Western Pigmy Rattlesnake
Sistrurus miliarius streckeri • Order: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Sistrurus, Species: Sistrurus miliarius
Natural range includes the south-central United States, specifically from East Texas through Oklahoma, Arkansas, Louisiana, and into Missouri and Tennessee. The specimen in San Jacinto County, Texas, is within its native range.
Look up Western Pigmy Rattlesnake in the Snake Encyclopedia →Venomous Status
Venomous (Solenoglyphous)
Danger Level
Moderate Risk. While their small size means lower venom yields, they are highly defensive and can cause severe localized reactions. Medical attention is always required for a bite.
Family
Order: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Sistrurus, Species: Sistrurus miliarius
Conservation
Least Concern (IUCN), though localized populations may face threats from habitat loss and road mortality.
Physical Description
Small, stout body with grayish to brownish ground color and dark, irregular blotches along the back. It often features a thin reddish-orange dorsal stripe. The head is distinct from the neck with a dark line through the eye. Tail ends in a tiny, barely audible rattle. Eyes have vertical pupils. Scales are keeled.
Size & Dimensions
The specimen in the photo appears to be a juvenile or small adult, approximately 6-8 inches. Adults typically range from 14 to 22 inches (36-56 cm).
Habitat
Inhabits pine-hardwood forests, mixed woods, and areas near water such as marshes or floodplains. They are often found in leaf litter or under logs from sea level to moderate elevations.
Behavior & Temperament
Known for a 'feisty' temperament; they are quick to strike and vibrate their tails when threatened, though the rattle is so small it sounds like a buzzing insect. Primarily crepuscular or nocturnal during hot months.
Diet & Feeding
Feeds on a variety of small prey including lizards, small snakes, frogs, and occasionally small rodents or large insects. They use both ambush and active foraging strategies.
Reproduction
Ovoviviparous (gives birth to live young). Litters typically consist of 3 to 8 neonates, born in late summer or early fall.
Venom Profile
Hemotoxic venom that causes localized tissue damage, pain, and swelling; however, due to small yield, it is rarely fatal to healthy adult humans.
Look-alikes
Commonly confused with juvenile North American Racers (Coluber constrictor) or juvenile Ratsnakes (Pantherophis), but distinguished by the heat-sensing pits, vertical pupils, and presence of a rattle.
Conservation Status
Least Concern (IUCN), though localized populations may face threats from habitat loss and road mortality.
Cultural Significance
Often feared due to its rattlesnake status, it plays a vital ecological role in controlling populations of small vertebrates and is a subject of study for its unique venom proteins.
Notable Features
The 'Sistrurus' genus is distinguished from 'Crotalus' (larger rattlesnakes) by having nine large plates on the top of the head rather than many small scales. Its 'insect-like' rattle sound is a signature characteristic.