Crotalus atrox - Rattlesnake
Common name: Western rattlesnake or rattlesnake
- Average body length: 1.5 - 2 meters
- Weight: 6 kg
- Lifespan: 20 years (usually less due to hunting and anthropization)
- Sexual maturity:3 years
HABITAT AND GEOGRAPHICAL DISTRIBUTION
The Crotalux atrox it is certainly, among the members of the genus Crotalus, the most famous rattlesnake. It is an animal that is found exclusively in the American continent, in California, Arizona, Mexico, Texas, Oklahoma, Arkansas and in the United States.
Its habitat is mainly terrestrial from sea level up to 2,400 m above sea level even if the greatest concentration is below 1,500 m s.l.m.
The rattlesnake is found in almost all habitats: sandy, rocky, wooded, shrubby, desert and even coastal areas.
The rattlesnake has a body that reaches an average length of about 1.5 m for a weight of about 6 kg; covered with scales and with a variable color from gray to yellowish to brown to pink.
It has a triangular-shaped head and between the eye and the nostril there is a dimple (one per nostril, therefore two in total) about 5 mm deep where thermoreceptors are located which are used to identify prey thanks to the heat emanating from their body. as it has been established that the rattlesnake is deaf.
The rattlesnake is an animal with retractable fangs with which, when it bites, it injects into its victim a venom whose flow is controlled by the muscles surrounding the venom glands and is deadly. When it bites it often happens that the teeth can remain inside the prey's tissues for this reason they are replaced 2-4 times a year.
The tail is white in color and has characteristic rings of horny consistency that are derived from the residues of the moult. They are real resonance organs that when agitated emit a characteristic noise in fact the tail muscles are structured in such a way as to have high frequency contractions to allow rapid movement.
CHARACTER, BEHAVIOR AND SOCIAL LIFE
Characteristically this rattlesnake is an aggressive animal due to the fact that it takes very little to make it feel threatened. When this happens, it coils on itself in a spiral flattening, raised its head and keeps its tail raised by waving it back and forth quickly and causing the characteristic sound that represents a warning.
The males often undertake fights during the mating period but also to defend their territory, during which they rise from the ground by rushing against each other, moving repeatedly against their opponent until one of the two gives up and He goes away.
Rattlesnakes with the arrival of winter either hibernate or move to warmer areas. To hibernate, rattlesnakes, if they live in areas where winter is not particularly cold, use makeshift dens; vice versa, if they are in areas where temperatures become particularly rigid, then they seek and expropriate the burrows dug in the ground by other mammals. Generally the burrows are used by several individuals at the same time.
They are mainly diurnal and crepuscular animals in spring but become crepuscular and nocturnal during the hot summer months while during the day they remain protected in the bushes or in the crevices of the ground.
This rattlesnake feeds on birds, small mammals, amphibians and sometimes even manages to catch fish.
To capture its prey, the snake remains hidden waiting for its victim to pass, lurking along its usual paths. Once sighted, it pounces on it by biting it; the prey dies within a few minutes and is swallowed whole and digested over the next few days. Since it takes a certain amount of time for digestion, they typically eat every 2-3 weeks.
They do not have a great need for water and in arid areas, they obtain the water necessary for their sustenance directly from the assimilation of prey.
REPRODUCTION AND GROWTH OF THE SMALL
Sexual maturity in the rattlesnake is reached around 3 years of age.
Mating occurs during the spring, when hibernation ends. In order to be accepted by females, males perform characteristic ritual dances.
These are ovoviviparous animals therefore the male of the rattlesnake puts his hemipenis inside the female's cloaca where the eggs are fertilized; the gestation of the eggs lasts a little more than 5 months at the end of which 10 to 20 young live snakes are born that stay with the mother for a maximum of one day after which they disperse to make an independent life.
Mortality rates in the first year of life are very high due to lack of food, low temperatures and predators.
Rattlesnakes are normally preyed upon by hawks, eagles.
STATE OF THE POPULATION
The species Crotalus atrox it is classified in the IUNC Red list among species at low risk of extinction LEAST CONCERN (LC). The population is in fact considered stable and greater than 100,000 adult specimens and no particular dangers for their survival have been highlighted apart from a decrease in their natural habitat due to urbanization or killing by man for an instinctive deep sense. of fear towards these animals.
SOCIAL, ECONOMIC AND ECOSYSTEM IMPORTANCE
The rattlesnake is a very important animal for keeping the population of small mammals under control, especially rodents.
In the past it was a very important animal in the Native American culture who used its meat as food, poison to prepare medicines and the skin to make belts and shoes.
It is the species that causes the greatest number of deaths in America due to snake bites.To hear the cries and noises emitted by this animal, go to the article: The sounds made by the rattlesnake.
(1) Original photograph courtesy of U.S. Fish and Wildlife Service.