Search Results (115)

Since the 1980s, earlier European springs have led to the earlier arrival of migrant passerines. We predict that arrival is related to a suite of climate indices operating during the annual cycle (breeding, autumn migration, wintering, spring migration) in Europe and Africa over the year preceding arrival. The climate variables include the Indian Ocean Dipole (IOD), Southern Oscillation Index (SOI), and North Atlantic Oscillation (NAO). Furthermore, because migrants arrive sequentially from different wintering areas across Africa, we predict that relationships with climate variables operating in different parts of Africa will change within the season. We tested this using daily ringing data at Bukowo, a spring stopover site on the Baltic coast. We calculated an Annual Anomaly (AA) of spring passage (26 March–15 May, 1982–2024) for four long-distance migrants (Blackcap, Lesser Whitethroat, Willow Warbler, Chiffchaff). We decomposed the anomaly in two ways: into three independent main periods and nine overlapping periods. We used multiple regression to explore the relationships of the arrival of these species at Bukowo. We found sequential effects of climate indices. Bukowo is thus at a crossroads of populations arriving from different wintering regions. The drivers of phenological shifts in passage of wide-ranging species are related to climate indices encountered during breeding, wintering, and migration. Full article

In the past two decades, little information has been updated to understand the resource status of the crab species Ovalipes punctatus in the East China Sea Region. In this study, we conducted surveys in 2018 and 2019 to identify the seasonal spatial distribution patterns of the economically important sand crab Ovalipes punctatus (De Haan 1833) in the southern Yellow and East China Seas. In the study area, the largest biomass of crabs was observed in the fishing grounds of Dasha and the Yangtze River mouth, and the second largest biomass was detected in the Jiangwai-Zhouwai area. Seasonally, the total biomass order in these areas was summer > autumn & winter > spring, and the mean average individual weight order was spring & summer > winter > autumn. These findings provided maps of the seasonal spatial distribution pattern of the species across seasons, which were then used in climate-change scenario models. Model predictions suggested that O. punctatus might migrate northward and offshore under climate warming conditions, and that the climate scenario SSP585-2100 might be the most negative case, respectively, for the habitat area of gain% minus loss%. These data can be used to develop robust and systematic regional fisheries resource management policies that consider adaptation measures to address the impact of environmental and climate change along China’s coasts and other areas in the world. Full article

Microsporidiosis is a zoonotic disease that derives from disparate sources. Most of the microsporidial agents are host-specific but some are capable of interspecies transmission, causing disease in various animals including humans. Human microsporidiosis may be caused by 17 species, with Encephalitozoon cuniculi, E. intestinalis and E. hellem mostly being responsible for human infections worldwide. Wildlife and migratory waterfowl can serve as reservoirs of these human-infectious agents and play a significant role in disseminating these pathogens into the environment. The aim of the study was to detect E. cuniculi, E. intestinalis and E. hellem in wild, migratory greater white-fronted geese (Anser albifrons) and other Anatidae members in feacal samples obtained in north-western Poland, using a molecular method. We collected 189 fecal droppings from Anatidae species (75 samples from greater white-fronted geese and 114 from other Anser spp.) during autumn migration. New species specific primers for PCR amplification were used to amplify a fragment of the small subunit ribosomal (SSU) rRNA of E. cuniculi, E. intestinalis and E. hellem. All fecal droppings were negative for E. intestinalis and E. hellem whereas E cuniculi was detected in 6 of 189 fecal samples (3.2%; 95% CI: 1.3–6.3%). In total, 1 of 75 tested fecal samples of greater white-fronted geese was positive (1.3%; 95% CI: 0.08–5.7%) while 5 of 114 (4.4%; 95% CI: 1.6–9.1%) tested fecal samples without exact species affiliation (only Anser sp.) were also positive. The phylogenetic analysis placed the sequences obtained from the birds’ droppings in the clade E. cuniculi from various rodents, wild carnivores and humans. Our results provide the first description of the occurrence and genotyping of the microsporidian E. cuniculi in greater white-fronted geese and in other members of the Anserinae Subfamily. Our findings support the results of other authors that E. cuniculi may originate from diverse sources, including common waterfowl. Our results are important in a One Health context, as wild migrating waterfowl may disseminate this zoonotic agent in remote regions through their migratory behaviour. These species should be considered significant sources of zoonotic pathogens, potentially hazardous to domestic and farmed animals as well as humans. Full article

