Santa Catalina Island rattlesnake (Crotalus catalinensis)

loading
Santa Catalina Island rattlesnake in habitat
loading
Loading more images and videos...

Santa Catalina Island rattlesnake fact file

Santa Catalina Island rattlesnake description

KingdomAnimalia
PhylumChordata
ClassReptilia
OrderSquamata
FamilyViperidae
GenusCrotalus (1)

One of the most notable features of the Santa Catalina Island rattlesnake, and in contradiction to its name, is the lack of a functioning rattle (2). This is believed to be an adaptation for stealth, enabling this rattlesnake to slink silently towards prey (2) (3). It has a relatively slender and short body, with a triangular head distinctly separated from the neck. The Santa Catalina Island rattlesnake may be one of two colour forms (2); the most common form has a light brown or reddish-brown body, patterned with darker diamond-shaped markings, each diamond having a dark and then light border. The less frequently seen colour form is ashy-grey with darker grey markings (2) (4). It has elliptical pupils and, unlike other snakes living in the same region, a heat-sensing pit situated between the nostrils and eyes (2).

Size
Snout-vent length: 68 cm (2)
Top

Santa Catalina Island rattlesnake biology

While the Santa Catalina Island rattlesnake is a largely nocturnal snake (1), this can vary depending on the time of the year. During spring, when temperatures are a little cooler, the Santa Catalina Island rattlesnake can be observed crawling about during mid-morning as well as at night, while during the heat of summer, this snake is rarely seen out during the day, possibly spending most of the daylight hours in a burrow (2).

Unlike many rattlesnakes, this species is known to be an agile and capable climber. It can move rapidly across the ground, and then swiftly climb into vegetation, to escape danger or to pursue prey (2). It was once thought that its climbing ability, as well as lack of functioning rattle, was an adaptation to eat birds (2). However, more recent research has revealed that the majority of this snake’s diet is comprised of the Santa Catalina deer mouse (Peromyscus slevini), with the remainder consisting of lizards (3). So although this argues against the theory that the lack of a rattle is for silently hunting birds in vegetation, it could have evolved to allow the rattlesnake to hunt these partially arboreal rodents instead (3).

Very little is known about reproduction in this snake. Males have been observed bobbing their heads and flicking their tongues during courtship (5), and evidence suggests that the breeding season falls between spring and early summer, with young being born in late summer to early autumn (2).

Top

Santa Catalina Island rattlesnake range

This highly threatened snake occurs only on Santa Catalina Island, an island covering just 40 square kilometres, situated in the Gulf of California off the coast of Mexico (1).

Top

Santa Catalina Island rattlesnake habitat

Santa Catalina is a rather barren island (5), consisting of rocky hillsides separated by narrow, sandy, dry creeks, known locally as arroyos (1). The Santa Catalina Island rattlesnake occurs mainly in these arroyos, where there is abundant vegetation (1) (2), but may also sometimes be found beneath roots and rocks on the hillsides, or in open areas of sandy soils (1).

Top

Santa Catalina Island rattlesnake status

Classified as Critically Endangered (CR) on the IUCN Red List (1).

IUCN Red List species status – Critically Endangered

Top

Santa Catalina Island rattlesnake threats

Once thought to be a common species, the Santa Catalina Island rattlensnake has suffered declines, primarily due to the killing and illegal collection of individuals; unfortunately its reported passive behaviour makes it an easy target (1). On Santa Catalina Island, ‘pit fall’ traps have been found and people have been seen collecting reptiles in bags. In addition, predation by feral cats, and a decline in the Santa Catalina Island rattlesnake’s main prey, the deer mouse, may pose a threat to this now Critically Endangered species (1).

Top

Santa Catalina Island rattlesnake conservation

There are currently no conservation plans in place for this highly threatened reptile. Like many other snakes, this species may receive less conservation attention than it deserves due to long-standing and fairly widespread negative attitudes towards snakes (4). The implementation of a program to control the population of feral cats on the island has been suggested as a measure to help secure the survival of this rare and fascinating snake (1).

View information on this species at the UNEP World Conservation Monitoring Centre.
Top

Find out more

For further information on the conservation of reptiles see:

Top

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: arkive@wildscreen.org.uk
Top

Glossary

Arboreal
An animal which lives or spends a large amount of time in trees.
Nocturnal
Active at night.
Top

References

  1. IUCN Red List (December, 2007)
    http://www.iucnredlist.org
  2. Grismer, L.L. (2002) Amphibians and Reptiles of Baja California, Including Its Pacific Islands, and the Islands in the Sea of Cortés. University of California Press, California.
  3. Avila-Villegas, H., Martins, M. and Arnaud, G. (2007) Feeding Ecology of the Endemic Rattleless Rattlesnake, Crotalus catalinensis, of Santa Catalina Island, Gulf of California, Mexico. Copeia, 2007(1): 80 - 84.
  4. San Diego Natural History Museum (August, 2008)
    http://www.sdnhm.org/fieldguide/herps/crot-cat.html
  5. Armstrong, B.L. and Murphy, J.B. (1979) The Natural History of Mexican Rattlesnakes. University of Kansas Publications, Kansas.
X
Close

Image credit

Santa Catalina Island rattlesnake in habitat  
Santa Catalina Island rattlesnake in habitat

© Eli Garcia

Eli Garcia
http://www.flickr.com/people/elicoatl/

X
Close

Link to this photo

ARKive species - Santa Catalina Island rattlesnake (Crotalus catalinensis) Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.

Read more about

X
Close

MyARKive

MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.

Play the Team WILD game:

Team WILD, an elite squadron of science superheroes, needs your help! Your mission: protect and conserve the planet’s species and habitats from destruction.

Conservation in Action

Which species are on the road to recovery? Find out now »

This species is featured in:

Learn more about the world’s snakes on our topic page.

Help us share the wonders of the natural world. Donate today!

Blog