The tamarack swamps and floodplain forests which line this river are ideal habitat for Michigan's only venomous species of snake. We decided to walk some of these areas on Sunday afternoon, the sun was shining and temps were hovering in the low 60s. The thick underbrush in this habitat made navigating through it a bit difficult, but I was optimistic about our chances of seeing a rattlesnake out basking. Within a few short minutes, I came across this hefty adult trying to soak up some late October sun.
Eastern Massasauga Rattlesnake - Sistrurus catenatus catenatus
This snake showed clear signs of having spent time in a crayfish burrow, but was still sharp. But upon further investigation, the snake appeared to have a large, bulbous sore on its neck the size of a half dollar.
I've seen photos of others snakes with large sores like this, sometimes they can be sores from below breezing temperatures and other times it can just be an injury in the process of healing. There are other concerns with this type of abscess, one of Illinois' only viable populations had recently been hit by a fungal infection which has been fatal to several snakes, usually due large tumors on the head and neck. You can read about that issue here; Fungal Infection Poses a New Threat to the Eastern Massasauga. Nonetheless, it was great to find a massasauga at a new site so late in the season. But it will be something to keep an eye on with this population in the future.