Several studies have examined the transmission dynamics of the novel COVID-19 disease in different parts of the world. Some have reported relationships with various environmental variables, suggesting that spread of the disease is enhanced in colder and drier climates. However, evidence is still scarce and mostly limited to a few countries, particularly from Asia. We examined the potential role of multiple environmental variables in COVID-19 infection rate [measured as mean relative infection rate = (number of infected inhabitants per week / total population) × 100.000) from February 23 to August 16, 2020 across 360 cities of Chile. Chile has a large climatic gradient (≈ 40º of latitude, ≈ 4000 m of altitude and 5 climatic zones, from desert to tundra), but all cities share their social behaviour patterns and regulations. Our results indicated that COVID-19 transmission in Chile was mostly related to three main climatic factors (minimum temperature, atmospheric pressure and relative humidity). Transmission was greater in colder and drier cities and when atmospheric pressure was lower. The results of this study support some previous findings about the main climatic determinants of COVID-19 transmission, which may be useful for decision-making and management of the disease.

Several studies have examined the transmission dynamics of the novel COVID-19 disease in different parts of the world. Some have reported relationships with several environmental variables, suggesting that spread of the disease is enhanced in colder and drier climates. However, evidence is still scarce and mostly limited to a few countries, particularly from Asia. We examined the potential role of multiple environmental variables in COVID-19 transmission rates and patterns from February 23 to April 16 across 121 cities of Chile; this country covers a large climatic gradient (≈ 40º of latitude, ≈ 4,000 m of altitude and 5 climatic regions, from desert to tundra), but all cities share their social behaviour patterns and regulations. Our results indicated that COVID-19 transmission in Chile was mostly related to 3 main climatic factors (mean temperature, relative humidity and wind speed) and population size. Transmission was greater in colder and drier cities (although wind modulated the effect of temperature) and when wind speed was higher; finally, transmission increased with population size. The results of this study support some previous findings about the main environmental and demographic determinants of COVID-19 transmission, which may be useful for decision-making and management of the disease.

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The tiger crab, Aegla concepcionensis, is a threatened endemic freshwater decapod of Chile, distributed throughout small areas of the Mediterranean region of Central Chile (37°30′-38°00′S). Its habitat includes streams and lakes with riparian areas dominated by native plants, with little or null human intervention. To our knowledge, the tiger crab’s distribution is limited and human stressors (e.g., water withdrawal, exotic tree plantations and climate change) have led to degradation of its habitat. Based on the presence of these stressors and the virtual lack of knowledge of its ecology, the tiger crab has been categorized as Endangered (EN). This study presents a preliminary description of the species’ ecology based on its abundance and its morphometrics, as well as on its feeding habits in Caburgua lake, South Central Chile. We established 16 sampling points, half of which in the shallow bathymetric stratum (0-10 m depth) of the lake itself, and half in the Lumaco stream, one of the lake’s tributaries. We used baited traps to capture specimens. A. concepcionensis appeared to be found in the lake’s shallow bathymetric stratum, but not in the stream. Individuals showed negative allometric growth, males were larger than females, and they showed scavenger feeding behaviour. Our findings provide useful information to help with tiger crab conservation, although more extensive surveys will be required to collect sufficient data for establishing a robust conservation program for the species in the study area.