Natural History: Green Treefrog (Hyla cinerea)

On March 6, 2018 our class traveled to the Caw Caw county park here in a pile of leaves next to a pond I caught this adorable Hyla cinerea, or the green treefrog. The specimen was just over an inch long and was easily identifiable due to the lateral stripe on it's side, yellow spots on it's back, and large toepads. Unsurprisingly it was quite agile as this is an arboreal species that has adapted to move far and quickly. If the species had been in a tree with vegetation it would have been almost impossible to see, but luckily it was surrounded by dead vegetation making it an easier target to spot. It was also later determined to be a male due to the fact that  "The external, subgular vocal sac is mostly white or yellow in males when not inflated"(Conant and Collins, 1998).  One of the most difficult and surprising parts about holding on to him was that he was very slippery, and excreted a lot of mucus. This species goes through classic metamorphosis as "the tadpoles can reach as much as 60 mm in length before metamorphosis in a 28- 44 day span."(Green Tree Frog, 2015). This species carries a complex life cycle that is one of evolutions oldest traits. 

Sources: 

Collins, J. T. (1993). Amphibians and Reptiles in Kansas: Third Edition, revised. University of Kansas Museum of Natural History, Lawrence.

“Green Tree Frog - Hyla Cinerea - Details.” Encyclopedia of Life, eol.org/pages/1025215/details. 2015

Natural History: Mole Salamander (Ambystoma talpoidea)

The mole salamander (Ambystoma talpoidea), was encountered at Caw Caw county park, underneath a damp log, just off of the main trail. This animal was about 3 inches in size, and was identified easily by the large flattened head and robust body, with speckling of gray on the sides and stomach. These animals possess a 4-5 digitation scheme, and are nocturnal, burrowing during the day, and coming out at night to travel and feed. These animals are facultatively metamorphic, meaning that they have the ability to "decide" to retain paedomorphic traits and remain aquatic like their larval forms, or reduce these traits and become terrestrial. The animal found in Caw Caw county park, had a swollen cloaca, which is representative of male mole salamanders. The animal also had metamorphic traits, and did not retain external gills, and had eyelids. I was very surprised to find this salamander so quickly, seemingly the first or second log that I had overturned held him, and was the only amphibian I ended up catching the rest of the afternoon. This is the first time that I have caught a mole salamander, and hope I get lucky enough to find one again.

Pertinent References:Ryan, T. J. and G. R. Plague. 2004. Hatching asynchrony, survival, and the fitness of alternative adult morphs in Ambystoma talpoideum. Oecologia 140:46-51.

Natural History: Lithobates grylio

 This past field trip, our class went to Caw Caw county park. Here we found many different herps, one of them being Lithobates grylio, the pig frog. I encountered this frog while looking through the traps set in the middle of a pool of swamp water. These frogs typically inhabit areas with permanent bodies of water, so it makes sense that we found this guy here. Although they do live near permanent bodies of water, pig frogs also travel on land at night and when the weather is wetter for their moist skin. Although hard to see in the picture, pig frogs have extensively webbed feet where the webbing extends all the way to the tips of every toe. This helps them to move around in their aquatic environments.
Male pig frogs typically have an external eardrum that is larger than their eyes. The pig frog found at Caw Caw does not seem to have this feature, so it is most likely female. The breeding seasons of these frogs are typically at the end of spring and into summer. Like most anurans, pig frogs have external fertilization and a complex life cycle with a tadpole stage. Pig frog's tadpole stage can even last up to a year long before fully metamorphosing into a mature frog.
This was an exciting find because we could compare this species of Lithobates to the other we found at Caw Caw, Lithobates clamitans, as well as the more commonly known species of Lithobates, the bull frog. It was also amazing to see where the pig frogs like to hang out, and how the environment at Caw Caw was the perfect fit for this species.

