''Crotalus enyo furvus'', also known as the Rosario rattlesnake or the dusky Baja California rattlesnake, is a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of Baja California rattlesnake, a kind of

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

ous

pit viper The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or pit adders, are a subfamily (biology), subfamily of Viperidae, vipers found in Asia and the ...

. It is named after the

latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

'furvus' meaning 'dark complexion' or 'swarthy', referring to the colouration of the subspecies. It is found on the San Quentin Plain in Baja California del Norte - due to the area's restricted and largely inaccessible habitat not much is known about the subspecies.

Description

''Crotalus enyo furvus'' is usually dark to grey brown in colouring, with specific

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

different sizes and in different positions to other ''C. enyo'' subspecies. Specifically, ''C. e. furvus'' is the only subspecies of the species to display subfoveal scales. They are also known to have an average length smaller than the other two subspecies.

Diet & behaviour

The Rosario rattlesnake is thought to eat mostly small

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s, using

burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...

s to

hunt Hunting is the Human activity, human practice of seeking, pursuing, capturing, and killing wildlife or feral animals. The most common reasons for humans to hunt are to obtain the animal's body for meat and useful animal products (fur/hide (sk ...

and for shelter. It is known to be at least partly nocturnal.

Reproduction

The dusky Baja California rattlesnake is known to give

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

to less than ten

neonate In common terminology, a baby is the very young offspring of adult human beings, while infant (from the Latin word ''infans'', meaning 'baby' or 'child') is a formal or specialised synonym. The terms may also be used to refer to Juvenile (orga ...

s in one brood.

References

enyo furvus Reptiles described in 1954 Reptiles of Mexico {{Snake-stub