Garter snakes are known predators of Pacific treefrogs. Other predators include other species of frogs, raccoons, Virginia opossums, fish, and birds. Their primary defense against predators is to remain motionless, though this technique is only effective if the frog matches its environment very well. They also tend to hide in areas of tall grass or jump into water when threatened. The primary predator of Pacific treefrog tadpoles is mosquitofish. Research has shown that even when presented with mosquito larva, mosquitofish often prefer treefrog tadpoles. Other predators on tadpoles include numerous species of fish and some aquatic invertebrates.
The best defense of Pacific treefrogs against predation is their camouflage. The coloration of their dorsal surface varies from shades of brown to shades of green. They tend to stay in habitats that have coloring similar to their bodies. Recent studies have shown that Pacific treefrogs can vary their coloring based on the presence or absence of green foliage. In addition, during spring and summer, when green foliage is abundant, these frogs tend to be greenish in color; in fall and winter, they tend to be shades of brown.
Anti-predator Adaptations: cryptic
- Goodsell, J., L. Kats. 1999. Effect of introduced mosquitofish on Pacific treefrogs and the role of alternative prey. Conservation Biology, 13/4: 921-924.