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!

Cicada Cycles

A Cactus Dodger cicada found in Big Bend National Park, TX

A sure sign that we are in the midst of a hot summer is the sound of cicadas buzzing in the air.  For their size, cicadas make as much noise as a large animal, and can be heard up to a quarter of a mile away.  In fact, the word ‘cicada’ is a direct derivation from the Latin meaning ‘buzzer.’ 

Most species of cicadas in North America are in the genus Tibicen, and are generally called the annual or ‘dog-day’ cicadas because they emerge every year in July and August, the dog days of summer.  More widely known are the periodical cicadas from the genus Magicicada, who have a very long lifecycle of 13 to 17 years, and when they emerge, do so in great numbers.     

Tibicen resh, cicada found in Austin, TX

Male cicadas have structures called ‘timbals’ on the sides of their abdomens, and it is with these structures that they create their buzzy songs.  Unlike grasshoppers or crickets that rub their wings or legs together to produce sound, cicadas vibrate these timbals against their hollow abdomens which amplifies the resonance of the sounds.  They can even modulate the sounds by wiggling their abdomens toward or away from the tree trunk on which they are perched.  Each species has its own distinctive sound, and they use different mating songs to attract the appropriate mate.

The lifecycle of a cicada is quite fascinating.  After mating, females deposit hundreds of eggs in a slit made in the bark of a twig, normally on an oak tree.  When the eggs hatch, the nymphs drop to the ground and burrow from 1 to 8 feet, feeding on the juices of the tree roots.  These nymphs spend most of their lives underground, from 2 up to 17 years, depending on the species.  The nymphs then construct an exit tunnel to return to the surface in mid-summer, molt or shed their skin on the bark of the tree, and emerge as adults.  These adult insects are usually 1-2 inches long, have prominent, wide-set eyes, short antennae, and transparent, membranous front wings.   

Empty shell of newly emerged Tibicen resh cicada

While there are over 40 species of cicadas in Texas, the late summer afternoon air in Austin vibrates with the sounds of several annual cicada species such as Tibicen resh (which has no common name) and the Superb Green Cicada (Tibicen superba).  Once every 13 years, the periodical cicadas Magicicada septendecula (which also have no common name) emerges but they are becoming increasingly scarce.  

Cicadas go by a number of common names: locusts (which is technically not correct as cicadas are unrelated to true locusts which are part of the grasshopper family), jar flies (for the way they vibrate or ‘jar’ when held in the hand), June bugs or July flies (in the southeastern US), heat bugs (in Canada and the mid-West), and dry flies (in parts of the southern Appalachian mountains for the shell they leave behind).  Whatever you call them, you’ll be sure to hear and see them in the heat of a Central Texas summer! 

Turtle Teachings

Texas Cooter, Pseudemys texana

Hardly a day goes by in the summer months when you can't find a turtle basking in the sun.  Like other reptiles, turtles are cold-blooded or ectotherms, who vary their internal temperature according to the ambient environment.  Turtles have been around for over 250 million years, even longer than their snake and lizard relatives.  We tend to use the word turtle for all freshwater and some land-dwelling species, while tortoise is used only to describe members of the true tortoise family.

Red-eared Slider, Trachemys scripta elegans

The shell of a turtle has two parts:  the upper is called the carapace, while the lower is called the plastron.  Many turtles have a bony bridge that connects the top and bottom and lends strength and rigidity to the structure.  Carapaces of turtles vary widely, and shape, colors, and patterns are among the field marks that often distinguish one species from another.  Scutes, from the Latin scutum or shield, are the plates which cloak the outside of the turtle's shell.  Most turtles have 54 scutes, with 38 covering the carapace, and 16 covering the plastron.  Made from the protein keratin, scutes can be thought of as the epidermis that covers the bony shell.  It is even possible, by counting the stack of smaller, older scutes on top of the larger, newer ones, to estimate the age of a turtle.  The accuracy of this method, however, is somewhat muddled by the variable growth rate of the scutes and the fact that, like fingernails or horns, they eventually fall away from the shell.  

Texas Cooter, Pseudemys texana

Regardless of the length of a turtle’s neck, they all have 8 vertebrae.  In spite of their highly muscular necks, turtles are often called ‘hidden-necks’, for their ability to retract their head and neck into the shell by bending it into a vertical S-curve and withdrawing from sight.  Some species like box turtles go even further, and gain an added degree of protection from predators by having a hinge in their plastron, dividing it into two lobes, and giving them the ability to draw up those lobes and completely seal the turtle inside.

Eastern Box Turtle, Terrapene carolina

Turtles may spend most of their life in or around water, but they breathe air and often range widely when searching for a mate in the warmer months.  With smell being the keenest sense possessed by a turtle, the males will chase any object of approximately the correct size, and once close, will use smell to determine if the object is a female of the same species.  Pregnant females will dig a hole, often called a body pit, and deposit eggs in the hole, covering them with dirt.  In some species of turtles, temperature determines whether an egg develops into a male or a female, with a higher temperature producing a female and a lower temperature producing a male.  Hatchlings squirm their way to the surface and head toward water alone, as there is no known turtle species where the female cares for the young. 

Spiny Softshell Turtle, Apalone spinifera

The more common turtles you will see in central Texas include the Common snapping turtle (Chelydra serpetina), Eastern box turtle (Terrapene carolina), Red-eared slider (Trachemys scripta elegans), Texas map turtle (Graptemys versa), and the Spiny softshell (Apalone spinifera).  All but the box turtle are generally found in wetlands, ponds, streams, and lakes where heavy vegetation is present, although box turtles are activated by rain events. 

Symbolically, the turtle has represented patience, strength, endurance, stability, and protection to many native peoples, who have observed the often slow but deliberate life of the turtle.  This is a fascinating fact, since researchers have recently discovered that turtles’ major organs, such as the liver, lungs, and kidneys, do not gradually break down or become less efficient over time.  Understandably, this has inspired geneticists to begin a detailed study of the turtle genome, hoping it can unlock the secrets of longevity!