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Thursday, August 22, 2013

Meet the Jollyville Plateau Salamander

Jollyville Plateau Salamander, Eurycea tonkawae

Rare and under threat of decreasing population, the U.S. Fish & Wildlife Service has stated that the Jollyville Plateau Salamander (Eurycea tonkawae) warrants protection under the Endangered Species Act, due to its habitat undergoing rapid degradation as a result of urban and suburban sprawl.  Found only in the wet springs and caves of the Jollyville segment of the Edwards Plateau region of Travis and Williamson counties, the area this salamander inhabits is roughly bounded by the Colorado River, Mopac (Loop 1), Lake Travis, and U.S. 183.  More specifically, its known range is limited to only six stream drainages, all of which are facing water quality issues.    

Jollyville Plateau Salamander, Eurycea tonkawae

Very little is known about this small, localized amphibian.  Juvenile Jollyville Plateau Salamanders are less than 1.5 inches long, and the adults grow to up to 2 inches long.  They have large well-developed eyes, wide yellowish heads, feathery  external gills, blunt rounded snouts, dark greenish-brown bodies, and yellowish-orange tails. Most salamanders have feather-like external gills when they are young, but the Jollyville Plateau Salamander is neotenic, or keeps these external gills and remains aquatic for its entire adult life.  Since they never take a terrestrial form, these salamanders prefer cool, shallow, clean water containing loose gravel.  During drier periods, they remain in underground caves and water is provided for them by the infiltration of surface water through the soil into the aquifer which discharges from the springs as groundwater.  

Two other local salamanders have received protected status by the US Fish & Wildlife Service. These are the Barton Springs Salamander (Eurycea sosorum) and its lesser-known cousin the Austin Blind Salamander (Eurycea waterlooensis).  

Barton Springs Salamander, Eurycea sosorum
Austin Blind Salamander, Eurycea waterlooensis

Urbanization has been known to cause excess sediment to accumulate into the aquifer the salamanders inhabit and this sediment impairs their ability to avoid predators, locate food, and find mates.  In addition, development of upstream salamander habitat provides sources of various other pollutants such as chemical fertilizers, pesticides, and petroleum products.  During rainstorms, water runs off these urban areas and transports these pollutants into the salamander’s aquatic  habitat.  This degradation of water quality has been shown to be linked to deformities of the Jollyville salamander in some locations, as well as to declines in abundance of salamanders compared to areas that are undeveloped.

While the Balcones Canyonlands Preserve (BCP) provides some water quality benefits for the Jollyville Plateau Salamander through the preservation of drainages in the open space, several of the areas within its range have been or are being affected by water quality degradation occurring upstream and outside of the preserved tracts.  Work is being done to monitor and improve these areas within the BCP, but residents in neighborhoods surrounding the preserve can go a long way in helping to restore and maintain water quality by carefully disposing motor vehicle fluids, washing cars at a commercial car wash (where the water is captured & recycled), fertilizing wisely (organically), using compost, and planting native plants that have no need for chemical pesticides & herbicides.

And lastly, do what you can to help support the purchase and preservation of open space, unique natural features, and rare inhabitants of the hill country -- it Keeps Austin Beautiful!