Thursday, October 22, 2009

October's Featured Wisconsin Endangered Species: Massasauga Rattlesnake

The Massasauga Rattlesnake’s, or Eastern Massasauga’s (Sistrurus catenatus) story is like the Fugitive’s – a species unjustly convicted of and punished for horrendous crimes it didn’t commit. The Massasauga Rattlesnake is a shy, retiring creature that has been vilified over the years. There are no records of anyone killed in Wisconsin by a Massasauga Rattlesnake since the 1900s. By contrast, thousands of Massasauga Rattlesnakes were killed in the late 1800s in the Milwaukee area as the city was expanded, and there were bounties on rattlers until as late as 1975. At the sight, sound, and even thought of rattlers many of us feel so much fear – to the point of killing them, and to the point of not studying them thoroughly enough to truly understand them! The Massasauga is even helpful to people, because it primarily preys on mice, voles and other small rodents. And, they thoughtfully (and self-protectively) most commonly don’t use venom on people - 60% of poisonous snake bites to people don’t contain venom - which is saved for their prey.

1. How has the Massasauga Rattlesnake become endangered? As you might have guessed, it has been a victim of our fears. The killings during settlement and then the bounties dangerously lowered their population. Animals that have become over populous because of our destruction of top predators – raccoons and skunks –newly introduced species such as hogs, as well as foxes, hawks, and eagles, prey on the Massasauga. The Massasauga is a favorite venomous species pet, so they are being illegally captured. Off-road vehicles on their habitat is harmful to them. Though the primary reason for their being endangered today, is that we are indirectly killing them by destroying their wetland habitats. Because of our lack of knowledge about the Massasauga, we’re not sure how to manage their existing habitat.

2. What do we know about the Massasauga Rattlesnake? They are found in isolated spots in southeastern, central, and west central Wisconsin.
When the soil temperature is high enough, Massasaugas become active. During their active season, from April to early, mid October, they live in floodplain habitats along medium to large rivers, especially near river confluences – which is why the Ojibwa called them Massasauga, meaning great river mouth – where they favor open canopy wetlands, such as sedge meadows, fresh wet meadows, scrub carr and adjacent upland prairies and old fields. They enjoy warm, humid, overcast days and sun themselves in concealing vegetation. They are primarily active during the early morning, but also on summer evenings.
Female Massasauga Rattlesnakes are pregnant from late July through August. They prefer dry to dry-mesic prairies during this incubation period. They give birth to 8 to 20 young, live rather than eggs. Their young are usually born beneath a log, in a wood pile, or abandoned mammal burrow, where they will stay for 4 or 5 days, until shedding into more protective skins.
The beginning of hibernation is dependent on air temperature. Unlike other snake species, each snake hibernates alone. They prefer crayfish burrows, built in river bottom dugouts with above ground mud chimneys, in which they choose the at or near water level spots. They will also use mammal burrows, sawdust piles, or old root canals.

3. What does this mean for habitat management? It will have to encompass the Massasauga Rattlesnake’s needs at different times of year and at different times in its lifecycle – through its active time including basking, its hibernation, and its reproductive times and youth. Allowing meadows and wetlands to fill in with vegetation will compromise their active habitat. Managing to leave some open canopy is necessary for basking. Prescribed burning, mowing and herbicide application should only be done during their hibernation http://dnr.wi.gov/news/DNRNews_Article_Lookup.asp?id=924 . During hibernation, recent research shows that lowering water levels (drawdown management) in wetland habitats during the fall may harm them. Impounding, or containing, sedge meadows and wetlands will also be detrimental to the Massasauga during hibernation. And it’s important that crayfish are allowed to flourish, so the Massasaugas can use their burrows.

4. What can you do to help? Tell everyone you know that the Massasauga Rattlesnake is not aggressive towards people! Let them know all the interesting facts about them and reveal their true natures! See this artful photo, where the Massasauga looks like a work of art itself http://k41.pbase.com/u13/eddie_sanchez/upload/38428436.DSCN5316.jpg (I’ve based my poster on it). Donate to the WI DNR http://dnr.wi.gov/org/land/er/support/how_you_can_help.htm (all of my information about the Massasauga comes from their website – where you can find out even more interesting facts about them http://dnr.wi.gov/org/land/er/biodiversity/index.asp?mode=info&Grp=49&SpecCode=ARADE03011 , under Detailed Information). Donate to and volunteer with conservation organizations, to support their work helping endangered species, even some that don’t seem, at first glance, worth saving!