Black-tailed rattlesnake

The Black-tailed rattlesnake ("Crotalus Molossus") is a species of venomous Pit vipers, found in southwestern United States of America and Mexico. There are currently three subspecies recognized.
Description.
Most Black-tailed rattlesnakes grow to the length of . They can be as long as . Females are said to be larger than males.
The Black-tailed rattlesnake is olive green, yellow, brown, or black in color. They are called the "Black-tailed rattlesnake" because of their tail which is the color of black. Like other rattlesnakes the Black-tailed rattlesnake has a rattle on the end of its tail, but its rattle is weak and can be broken. They can shed their skin several times a year.
Common Names.
The Black-tailed rattlesnake is also called the "Green rattler", the "Dog-faced rattlesnake", and the "Mountain Diamondback".
Where they live.
The Black-tailed rattlesnake is found in southwestern United States of America and Mexico. In the U.S.A it is found in Arizona, New Mexico, and west and central Texas, in Mexico it is found in Oaxaca. It is also found on islands of the Gulf of California, like San Estèban Island and Tiburòn Island.
Behavior.
In the spring and fall the Black-tailed rattlesnake are diurnal, in the summer they are nocturnal so they can avoid the heat, and in the winter they hibernate in other animals dens. Even though they are okay climbers and good swimmers they are terrestrial. They live in grasslands, deserts, mountain areas, and forests.
Feeding.
Like all rattlesnakes they are carnivores and eat rodents, other small mammals, birds, and small reptiles.
Reproduction.
The Black-tailed rattlesnakes mate in the spring, once they have mated the male stays with the female to stop other males from mating with her. It is in the summer that the female gives birth to her young, the young stay with their mother for around a day or two before leaving by their selves. A female usually mates every year and has 10-12 young at a time. They live for around 15–20 years.