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How to capture and monitor a rare native rattlesnake

  • ##Eastern massasauga rattlesnakes are one of Wisconsin’s rarest native snakes, and state conservation biologists have launched long-term monitoring for the species, in conjunction with the U.S. Fish and Wildlife Service. Massasaugas are one of two native rattlesnake species in Wisconsin; the other is the timber rattlesnake. Massasaugas are listed as state endangered species and federally threatened species. Photo by Joe Krumrie
  • ##While timber rattlesnakes are an upland species, massasaugas are more often associated with wetland habitats. Here, conservation biologists from DNR’s Natural Heritage Conservation (NHC) and Wildlife Management programs travel to a remote wetland area where eastern massasaugas are present. Photo by Rori Paloski
  • ##Conservation biologists conduct visual surveys for massasaugas in one of a handful of known sites. The snakes were historically found in southern and west central Wisconsin, but bounties several decades ago greatly reduced their numbers. Photo by Rori Paloski
  • ##DNR removes invasive brush on sites with the rare snakes to provide the open meadows and prairies they need to receive sunlight that allows these cold-blooded reptiles to regulate their body temperature. Crayfish holes like this one in the inset photo provide a winter home for massasaugas. Photo by Rori Paloski
  • ##Conservation biologists use “snake tongs” to grab the venomous snake safely at a distance without injuring the snake. NHC conservation biologist Rich Staffen, center, successfully captures a massasauga in 2018.Photo by Rori Paloski
  • ##Venomous snakes have a triangular shaped head(wider than neck), oblong pupils, and a sensory pit below the eyes which differentiates them from nonvenomous snakes. Adult massasaugas have oblong dark blotches on their sides while timber rattlers have dark or black-colored bands and are much larger.Photo by Rori Paloski
  • ##Once conservation biologists capture a snake, they place a tube in front of it and the snake instinctively moves forward and into the tube. While conservation biologists describe massasaguas as nonaggressive, docile even, this method allows biologists, including USFWS biologist Mike Redmer shown here, to safely handle the snake.Photo by Rich Staffen
  • ##Once the snake is in the tube, biologists measure it, assess its condition, age it, inspect its pattern, and determine whether it is a male or female.Photo by Rori Paloski
  • ##Conservation biologist Rich Staffen holds the snake while USFWS biologist Mike Redmer marks the rattler’s tail with a green marker so if the snake is seen again that field season biologists will know it has already been measured, weighed and identified. NHC conservation biologist Sarah Herrick records information on the snake. Photo by Rori Paloski
  • ##USFWS biologist Mike Redmer weighs the massasauga in a cloth bag.Photo by Rori Paloski.
  • ##The view down a tube. The blue, milky appearance of the snake’s eye is a sign the snake is soon to shed, or molt, its skin. Unfortunately, this particular snake was found to have snake fungal disease, SFD for short, which was suspected based on the inflammation on the snake’s lower jaw. It was the first massasauga in Wisconsin found to have the fungus, despite DNR surveys in recent years to look for the fungus.Photo by Rori Paloski
  • ##To date, snake fungal disease has been found in 10 snake species in Wisconsin. In other states, including Illinois, it has been known to extirpate local snake populations. SFD can prevent snakes from effectively feeding and drinking, and cause them to bask conspicuously, making them more susceptible to predators. Photo by Rori Paloski
  • ##NHC conservation biologists found only the one massasauga with SFD, so they hope it is an isolated incident, but future monitoring will help answer this and other questions about the disease. Please submit photos of snakes with symptoms -- lumps or lesions along their face, neck and body -- to

    Learn more about Wisconsin’s other native snakes. Photo by Rori Paloski
Last Revised: Tuesday November 6, 2018