Restoration of the Middle Irtysh population of European beaver.
As a result of reintroduction of individuals of the Eastern European and Belorussian subspecies of European beaver populations, a Middle Irtysh population was formed. Five stages can be distinguished in its development: adaptation (1953-1966); recovery (1967-1975); stabilization (1976-1988); depression (1989-2000); and expansion (2001-2012, not finished). Each stage has its own individual statistical and mathematical characteristics. A complete restoration of the European beaver range has not been achieved in the oblast, since the introduction of commercial hunting led to a depression in the number and number dilution of the range. Therefore, the quantitative and spatial development of the Middle Irtysh European beaver population was delayed for 25 years.