Crotalus tortugensis
Encyclopedia
- Common names: Tortuga Island diamond rattlesnake, Tortuga Island rattlesnake, more.
Crotalus tortugensis is a venomous
Venomous snake
"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...
pitviper
Crotalinae
The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
found only on Tortuga Island in the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
. No subspecies are currently recognized.
Description
This species is smaller than its close relative, C. atroxCrotalus atrox
Crotalus atrox, the "western diamondback rattlesnake", is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second greatest number in the USA after C. adamanteus. No subspecies are...
, with large males not growing to much more than 100 cm in length. The largest specimen on record is 105.8 cm (Klauber, 1972). Compared to C. atrox, the head is shorter relative to the length of the body -- a trait considered to be an indication of dwarfing, which is common in island populations.
The color pattern consists of a gray to gray-brown ground color, occasionally with a slight purplish or pinkish hue, overlaid dorsally with a series of 32-41 dark brown to purplish brown blotches running down the length of the body. The blotches are hexagonal or diamond shaped, marked with black spots, and bordered with irregular black mottling.
Common names
Tortuga Island diamond rattlesnake, Tortuga Island rattlesnake, Tortuga diamond rattlesnake.Geographic range
Found only on Tortuga Island, Baja California SurBaja California Sur
Baja California Sur , is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. Before becoming a state on October 8, 1974, the area was known as the South Territory of Baja California. It has an area of , or 3.57% of the land mass of Mexico and comprises...
, in the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The type locality is "Tortuga Island."
Conservation status
This species is classified as Least Concern (LC) on the IUCNWorld Conservation Union
The International Union for Conservation of Nature and Natural Resources is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." The organization publishes the IUCN Red List, compiling information from a network of...
Red List of Threatened Species
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
(v3.1, 2001). Species are listed as such due to their wide distribution, presumed large population, or because it is unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend is stable. Year assessed: 2007.
However, this it is threatened due to its limited range, even though it is common on the island.
Behavior
Although Van Denburgh reported that they would rattle vigorously when approached, it has been described as being less excitable than C. atroxCrotalus atrox
Crotalus atrox, the "western diamondback rattlesnake", is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second greatest number in the USA after C. adamanteus. No subspecies are...
, its mainland relative.
Feeding
Its diet apparently consists of mice. Several specimens from the island are reported to have contained mammal hair, and a white-footed mouse, Peromyscus dickeyi, is common on the island.Venom
Klauber (1997) gives an average venom yield of 56 mg for this species. For comparison, the same study yielded an average of 277 mg for C. atroxCrotalus atrox
Crotalus atrox, the "western diamondback rattlesnake", is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second greatest number in the USA after C. adamanteus. No subspecies are...
.
Taxonomy
Even though most recent authors consider this taxon to be distinct, it may actually be conspecific with C. atroxCrotalus atrox
Crotalus atrox, the "western diamondback rattlesnake", is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second greatest number in the USA after C. adamanteus. No subspecies are...
.
External links
- Crotalus tortugensis, incl. brief info and picture, at San Diego Natural History Museum. Accessed 23 April 2007.