Passerine birds (n = 3335) of 19 species were caught and investigated for the presence of Trypanosomatidae and Onchocercidae parasites using the buffy coat method, microscopy and PCR in Ventės Ragas, Lithuania. Data on the spread patterns of these parasites are still lacking. The prevalences of Trypanosoma parasites in birds of different species varied from 2.2% to 36.1%, while the prevalences of Onchocercidae parasites varied from 0% to 17.3%. Statistically significant differences between spring and autumn in the prevalences of Trypanosomatidae were determined for Acrocephalus schoenobaenus, Hirundo rustica and Turdus philomelos. No significant differences between the prevalences of Onchocercidae in spring and autumn were determined. The prevalence of Trypanosoma was significantly higher for long-distance migrant birds compared with short-distance migrants, for omnivorous birds compared with insectivorous birds, and for open-nesting birds compared with birds nesting in nest boxes. The prevalences of Onchocercidae parasites did not differ for the same bird groups except for the prevalence in omnivorous birds, which was higher compared with insectivorous birds. Both groups of parasites were detected in juveniles, showing the presence of transmission in the study area. The diet, breeding behaviour and migration features of avian hosts can influence the prevalence of avian blood parasites. Full article

Rapid environmental changes driven by human activities are contributing to a significant decline in global biodiversity, with avian species being particularly affected due to their migratory behavior. As highly mobile hosts, birds facilitate the geographic dispersal of ectoparasites, including ticks, which serve as vectors for numerous zoonotic pathogens. This study, conducted in collaboration with the Faunistic Observatory of the Asinara National Park between 2021 and 2023, aimed to investigate the potential role of migratory birds in tick dispersal and the presence of Borrelia spp. DNA. Birds were captured using mist nets during pre-breeding (April–May) and post-breeding (October–November) migration periods. Ticks were systematically collected and identified at the species level, and molecular analyses were performed using real-time and conventional PCR to detect the presence of Borrelia spp. DNA. Results showed a distinct seasonal variation in tick species composition. In autumn, Ixodes ricinus was predominant (99%), whereas Hyalomma species were more frequently observed in spring (78%). Molecular screening revealed Borrelia spp. DNA in 26.1% of the collected ticks, with Borrelia garinii being the most prevalent species. These findings underscore the ecological significance of migratory birds in the dissemination of ticks and tick-borne pathogens, highlighting their potential role in shaping disease transmission dynamics across different geographic regions. This study provides valuable insights into the seasonal fluctuations in tick populations associated with migratory avifauna and the epidemiological risks posed by these interactions. Continued surveillance of migratory birds as vectors of zoonotic pathogens is essential for informing public health strategies and mitigating the risks of emerging infectious diseases, but further investigation is needed to clarify the actual role of migratory birds in the transmission of Borrelia spp. Full article

Sthenoteuthis oualaniensis is one of the most commercially important marine cephalopod species distributed throughout tropical and subtropical waters of the Indo-Pacific Seas. The Indian Ocean is a main fishing ground for S. oualaniensis with a high population density. To explore the distribution of S. oualaniensis in the east equatorial Indian Ocean, four surveys were carried out using light-lift-net fishing vessels. Meanwhile, marine environmental data were also collected, including the sea surface temperature, sea temperature at 100 m depth, mixed layer depth, sea surface chlorophyll-a concentration, sea surface height, and eddy kinetic energy. Generalized Additive Models were used to analyze the relationship between the catch per unit effort (CPUE) for S. oualaniensis and environmental factors. The results showed that the average CPUE of S. oualaniensis was 14.55 kg/h in the four surveys, which was considerably lower than in the South China Sea and Northwest Indian Ocean. In terms of seasonal distribution, the high-CPUE stations were closer to the continental shelf in spring, while they shifted towards the deeper and offshore water in autumn, demonstrating a seasonal migration trend. Pearson correlation analysis showed that CPUE reflected a significant negative correlation with both sea temperature at 100 m depth and eddy kinetic energy (p < 0.001). The Generalized Additive Models revealed that sea surface height was the most significant factor affecting CPUE with a variance explanation of 30.1%. Furthermore, the optimal CPUE prediction model was established by stepwise regression, which contains two factors, sea surface height and eddy kinetic energy, with a variance explanation of 34.9%. This study provides insights into the environmental factors influencing the distribution of S. oualaniensis, which is essential for the sustainable utilization and management of this species. Full article

