Respiratory infectious diseases are highly influenced by climate and feature seasonality, whose peak is December to February in the Northern Hemisphere. SARS-CoV-2 produced consistent debate regarding the relationship between its emergence and weather conditions. Our study explored these conditions, expressed by three main parameters-ultraviolet radiation, air temperature and relative humidity-that characterized Hubei (China), the source region of COVID-19 pandemic, in November 2019-March 2020. During COVID-19 outbreak, the low amounts of UV radiation (down to-273 kJ m-2 in January 2020) were associated with the early stage environmental survival of the novel coronavirus. As well, this period was characterized by a high relative humidity during peak hours of the day, and a positive air temperature anomaly (+1.7°C in December 2019), which also favored the outdoor people mobility in winter. Based on Hubei analysis, a presumed optimal weather frame was set in order to identify other world regions with similar weather characteristics. In brief, the "Hubei weather profile" was recorded in those regions of COVID-19 outbreak in February 2020, such as northern Iran, Italy or Spain. Our results, which focused on the role of the UV solar radiation, could be used as a prediction tool for identifying the world regions with a higher risk of future faster increase in COVID-19 cases.

The present paper aims to evaluate if the Natura 2000 sites in Romania are placed over dynamic areas from a land cover changes perspective, or if they are placed in areas with low human interest and what the impact of these changes are. The effectiveness of conservation measures was addressed by analyzing the number of land cover changes and their areas in Natura 2000 sites, before and after declaring them as protected areas. Corine Land Cover (CLC) data were used as a tool to identify threats and pressures from each Natura 2000 site, and also assess whether land cover changes are more frequent in sites with a high biodiversity index, compared to those with low diversity, in order to estimate the conservation status. Changes in the land cover during 1990–2018 are characterized by three types of events, from 1990 to 2000 with most changes recorded, followed by a relative period of stability from 2000 to 2012; the most dynamic period is from 2012 to 2018. The main changes are due to deforestation. Only 29.7% ROSCI (Romanian Sites of Community Importance) and 36.5% ROSPA (Romanian Special Protected Areas) sites are characterized by a good degree of conservation without or with low modifications regarding the land cover. The most frequent threats and pressures that were found through CLC changes in the ROSCIs in Romania are related to forestry, grazing, the extent of the urbanized environment and those related to agriculture. The correspondence between Corine Land Cover and Natura 2000 specific threats and pressures emphasizes new guidelines for the Corine Land Cover program; therefore, this correspondence can be a potential tool to get more information for Natura 2000 sites.

The Yellow-browed Warbler is a species of the Sylviidae family that breeds in Asia and winters in South East Asia and western Europe. In northern and north-western Europe it is considered one of the most numerous nocturnal migratory species from Siberia. In the southern and eastern part of the continent there are fewer observations of the presence of the species in passage or in winter. On 29 September 2013, during a ringing session in the southern part of the Danube Delta (Romania), we captured a juvenile individual of the Yellow-browed Warbler. This is the first record of the species in Romania.

The present paper aims to highlight the impact of the partial or total drying of the Nuntași and Tuzla lakes (from the Danube Delta Biosphere Reserve) as a result of intense drought phenomena on groups of waterfowl that are encountered in this region. Our analysis combined satellite remote sensing techniques with bird observations that were made monthly during the analyzed period, corroborated with the meteorological context of the time interval that was taken into account. The results of the satellite image processing show a partial drying in 2013 and a total drying in 2020 of the Nuntași and Tuzla lakes, which were caused by both natural factors (drought) and anthropogenic factors (inadequate management of the area—e.g.,: communication channels with surrounding lakes are clogged). These situations have led to repercussions for groups of birds, which behave differently depending on their ecology. Pelicans and swans are the most affected birds, they leave the area in the absence of water, whereas gulls and terns are not affected by the decrease in the water surface, they even increase their numbers in such conditions. Our study also shows that from 2010 to 2020 the largest numbers of birds (total numbers of birds), with the exception of pelicans, were recorded in 2013 and 2020, more precisely in the years when the water surface decreased considerably. Another important feature of this paper involves highlighting how fragile an ecosystem can be in the context of climate change, but also how important it is to involve human society in maintaining the adequate conditions for an ecosystem that is part of one of the most important biodiversity hotspots on the planet, the Danube Delta Biosphere Reserve.

Long-legged Buzzard (Buteo rufinus) is a medium sized bird of prey which is known as a breeding species for Romania. In the last years it started to become a common wintering presence in the south-eastern part of Romania (Dobrogea) but it was also recorded in the more northern areas (Moldova) during the cold season. Its presence in Moldova, during the winter period, was recorded in large river valleys, with agricultural lands or grasslands and with trees or timber poles, which are used for perching. Long-legged Buzzard is a new presence for Moldavian winter seasons and it could be observed only in warm periods of winter, when the daily mean temperature is above 0°C. The wintering places are maintained not only for all winter period, but also for the next years. This behaviour could be explained by its territorial fidelity, which was recorded also in other European buzzard species during the winter period.