Animal
Pacific tree frog
This small frog has a dark stripe through its eye, like a mask. It can be green or brown.
The Pacific tree frog is a small frog of the Pacific Northwest of North America. It has round, sticky toe pads and a dark mask through each eye, and its body can be green, brown, gray or even reddish. Despite its name, it lives mostly on the ground and in shrubs. In Washington it is the most common frog, and its 'rib-it' chorus is the frog call heard most often there.
Pseudacris regilla (family Hylidae) is now thought to live west of the Cascades and along the Coast Range of California into Oregon, Washington and southern British Columbia, after a 2006 study split the former species into three; the range limits are still being worked out. It breeds in almost any still or slow water. The IUCN SSC Amphibian Specialist Group listed it as Least Concern (assessed 23 October 2019, published 2022), with a stable population trend.
Photo: The High Fin Sperm Whale, CC BY-SA 3.0, via Wikimedia Commons
Meet the Pacific tree frog
This frog is small.
It has a dark stripe through each eye, like a mask.
It has round, sticky pads on its toes.
The Pacific tree frog is a small frog with a pointed snout, long legs and fairly smooth skin. Grown-ups are usually less than 5 centimeters long from the snout to the end of the body, and females grow bigger than males.
A dark stripe, like a mask, runs from the tip of the nose through the eye to the shoulder. The tips of its fingers and toes have round, sticky pads that hold on well to smooth surfaces.
WDFW describes a small frog with a somewhat flattened body, narrow waist, long legs, relatively smooth skin and a pointed snout; adults usually under 2 in snout-vent, females larger; a conspicuous dark mask from the snout tip through the nostril, eye and tympanum to the shoulder; often two or three back stripes and a Y-shaped mark between the eyes, which may be broken, faint or absent; and sticky, broadened circular toe discs that adhere well to smooth surfaces. Mature males have dark throats. CaliforniaHerps gives 1.9 to 5.1 cm (Stebbins 2003).
Quick facts
- Group
- Amphibian
- Length
- 0.02 to 0.05 m
From forests to backyards
These frogs live in forests, fields and gardens.
They lay their eggs in ponds and puddles.
Pacific tree frogs live in many kinds of places: grasslands, scrub, woodlands, forests and farmland, and even towns and cities where some wild patches remain. They are found among low plants near water, on the ground, or in bushes and trees far from water.
To breed they use almost any still or slow water: marshes, ponds, lakes, ditches and slow streams, and even deep tire ruts and children's wading pools.
IUCN habitat: grassland, chaparral, woodland, forest and farmland; among low vegetation near water, or on the ground, in shrubs or in trees far from water; breeding in marshes, lakes, ponds, ditches, reservoirs and slow streams, sometimes in weakly brackish water; sea level to over 1,585 m. WDFW (Washington) adds wetlands, river edges, springs, irrigation and road ditches, seasonal pools, puddles, deep tire ruts, wading pools and spring boxes, and notes that the species persists in urban and disturbed areas where pockets of undeveloped habitat remain.
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)
Lives here naturally · Countries and seas named by a scientific source
Since a 2006 study split it into three species, it is thought to live west of the Cascades and along California's Coast Range, into Oregon, Washington and southern British Columbia; the boundaries are not yet settled (IUCN). Introduced in southeastern Alaska and on Haida Gwaii, British Columbia. Treefrogs once included in it, farther south to Baja California, Mexico, are now thought to belong to t
Places: Canada and United States.
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 United States, Canada, Mexico and Argentina.
Source: gbif · checked October 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.
Bugs at night, algae for tadpoles
Grown-up frogs eat bugs.
Tadpoles eat tiny bits in the water.
Pacific tree frogs eat many kinds of small animals without backbones, mostly on the ground at night, and many of them are flying insects. Like most frogs, a tree frog finds its food by sight, then lunges and catches it with a big, sticky tongue.
The tadpoles feed on tiny things in the water, such as algae, bacteria and bits of debris.
Adults eat a wide variety of invertebrates, mainly on the ground at night, including a high percentage of flying insects; prey is located by vision and caught with a lunge of the large sticky tongue. Tadpoles are suspension feeders on algae, bacteria, protozoa and organic and inorganic debris (CaliforniaHerps). Introduced mosquitofish prey heavily on the tadpoles in some places (IUCN).
Did you know?
It is a tree frog that mostly lives on the ground.
Despite its name, the Pacific tree frog is usually found on the ground or in shrubs, though it can climb.
Chiefly a ground-dweller among shrubs and grass (CaliforniaHerps; WDFW).
A frog that changes color
This frog can change color!
It can turn from brown to green, or green to brown.
Pacific tree frogs are usually green or brown, but they can also be gray, reddish, copper-colored or a mix. Their color can change: they can go from brown to green, or lighter or darker, in just minutes. Scientists who studied these frogs in Washington think this lets a frog quickly match its background as it moves from place to place.
When disturbed, it usually makes a long hop or jumps into water and hides, but sometimes it simply keeps still and relies on its colors.
