Guest post: A Herpetologist Chases Frogs with Tails

We were so pleased to receive a guest post from Sara E. Viernum, a herpetologist with over 10 years of experience chasing snakes and salamanders around the U.S. When she’s not chasing reptiles and amphibians in the field, Sara is blogging about them on her website The Wandering Herpetologist, which is devoted to all things reptile and amphibian related. She currently resides in San Antonio, Texas, with her wonderful husband and her pet milk snake, Nyarla The Crawling Chaos. Sara also has a Facebook page.

For two field seasons in 2010 and 2011 I had the pleasure of hunting for aquatic amphibians in the Tillamook State Forest in Western Oregon. I was helping a friend with her graduate research focusing on the effects of fish passable culverts on aquatic amphibians. We spent many, many fun-filled hours crawling around in streams in the forest looking for Pacific giant salamanders (Dicamptodon tenebrosus), Columbia torrent salamanders (Rhyacotriton kezeri), and Pacific tailed frogs (Ascaphus truei).

Male Pacific tailed frog showing his "tail". Photo courtesy Sara Viernum.

The tailed frogs were such interesting amphibians. I had never seen these strange little frogs before we started the stream surveys. The tadpoles have specialized sucker mouths that they use to hold onto the rocks in the fast-flowing currents of the streams. They will also adhere to a collection bucket and your hand. If that’s not strange enough the adult males have a little “tail.” The “tail” is actually an extended cloaca that is used for internal fertilization. The Ascaphus frogs are the only frog species that have internal fertilization.

Pacific tailed froglets showing color variations. Photo courtesy Sara Viernum.

Tailed frogs are members of the Leiopelmatidae family (Tail-wagging frogs). There are only two species in this family found in North America – the Pacific tailed frog and the Rocky Mountain tailed frog (Ascaphus montanus). The family is considered to be one of the most primitive. The frogs cannot vocalize (call) and they do not have an external ear or a middle ear bone. Their closest relatives are the Leiopelma frogs from New Zealand which are also considered to be primitive frogs too.

Pacific tailed frog tadpole suctioned to Sara's hand. Photo courtesy Sara Viernum.

The Pacific tailed frogs could be quite common in some of the streams and were always a treat to find, although it was sometimes difficult to get to tadpoles to let go of your hand.

Pacific tailed frog tadpole showing its sucker mouth. Photo courtesy Sara Viernum.