Eastern Black-tailed Rattlesnake

Crotalus ornatus

Reptiles & AmphibiansIn the app

This is a venomous, medium-sized species of snake that averages a length range of 30-40 in, with a maximum length of about 50 inches in rare cases. Females are usually la…

Eastern Black-tailed Rattlesnake illustration

How to identify

This is a venomous, medium-sized species of snake that averages a length range of 30-40 in, with a maximum length of about 50 inches in rare cases. Females are usually larger than males. The colors range from yellow and olive green to brown and black and as the name implies, their tails are completely composed of black scales. Most specimens have a black band across the eye that runs diagonally and ends at the corners of the mouth, this gives them the appearance of a mask. This rattlesnake has a keratin rattle at the end of its tail. The rattle itself is a bit fragile and is susceptible to breakage.

Range

This snake can be found in the southwestern parts of the United States, Mexico, south to Oaxaca. In the US, you can find it in Arizona, central and west Texas, the Gulf of California, Tiburón Islands, and San Estéban.

Habitat

This species is terrestrial and can be found on grasslands, deserts, and rocky areas. Even though they are terrestrial, they are able swimmers and climbers. They are diurnal in spring and fall but become nocturnal in the heat of summer, but in winter they hibernate in borrowed dens. They feed primarily on rodents, small mammals, small reptiles and birds. Females give birth to live young ones in the summer. The young hatch and are cared for by their mothers in less than two days. The litters can be as many as ten or twelve.

Variations

Crotalus ornatus molossus Crotalus ornatus nigrescens Crotalus ornatus oaxacus

Similar species

The Western Diamondback Rattlesnake (Crotalus atrox) is also a venomous rattlesnake species with slightly more length. However, males of this species grow bigger than the females at sexual maturity. The color patterns on the western diamondback rattlesnake are often gray-brown, pinkish-brown, yellowish, pinkish, brick red or white. The Western Rattlesnake (Crotalus oreganus) is another venomous pit viper species endemic to North America. This species is usually smaller (with some populations stunted), at an average length of 39 in. It has a dark-brown, dark-gray, olive-brown, and occasionally black or a pale yellowish background color. It has a series of large dark dorsal blotches that are relatively wide. Timber Rattlesnake (Crotalus horridus) can grow lengths between 36 and 60 inches. It has keeled dorsal scales and a pattern of dark brown or black crossbands on a yellow-brown ground color. The crossbands are irregularly shaped and can take the form of an ‘M’ or a ‘V’.