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Moor Frog 

The Moor Frog has a large geographical range in Eastern Europe and Western Russian. They are a common frog with large population throughout their range. Males turn blue during mating season in order to distinguish from females.

While they may seem plain, they have some patterning and behavioral color change that makes this species so interesting. 

Common NameMoor Frog
Other NameNone
Scientific NameRana arvalis 
LocationsNorthern, Central, Eastern Europe 
CharacteristicsVomerine teeth
Horizontal eye pupil
Pointed snout 
ColorDorsum can be grey, light brown, reddish, spots 
Ventrum is usually paler and lacks pattern
Males blue during mating season
OriginEastern Europe 
Conservation StatusLeast Concern 
SpeciesRana arvalis 
Max Length5.5cm-6cm (2-2.4 inches)
Max length 7cm (2.8 inches) 
Max Weight57 grams 
Lifespan11 years in the wild 

Geographical Range and Habitat  

Moor Frogs originate from Europe, specifically northern, central, and eastern Europe countries.

They can be found in Germany, Poland, Finland, and Western Russia in Asia.

Moor Frogs have been found to be extinct in Switzerland, but did live there historically. 

This species has adapted to live in a variety of habitats and altitudes.

Male Moor Frogs With Their Eggs During Mating Season

They can be found anywhere from the tundra, to forest and forest steppes and edges.

Moor Frogs also frequent open fields and meadows and semi-desert landscapes. 

This species is mainly aquatic and prefers shallow, stagnant water.

Because of this they can be found in a variety of wetlands.

Swamps, peats, and moorlands are frequent habitats for these frogs. 

Threats and Current Conservation Status 

The International Union for the Conservation of Nature (IUCN) categories this species as least concern.

However, their last assessment was done in 2008.

To further understand the population distribution, it is necessary to reassess the species. -iucn least concern last assessed in 2008 

Threats to moor frogs include habitat destruction and degradation of breeding ponds.

Male Moor Frogs

Urbanization and agricultural cattle grazing are potential threats as well as predation by waterfowl. 

Moor frogs have been found in gardens and near urban houses, suggesting they have adapted to urban settings. 

The fatal chytrid fungus that affects amphibians has been found in moor frogs in Germany.

This fungus is easily spread and more frequently than not causes death of the affected animal. 

Coloration and Patterns 

Moor frogs can look similar to other common frogs in Europe.

Their dorsum side is darker than their bellies and display colors like gray, red, brown, and yellow, and variations of those.

They have dark spots on their backs near their head and necks and down their lateral sides.

Moor frog (Rana arvalis) couple in amplexus mating position in the reproduction season

Their ventral belly is pale and has very little pattern.

They display colors like white and pale yellowish. Slightly darker, but still pale, spots decorate their throats and chests. 

There is a large dark spot by their eyes and a light line that resides on top of their lips.

The face and dorsum area most near the neck and face shows the most pattern. 

Hibernation Season and Breeding Habits  

Moor frogs hibernate anywhere between September and June.

The length of their hibernation depends on where the specific population falls in their geographical range latitude.

So, if a frog enters hibernation in September, it will emerge earlier than June.

The reproduction season occurs around March through June, of course, depending on when the population emerges from hibernation.

Males form breeding choruses to attract females to them.

Blue Male Moor Frog (top) and Brown Female Moor Frog (bottom) in amplexus during mating season

Males tend to turn blue during breeding season to distinguish themselves from females.

Amplexus is pectoral and afterwards females release anywhere between 500-3000 eggs into shallow, stagnant, ponds in one clump.

This is why degradation of breeding ponds can be detrimental to frog species around the world. 

Are Moor Frogs Common Pets? 

Moor frogs are not commonly found in the pet trade.

Not every frog species becomes a common pet.

Though, if this species did enter the pet trade it would likely need a more saturated or primarily aquatic environment to be housed in. 

Moor Frogs Are Freeze Tolerant 

Freeze tolerance refers to a state amphibians and reptiles enter during the freezing winter months.

Basically, they enter a comatose state where the ground and water systems, as well as the rest of their environment, freezes. 

The frogs themselves can quite literally freeze, but they will survive and thaw out with the spring.

This phenomenon occurs because they can retain water.

Their bodies produce more glycerin that allows them to survive. 

Animals that are freeze tolerant will remain in one spot over the winter.

They do not appear to be living or breathing when one is found in the wild.

They will be covered in ice crystals and remain perfectly still. 

When the spring comes and the snow and ice melts, so does the frog.

They will thaw and carry on with their lives.

This can be seen in turtles that remain under the frozen surface of ponds and is just another way of hibernation. 

Some reptiles will form dens and share body heat in an alternative hibernation method. 

How to Find A Moor Frog In the Wild

  • Be sure to be in an area in their geographical range; eastern, central Europe or Western Russia¬†
  • Since they exist in diverse habitats, simply find one in their range that contains lots of ponds.¬†
  • Do not try to find them between September and the spring months. They will be hibernating!¬†
  • Moor frogs breed during the day and night, so it does not matter what time you go searching.¬†
  • Listen for calling choruses during breeding season (April through June) and follow the sound.  

Fun Facts About Moor Frogs! 

  • Male frogs can turn blue during breeding season! This is super cool and likely to attract a female mate.¬†
  • Female moor frogs do not eat during reproduction season. This can be to conserve energy for producing offspring.¬†
  • Tadpole moor frogs eat algae, plants, and small invertebrates that occur on the surface of their aquatic habitat.¬†¬†
  • Adult frogs eat terrestrial prey and aquatic invertebrates.¬†


AmphibiaWeb. (n.d.). Retrieved from https://amphibiaweb.org

IUCN. 2022. The IUCN Red List of Threatened Species. Version 2022-2. https://www.iucnredlist.org.