Description: The Pacific tree frog grows up to 2 inches from snout to urostyle. The males are usually smaller than the females and have a dark patch on their throats. The dark patch is the vocal sac, which stretches out when the male is calling. Pacific tree frogs can be a number of different colors, including green, tan, reddish, gray, brown, cream, and black, but most are a shade of green or brown, with pale or white bellies. They have a variety of dark and spotty markings on their backs and sides and can be identified by a black or dark brown eye stripe that stretches from the nose, across the eye, and back to the shoulder. They can change color seasonally to better match their environments. Their skin is covered in small bumps. They have long legs compared to their bodies and they tend to be slender. Their toes are long and only very slightly webbed. On the end of each toe is a round, sticky toe pad or disk used for climbing and sticking to surfaces. Males also have an extra, and far less noticeable toe on their outer thumbs used exclusively in amplexus.

These frogs have the ability to change color from brown to green. Previously, adults were thought to occur in two different fixed colors. Now, some of them have been found to be able to change between the two. They can also change from lighter to darker, shift from patterned markings to pure colors and vice versa, and even display combinations of colors, brown/green being the most frequent.

These color-changing morphs are triggered not by color change in their environments, but a change in background brightness. This type of environmental change would be caused by seasonal fluctuation. A full change in the dorsal coloration of a color morph can take from weeks to months, but initial changes can occur in just a few hours. This has been shown to be a very useful cryptic survival feature for these frogs.

Habitat: They are found upland in ponds, streams, lakes and sometimes even further away from water; their habitat includes a wide variety of climate and vegetation from sea level to high altitudes. The Pacific tree frog makes its home in riparian habitat, as well as woodlands, grassland, chaparral, pasture land, and even urban areas including back yard ponds. Eggs of the Pacific tree frog may be consumed by the rough-skinned newt and other amphibians.

Range: Pacific tree frogs are common on the Pacific coast of Oregon and Washington, but they are found from extreme northern California to British Columbia.

Found in these States: AK | CA | OR | WA

Diet: Much of their diets consists of spiders, beetles, flies, ants, and other insects and arthropods; they can and do eat insects that are almost as large as they are, and will expand their bodies slightly to accommodate these meals.

Reproduction: The Pacific tree frog begins mating in early winter to early spring. Since these frogs are so widespread geographically, their breeding season is thought to be determined by local conditions. When it is time, the males migrate to the water. They then make a call at the same time, calling "ooh-yeeh" or ribbiting loudly. This lures the females to the water and they mate. The females lay their eggs in clumps of 10 to 90, and usually put them on and under vegetation and leaf litter in the pond. Females usually lay their eggs in shallow, calm water that has little action around it. If they survive, embryos will hatch into tadpoles within one to three weeks. The tadpoles feed on periphyton, filamentous algae, diatoms, and pollen in or on the surface of the water. They feed using suction, and a beak-like structure that helps scrape vegetation off surfaces.

The species attracts mates using a choral song. Males call to females as loudly as possible and produce a croak so loud that they sound as though they are produced by multiple males. These sounds can be heard by numerous females. Once a female approaches, the male stops singing and attempts amplexus. Breeding takes place at night, near shallow water, typically after rainfall. Mating season usually extends from December to May, although some variation occurs. Altitude often affects the length of the breeding season.

Status: These frogs are the most common frogs on the West Coast of North America. Although Pacific tree frogs remain abundant, some other species found in the same areas, such as California red-legged frogs, are declining. Most populations of tree frogs appear healthy, and they have no concern or conservation status.

Subspecies: None

Taxonomy: