Animal
European tree frog
This little frog is bright grass-green. It climbs in bushes with sticky toe pads, and it sings loudly at night!
The European tree frog is a small, grass-green frog with a dark band along each side and sticky pads on its fingers and toes. It climbs in hedges, bushes and trees, where its green color hides it well. In spring, males call so loudly at night that their choruses can be heard kilometers away. It has disappeared from many places in western Europe, but ponds dug for it are helping it come back.
Hyla arborea (family Hylidae) is now considered endemic to Europe, from Atlantic France east to central Poland, central Bulgaria and Greece, since Iberian and eastern populations were split off as H. molleri and H. orientalis (Stöck et al. 2008). It breeds in sunny, fish-free ponds. The IUCN listed it as Least Concern (global and European assessment, assessed 21 February 2023, published 2024) with a decreasing trend, fragmented and declining over much of western Europe.
Photo: Christian Fischer, CC BY-SA 3.0, via Wikimedia Commons
Meet the European tree frog
This frog is small and grass-green.
It has a dark stripe along its side.
Its fingers and toes have sticky pads for climbing.
The European tree frog is a small, grass-green frog that grows to about 5 centimeters long. A brown-black band runs along each side, between its green back and its pale belly. Its eyes are orange, with a pupil shaped like a flat line.
The ends of its fingers and toes have little suction pads, so it is a very good climber. It can also change color, from light brown to dark green.
RAVON (the Dutch reptile, amphibian and fish conservation organization) describes a small grass-green frog with suction pads on the finger and toe tips that make it a good climber; a brown-black flank band between the green back and pale belly; orange eyes with a horizontal pupil; a clearly visible eardrum; color change from light brown to dark green; a very large vocal sac under the male's chin, seen only when calling; a size of up to 5 cm; and young that look like adults. BfN notes that it climbs in bushes and trees, where its green color camouflages it.
Quick facts
- Group
- Amphibian
- Length
- up to 0.05 m
- Lifespan in the wild
- 3 to 6 years
Sunny ponds and leafy hedges
These frogs live near sunny ponds.
In summer they sit in bushes and hedges.
In winter they hide under roots and stones.
European tree frogs like open, sunny places: light forests and forest edges, bushes, meadows, gardens, orchards, parks and lake shores. They stay away from dark, thick forests.
They lay their eggs in sunny, shallow ponds full of plants, where no fish live. In summer they sit on broad, sunny leaves in hedges and brambles, and in winter they shelter on land, in frost-free holes under roots, wood or stones.
IUCN: open, well-lit broad-leaved and mixed forests, bush and shrubland, meadows, gardens, vineyards, orchards, parks, lake shores and low riparian vegetation; dark, dense forest avoided; also in anthropogenic landscapes, including large cities; spawning in stagnant water. BfN (Germany): fish-free, shallow, plant-rich, fully sunlit ponds that warm quickly; summer habitat sheltered and humid with broad-leaved sunny perches, such as hedges, bramble, forest edges and wet fallow land; winter quarters mostly in mixed deciduous woods or copses, in frost-free cavities under roots, wood or stones.
Continent
Its habitats
Where can you find this animal?
- Lives here naturally · Countries and seas named by a scientific source
- Sightings recorded · Records of wild sightings (GBIF)
- Brought back by people · Countries and seas named by a scientific source
Lives here naturally · Countries and seas named by a scientific source
Europe only: from the Atlantic coast of France east to central Poland, central Bulgaria and Greece, including Crete; in Scandinavia only in southern and eastern Denmark and the far south of Sweden (IUCN). Liechtenstein is listed too. Frogs in Spain and Portugal, and from Turkey, eastern Poland and Ukraine eastward, now belong to two other species. Romania is on the IUCN country list but is not sha
Places: Albania, Austria, Belgium, Bosnia & Herz., Bulgaria, Croatia, Czechia, Denmark and 16 more places.
Source: iucn-red-list · checked November 2026
Sightings recorded · Records of wild sightings (GBIF)
Counts of GBIF records of wild observations (human and machine) and preserved specimens. Records include introduced populations, vagrants, escaped or released animals and misidentifications, so a country with records is not necessarily part of the native range.