Air pollution is a major trigger for chronic respiratory and circulatory diseases. As a key component of air pollution, fine particulate matter (PM_2.5) exposure is largely determined by land use type and population density. However, simultaneous consideration of their spatiotemporal distribution is lacking in existing studies on PM_2.5 exposure. In this paper, we first assess the dynamic evolution of land use patterns in Gansu Province, China, from 2000 to 2020, using a land use transfer matrix and dynamic degree. Population-weighted exposure (PWE) to PM_2.5 is then evaluated for each land use type at provincial, city, and county levels, with seasonal variations analyzed. Spatial autocorrelation analysis is finally performed to explore the spatiotemporal evolution of PM_2.5 exposure, whereas standard deviation ellipses and gravity center migration models highlight spatial distribution characteristics and shifting trends. Experimental results showed that 2010 was a turning point for annual PM_2.5 exposure at the provincial level in Gansu Province, with an initial increase followed by a decrease. Construction land had the highest annual PM_2.5 exposure, whereas forest had the lowest exposure (except in 2005). Exposure levels showed a seasonal pattern: higher in winter and spring and lower in summer and autumn. At city and county levels, southern Gansu indicated a continuous decline in annual PM_2.5 exposure across all land use types since 2000. Exposure levels exhibited a strong spatial positive correlation, with a fluctuating spatial convergence. This study comprehensively analyzes the multi-scale differences and spatiotemporal evolution patterns of PM_2.5 exposure across various land use types, contributing to provide scientific evidence and decision-making support for mitigating air pollution and enhancing coordinated air pollution control at multi-scale administrative levels. Full article

Urban heat island (UHI) effect significantly influences the urban sustainability and health of cities and varies seasonally. However, spring and autumn have received less attention. Furthermore, research on long-term seasonal UHI changes and impacts is insufficient. This study examines the seasonal spatiotemporal dynamics and gradient characteristics of UHI in spring, summer, autumn, and winter in Changsha, a typical subtropical “furnace city” from 2006 to 2022. (1) Spatiotemporal dynamics: The high-temperature UHI (relatively high-temperature zone and high-temperature zone) range expands most significantly in spring and least in autumn. Additionally, the UHI migrates northward within the study area, and proximity to the urban core results in multiple high-temperature UHI effects. (2) Gradient characteristics: The proportion of the high-temperature UHI in spring, summer, autumn, and winter decreases to varying degrees within the 5 km gradient from the central point, but increases within the 6–8 km and 11–13 km gradients, especially in spring and autumn. Additionally, within the 8 km gradient in spring, the aggregation index (AI), contagion index (CONTAG), and largest patch index (LPI) decreased, with UHI patches more affected by these metrics in autumn. Overall, this study offers new insights into the seasonal effects and development of UHI, which are crucial for addressing climate change, promoting sustainability, and improving human well-being. Full article

Given their small size and low value in commercial fishing and aquaculture, little is known about the seasonal spatial distribution patterns and characteristics of the bobtail squid Euprymna berryi and Euprymna morsei in seas around China. Thus, we conducted seasonal bottom-trawling surveys in the southern Yellow and East China Seas during 2018 and 2019. Our results showed that E. berryi migrated from inshore areas (Yushan fishing grounds) during the summer and autumn to offshore areas (Wentai fishing grounds) during the winter. In contrast, E. morsei migrated from shallower water areas during the spring to deeper water areas during the winter. The highest abundance of E. berryi versus E. morsei was found in areas where temperatures were 25.29–28.02 °C compared with 19.54 °C (33.43–34.04‰ versus 34.43‰), respectively, during the summer; 20.99–21.69 °C compared with 21.98–22.70 °C (34.07–34.50‰ versus 33.80–33.60‰), respectively, during autumn; and 17.13–20.36 °C compared with 10.51–13.49 °C (34.23–34.46‰ versus 31.69–33.42‰), respectively, during winter. We predict that suitable habitats for E. berryi would expand more northward under SSP585-2050, whereas those for E. morsei would shrink into more northern locations under SSP370-2100 and SSP585-2100. The SSP245-2100 and SSP585-2100 scenarios had the most negative impacts on the distributions of both species. Such insights improve our understanding of the population dynamics and habitat requirements of both species to support their population management and exploitation in response to future climate change. Full article

