more extreme heat. The snakes will exhibit a degree of activity even during hibernation, moving around to keep a body temperature near and occasionally emerging to bask on sunny days. The average home range for French populations has been calculated at , however males will travel longer distances of up to to find females during the mating season and females to find suitable hatching sites to lay eggs. The Aesculapian snakes are deemed secretive and not always easy to find even in areas of positive presence, or found in surprising contexts. In contact with humans, they can be rather tame, possibly due to their cryptic coloration keeping them hidden within their natural environment. They usually disappear and hide, but if cornered they may sometimes stand their ground and try to intimidate their opponent, sometimes with a chewing-like movement of the mouth and occasionally biting. It has been speculated that the species may be actually more prevalent than thought due to spending a significant part of its time in tree canopy, however no reliable data exist as to what part that would be. In France it is said to be the only snake species that occurs inside dense, shadowy forests with minimum undergrowth, presumably because of using foliage for basking and foraging. In other parts of the range it has been reported to only use the canopy on a more substantial basis in largely uninhabited areas, such as the natural beech forests of the East Slovak and Ukrainian Carpathians, with similar characteristics. Reproduction Minimum length of individuals entering the reproductive cycle has been reported at 85–100 cm, which corresponds to sexual maturity age of about 4–6 years. Breeding occurs annually after hibernation in spring, typically from mid-May to mid-June. In this time the snakes actively seek each other and mating begins. Rival males engage in ritual fights the aim of which is to pin down the opponent's head with one's own or coils of one's body; biting may occur but is not typical. The actual courtship takes the form of an elegant dance between the male and female, with anterior portions of the bodies raised in an S-shape and the tails entwined. The male may also grasp the female's head with its jaw (Lotze 1975). 4 to 6 weeks after about 10 eggs are laid (extremes are from 2 to 20, with 5–11 on average) in a moist, warm spot where