Wild sightings have been recorded in France, Switzerland, Netherlands, Austria, Denmark, Germany, Sweden, Spain and 47 more places.
Source: gbif · checked October 2026
Brought back by people · Countries and seas named by a scientific source
Reintroduced to Latvia (Gauja National Park) in 1987 to 1992 (IUCN).
Places: Latvia.
Source: iucn-red-list · checked November 2026
Range maps show where scientists say an animal lives, often country by country. An animal may live in only part of a country shown, and sightings records can include animals that wandered far from home.
Insects from a sunny perch
These frogs eat insects and other small bugs.
They hunt in leafy bushes and flowers.
European tree frogs eat insects and other small animals with jointed legs. In summer they choose damp places sheltered from the wind, with broad leaves to sit on in the sun and plenty of food nearby.
Both young and grown-up frogs like to bask and feed in patches full of flowers and along the grassy edges of fields and paths. Mowing and mulching these edges can harm them.
Food: insects and other arthropods (BfN). Summer habitat is chosen for shelter from wind, high humidity, broad-leaved sunny perches and a good food supply; juveniles and adults use flower-rich vegetation, field margins and verges for basking and feeding, which exposes them to mowing and mulching (BfN, after Grosse and Günther 1996).
Did you know?
Some tree frogs travel a very long way.
Young tree frogs are good at finding new ponds. Some have traveled more than 10 kilometers in 2 to 3 years.
Over 10 km in 2 to 3 years (Clausnitzer and Berninghausen 1991, via BfN).
Suction pads and a giant throat bubble
Sticky pads help it hold on to leaves.
When a male sings, his throat blows up like a big bubble!
A European tree frog's finger and toe pads work like tiny suction cups, so it can climb well. Its bright green color hides it among leaves, and it can change color from light brown to dark green.
When a male calls, a huge vocal sac under his chin puffs up like a balloon. You only see it while he is calling.
Suction pads on the finger and toe tips; color change from light brown to dark green; male vocal sac very large, under the chin, visible only during calling (RAVON). Green coloration gives camouflage in bushes and trees (BfN). The resting posture keeps the fingers and toes pressed against the body, as in the photo (Commons description).
Walnut-sized egg clumps
The mother lays small clumps of eggs in a pond.
Tadpoles grow in the warm water.
In summer, tiny frogs climb into the bushes.
In spring, females lay their eggs in small clumps about the size of a walnut, stuck to plants in shallow water. In Germany a female lays 2 to 10 clumps of about 25 eggs each.
The tadpoles take 50 to 70 days to turn into froglets, depending on how warm the water is and how much food there is. In Germany, the first tiny frogs leave the water in mid to late June, and most in July and August.
Breeding April to June (sometimes July) depending on climate; in favorable weather adults move to the ponds from late February. Each female lays 2 to 10 egg clumps of about 25 eggs on average, mostly on plants; larval development takes 50 to 70 days, varying with water temperature, food and tadpole density; froglets leave the water from mid or late June, most in July and August. Females usually mature after their second winter, males sometimes a year earlier (BfN). In the Netherlands: 150 to 300 eggs a season, in walnut-sized clumps less than 10 cm deep (RAVON).
A chorus you can hear for kilometers
At night, male frogs sing: ke-ke-ke-ke!
Their song is very loud.
From about April to June, males gather at the ponds and call on warm evenings and at night: a fast, loud 'ke-ke-ke-ke-ke'. A tree frog chorus can be heard several kilometers away! They call a little in late summer, too.
Tree frogs are good travelers. Young frogs quickly find new ponds, and some have moved more than 10 kilometers in 2 to 3 years.
