Winter months’ temperature rises effect on duration of phenological phases for Spermophilus pygmaeus Pallas, 1778 populations located in Caspian depression (Astrakhan oblast)

Abstract

This article provides comparison analysis between 1950–1959’s and 2000–2009’s periods for duration and schedule dates of awakening, spreading and hibernation phases for Spermophilus pygmaeus populations located in the Caspian Depression (by example of Astrakhan Oblast). We learned that within a period of maximum temperature rise in February 2000–2009’s durations of S.pygmaeus’ populations of every phonological phase have shortened and been rescheduled with earlier dates (in comparison to 1950–1959’s). The study also shows that these changes caused its population reduction on the Caspian Depression’s territory.