Search

The article is based on long-term (1958–2017) expedition and stationary research in the Kivach, Kostomuksha and Lapland nature reserves and Karelian field stations – Priladozhsky, Kaskesnavoloksky and Gomselsky covering a vast part of taiga of the North-West of Russia. The article analyzes the population and ecological features of the equal -toothed shrew (Sorex isodon Turov) associated with its habitat near the North- Western borders of its range. It was found that in these conditions, the species was characterized by a generally low level of abundance compared to the optimal for the range (an average, 0.02 per 100 trap days and 0.1 per 10 trench days), distinct transition to stenotopy and obvious fixation on elements of the anthropogenic landscape. It is also characterized by the peculiarity of the territorial structure, the shift of reproduction to a later date and its general extension until mid –September. During the reproduction season, wintering adult females bring two litters: the first – in late May-early June, the second – in July. The litter size ranges from 2 to 11 per adult female (an average, 7.7 + 0.3). The share of mature and offspring-bearing profitable animals in general is small (up to 5-8 %) and varies by year depending on the state of the population and weather conditions.

Monitoring of two tick species (Ixodes persulcatus Schulze 1930 and Ixodes pavlovskyi Pomerantsev) was performed in four city parks of Tomsk, Russia (Camp Garden, University Park, Southern Cemetery, and Polytechnic Stadium) and in a control wild biotope in city environs (Kolarovo) in 2002-2013. Ticks were collected by flagging repeatedly after each 10 ± 1 days, starting from the disappearance of the snow cover till the end of tick activity (April-August). Gradual penetration of both tick species into city parks was demonstrated. In the wild biotope, I. persulcatus dominated during the whole period of monitoring, forming about 95% of tick population, whereas in urban biotopes I. pavlovskyi became the dominant species. Two peaks of population density during each season of spring-summer activity were observed in both species. Possible explanations of the phenomena are discussed.