Dione rat snake Elaphe dione (Pallas, 1773)
Dione rat snake is a widely spread species of the genus Elaphe which includes 11 members according to the latest expert estimates. The range of the species extends from Eastern Ukraine and Transcaucasia to Far East through Iran, Central Asia, Mongolia and Northern China.
Dione rat snake owes his name to the distinctive pattern on a top of the head which originates from combination of axial and lateral spots and streaks. The pattern of any individual is inimitable and unique.
Dione rat snake is a highly adaptable reptile and frequents diverse habitats throughout its range. It may be seen in steppes and deserts, in coniferous and mixed forests, on mountain slopes and in ravines overgrown with shrubs, in river flood-plains and bottomland forests, on salt marshes and alpine meadows.
Small rodents and lizards are the preferred prey of Dione rat snake but not infrequently it depredates also the nests of small passerines.
The period of active life begins in late March to early April and lasts till mid October when rat snakes go into hibernation. Pairing takes place almost immediately after leaving the winter shelters. In early summer females lay 5 to 20 eggs from which young individuals up to 25 cm length emerge in 1,5-2 months.
Hibernation is a very interesting period of high importance for rat snake’s life. The snakes use certain site for hibernation persistently through the whole life. Dione rat snakes congregate before hibernation. Such gatherings tend to be numerous and at times hundreds of individuals join each other in this period. Besides, the same sites often are used by other species of reptiles and even amphibians e.g. European Smooth snake and European Green toad.
In Ukraine Dione rat snake is a steppe species. Its status is quite favourable within major part of the range. But in Ukraine it is considered endangered and listed in the third edition of the country’s Red Data Book. The decline of the species is caused mainly by the shortage of suitable habitats e.g. steppe areas which are either afforested or transformed into arable lands.
Local people often consider Dione rat snake venomous. As a result, the species suffers greatly from direct persecution. When encountering humans Dione rat snake usually flees. It poses virtually no threat neither for the life, nor for the health of humans.