As a comprehensive reflection of the thermal characteristics of the urban environment, the urban heat island (UHI) effect has triggered a series of ecological and environmental issues. Existing studies on the UHI effect in Shijiazhuang, the capital of Hebei Province, China, have primarily focused on spatial–temporal distribution characteristics and migration trends, with less focus on the influences of other contributing factors. This study focuses on Shijiazhuang city, using Landsat ETM+/OLI data from 2000 to 2020 to analyze the spatiotemporal traits of the UHI effect. The mono-window algorithm (MW) was used to retrieve land surface temperatures (LSTs), and the seasonal autoregressive integrated moving average (SARIMA) model was used to predict LST trends. Key factors such as the normalized difference vegetation index (NDVI), digital elevation model (DEM), population (POP), precipitation (PPT), impervious surface (IPS), potential evapotranspiration (PET), particulate matter 2.5 (PM2.5), and night light (NL) were analyzed using spatial autocorrelation to explore their dynamic relationship with the UHI. Specifically, a multi-scale analysis model was developed to search for the optimum urban spatial scale, enabling a comprehensive assessment of the spatiotemporal evolution and drivers of the UHI in Shijiazhuang. The UHI showed pronounced spatial clustering, expanding annually by 44.288 km², with a southeastward shift. Autumn exhibited the greatest reduction in UHI, while predictions suggested peak temperatures in summer 2027. According to the bivariate clustering analysis, the NDVI was the most influential factor in mitigating the UHI, while the IPS spatially showed the most significant enhancement in the UHI in the central urban areas. Other factors generally promoted the UHI after 2005. The multi-scale geographically weighted regression (MGWR) model was best fitted at a 3 km × 3 km scale. Considering the joint effects of multiple factors, the ranking of contributing factors to the model prediction is as follows: PET > DEM > NDVI > IPS > PPT > PM2.5 > NL > POP. The interactive effects, especially between the PET and DEM, reach a significant value of 0.72. These findings may address concerns regarding both future trends and mitigation indications for UHI variations in Shijiazhuang. Full article

Climate change has a great impact on wildlife, which needs to be considered when designing conservation and management practices in habitats rich in biodiversity, such as wetlands and forests. Varied responses to climate change of species with different environmental preferences can be used to monitor different aspects of the environment. Since 2000, we have observed contrasting changes in the numbers of two related forest bird species, Goldcrest and Firecrest, monitored during autumn migration (14 August–1 November) over 1976–2024 by mist netting at 2 bird ringing stations on the Polish coast of the Baltic Sea. At both stations of the Operation Baltic project (Bukowo-Kopań and Mierzeja Wiślana), located ca 200 km apart, we observed a long-term decline in the number of Goldcrest since the 1980s but an increase in the number of Firecrest since the year 2000. These two species with ranges overlapping in Europe slightly differ in their preferences for breeding habitat and migration strategies. We found that in both species, the changes in migrating bird abundance in autumn at both stations were correlated with the Pan-European breeding population trends from the Pan-European Common Bird Monitoring Scheme (PECBMS) over 1982–2022. These correlations suggest that some Europe-wide factors underly these changes. Thus, we analyzed the effects of seven climate factors: the European Temperature Anomaly and the North Atlantic Oscillation Index in spring (March–April), summer (May–July) and autumn (October), and the Eurasian Snow Cover in October, on bird abundance indexes during breeding and autumn migration, using multiple regression models. Both species were more abundant during breeding and migration after warm springs, which conduce their early breeding and two broods per season, thus improving their breeding success. But with warm summers, Goldcrest were less abundant during breeding in Europe and on migration at Bukowo-Kopań. We attribute that pattern to Goldcrest’s tendency to overwinter in Scandinavia after warm summers. We suggest that this strategy became an ecological trap, as the climate change in Europe involves the increase of summer temperatures by 2 °C over the last 42 years but also earlier snow in October, which impedes Goldcrest’s feeding. These factors, combined with the decreasing proportion of coniferous forests in Scandinavia, which are Goldcrest’s main breeding habitat, assumably caused the species’ decline, which we expect to continue. Firecrest showed a weaker response to snow in October, but their autumn migration at both stations shifted earlier since the late 1980s, alleviating any effect of early winters. Warm spring and summers favor Firecrest abundance during breeding and migration. Firecrest also benefit from more broadleaf trees in Fennoscandia, thus we expect this species to expand its breeding range farther northeast and to continue the population increase. The change in forest management policy in Scandinavia by planting more broadleaf trees aims at increasing biodiversity and might considerably influence the forest environment. Thus, it is imperative to identify the methods suited for early detection of such changes. We showed that monitoring the numbers of migrating birds provides good indicators of the effects of short- and long-term environmental changes on bird populations. Full article

