Perez's FrogPelophylax pereziWhere and when to see them

Perez's Frog is a highly aquatic frog native to the Iberian Peninsula and southern France. It is widespread in Portugal and occurs in suitable freshwater habitats throughout the Douro catchment. Its colouring ranges from bright green to brown, usually with darker markings. Breeding males produce conspicuous calls that can make these otherwise well-camouflaged frogs easier to notice. Although globally assessed as Least Concern, local populations can be affected by wetland loss, pollution and introduced predators.

Size

Usually about 4–7 cm from snout to vent; large females can reach around 10 cm.

Weight

Variable with size and condition; females are generally larger and heavier than males.

Lifespan

Several years; reliable estimates of typical lifespan in the wild are limited.

Status

Least Concern (IUCN).

Perez's Frogs spend much of their time in water or close to its edge. They often bask on sunny banks, stones or floating vegetation, diving into the water when disturbed. Activity can occur during both daylight and darkness, depending on temperature and conditions. During the breeding season, males gather in calling groups and use paired vocal sacs to amplify their calls. Males may defend small calling spaces against rivals. Females lay eggs in water, commonly among aquatic vegetation, and the tadpoles develop there before metamorphosing. Activity decreases during cold weather, when frogs shelter in protected places in or near the water.

• Its scientific name honours the Spanish naturalist Laureano Pérez Arcas.
• Individuals can be predominantly green or brown.
• Calling males inflate two vocal sacs, one on each side of the mouth.
• It can live in artificial waters as well as natural wetlands.

Wildlife opportunities depend on the river reach, water levels and species. River-specific viewing months have not been confirmed; general species seasons are not a local sighting forecast.

This species occupies ponds, lakes, reservoirs, irrigation channels and slow-moving stretches of rivers and streams. It generally favours freshwater with sunny margins and access to aquatic or bankside vegetation. Along the Douro, sheltered bays, tributary margins and nearby ponds can provide more suitable habitat than exposed, fast-flowing channels. It also uses modified waters, including farm ponds and some urban wetlands. Its tolerance of a range of conditions does not make it immune to pollution, drainage or severe drought.

Adults are opportunistic predators that take a wide variety of small animals. Insects, spiders and other invertebrates form much of their diet, captured at the water's edge or in the water. Larger individuals may also take small vertebrates, including other amphibians. Tadpoles feed largely on algae, microorganisms and organic debris, although they can also consume animal material.

Common name

Perez's Frog

Scientific name

Pelophylax perezi

Animal group

Amphibians

Size

Usually about 4–7 cm from snout to vent; large females can reach around 10 cm.

Weight

Variable with size and condition; females are generally larger and heavier than males.

Lifespan

Several years; reliable estimates of typical lifespan in the wild are limited.

Status

Least Concern (IUCN).

Identification

Look for a green, olive or brown frog with dark spots, prominent folds running along each side of the back, and long hind legs. A pale stripe often runs down the centre of the back, but it is not present in every individual. The underside is usually whitish, sometimes with grey mottling, and breeding males have paired external vocal sacs at the sides of the mouth. Colour alone is not diagnostic, and distinguishing it from closely related water frogs or hybrids may require expert assessment.