Distribution, population densiti and behavior in the space of ermine (Mustela erminea L.) in conditions Roztotchya and Nadsyannya

Abstract

Peculiarities of distribution, population density and spatial behavior of ermine in the winter season in the natural regions of Roztotchya and Nadsyannia have been studied. About 60 % of the district’s territory lies within the hilly region of Roztocko-Opil, in particular Roztocze, the other part belongs to Prykarpattia, namely the Nadsyan plain. Methods of tracking and accounting of traces on snow were used. Population density calculations were performed according to the updated formula Formozova. The results of research have shown that the ermine is a fairly common species on both the Roztoc Upland and the Nadsyan Plain. However, the habitats of this predator mostly cover aquatic habitats (67 %). The best stations are primarily the coastal strip of small rivers and streams. In second place in terms of the number of registered traces of the species is the border of forests and arable fields, or meadows (20 %). In large forests, the species is mostly registered on fellings and young forest crops (8 %). In fields more than 500 m away from forests and water bodies, ermine is rare (3 %). Occasionally ermine is registered in settlements – near buildings (2 %). The highest population density of the species was observed in 2010 (8 individuals / 1000 ha). The lowest rates were registered in 2012 (2 individuals / 1000 ha). On average, the amplitude of fluctuations in ermine population density for 10 consecutive years reached 4 times the value. However, in coastal stations, the difference between the extreme indicators was 6 times (2–12 individuals / 1000 ha). The length of the daily course of ermines in winter is from 200 m to 4.5 km, on average 1.2 km. The average size of a single area of ​​the animal along the shores of reservoirs is 15–20 hectares, in the depths of the forest can be 100 hectares or more. Individual areas of males are slightly larger than females and are often superimposed on them. Instead, individual areas of males or females that live nearby almost never overlap. Some ermines can lead a nomadic lifestyle. The species is often active during the light period of the day.