Timing and spatial distribution patterns of migratory birds are crucial for their conservation, particularly in Greece, which serves as a vital migratory corridor between Europe, Asia, and Africa. Traditional monitoring methods face challenges due to resource limitations and the country’s complex geography. This study aimed to determine the migration phenology and spatial distribution of 18 species of raptors and soaring birds in Greece using citizen science data from eBird, analyzed with generalized additive models (GAMs). We processed 15,940 checklists for spring migration and 9131 for autumn migration from 2010 to 2023. GAMs successfully modeled the migration phenology for most species, revealing variable peak migration dates in spring and more synchronized migration in autumn, with most species migrating in early September. A spatial analysis highlighted the importance of coastal areas and islands (particularly the Aegean islands and Crete) as key migratory routes and stopover sites. Validation with standardized counts from the Antikythira Bird Observatory showed some discrepancies, emphasizing the limitations of relying on a single monitoring site and the value of broad-scale citizen science data. Our findings demonstrate the effectiveness of integrating citizen science data with robust analytical techniques to fill knowledge gaps, providing valuable insights for designing monitoring programs and informing conservation strategies. Full article

This study was conducted in Sawena district, located in the Eastern Bale Zone of Ethiopia, with the aim of analyzing climate variability and identifying adaptation strategies. Secondary data covering the period from 1984 to 2023 were utilized, along with structured and unstructured questionnaires. Primary data were gathered from 350 pastoralist households across six kebeles through a household survey. This study used the Mann–Kendall test, Sen’s slope estimator, the coefficient of variation, descriptive statistics, and a multivariate probit model to analyze climate variability and adaptation strategies. The Mann–Kendall test, Sen’s slope estimator, and coefficient of variation analysis results showed significant rainfall increases in September, October, and November, with high winter variability and an upward autumn trend. Temperature analysis revealed consistent warming, with the greatest increases in September (0.049 °C/year) and summer (0.038 °C/year), and an annual mean rise of 0.034 °C per year, indicating climate shifts affecting pastoralist and agro-pastoral livelihood strategies and water resources that lead the area toward vulnerability. The descriptive results indicated that pastoralist households have adopted various adaptation strategies: 45.1% participate in seasonal livestock migration, 26.3% rely on productive safety net programs, 19% pursue livelihood diversification, and 9.7% engage in agroforestry. Multivariate analysis indicates that education, age, credit access, livestock ownership, asset value, and media exposure influence these strategies. The findings highlight the importance of policies to enhance climate resilience through diversification, sustainable land management, and improved access to resources like credit and markets, alongside strengthened education and targeted extension services. Full article

The beet armyworm Spodoptera exigua (Hübner), a global pest, feeds on and affects a wide range of crops. Its long-distance migration with the East Asian monsoon frequently causes large-scale outbreaks in East and Southeast Asia. This pest mainly breeds in tropical regions in the winter season every year; however, few studies have investigated associations with its population movements in this region. From 2017 to 2023, we monitored its population dynamics in a tropical site, located in Hainan Province of China, using a searchlight trap. Dissection of the ovaries of female S. exigua moths captured from the air revealed that most of them were reproductively mature and could be classified as a transit migratory population. Migration occurred most often in summer and least often in winter, with an increasing trend over the years. According to a trajectory model analysis based on the Weather Research and Forecasting (WRF) model, S. exigua migrated from Hainan Island to mainland China in the spring, primarily moved from the areas of Southeast Asia to Hainan and mainland China during the summer, and returned from China to Southeast Asia in the autumn and winter. Overall, our research defines the movement paths of S. exigua in the tropical area of China, establishing a theoretical foundation for its regional monitoring, early warning, and management in China and Southeast Asian countries. Full article

Many species of noctuid moths exhibit long-distance migratory behavior and have an important pollination service function in terrestrial ecosystems. Spodoptera litura (Fabricius) is a globally distributed insect; however, its role in pollination remains underexplored. In this study, the feeding preferences and inter regional pollination of S. litura adults were explored. We conducted pollen analysis on 1253 S. litura migrants captured from 2018 to 2021 on Beihuangcheng Island in the Bohai Strait of China, which is located in the East Asian insect migration path. The results show that an average of 51.1% of S. litura migrants carry plant pollen each year, and the carrying rate shows fluctuations based on sex, year, and season. By combining morphological identification and DNA barcoding, pollen species were identified from 40 species of plants, representing 21 families and 26 genera, mainly from angiosperms of Dicotyledoneae, with Asteraceae, Apocynaceae, and Amaranthaceae being the dominant taxa. The geographical distribution range of Chrysanthemum zawadskii and Adenophora trachelioides and a migration trajectory simulation analysis indicate that S. litura predominantly migrate from Liaoning Province in Northeast China to North China over the Bohai Sea in autumn. These findings indicate the potential pollination activities of S. litura in North China and Northeast China, enriching our understanding of the interaction between S. litura and the plants it pollinates. Full article