Loud nocturnal choruses April to June, audible over several kilometers (BfN); the call is a 'kè-kè-kè-kè' given mostly on warm evenings, with some calling in late summer; in the Netherlands older males reach the water first in mid-April (RAVON). Seasonal moves between spawning ponds, summer habitat and winter quarters are usually a few hundred meters, at most about 3 km (Fog 1993); juveniles colonize new ponds quickly, and movements of over 10 km in 2 to 3 years are recorded (Clausnitzer and Berninghausen 1991, via BfN). Outside the breeding season they live on land (RAVON).
Did you know?
Tree frog eggs come in clumps as big as a walnut.
Tree frog eggs are laid in clumps about the size of a walnut, so they are hard to spot.
Walnut-sized egg clumps, laid less than 10 cm deep (RAVON).
Ponds bring tree frogs back
In many places, tree frogs have gone away.
People are digging new ponds to help them come back.
The European tree frog is listed as least concern in the world, but it is shrinking in many places. Over much of western Europe its numbers have fallen a lot, as wetlands were drained and polluted, meadows and hedges were lost, and fish were put into ponds. Some are also collected as pets.
New ponds help. In Sweden, the number of tree frogs grew from 2,000 in 1980 to 50,000 in 2008 in about 900 ponds, and in the Netherlands the species is increasing again.
Least Concern (IUCN; Global and Europe; assessed 21 February 2023, published 2024; trend decreasing): wide distribution, presumed large population; fragmented and in significant decline over much of western Europe. Threats: loss and fragmentation of forest, bush and meadow habitat, wetland drainage and pollution, predatory fish such as pumpkinseed, the pet trade, road traffic, low genetic variability in the west. Berne Convention Appendix II, EU Habitats Directive Annex IV; reintroduced to Latvia (1987 to 1992); Swedish restocking from 2,000 (1980) to 50,000 (2008) in about 900 ponds (IUCN). Germany's Red List: category 3, 'threatened' (gefährdet) (BfN). Netherlands: range down 80% by the late 20th century, now increasing again (RAVON).
IUCN Red List
How is the european tree frog doing in the wild?
- Least Concern (this animal)
- Near Threatened
- Vulnerable
- Endangered
- Critically Endangered
- Extinct in the Wild
- Extinct
Least Concern
Not at risk of disappearing from the wild right now.
Amazing facts
-
A tree frog chorus is so loud you can hear it far away!
A chorus of European tree frogs can be heard several kilometers away.
Choruses audible over several kilometers (BfN).
-
This frog can change color!
A European tree frog can change its color from light brown to dark green.
Color change from light brown to dark green (RAVON).
-
Tree frog eggs come in clumps as big as a walnut.
Tree frog eggs are laid in clumps about the size of a walnut, so they are hard to spot.
Walnut-sized egg clumps, laid less than 10 cm deep (RAVON).
-
Some tree frogs travel a very long way.
Young tree frogs are good at finding new ponds. Some have traveled more than 10 kilometers in 2 to 3 years.
Over 10 km in 2 to 3 years (Clausnitzer and Berninghausen 1991, via BfN).
Words to know
- vocal sac
- a stretchy pouch of skin that a male frog blows up when he calls
- tadpole
- a young frog that lives in water
- froglet
- a tiny young frog that has just changed from a tadpole
- hedge
- a row of bushes growing close together
- reintroduce
- to bring an animal back to a place where it used to live
- least concern
- not currently at serious risk of dying out in the wild
Discovery challenge
-
What kind of pond do tree frogs like?
What kind of pond do European tree frogs need for their eggs and tadpoles?
Which breeding waters does Hyla arborea prefer?
- Sunny ponds with no fish
- Dark ponds full of fish
- Salty sea water
Show the answer
Sunny ponds with no fish
Sunny ponds with no fish!
They need shallow, sunny ponds full of plants, where no fish live.
Fish-free, shallow, plant-rich, fully sunlit waters (BfN; RAVON).
-
What helps this frog climb?
What is on the tips of a European tree frog's fingers and toes?
What structures tip the digits of Hyla arborea?
- Little suction pads
- Sharp claws
- Long hairs
Show the answer
Little suction pads
Little suction pads!
Suction pads on its fingers and toes make it a good climber.
Suction pads on the finger and toe tips (RAVON).
