Intro

Welcome! My name is Brad and I’m a new Master’s Student at Tennessee State University studying the spatial ecology of Eastern Hellbenders in Dr. William Sutton’s Wildlife Ecology lab.  What is a Hellbender? What’s spatial ecology? Why bother to study that? – Good questions!

Hellbenders are the largest salamanders in North America; they can grow to be 2 feet long (~60 cm) and they can live for over 30 years (Taber et al. 1975). They’re fully aquatic, which means they spend their entire lives underwater – from egg to adult. They breathe through folds in their skin, which is also known as cutaneous respiration. These folds have earned them the nickname,  “ol’ lasagna sides.” They’re really cool animals! Most people never get to see one because they spend most of their lives hiding under rocks in cool, fast-moving mountain streams throughout the east coast of the United States.

Because Hellbenders live in the water and breathe through their skin, they are extremely susceptible to pollutants and other environmental contaminants. They require high quality habitat (think clear, cold water) in order to thrive – which is why they are often considered “indicator species” , meaning their presence is a sign of a healthy ecosystem. Unfortunately, Hellbenders are declining throughout their range in the eastern U.S. and they are currently being considered for endangered status by the U.S. Fish and Wildlife Service.  Luckily, in East Tennessee we have a few streams that currently support a large number of Hellbenders, such as the Hiwassee River, and the populations there seem to be doing well  (Freake and DePearno, 2017).

There are other streams in Tennessee however where Hellbenders aren’t doing as well as they used to be years ago. What’s worse, the Tennessee Valley Authority (TVA) has built dams on many of these streams so Hellbenders from healthy populations are no longer able to disperse into these areas. So, we have proposed a conservation strategy to help increase the populations in those streams where Hellbender numbers are dropping – move a few from the streams where there are plenty! But, we can’t just go out and move a bunch and call it a day. We need to study what types of movements they make and what types of habitats (i.e. parts of the stream) they use, in order to understand what they will need when they are moved to the new streams. This is spatial ecology – understanding how an animal uses the space around it. By understanding the habits of these Hellbenders, we will have a better idea of what is considered “normal” for them, essentially establishing a baseline. After the animals are moved – we will compare their movements in these new habitats to the baseline and see if this is a conservation strategy that works.

So how do we study the movements of these underwater salamanders? We use radio-telemetry – which involves a radio transmitter that is surgically implanted into the Hellbenders (we are currently tracking 25) and a receiver with an antennae that can pick up the signal from that transmitter. It sounds like a small “beep… beep…. beep,” and when you get closer to the animal, it will get louder. It is essentially a game of “hotter, colder” – and at the end you will find yourself standing over a rock, which presumably has a Hellbender hiding underneath it. Once we locate where they are hiding, we will take down some data about how big the rock is and how many other big rocks are nearby, along with a GPS point and other data that we believe may be important such as water temperature and flow rate.

Stay tuned to find out more about our adventures in the field and how the Hellbenders are doing!