SLIPPERY ROCK — Most Pennsylvanians likely have never heard of the Eastern Mississauga rattlesnake, as this little-known snake lived in a small area of the state’s western region, which is dotted with wetlands.
The small-bodied, timid rattlesnake is on the brink of extinction and is both a federally threatened species, first listed in 2016, and a Pennsylvania state-endangered species. The often-spotted Timber Rattlesnake gets most of the public’s attention and mentions in folklore, but the mysterious Mississauga is seldom seen, rarely discussed, and lives a secretive life that even herpetologists struggle to find and study.
One of the rarest vertebrates in the Commonwealth and rarest venomous snake, shrinking habitat and increased land development has dramatically increased the pressure on this snake to find a home today. The fact is, the Mississauga does not fit modern landscapes and scientists and land managers are offering some hope and are working urgently to protect what remains of this quiet species.
Historically, the Mississauga inhabited a patchwork of marshes, wet open fields and brushy lowlands across the Great Lakes region and into western Pennsylvania. The damp open ground with thick grasses and scattered shrubs, which this snake prefers, was more common in the past, but the 20th Century brought disaster to its habitat with meadows drained and plowed for farming, other suitable areas were mined or developed, fields grew into forests and the widespread construction of roadways and highways fragmented what remained.
By the late 1900s, the Mississauga had faded from most of Pennsylvania, and surveys that once yielded regular sightings eventually came up empty of evidence. Today, only a limited number of populations survive, all in the western counties, and even those are small-scale and sporadic.
While a Timber Rattlesnake can live on rocky ridges or in deep forest areas, the Mississauga thrives in habitats that receive sunlight, support dense, low vegetation, and provide small-mammal prey. Ideal Mississauga habitat is the first to be developed for housing or agriculture, and its habitat area is usually small and fragmented, so when suitable habitat becomes available, it does not provide for large enough migration corridors for neighboring populations to exchange genetic material.
Many Pennsylvanians are unaware that a rattlesnake once thrived in the state’s wetlands. A significant difference between this snake and its cousin, the Timber Rattlesnake, is that it does not grow very large – with its average length is just more than two and its tiny rattle is more like a low hum.
It has a marbled appearance, with brown spots on a lighter gray background, with is coloring providing excellent camouflage. Its temperament is generally considered quite shy, and if encountered expect it to either freeze or attempt to disappear when approached.
Despite the serious medical implications of venomous snake bites, Mississauga bites are uncommon and usually occur when a person steps directly on a snake or attempts to handle it. Its venom is intended to subdue small rodents, playing a vital role in wetland ecosystems by maintaining the population levels of small mammals.
Public education is a key part of a larger strategy to protect it, and education can help increase its ecological value and support safe coexistence with wetlands. Once the public understands the non-aggressive nature of this species and that its survival is at stake due to habitat loss, we will have a better chance of gaining their support in protecting the Mississauga.
Encountering a Mississauga in its natural environment remains extremely low, as they would rather not be found. They can be thought of as a phantom of the Pennsylvania wetlands: seldom seen, never discussed, and barely clinging to survival in the few remaining geographic pockets of wilderness that can support its existence.
(Dempsey is a member of the Pennsylvania Outdoor Writers Association. Contact the writer: outdoors@republicanherald.com.)