References:
Powell, R., Conant, R., & Collins, J.T. Perterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, 4th edition, pg. 154-155. 2016: Houghton Millfin Harcourt Publishing Company. 
https://srelherp.uga.edu/anurans/rangry.htm

Natural History: Chelydra serpentina (common snapping turtle)

     On our first Herpetology class field trip to Dixie Plantation, we were able to find and observe quite a few different herps in their natural habitat. In particular, I was fascinated by Chelydra serpentina, also known informally as the common snapping turtle. During the field trip, we made our way as a class to a swampy body of freshwater, removed a trap, and found this amazing reptile in the trap with some cool, cute yellow bellied slider turtles as well. Although the sliders were too cute, I couldn't stop looking at the size of the snapping turtles that were caught, compared to the sliders. The snapping turtles were much bigger, and also appeared rougher in terms of their shell, and even their facial features (ex: beak) appeared sharper and more intimidating. The sliders appeared to have a more friendly appearance with a more rounded beak and face, and a nice yellow pattern on their skin and bottom of their shell, while the snapping turtles were a darker black/brown color with no other visible colors, and had a pointy beak. The snapping turtles also had larger heads, and their heads and necks were highly moveable. This was apparent as we removed the turtles from the traps, and the snapping turtles became defensive and started turning their heads towards us to make sure they kept us in sight.
   Chelydra serpentina is a big, freshwater turtle that can be found locally in South Carolina. It belongs to the order Testudines and the family Chelydridae. They are characterized by their strong, pointy, powerful beaks (be advised to not touch), defensive and combative personality, and their ability to be feisty (they WILL hiss at you if provoked). Snapping turtle usually are harmless and keep to themselves by hiding underwater in sediment, unless they are provoked or feel threatened by another animal or human entering their habitat or getting close to them, although, they are mostly not dry social. Being freshwater reptiles, these snapping turtles can be found in shallow streams and ponds and maybe even brackish waters like estuaries. Having a powerful, strong beak, is beneficial to this turtle in terms of self defense, and also in terms of what it can eat. These turtles are omnivorous, meaning they can eat plants in their aquatic habitat and also aquatic invertebrates, fish, frogs, and smaller reptiles like snakes and other smaller turtles on occasion.
    According to the source cited below, these snapping turtles can live for up to 30 years in the wild, if they can make it as hatchlings. The female turtle finds a nesting ground on land where she deposits the eggs, and the eggs undergo an incubation phase. Their eggs could potentially be eaten by birds and mammals, but if they make it past this stage, they must also make it past the hatchling stage to be in their safest zone. The source suggests that the most vulnerable life stage for these turtles is when they are hatchlings, and we can infer this because they are still at a small size and can be subjected to larger predators. Once they get a bit bigger, there are fewer predators that they are at risk of being hunted by, and have a higher chance of making it to adult stage where they can then reproduce and the whole cycle starts again. Unfortunately, some get hit by cars as they are looking for new nesting sites or a new habitat, but the good news is that, according to this source, these turtles are not even close to being endangered, extinct, or threatened.
    According to the source, these turtles have a tail that is almost as long as the shell, their extremities are largely exposed from their shell, and they are characterized by having saw-toothed keels on their tail. In terms of behavior, there is much aggressive interaction between males, and from our studies, we can attribute that to them being territorial, and also looking for mates. Also, aggression may be attributed to food availability, and whether or not the turtle was provoked. When the turtles were removed from the trap, I observed a turtle aggressively hissing at us and following us as we tried to lead it back to the pond. I wouldn't attempt to touch them of course, but I managed to get some close photos of them.  They were so feisty we had to use a hook and logs to push them back to their habitat. Also, I noticed that there were aquatic plants on the carapace of the turtles, which implied that they may have been hiding underwater in some sediment. Ultimately, I was fascinated by their really long nails, their pointy beaks, large size, and aggressive behavior when compared to the more docile, friendly yellow bellied sliders. Chelydra serpentina are some tough fellows.


Sources:

Bosch, A. 2003. "Chelydra serpentina" (On-line), Animal Diversity Web. Accessed March 12, 2018 at http://animaldiversity.org/accounts/Chelydra_serpentina/

Natural History: Anaxyrus Terrestris

During our field trip to Caw Caw County Park, we lifted many limbs and logs to look for local herps hiding underneath. Finally, we found two Southern Toads together under a dead log. This species usually hides under forest litter or burrows under loose soil, so it's not surprise where we found them. Their wide bodies and the keratinized spade on their hind limbs allow for efficient burrowing. The two frogs were of different life stages. We determined that the larger was sexually mature, but the smaller was still a juvenile and not yet sexually mature. Males are typically smaller than females, so the smaller could possibly have been a developing male. 

