This article was written by University of Florida Master’s student Ashlynn Canode. Originally from Ohio, Ashlynn earned her bachelor’s degree in Wildlife Conservation and Biology from Ohio University in 2023. She is currently pursuing a master’s degree in Wildlife Ecology and Conservation at the University of Florida, where she focuses on the snake ecology of the Red Hills region and the prevalence of pathogens affecting these snakes. Her favorite snake is the eastern mud snake.
Twenty years ago, Kim Sash, Biological Monitoring Coordinator at Tall Timbers, conducted a foundational study on snake ecology in the Red Hills region.
I am building on this work by revisiting these snake populations to assess changes in abundance and diversity over time, as well as exploring potential causes for these changes. Additionally, my study examines the presence of pathogens that may be impacting the snake population.
This research involves extensive fieldwork, with daily snake trap checks for three weeks each month from March to October.
The traps are placed in the same locations as the original study, using 21 drift fence arrays in a variety of habitats, including upland areas, mixed hardwood bottomlands, and fallow fields.
Each trap array consists of four 50-meter-long silt fences ending in four funnel traps, which extend from a wooden box trap in the center.
For each captured snake, basic morphometric data (length, weight, species, and sex) is collected. The snakes are then PIT-tagged (passive integrative transponder), similar to a pet microchip, for future identification. Lastly, swabs and fecal samples are collected for pathogen testing before the snakes are released at the capture site.
Snake populations are declining worldwide, and the southeastern U.S. has seen a significant drop in their numbers.
While habitat loss, climate change, and the pet trade all contribute to these declines, snakes also face serious threats from pathogens. One major concern is snake fungal disease (SFD), caused by Ophidiomyces ophiodiicola.
Ashlynn Canode processes and Eastern Diamondback Rattlesnake
This globally detected disease can severely impact snake health, causing skin lesions, abnormal shedding, and crusting around the eyes, nose, and mouth. In severe cases, it can lead to death. The full distribution of SFD is still unknown as new cases continue to emerge. Another dangerous pathogen is cryptosporidiosis (Crypto), caused by Cryptosporidium serpentis. This life-threatening gastric disease results in chronic infection and digestive issues.
In addition to these pathogens, an invasive pentastome is also an emerging threat. Raillietiella orientalis is a pentastome (parasitic crustacean) introduced by the invasive Burmese pythons in Florida.
It is now found in multiple native snake species, including banded water snakes, corn snakes, and cottonmouths. This parasite spreads through intermediate hosts (insects and amphibians), before infecting its definite host, snakes. Navigating to the lungs it matures and causes weight loss, lethargy, and eventually death.
See our previous article on pentastomes here for more information
The first round of pathogen testing (50 swabs, two per snake) by the University of Illinois has been completed.
While no snakes tested positive for Crypto, nine snakes tested positive for SFD, including species such as Florida cottonmouth, corn snake, southern black racer, eastern garter snake, eastern mud snake, and eastern diamondback rattlesnake (which is being considered for federal protection).
We have not yet seen any evidence of the invasive pentastome Raillietiella orientalis, but we are continuing to monitor as its presence in this area seems imminent.
Additional samples will be sent for testing in the middle and at the end of the 2025 trapping season to continue monitoring pathogen presence. To assist with monitoring efforts, we encourage reporting of sick snakes in the Greater Red Hills region to Kim Sash or through the Partners in Amphibian and Reptile Conservation website.
