Rodents are essential components of many terrestrial ecosystems and have several beneficial activities in nature, such as soil aeration and insect control, however, rodents are also sources of zoonotic pathogens. As pests they are known to be reservoirs of tick-borne zoonotic infections of viral, bacterial and protozoan origin, and are important hosts of the immature stages of Ixodes ticks. Recent studies in Europe have demonstrated the role of rodents, especially Sylvaemus mice and Myodes voles, in the epidemiology of tick-borne bacterial zoonoses, such as Lyme borreliosis and anaplasmosis. In particular, the yellow-necked mouse, Sylvaemus tauricus (Pallas, 1811; syn.: Apodemus flavicollis (Melchior, 1834)), supports the transmission of the most important pathogens carried by the castor bean tick, Ixodes ricinus. Using a species distribution modelling approach, an assessment was carried out of the probability of presence of the yellow-necked mouse in different parts of Ukraine and a search accomplished to find effective environmental factors that play roles in its distribution. We considered this task important given the ecological and epidemiological significance of this particular rodent species and the urgency of the problem exacerbated by Russia’s armed aggression in Ukraine. Results showed a broad potential for the distribution of the species in the western and central parts of Ukraine, and in the Crimea. Areas predominantly in western and central Ukraine, and in the Crimea, are highly favourable for the mouse, whereas in the south and, to a smaller scale, in the easternmost part of the country they are the least favourable. Amongst the bioclimatic environmental factors that play roles in shaping the species’ niche are the ones that are fully or mostly temperature-related (for instance, annual mean temperature, continentality, etc.). Other factors in a declining order of their roles are associated with soil and land cover features, cloud frequency and standardised human impact. A moderate, though statistically significant, correlation has been found between the distribution of the Lyme disease agent Borrelia burgdorferi s. l. and predicted habitat suitability values for S. tauricus.
Read full abstract