The common frog, Rana temporaria, is one of the most recognizable amphibians across Europe and parts of Asia. This species is a familiar sight in a variety of landscapes, from remote woodlands to suburban gardens. Its adaptability has allowed it to thrive in diverse climates, reaching as far north as the Arctic Circle.
Appearance and Habitat
The common frog has smooth skin and measures between 6 and 9 centimeters in length, with females often growing larger than males. Its coloration is variable, ranging from olive green and grey to shades of brown and yellow, which helps it blend in with its surroundings. Many individuals have irregular dark blotches on their backs and flanks, along with striped patterns on their long hind legs. The most consistent identifying feature is a dark patch or “mask” that runs from behind the eye over the eardrum.
This amphibian leads a dual life, requiring access to both land and water. While they depend on bodies of water like ponds, lakes, and even canals for breeding, they spend much of their adult lives in terrestrial environments. You can find them in damp woodlands, wet meadows, grasslands, and gardens, where they seek out cool, moist conditions.
The Life Cycle of a Common Frog
The life cycle begins in early spring when frogs migrate to shallow, still waters to breed. Males attract females with a repetitive croaking call, and once a pair forms, the male grasps the female in a mating hold called amplexus. The female lays a single, large clump of spawn, which can contain up to 2,000 small, black eggs encased in a clear, jelly-like substance. This distinguishes it from toad spawn, which is laid in long strings.
After about three weeks, depending on water temperature, the eggs hatch into tadpoles. Initially, these fully aquatic larvae feed on algae and have gills for breathing. They are dark brown at first, developing golden speckles as they grow. The process of metamorphosis begins as the tadpoles start to develop hind legs, followed by the appearance of front legs.
Over a period of up to 16 weeks, the tadpole’s tail is gradually absorbed by the body for nutrients, and its gills are replaced by lungs, preparing it for life on land. Its digestive system also shifts to accommodate a carnivorous diet. Once this transformation is complete, the tiny froglet leaves the water to begin its terrestrial existence.
Diet and Seasonal Habits
As adults, common frogs are carnivorous predators, feeding on a wide variety of invertebrates. Their diet commonly includes slugs, snails, worms, spiders, and many types of insects, making them a welcome presence in gardens. To capture their fast-moving prey, the frog uses its long, sticky tongue, which it can flick out quickly. While younger frogs may feed in the water, adults typically hunt on land.
To survive the cold winter months, common frogs enter a state of hibernation. They can do this at the bottom of a pond, where they bury themselves in mud and decaying leaves, or on land in places like compost heaps, under log piles, or deep within rock crevices. They do not eat during this period, re-emerging as temperatures rise in the spring to begin the breeding cycle anew.
Conservation Status and Garden Habitats
While the common frog is widespread, it faces threats from habitat loss due to the drainage of wetlands and ponds, as well as pollution. Diseases such as ranavirus also present a risk. Conservation efforts focus on preserving and restoring the freshwater habitats that these amphibians rely on for breeding.
Homeowners can support local frog populations by creating suitable garden habitats. Building a wildlife pond with gently sloping sides allows frogs to easily get in and out. Avoiding the use of garden chemicals like pesticides and slug pellets protects frogs and their invertebrate food sources from poisoning. Providing shelter like log piles, rockeries, or leaving an area of grass to grow long offers them a safe place to rest and hide from predators.