The Coronella genus encompasses a group of snakes commonly known as smooth snakes, recognized for their non-venomous nature and generally small size. They are often docile. The genus includes two primary species: the smooth snake (Coronella austriaca) and the southern smooth snake (Coronella girondica). These snakes are found across various parts of Europe and into sections of Asia.
Identification and Key Traits
Smooth snakes have slender bodies and smooth, flat scales, distinguishing them from snakes like adders which have keeled scales. Their coloration usually ranges from shades of brown and grey to a coppery tone, often featuring darker spots or a subtle dorsal stripe. This patterning provides effective camouflage.
An adult smooth snake measures between 60 to 75 centimeters (approximately 24 to 30 inches), though some individuals can reach up to 92 centimeters (36 inches). Females are often larger than males. The head of a Coronella snake is relatively narrow, with a dark marking on top that sometimes resembles a crown.
A distinct dark stripe extends from each nostril, through the eye, and along the side of the head, and their pupils are round. These snakes are non-venomous and lack fangs.
Natural Habitat and Behavior
Coronella snakes are primarily found across northern and central Europe, extending eastward into parts of Asia, including northern Iran. They inhabit a variety of environments, including heathlands, grasslands, shrublands, mixed woodlands, and rocky areas. In the United Kingdom, their distribution is more restricted, mainly to heathland habitats. These snakes are largely terrestrial, though they can occasionally climb into low shrubs.
Smooth snakes are secretive and elusive, often remaining hidden. They conceal themselves under rocks, logs, dense vegetation, or within crevices, venturing out to hunt or bask. While generally diurnal, they may exhibit nocturnal activity in warmer weather. If threatened, they attempt to flee or hide. If cornered, they might coil tightly, hide their head, or release a foul-smelling substance from their anal glands.
Diet and Ecological Role
The diet of Coronella snakes consists mainly of other reptiles, particularly lizards and other snakes, including venomous ones like adders. Specific prey items include viviparous lizards (Zootoca vivipara) and slow worms (Anguis fragilis). Larger smooth snakes may also prey on small rodents and, occasionally, birds. Juvenile smooth snakes feed exclusively on reptiles.
When hunting, smooth snakes employ a constriction method to subdue their prey, although unlike true constrictors, they do not kill by this method. They act as predators, helping to regulate populations of smaller reptiles, while also serving as prey for larger animals such as birds of prey, foxes, badgers, and weasels. Their presence often indicates a healthy ecosystem with a robust population of their preferred prey.
Conservation Status
The conservation status of the smooth snake (Coronella austriaca) is “Least Concern” by the IUCN Red List, though population trends are decreasing in some areas. Habitat loss, fragmentation, and degradation are considered primary threats to their populations. In specific regions, such as the United Kingdom, the smooth snake is considered the rarest native reptile, with its distribution confined to sandy heathlands in southern counties.
Due to these vulnerabilities, Coronella species are protected under various laws and directives in different regions. For instance, in the UK, they receive full legal protection under the Wildlife and Countryside Act of 1981, prohibiting harm, capture, disturbance, or habitat destruction. Conservation efforts focus on managing and preserving their specific heathland habitats, which are susceptible to issues like overgrazing. Their secretive nature and slow reproductive rates, with females giving birth to 4-15 live young around September after internal incubation, further contribute to their sensitivity to environmental changes.