Clear cold creeks and the Pacific Tailed Frog

We recently spent some time on a Forest Service road (an active logging road) near Sunshine Valley, just west of Hope. This is a rough gravel road that is heavily used by ATVs. There were many ATVs coming and going while we were there, sending dust billowing into the air each time they passed by with a roar. We had no idea ATV-ing was such a growing sport. Most of the drivers were children, ten and twelve year olds, who ripped along the road as fast as they could. A few were with adults, but many were not. At a fork in the road, we watched as two young ATV-ers, descending rapily downhill on one fork, skidded to a halt, narrowly avoiding crashing into another ATV-er on the other fork. They were wearing helmets, but even so a crash at the speeds they were going would not be pleasant.

Trying to avoid the ATV-ers, and their dust storms, we did some poking around part way up the logging road, in a tiny fast flowing creek that emptied into the Somallo River thirty feet below. The creek tumbled its way down a shaded slope following a very narrow (no more than three feet across in some spots) path. It was overhung in several spot by devil's club (Oplopanax horridus), with plenty of woody debris and small rocks, and a series of tiny ponds dotted its course. The water was ice cold. This was snow melt water from the snow-covered mountains above the creek.

We have seen plenty of creeks like this in the Mount Baker area. The habitat is distinctive and our thought was that it looked just right for Coastal Giant Salamander (Dicamptodon tenebrosus). Although they are not known from this area, it was worth a stop to investigate. Armed with high tech field tools (a ziplock baggy and a pair of hands), we began lifting small rocks in an upper, tiny, pool on the creek (did I mention the water was cold?), and quickly spotted two salamanders each about 4 inches long. But they were fast, and moved beneath some overhanging devil's club that made reaching into the tiny pond very difficult (painful would be the right word)--so eluded capture. It's possible they were giant salamanders, but they could also be Northwestern salamanders (Ovaska pers. comm.). We will have to go back and try this again, and see if we can determine which species these are.

We moved down the creek to another tiny pond (with no overhanging devil's club) to try our luck there. No salamanders, but this time we managed to capture a tadpole and placed it in a baggie of cold water to photograph. As it turned out, this was not just any tadpole. When we looked at it in the baggie, we saw that it was clinging by its mouth to the side of the baggie--it had a distinctive sucker shaped mouth (see the photo below). A surprise! This was a Coastal or Pacific Tailed Frog tadpole, and a new species for us. Tailed Frogs are the only stream-breeding frogs in Canada (Dupuis et al. 2000), which, along with the sucker mouth, makes identification easy.

Pacific Tailed Frogs (Ascaphus truei) are well adapted to life in fast flowing water. Tadpoles like this one have a "flattened oral disc that produces a sucker-like mouth" (Matsuda 2009). This allows them to cling to rocks and other surfaces (including baggies), so they are not swept away downstream. According to Matsuda (2009), "streams with step-pools and cobbled stretches, with low amounts of detritus and fine sediment flowing through old growth, or older-stage second growth forests with dense understory, are prime habitats". The little creek we found this tadpole in was perfect habitat, with a series of tiny "step-pools", and small rocks and some sediment on the bottom.




Pacific Tailed Frogs are found in "the Coast and Cascade Mountain Ranges, from northern California to the Alaskan panhandle...in BC [they] are found in the Coast Mountains from the Lower Mainland to the Nass River on the North Coast" (Matsuda 2009).

References:

Dupuis, L. A., F. L. Bunnell and P. A. Friele. 2000. Determinants of the tailed frog's range in British Columbia, Canada. Northwest Science 74(2): 109-115.

Matsuda, Brent. 2009. Coastal Tailed Frog Atlas Page. In: Klinkenberg, Brian. (Editor) 2009. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [www.efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. Available: http://linnet.geog.ubc.ca/efauna/Atlas/Atlas.aspx?sciname=Ascaphus%20truei. Accessed July, 2009.