difference vegetation index (NDVI) to predict biomass yield and enhance selection efficiency in alfalfa breeding programs. Specifically, nineteen alfalfa experimental populations (AEXP 1–19) and one control cultivar (OS 66) were evaluated over two growing seasons in Croatia. NDVI was measured at four development stages using a GreenSeeker sensor and compared with forage yield, dry matter yield, and plant height. NDVI values varied significantly among genotypes, years, and growth stages, ranging from 0.23 to 0.87, and increased consistently from early to late vegetative phases. Strong positive correlations were observed between NDVI and forage yield (r = 0.543–0.843) and plant height (r = 0.537–0.738) at early vegetative, late vegetative, and early bud stages. Conversely, NDVI at the mid-vegetative stage correlated negatively with yield and height (r = –0.622 to –0.794). High-performing populations (AEXP 2, AEXP 15, AEXP 18) also exhibited the highest NDVI values. NDVI is a reliable, non-destructive indicator for early selection of high-yielding alfalfa genotypes, although multi-location validation is advised to confirm its broader applicability. Full article

The non-destructive estimation of grain yield could increase the efficiency of soybean breeding through early genotype testing, allowing for more precise selection of superior varieties. High-throughput phenotyping (HTPP) data can be combined with machine learning (ML) to develop accurate prediction models. In this study, an unmanned aerial vehicle (UAV) equipped with a multispectral camera was utilized to collect data on plant density (PD), plant height (PH), canopy cover (CC), biomass (BM), and various vegetation indices (VIs) from different stages of soybean development. These traits were used within random forest (RF) and partial least squares regression (PLSR) algorithms to develop models for soybean yield estimation. The initial RF model produced more accurate results, as it had a smaller error between actual and predicted yield compared with the PLSR model. To increase the efficiency of the RF model and optimize the data collection process, the number of predictors was gradually decreased by eliminating highly correlated VIs and selecting the most important variables. The final prediction was based only on several VIs calculated from a few mid-soybean stages. Although the reduction in the number of predictors increased the yield estimation error to some extent, the R² in the final model remained high (R² = 0.79). Therefore, the proposed ML model based on specific HTPP variables represents an optimal balance between efficiency and prediction accuracy for in-season soybean yield estimation. Full article

Improving rye (Secale cereale) yield under increasing climatic stress remains a major challenge for sustainable cereal production. We examined whether early-vegetative physiological, biochemical, and molecular traits can predict final grain yield in hybrid-breeding components. Across three consecutive seasons, 14 genotypes were evaluated under controlled cold-greenhouse conditions for chlorophyll fluorescence, pigment content, hydrogen peroxide (H₂O₂), salicylic acid (SA) levels, and the expression of selected antioxidant and defence-related genes, and these traits were related to yield components. Across years, photosynthetic efficiency (F_v/F_m, Rfd), chlorophyll content, and foliar H₂O₂ emerged as the most consistent predictors of kernel mass, spike number, and kernel number. In contrast, non-photochemical quenching, SA, and carotenoid contents showed weak or inconsistent relationships with yield. These findings indicate that light-harvesting capacity, PSII performance, and oxidative balance are central to reproductive success in rye. The stability of these trait–yield correlations across three seasons provides the basis for a physiological robustness index for hybrid rye, with predictive models achieving accuracies up to R = 0.51. This work demonstrates the potential of using a compact set of early-stage, high-throughput physiological traits to accelerate selection for stress-resilient, high-yielding rye cultivars. Full article

