Coastal Tailed Frog

“Coastal tailed frogs (Ascaphus truei), natives of the Pacific northwest, rely on healthy rivers for their complex and unique life history. As an adaptation to their fast-flowing stream habitats, they exhibit internal fertilization– unique among North American frogs and, in fact, among all frogs except their closest living relatives in New Zealand. Though their tadpoles are rheotactic, orienting themselves parallel to river flow, they still tend to drift downstream across the course of their protracted larval period. After perhaps one to four years of development and drift, they will emerge as froglets. Their terrestrial life stage will then exhibit upstream-biased movement patterns to compensate for this drift. As with so many species, dams serve as major barriers to their free dispersal. Thanks so the folks working on understanding the repercussions rippling across their range and their populations!” – Emma Steigerwald