Grass snakes are a non-venomous reptile found across various European landscapes, extending into parts of Asia and Africa. These snakes commonly inhabit areas near water sources such as ponds, lakes, and canals, but also thrive in woodlands, grasslands, and even gardens. As one of the largest native snakes in some regions, they can grow to exceed a meter in length.
Primary Prey: Amphibians
Amphibians form the core diet of the grass snake. Common frogs and toads are frequently targeted due to their prevalence in aquatic and semi-aquatic habitats. Newts, such as smooth and great crested newts, also form a significant portion of their meals. The abundance of these amphibian species near water bodies makes them an easily accessible and reliable food source for the snakes. A single adult grass snake may consume a full-grown frog each week during active periods, or several newts.
Young grass snakes, especially hatchlings, begin feeding on smaller versions of these primary prey, often including tadpoles. The specific amphibian species consumed can vary based on local availability, demonstrating the snake’s adaptability to its immediate environment.
Additional Food Sources
While amphibians are a staple, grass snakes supplement their diet with other opportunistic prey. Small fish found in shallow waters, such as minnows or even goldfish in garden ponds, are readily eaten. Small mammals, including voles, shrews, and very young mice, also occasionally fall prey to grass snakes. On rarer occasions, they may consume small birds or their chicks.
The diet of grass snakes is flexible, adapting to what is available in their surroundings. This opportunistic strategy allows them to thrive in diverse habitats. Very young grass snakes might initially consume invertebrates, such as worms, before transitioning to a larger prey diet as they grow. This dietary breadth ensures their survival even when primary prey sources might be less plentiful.
Hunting Behavior
Grass snakes are active hunters, primarily foraging during the daytime. They are particularly adept in and around water, often found near pond edges or stream banks where their main prey resides. These snakes are excellent swimmers, capable of hunting efficiently both on the surface and submerged. They locate their prey using a combination of keen eyesight and a sophisticated sense of smell, aided by their Jacobson’s organ.
Their hunting method involves ambushing or stalking unsuspecting prey. Once close, the snake strikes quickly, seizing its victim. Grass snakes swallow their prey whole, often while it is still alive.
Notably, unlike some other snake species, grass snakes do not constrict their prey before consumption. A large meal can sustain a grass snake for an extended period, sometimes requiring only a few significant prey items over a season. After a large meal, they often bask in the sun to aid in digestion.