About This Project

Snake fungal disease, SFD, is widespread in snake populations across eastern North America. SFD causes skin lesions and often leads to death. We hypothesize increased stress and stress reactivity in timber rattlesnakes makes them more susceptible to SFD and makes it harder for snakes to fight off the disease. We will tag and track 20 timber rattlesnakes to test this hypothesis. We will also use these data to see how SFD influences snake habitat selection and movement patterns.

Ask the Scientists

What is the context of this research?

We know little about variability in susceptibility to SFD infection in snakes. We hypothesize environmental stressors, such as food restriction, land use change, and predation risk, influence SFD transmission. Chronically elevated corticosterone (CORT), a stress hormone secreted by the adrenal cortex, can be immunosuppressive and increase disease susceptibility. We predict that elevated CORT and greater stress reactivity (difference in CORT pre- and post- stressor) will increase susceptibility to SFD. We will also hypothesize that individual level behaviors, habitat selection and movement, will be influenced by SFD. Few studies have documented these relationships.

What is the significance of this project?

Snakes provide important ecosystem services. They are known to be predators and prey in terrestrial and aquatic food webs, seed dispersers, and mitigate tick-borne diseases. Timber rattlesnakes are slow to mature and have few offspring, which may make their populations more vulnerable to the effects of SFD. By understanding how stress and stress reactivity influences SFD dynamics and how SFD influences habitat selection and movement patterns, we are better able to conserve and manage snake species populations affected by SFD.

What are the goals of the project?

Our objectives are to determine the influence of stress on susceptibility to and ability to recover from SFD and assess whether infection by SFD influences timber rattlesnake habitat selection and movements. We hypothesize greater stress increases susceptibility to SFD and decreases the ability to recover from SFD. We are already tracking 10 timber rattlesnakes with telemetry and will track another 10 snakes during summer 2019. We will track the snakes for 18 months via homing 2-3 times per week from May - Oct and once every 2 weeks during the winter. Once per month from May - Sept we will collect blood samples to measure baseline and elevated CORT. We will also swab each snake to test for SFD via qPCR.