Dorsal color green or brown, also gray, red, copper or combinations (WDFW). The dark eye stripe does not change, but body color and markings can shift between brown and green and from dark to light; a Washington study found the frog controls hue, chroma and lightness over minutes and supported rapid background matching as its function (Stegen et al. 2004, via CaliforniaHerps). Disturbed frogs hop a long way or jump into water and hide, or stay motionless relying on cryptic color (CaliforniaHerps).
Egg packets and fast-growing tadpoles
The mother lays small clumps of eggs on water plants.
Tadpoles hatch and grow.
They turn into tiny frogs in summer.
The female lays her eggs in small, loose clumps of about 9 to 70 eggs, usually stuck to a plant stem or twig in shallow water. On average, a female lays about 400 to 750 eggs in all.
The tadpoles grow to about 5 centimeters long, eyes poking out at the sides of the head. After about 2 to 2½ months they turn into tiny froglets only about 1.3 to 1.8 centimeters long, and they probably become grown-ups in their first year.
Eggs are laid in small, loose packets of about 9 to 70, packets 0.8 to 1.6 in across, usually attached to vegetation, less often on the sediment (WDFW; IUCN: on submerged plant stems or on the bottom). Females lay on average 400 to 750 eggs in clusters of 10 to 80; tadpoles metamorphose in about 2 to 2.5 months, generally June to late August; adults probably mature in their first year (CaliforniaHerps). Tadpoles reach about 2 in total length; their eyes sit on the margins of the head seen from above; new metamorphs are about 0.5 to 0.7 in snout-vent (WDFW).
Rib-it! A famous chorus
Male frogs call: rib-it, rib-it!
Many frogs call together in a loud chorus.
In the breeding season, males call from the water with a two-part 'rib-it' or 'crek-ek', and their choruses can be heard from far away. They have other calls too: a trill to warn other males, and a call they give on land outside the breeding season.
Much of their activity is at night, especially in lowlands, but you can find them out in the daytime too. In very cold or very hot places, they rest in moist hiding places such as thick plants, piles of debris and burrows.
Males give a two-part advertisement call ('rib-it' or 'crek-ek'), an enhanced mate-attraction call and a trilled encounter call; choruses are audible from great distances; outside the breeding season males give a one-part land call, heard all year except in the driest and coldest periods (WDFW). Much activity is nocturnal, especially at low elevations, but frogs are often out by day (WDFW); in dry periods they become mainly nocturnal and seek cool, moist retreats to aestivate and hibernate (IUCN). Breeding and egg-laying run from November to July depending on location (CaliforniaHerps).
Did you know?
It is the most common frog in Washington state.
In Washington state, the Pacific tree frog is the most common frog and the one people hear most often.
Most common and most commonly heard frog in Washington (WDFW).
Common and widespread
There are lots of Pacific tree frogs.
They are doing well.
The Pacific tree frog is listed as least concern. Where it lives, it is usually the most common amphibian, and in most places it is probably as common today as it ever was. Its numbers seem to be stable.
Some groups are shrinking where bullfrogs brought in by people have moved in, but the species also breeds in many ponds that have no bullfrogs. In some places, mosquitofish brought in by people eat many of its tadpoles.
Least Concern (IUCN SSC Amphibian Specialist Group; Global; assessed 23 October 2019, published 2022; trend stable): relatively wide distribution, some tolerance of habitat modification and a presumed large population; usually the most abundant amphibian at its sites and likely as common as historically at most localities. Some subpopulations are declining because of invasive bullfrogs; introduced mosquitofish might locally affect subpopulations; found in the pet trade at non-threatening levels; susceptibility to chytrid fungus unknown; range overlaps many protected areas (IUCN). WDFW rates it secure in Washington.
IUCN Red List
How is the pacific 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
-
This frog can change from brown to green!
A Pacific tree frog can change its color, from brown to green or from dark to light, in just minutes.
Physiological color change over minutes, for background matching (Stegen et al. 2004, via CaliforniaHerps).
-
It is a tree frog that mostly lives on the ground.
Despite its name, the Pacific tree frog is usually found on the ground or in shrubs, though it can climb.
Chiefly a ground-dweller among shrubs and grass (CaliforniaHerps; WDFW).
-
It can lay eggs in a puddle or a tire track!
Pacific tree frogs breed in almost any still or slow water, even deep tire ruts and children's wading pools.
Breeding sites include tire ruts, wading pools and spring boxes (WDFW).
-
It is the most common frog in Washington state.
In Washington state, the Pacific tree frog is the most common frog and the one people hear most often.
Most common and most commonly heard frog in Washington (WDFW).
Words to know
- toe pad
- a round, sticky pad on the tip of a frog's finger or toe
- tadpole
- a young frog that lives in water
- chorus
- many animals calling at the same time
- camouflage
- colors or patterns that help an animal blend in with what is around it
- froglet
- a tiny young frog that has just changed from a tadpole
- least concern
- not currently at serious risk of dying out in the wild
Discovery challenge
-
What can this frog's body do?
What can a Pacific tree frog's body color do?
What notable ability does the body coloration of Pseudacris regilla show?
- Change color
- Glow in the dark
- Turn see-through
Show the answer
Change color
It can change color!