-
How far away can you hear a tree frog chorus?
How far away can a chorus of European tree frogs be heard?
Over what distance can Hyla arborea choruses carry?
- Several kilometers
- Only a few centimeters
- Across an ocean
Show the answer
Several kilometers
Kilometers away!
Their loud night choruses can be heard several kilometers away.
Audible over several kilometers (BfN).
-
What helps tree frogs come back?
What has helped European tree frogs come back in places like Sweden?
Which conservation measure has helped Hyla arborea recover locally?
- New ponds
- More fish in ponds
- Draining wetlands
Show the answer
New ponds
New ponds!
In Sweden, numbers grew from 2,000 to 50,000 in about 900 ponds.
Pond creation and restocking programs (IUCN; RAVON).
Places where you might see it
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Watch
Country
Germany
Germany is a country in north-central Europe. The land rises from flat plains by the North Sea and the Baltic Sea to forested hills and, in the far south, the Alps. About 83.5 million people (2025) live there, and its capital is Berlin.
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Watch
Country
France
France is a country in northwestern Europe, between the Atlantic Ocean and the Mediterranean Sea. It has high mountains such as the Alps and the Pyrenees, long rivers such as the Loire and the Seine, and about 69.1 million people (2026). Its capital is Paris.
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France
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Amazon milk frog
The Amazon milk frog is a large tree frog that lives high in the treetops of the rainforest in northeastern South America. It is active at night, has big golden eyes, and lays its eggs in pools of rainwater trapped in holes in trees, where its tadpoles grow up.
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American bullfrog
The American bullfrog is the largest true frog in North America. It lives in warm, still ponds and lakes, sits and waits for food to come close, and the males' deep 'jug-o-rum' call carries more than a kilometer. Its tadpoles can take years to turn into frogs.
For parents & teachers
What children will learn
- Describe how to recognize a European tree frog.
- Explain what kind of ponds tree frogs need and why fish are a problem.
- Describe the stages from egg clump to froglet.
- Explain how new ponds have helped tree frogs come back.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- Why might a pond without fish be a better home for tadpoles?
- Why might a frog need ponds, hedges and woods all close together?
- What could a town or school do to help frogs?
Try at home or in class
- Walnut test: compare a walnut with a small ball of clear jelly or tapioca beads, and imagine about 25 tiny eggs inside a clump that size.
- Pond plan: draw a pond that would suit tree frogs: sunny, shallow edges, lots of plants, no fish, and hedges nearby.
Key vocabulary: vocal sac, tadpole, froglet, hedge, reintroduce, least concern
Where these facts come from
- GBIF Backbone Taxonomy and GBIF Occurrence Search , Global Biodiversity Information Facility (CC0 1.0 (backbone); occurrence counts are facts derived from records under CC0, CC BY and CC BY-NC)
- Wikidata , Wikimedia Foundation (CC0 1.0)
- The IUCN Red List of Threatened Species , International Union for Conservation of Nature (IUCN terms of use (no redistribution of Red List data or range maps))
- Hyla arborea (Agasyan, Avci, Tuniyev et al., assessed 21 February 2023, published 2024) , IUCN Red List of Threatened Species
- Hyla arborea: taxonomy, justification, range, population, habitat, threats and conservation text , IUCN Red List of Threatened Species
- Hyla arborea: IUCN Red List global assessment record (Agasyan et al. 2024), IUCN checklist on GBIF , GBIF
- Laubfrosch (Hyla arborea): Artenportrait (species portrait, in German) , Bundesamt für Naturschutz (German Federal Agency for Nature Conservation)
- Boomkikker (European tree frog, in Dutch) , RAVON
- File:Hyla arborea, juv 2.jpg (Christian Fischer, 13 August 2007, northeastern Lower Saxony) , Wikimedia Commons
- Wikimedia Commons , Wikimedia Foundation (Per file: Public domain, CC0, CC BY or CC BY-SA only (credited on each page))
Checked, not yet human-reviewed. Last updated November 1, 2026. Spotted a mistake? Tell us.