Southern Toads are found in the southeast ranging from Florida to Virginia and as far west as Louisiana, but they are not found in Tennessee. In their many habitats including: coastal scrub, agricultural fields, and pine woodlands, they remain extremely close to water. As Caw Caw County Park has historic rice fields, it creates the ideal habitat for Southern Toads. They are usually dark in color and have dry skins covered in warts. Their large parotid glands right behind their eyes are easily distinguishable.

I really enjoyed visiting Caw Caw County Park as we saw new species that we hadn’t seen at Dixie Plantation. We saw a few herps in the traps, but it’s always more exciting to find them by lifting limbs and looking near trees, such as with the Southern Toad. I find the burrowing frogs to be extremely cute with their wide, fat bodies and big eyes.

Source: https://srelherp.uga.edu/anurans/bufter.htm

Natural History: Anolis carolinensis

During the tour of Caw Caw historic rice plantation, a specimen of Carolina anole (Anolis carolinensis), also known as the American green anole, was spotted ~2 meter off the trail in a dry forest area covered with dry sticks and leaves. The weather was cloudy with light precipitation creating a moist environment which is preferred of anoles. The specimen was 13-14cm from snout to tail indicating this individual is likely a female adult. Also helping identify the sex is the size sexual dimorphism between males and females, females seldom exceeding 5-6 inches. Another indication of sex is a visible white stripe running down the middle of the back which was not observed on this specimen, along with the lightly colored dewlap (not pink which occurs in males). Other notable characteristics are the unique toepads with highly visible setal hairs helping them with climbing, among the triangular shaped head, and large eye socket. The body color can range from bright green to brown, with a visible white area along the lining of the mouth running to the dewlap is unique coloration.Once spotted and approached, the anole quickly evaded trying to escape capture. I was able to catch the specimen by grabbing him around the torso/head, avoiding grabbing by the tail to prevent tail autonomy at the fracture planes. Once held the anole became very angry trying to escape capture, this was noted because of his flashing of the pinkish dewlap. Once handed to Dr. Welch, he bit on to her finger slowly increasing grip strength. He maintained this bite for about 3 minutes.
Catching the Carolina anole was exciting due to the speed and difficulty in catching them. I was excited to see the size of the lizard and how large his mouth was.

Natural History: South Carolina slimy salamander

            Our trip to Caw Caw Interpretive Center last week was a bit too gray and rainy for spotting reptiles, but it turned out to be the perfect weather for catching plenty of amphibians!  The first Herp Alert of the day came when we turned over an old log to find this salamander hiding in the leaf mold underneath.  The salamander was about five inches long, with shiny black skin and mottled gray markings along its sides.  As soon as I picked it up, it began to secrete much more than any of the other amphibians we had handled (except maybe the amphiuma!).  I had scooped the salamander up along with a handful of leaves and dirt, and its defense mechanism managed to glue all the debris firmly onto my hands.  Dr. Welch told us the goo was a hint about its species, and sure enough, we were able to identify it as Plethodon variolatus, the South Carolina slimy salamander.

            Slimy salamanders are part of a large group, the Plethodon glutinosus species complex, which includes populations all across the southeast and mid-Atlantic regions of the US.  They belong to the Plethodontidae, the most diverse family of salamanders.  Salamanders in the Plethodontidae have no lungs and rely on the gas exchange they perform through their skin.  Many of them, including the slimy salamanders, have no larval stage and develop their terrestrial morphology in the egg instead.  Because of this, juveniles look like miniature versions of the adults in everything but their body proportions.  Based on its size, though, our salamander was most likely an adult.  Slimy salamanders do not need to reproduce in water, thanks to their direct development, so they instead lay their eggs in a damp, sheltered environment like the log where we found the adult.  Because salamanders tend to keep to a small home range, we released it back under the same log to continue enjoying the rainy day.

References:
Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America
Herpetology Program, Savannah River Ecology Laboratory, University of Georgia