Tuesday, January 4, 2011

Mole Salamander - New County Record






The last night of 2010 was a rainy one in northwest Georgia. Storms had moved in throughout the Great Valley by 9 PM. Flooding of local creeks and rivers was inevitable. It was the kind of weather that most would not want to be traveling in, even if it was New Years Eve. It was even a nasty night for many nocturnal creatures, unless of course, you are a salamander. Not just any salamander, but a MOLE SALAMANDER. Interestingly, this wet humid night had warm enough temperatures to trigger breeding for at least one amphibious crawler. I just happened to be in the right place at the right time to spy it crossing a road(see photo above).

Why did the salamander cross the road?

To get to the spawning pond on the other side.

The Mole Salamander (Ambystoma talpoideum) is a member of the family Ambystomatidae. Species of this family spend the majority of their lives underground. In fact, many of them are rarely observed by humans except during the breeding season. This period can begin as early as fall and continue through the winter months into early spring. As has already been noted, rainfall and temperatures play a major role in the salamanders' migration to wetlands. At these aquatic locations, adults will breed during suitable conditions.

The Mole Salamander is a very interesting amphibian. Some larvae fail to metamorphose completely, so some adults are paedomorphic. It was once thought to be confined to the Coastal Plain regions, but after several discoveries of it north of the Fall Line, it is believed that it could possibly have a statewide distribution. Due to its reclusive nature, this species is difficult to find. Its habitat preferences apparently evolve around the presence of wetlands. Therefore, it is often found in forests that surround these low "flooded" areas. The Southern Floodplain Forest is a perfect example of an ideal habitat for this salamander as well as several others. They inhabit the subterranean crevices of forested uplands. These areas are typically adjacent to swamps, that are a product of rivers or streams that rise past their banks to create an aquatic ecosystem. Sometimes these are only temporary pools, but in some cases the water doesn't recede. Obviously, these environments are much more prevalent in the Coastal regions of Georgia. As one would guess, the larger the rivers, the larger the floods. It is clear why the assumption that the Mole Salamander was absent from north Georgia would be supported by this hypothesis. Fortunately, small rivers and streams can flood to create new habitats that can be vital to the survival of smaller populations. This very well could be the case at this Murray County location.

The area where I found this individual is along some of the best floodplains in the county. This is the second I have found at this location. I believe these could be the product of a disjunct population that inhabit the forests bordering Holly Creek. The headwaters of Holly Creek begin near Potatopatch Mountain in the Cohutta Wilderness at approximately 3253' in alttitude. The creek runs approximately 38 miles to where it confluences with the Conasauga River at 653' above sea level. The entirety of Holly Creek lies within Murray County. It begins as highland slope seepages gathering to transform into soft bubbling brooks. Within miles these mountain streams widen into deeper bedrock steps that fall in altitude. Velocity increases as the water leaves continues through the coves of the Cohutta Mountains to meander through the wide valleys. A total fall of approximately 2600' from beginning to end. Reoccurring flooding possibilities present themselves when the creek's direction shifts from a north-to-south path to east-to-west. Here the creek begins to zig-zag creating an array of oxbows. It continues this pattern for the last twelve miles of its journey abutting the Brackett Ridges to the south. The ridges disallow the floods to spread uncontrollably as well as aid in the collection of rainwater, that runs down the steep slopes. Therefore, there can be extensive wetlands along Holly Creek year-round, but especially in the rainy season.

This population of salamanders probably extends along the Conasauga River as well as other large tributaries. This could be the case throughout the remainder of the Ridge & Valley and the Piedmont regions of Georgia. I would assume that their prevalence decreases in the Blue Ridge Mountains. I could only find eleven county records above the Fall Line, four of which were in the northern regions of the state. These were Bartow, Cherokee, Walker, and White Counties. This new county record will be submitted to the state's database.

The individual I found was an adult male. Its vents were swollen, signifying its readiness to mate. It measured 4 3/4" in length. As I said, I collected it as it was crossing a road, migrating to a wetland. Roads are a major obstacle for many amphibians. Hundreds, maybe thousands lose their lives each year along this single road. Imagine what the number is state, nation, or world-wide. The construction of roads through such areas fragment these habitats. Wetlands have historically been drained by landowners to get the most productive use out of property. Unfortunately, there have been many plants and animals depending on these aquatic habitats for centuries. In the case of a Mole Salamander population, it cannot survive without breeding waters. As those disappear, so will the population. Due to its inability to travel very long distances, finding new suitable locations is difficult. Upland habitats have been greatly altered as well, so this species, and many others alike have much to contend with.

After I measured and photographed the Mole Salamander I released him along side the wetland. I hope he is able to find a mate and many young are reproduced. Finding this salamander was a nice years-end surprise.

See map at:
http://www.pwrc.usgs.gov:8080/mapserver/naa/


The book below is an excellent reference book for Georgia herpetofauna. Follow link:




References:

Jensen, J. B., Camp C. D., Gibbons, W., Elliott, M. J., (2008). Amphibians and Reptiles of Georgia. Athens & London, GA: The University of Georgia Press.





1 comment:

  1. Love it! I always enjoy reading about your trips;)
    Your design junction I like very well. Thanks sharing these important information this post...



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