It can change from brown to green, or lighter or darker, in just minutes.
Rapid physiological color change for background matching (Stegen et al. 2004).
-
Where is this frog's dark stripe?
Where is the Pacific tree frog's dark mask stripe?
Where does the dark lateral head stripe of Pseudacris regilla run?
- Through its eye
- Down its belly
- Along its tail
Show the answer
Through its eye
Through its eye!
It runs from the nose through the eye to the shoulder.
Snout tip through nostril, eye and tympanum to the shoulder (WDFW).
-
What does this frog's call sound like?
How is the male Pacific tree frog's two-part call often written?
How is the two-part advertisement call of Pseudacris regilla usually rendered?
- Rib-it
- Guank
- Peep-peep-peep
Show the answer
Rib-it
Rib-it!
Males call 'rib-it' or 'crek-ek', and their choruses carry a long way.
Two-part 'rib-it' or 'crek-ek' (WDFW).
-
Where does this tree frog spend most of its time?
Where is the Pacific tree frog usually found, despite its name?
Which microhabitat does Pseudacris regilla mostly use?
- On the ground and in shrubs
- High in the treetops
- Deep under the sea
Show the answer
On the ground and in shrubs
On the ground and in bushes!
It is usually found on the ground or in shrubs, though it can climb.
Chiefly terrestrial, in shrubs and grass (WDFW; CaliforniaHerps).
Places where you might see it
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Watch
Country
Canada
Canada is the second-largest country in the world, stretching across the north of North America from the Atlantic to the Pacific and up into the Arctic. It has the Rocky Mountains, thousands of islands and about 42 million people, who speak English, French and many other languages.
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Watch
Country
United States
The United States is a large country in North America made of 50 states, from icy Alaska to the warm islands of Hawaii. It has the Grand Canyon, the Mississippi River and Yellowstone, and about 342 million people live there.
Explore next
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Animal
American green tree frog
The American green tree frog is a bright green frog of the southeastern United States, often with a pale stripe along each side. It lives in swamps, marshes and plant-filled pond edges, spending much of its life up in plants, and each finger and toe ends in a round, sticky pad. It is busy mostly at night, when males call a loud, nasal 'guank, guank'.
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Animal
Red-eyed tree frog
The red-eyed tree frog lives in the rainforests of Central America. By day it sleeps folded up on a leaf, looking plain green. When something disturbs it, it flashes huge red eyes, orange feet and blue-and-yellow sides.
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Animal
Northern leopard frog
The northern leopard frog is a spotted green or brown frog of Canada and the northern United States. It lives in and near marshes, ponds and slow streams, and in summer it often moves out into wet meadows and fields, which is why people also call it the meadow frog or grass frog. In spring, males call with a deep, rattling snore, and each female lays hundreds or thousands of eggs.
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Watch
Country
Canada
Canada is the second-largest country in the world, stretching across the north of North America from the Atlantic to the Pacific and up into the Arctic. It has the Rocky Mountains, thousands of islands and about 42 million people, who speak English, French and many other languages.
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Watch
Country
United States
The United States is a large country in North America made of 50 states, from icy Alaska to the warm islands of Hawaii. It has the Grand Canyon, the Mississippi River and Yellowstone, and about 342 million people live there.
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3D
Animal
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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3D
Animal
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.
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Animal
American toad
The American toad is a common, warty toad of eastern North America, found in forests, prairies, farms and backyards. It has big poison glands behind its eyes, hunts insects and worms at night, and in spring the males sing a long, musical trill from shallow ponds, where females lay thousands of eggs in long strings.
For parents & teachers
What children will learn
- Describe how to recognize a Pacific tree frog.
- Explain how changing color can help a frog.
- Name some of the places where Pacific tree frogs breed.
- Explain why scientists split one frog species into three.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- Why might a frog that changes color in minutes be harder for a predator to find?
- Why do you think a frog called a tree frog lives mostly on the ground?
- Why might ponds without bullfrogs matter for small frogs?
Try at home or in class
- Color match: cut a frog shape from clear plastic, then slide green, brown and gray paper under it. Which background hides it best?
- Puddle survey: after rain, look (with a grown-up) at puddles, ditches and ponds near home, and talk about which ones stay wet long enough for tadpoles.
Key vocabulary: toe pad, tadpole, chorus, camouflage, froglet, 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))
- Pseudacris regilla (IUCN SSC Amphibian Specialist Group, assessed 23 October 2019, published 2022) , IUCN Red List of Threatened Species
- Pseudacris regilla: taxonomy, justification, range, population, habitat, threats and conservation text , IUCN Red List of Threatened Species
- Pseudacris regilla: IUCN Red List global assessment record (IUCN SSC Amphibian Specialist Group 2022), IUCN checklist on GBIF , GBIF
- Pacific treefrog (Pseudacris regilla) , Washington Department of Fish and Wildlife
- Northern Pacific Treefrog - Pseudacris regilla , CaliforniaHerps (A Guide to the Amphibians and Reptiles of California)
- File:Pacific Tree Frog (Pseudacris regilla) 3.JPG (The High Fin Sperm Whale, 8 April 2012) , 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.