Background/Objectives: Bovine colostrum, the initial milk produced by cows postpartum, contains an array of key nutritional, immune, and microbial components that support the calf’s physiological development, immune maturation, and intestinal colonization. The composition and quality of colostrum can be influenced by multiple factors, including seasonal variation, breed, parity, and farm management practices. This study investigated the microbial profile of Irish bovine colostrum and the influence of antibiotic therapy and parity. Methods: Bovine colostrum samples were collected from five Irish dairy farms that implemented different methods of dry cow therapy (DCT): natural or blanket. For blanket DCT, four of the five farms administered intramammary antibiotics at the start of the drying off period. Two farms administered a fourth-generation cephalosporin, cefquinome, and two farms used an antibiotic of the penicillin class, with the active ingredients consisting of procaine benzylpenicillin, penethamate hydriodide, and framycetin sulphate. One farm did not administer antibiotics but applied a teat sealant (natural DCT). Following calving, colostrum samples from 90 healthy dairy cows were analysed. Results: 16S rRNA sequence analysis revealed Firmicutes, Actinobacteriota, Bacteroidota, and Proteobacteria as the most abundant phyla across all treatment groups, with Acinetobacter, Corynebacterium, Facklamia, Jeotgalicoccus, Lactococcus, Leuconostoc, Psychrobacter, and Staphylococcus dominating at genus level. Parity did not significantly affect the microbial composition in this study, but antibiotic treatment did. Cows receiving no antibiotics showed distinct microbial clustering compared with antibiotic-treated cows (β-diversity, p < 0.001). Microbial diversity also differed between the antibiotic-treated groups, with significant changes in both α-diversity (p < 0.01) and β-diversity (p < 0.001), suggesting that the choice of antibiotic may also influence the microbiota. An influence of farm was also observed. Differential abundance analysis showed no increase in mastitis-associated genera in colostrum following natural DCT, although increased abundance was demonstrated with blanket DCT. Conclusions: Our findings substantiate the diverse and unique microbial composition of bovine colostrum. The data indicate that the microbial profile of bovine colostrum is influenced by antibiotic treatment administered during the dry period and affirms the latest policies inhibiting prophylactic antibiotic administration. Future studies should elucidate strain level changes in the colostrum microbiota following on-farm antibiotic use, assess the associated risks of antimicrobial resistance, and explore non-antibiotic alternatives for drying off cows. Evidently, the microbial composition of bovine colostrum is influenced by farm management strategies and optimizing these measures may further increase the valuable constituents of bovine colostrum and confer added health benefits to the new-born calf. Full article

In bird eggs, the theoretical expectation of a primary sex ratio (at conception) of 50:50 males/females often fails to materialize. Using PCR technology for sex verification in this pilot study, we evaluated the primary sex ratio of 128 fertilized domestic goose eggs (Anser anser) early in the laying season. Over 24 consecutive days of egg collection, 37% more males were found (58% males vs. 42% females). This male-biased trend gradually declined over the period, but an excess of males was still observed. Among the factors for predicting the male sex ratio bias in a particular goose was the egg weight, i.e., heavier eggs tended towards a male phenotype. The embryo sex of the first egg laid and the egg weight change dynamics over the laying period were also noted. The correlation between actual and predicted data was calculated, taking into account three parameters, and found to be 0.724. To explain the effect of an implicit random/non-random process more adequately, we introduced the concept of biased randomness. As well as being of academic interest, research on sex ratio bias is crucial for goose breeding/reproduction programs and important as a step towards understanding the physiological mechanisms that underly sex ratio bias in these animals. Full article

The micronutrient content is a major aspect of food quality and has been under threat after a gain in production post-green revolution. Calcium (Ca) and magnesium (Mg) are the micronutrients that are cofactors for many enzymes and play a critical role in human physiology. Deciphering the accumulation of these micronutrients in wheat and the identification of QTLs associated with these elements is very significant for cutting the risk of malnutrition in humans. Here, a genome-wide association study (GWAS) of 105 lines from an elite panel of the Wheat Association Mapping Initiative (WAMI) was performed for the two cropping seasons of 2021–2022 and 2022–2023 for the grain calcium and magnesium content (GCaC and GMgC). Notably, two marker trait associations (MTAs), wsnp_Ex_c2718_5038582, Kukri_c11327_977, and RAC875_c9984_1003, were found for the GCaC, and similarly three MTAs (Tdurum_contig28802_213, wsnp_Ex_c34597_42879693, and RFL_Contig6053_3082) were identified for the GMgC in both the cropping seasons, proving their utility and non-redundancy. An MTA associated with a SNP marker (wsnp_Ex_c34597_42879718) was also identified in the two seasons and was significant for both the GCaC and GMgC. Candidate gene analysis showed the association of these MTAs with some of the very vital genes associated with activities where Ca and Mg play significant roles. Our study widens the insights on the genetic control of Ca and Mg accumulation in wheat and the utilization of this information for future breeding programs, wherein wheat improvement with enhanced Ca and Mg may be designed and conducted. Full article

Rice is a staple food grown worldwide. While white rice varieties have been extensively studied, there is limited information on the performance of pigmented rice genotypes and their tolerance to water deficit. This study evaluated nineteen black rice genotypes and one white cultivar over three years under contrasting water regimes: traditional flooding and non-flood irrigation (NFI). Genotype–environment interactions and their impact on agronomic, yield, and grain quality traits were assessed. Black genotypes under NFI showed reduced flowering and grain quality. The average yield was 31% lower than the white cultivar. Significant genetic correlations were found between grain yield and days to anthesis (DSA), grain weight (TGW), chalkiness (CHA), and translucency (TRAN), with high broad-sense heritability (H² > 0.9). Most traits exhibited high heritability (H² > 0.7), indicating strong genetic stability. Grain yield (GR) was highly and negatively correlated with percent sterility (PS) (r = −0.84) and had a heritability of 0.76. Environmental conditions significantly influenced yield, confirming the potential for selecting water stress–tolerant genotypes. These findings provide valuable insights into black rice breeding and optimizing water management practices to support sustainable production. To our knowledge, this study is the first to evaluate the performance of a diverse set of black rice genotypes across multiple seasons under contrasting water regimes in a Mediterranean environment. Full article

