A striking and relatively calm species of pit viper found in the southwestern United States and northern Mexico. True to its name, this rattlesnake is best known for its distinctive jet-black tail, which contrasts sharply with the rest of its patterned body. It’s one of the more colorful and visually appealing rattlesnakes, with a combination of olive green, yellow, or tan scales marked with darker diamond-shaped or blotchy patterns.

Black-tailed rattlesnakes are robust and muscular, with a broad triangular head, heat-sensing pits between their eyes and nostrils, and cat-like pupils — all classic signs of a pit viper. The black tail, ending in the iconic rattle, is a key identifying feature and can be a useful signal for humans to recognize and avoid disturbing them. When threatened, they shake their rattles as a warning — not because they want to bite, but because they want to be left alone.

Black-tailed rattlesnakes are ambush predators, feeding mostly on small mammals like rodents and rabbits and birds, lizards, and other reptiles. They use their venom, mostly hemotoxic (affecting blood and tissue), to subdue prey quickly and begin digestion. Like many snakes, they strike fast and then wait for the venom to do its work before tracking the scent of their meal. They are most active in spring and summer, especially in the early morning and late afternoon, though they may become more nocturnal during the hottest times of the year.

Black-tailed rattlesnakes are excellent climbers and swimmers, which people do not associate with rattlesnakes. They can be found in trees, rocky ledges, and even swimming across creeks, making them more versatile than many expect. Another interesting note is their generally mild temperament — they are likelier to flee or rattle than strike.

Distribution

Country

Population est.

Status

Year

Comments

Mexico

2007

United States

2007