Moor frog

Rana arvalis

Size: 5.5–7 cm
Diet: Carnivore
Activity: Seasonal
Sociality: Loose group
Lifespan: —

The moor frog is a wetland frog spread across Europe and Siberia. It is famous for males that turn bright blue for a short period during the breeding season.

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Key facts

Moor frog (Rana arvalis) is a carnivore animal classified as Amphibian · Anura · Ranidae.
Primary habitats are forest · grassland · freshwater, with a range across Palearctic.
Activity is seasonal, sociality is loose group, and conservation status is LC (Least Concern).
The moor frog is a wetland frog spread across Europe and Siberia.
It inhabits bogs, fens, wet meadows, forest ponds and floodplains.

Range

Habitat range map

Native rangeOccasional / Transient

Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)

Details

Habitat

It inhabits bogs, fens, wet meadows, forest ponds and floodplains. Acidic shallow still water and temporary pools are important breeding sites.

Appearance

Adults are about 5.5-7 cm long. The usual color is reddish to gray-brown with a dark patch behind the eye, while breeding males may become blue over much of the body.

Behavior

Adults gather to breed in spring, then live mostly alone on damp land. In cold regions, physiological adaptations help them survive freezing conditions.

Feeding

Adults eat insects, spiders, worms and small arthropods. Tadpoles use algae, organic matter and tiny aquatic organisms.

Reproduction

Spring breeding takes place in shallow ponds. Females lay large egg masses in water, and tadpoles grow quickly as temperatures rise.

Notes

The species is globally Least Concern, but some European populations are reduced by drainage, acidification and agricultural change. Blue males mark the brief breeding peak.