Urban soundscapes are increasingly recognized as fundamental for both ecological integrity and human well-being, yet the complex interplay between the vegetation structure, seasonal dynamics, and microclimatic factors in shaping these soundscapes remains poorly understood. This study tests the hypothesis that vegetation structure and seasonally driven biological activity mediate the balance and the quality of the urban acoustic environment. We investigated seasonal and spatial variations in five acoustic indices (NDSI, ACI, AEI, ADI, and BI) within a historical urban garden in Castelfranco Veneto, Italy. Using linear mixed-effects models, we analyzed the effects of season, microclimatic variables, and vegetation characteristics on soundscape composition. Non-parametric tests were used to assess spatial differences in vegetation metrics. Results revealed strong seasonal patterns, with spring showing increased NDSI (+0.17), ADI (+0.22), and BI (+1.15) values relative to winter, likely reflecting bird breeding phenology and enhanced biological productivity. Among microclimatic predictors, temperature (p < 0.001), humidity (p = 0.014), and solar radiation (p = 0.002) showed significant relationships with acoustic indices, confirming their influence on both animal behaviour and sound propagation. Spatial analyses showed significant differences in acoustic patterns across points (Kruskal–Wallis p < 0.01), with vegetation metrics such as tree density and evergreen proportion correlating with elevated biophonic activity. Although the canopy height model did not emerge as a significant predictor in the models, the observed spatial heterogeneity supports the role of vegetation in shaping urban sound environments. By integrating ecoacoustic indices, LiDAR-derived vegetation data, and microclimatic parameters, this study offers novel insights into how vegetational components should be considered to manage urban green areas to support biodiversity and foster acoustically restorative environments, advancing the evidence base for sound-informed urban planning. Full article

Suburban forest patches can have important conservation value for birds. This is a hopeful trend because the extent of urbanization is increasing, many avian populations are declining, and urban areas are where most people interact with wildlife. There is evidence that, despite an increased density of potential predators, the breeding success of birds in urban or suburban forest patches is comparable to that in rural areas. However, extremely limited data exists on the fledgling life stage of birds in urban or suburban areas, even though it is known that the fledgling stage strongly influences population growth rates. We used radio telemetry to look at the survival, movement, and habitat use of fledgling Wood Thrushes (Hylocichla mustelina) originating from nests in suburban forest patches and in larger swaths of rural, undeveloped forests in western Massachusetts. We tracked 168 fledglings over four field seasons and found that survival was similar for rural and suburban fledglings. Fledglings had lower mortality as they aged. Force-fledging and being left outside the nest after radio-tagging had a negative effect on survival, and we developed techniques to minimize its occurrence. We also found that rural fledglings moved farther from their natal nests, at any given age, than suburban fledglings. Fledglings in both suburban and rural sites selected denser understory growth, and the use of non-forested land cover increased as they aged. Full article

The activation mechanism of the reproductive axis in Kazakh ewes during the non-breeding season was explored by supplementation with glycerol complex (7% glycerol + tyrosine + vitamin B9). The experiment divided 50 ewes into five groups (n = 10). After 90 days of intervention, it was found that significant changes in serum DL-carnitine, N-methyl-lysine and other differential metabolites were observed in the GLY-Tyr-B9 group (p < 0.05, “p < 0.05” means significant difference, “p < 0.01” means “highly significant difference”). The bile acid metabolic pathway was specifically activated (p < 0.01). The group had a 50% estrus rate, ovaries contained 3–5 immature follicles, and HE staining showed intact granulosa cell structure. Serum E2/P4 fluctuated cyclically (p < 0.01), FSH/LH pulse frequency increased (p < 0.01), peak Glu/INS appeared on day 60 (p < 0.05), and LEP was negatively correlated with body fat percentage (p < 0.01). Molecular mechanisms revealed: upregulation of hypothalamic kiss-1/GPR54 expression (p < 0.01) drove GnRH pulses; ovarian CYP11A1/LHR/VEGF synergistically promoted follicular development (p < 0.05); the HSL of subcutaneous fat was significantly increased (p < 0.05), suggesting involvement of lipolytic supply. Glycerol activates the reproductive axis through a dual pathway—L-carnitine-mediated elevation of mitochondrial β-oxidation efficacy synergizes with kisspeptin/GPR54 signalling enhancement to re-establish HPO axis rhythms. This study reveals the central role of metabolic reprogramming in regulating seasonal reproduction in ruminants. Full article