Many wonder about the classification of rattlesnakes and their relationship to pit vipers. Understanding this connection requires exploring the features defining pit vipers and how rattlesnakes exhibit them. This article clarifies the taxonomic relationship between these reptiles.
What is a Pit Viper?
Pit vipers are a group of venomous snakes belonging to the subfamily Crotalinae, which is part of the larger Viperidae family. A defining characteristic of these snakes is the presence of specialized heat-sensing organs called loreal pits. These pits are located on each side of the head, positioned between the eye and the nostril, acting as highly sensitive infrared detectors. This unique sensory ability allows pit vipers to perceive the heat signatures of their surroundings, aiding them in hunting warm-blooded prey even in complete darkness.
Another notable feature of pit vipers is their advanced venom delivery system. They possess long, hollow fangs that are hinged, meaning they can fold back against the roof of the mouth when not in use and pivot forward when the snake is ready to strike. These fangs are connected to venom glands located behind the eyes, which often gives their heads a distinctively broad, triangular shape. Pit vipers are found across various regions of the Americas and Eurasia.
Meet the Rattlesnake
Rattlesnakes are venomous snakes primarily inhabiting the Americas. Their range extends from southern Canada to central Argentina, with a notable concentration in the southwestern United States. They display varied appearances, often featuring mottled or blotched patterns in earthy tones for effective camouflage.
The distinctive rattle at the tip of their tail is a recognized trait of rattlesnakes. This structure serves as a clear identifying feature. While known for this unique appendage, rattlesnakes also possess other adaptations supporting their predatory lifestyle.
Why Rattlesnakes are Pit Vipers
Rattlesnakes are classified as pit vipers, belonging to the subfamily Crotalinae. They possess the defining characteristics of this group, including heat-sensing loreal pits. These pits, located between their eyes and nostrils, enable rattlesnakes to detect subtle temperature differences, allowing them to effectively locate and strike warm-blooded prey in low-light conditions.
Rattlesnakes also exhibit the specialized venom delivery system characteristic of pit vipers. They possess hinged, hollow fangs that retract when the mouth is closed and extend for injecting venom. Venom, produced in glands behind the eyes, is delivered through these fangs. This combination of heat-sensing pits and a sophisticated venom apparatus firmly places rattlesnakes within the pit viper lineage.
Unique Rattlesnake Features
While sharing core pit viper traits, rattlesnakes possess distinct features, most notably their namesake rattle. This structure is composed of hollow, interlocking segments made from keratin, the same material found in human fingernails. A new segment is added to the rattle each time the snake sheds its skin, though the number of segments does not directly correspond to its age, as older segments can break off. Young rattlesnakes are born with a single “button,” and the characteristic buzzing sound becomes audible only after additional segments develop.
The rattle functions as a warning mechanism. When threatened, the rattlesnake rapidly vibrates specialized muscles in its tail, causing the keratin segments to click together and produce a distinctive buzzing sound. This audible signal serves to deter larger animals and potential predators, indicating the snake’s presence and encouraging them to retreat.