Crotalus catalinensis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Viperidae

Scientific Name: Crotalus catalinensis Cliff, 1954
Common Name(s):
English Santa Catalina Island Rattlesnake

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(v) ver 3.1
Year Published: 2007
Date Assessed: 2007-03-01
Assessor(s): Avila Villegas, H., Frost, D.R. & Arnaud, G.
Reviewer(s): Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)
Listed as Critically Endangered because it is known only from one location: Santa Catalina Island in the Gulf of California, Mexico. The species' highly restricted range, the recent past presence of feral cats, the persecution for illegal trade, the killing by occasional encounters with visitors to the island and the rubbish left by them; its vulnerability caused by the fact that 70% of its diet is composed of the only rodent species on the island, all qualify it for the Critically Endangered category.

Geographic Range [top]

Range Description:This species is endemic to Isla Santa Catalina, a 40 km2 island in the Gulf of California, off the coast of Loreto, in Mexico (Campbell and Lamar 1989).
Countries occurrence:
Mexico (Baja California Sur)
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:It was formerly a common species, but has probably declined, principally due to over-collecting. Abundance data gathered between 2003 and 2004 fluctuated between 0.23 (one snake every four person-hours) in June to 2.11 (two snakes per person-hour) in August (H. Avila-Villegas pers. comm.).
Current Population Trend:Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:The island topography is composed of rocky hillsides separated by wide and narrow sandy arroyos (dry creeks) bearing the typical Sonoran Desert vegetation. This species occurs mainly in heavily-vegetated arroyos, but can also be found on rocky and scrubby hillsides, beneath roots and rocks or even in open areas of sandy soils. It is mainly nocturnal and can be easily found and caught. Most of its diet (70%) is composed of the endemic mouse Peromyscus slevini, the only ground mammal species on the island.

Threats [top]

Major Threat(s): The main threat to this species is the loss of individuals by killing and illegal collection. "Pit fall" traps have been found on the island, and some fishermen have observed people collecting reptiles in bags. Other fisherman have allegedly taken people to the island to collect the species (what they get paid equals their profits in a week of hard work fishing). Santa Catalina Island is home to 10 reptile species, of which seven are endemic (Grismer 2002). Insular endemic species are the most wanted in the illegal trade market, hence, are the more threatened (Mellink 1995). Its passive behaviour makes it easy to catch or kill. Population declines of its main prey, P. slevini is also an important threat. A population of feral cats formerly invaded the island. G. Arnaud and Hector Avila-Villegas observed several remains of C. catalinensis in the scats (H. Avila-Villegas pers. comm. 2007). These cats were eradicated in 2002 (J. Donlan pers. comm. to H. Avila-Villegas).

Conservation Actions [top]

Conservation Actions: Although cats have been eradicated from the island, there is a need to ensure that they do not recolonize Isla Santa Catalina. There is a need to monitor populations and to prevent over-collection of this restricted range species.

Classifications [top]

0. Root -> 6. Rocky areas (eg. inland cliffs, mountain peaks)
8. Desert -> 8.1. Desert - Hot
2. Land/water management -> 2.1. Site/area management
2. Land/water management -> 2.2. Invasive/problematic species control
2. Land/water management -> 2.3. Habitat & natural process restoration
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management
3. Species management -> 3.1. Species management -> 3.1.2. Trade management
4. Education & awareness -> 4.3. Awareness & communications

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
In-Place Species Management
In-Place Education
5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.1. Intentional use (species is the target)
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.3. Persecution/control
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

6. Human intrusions & disturbance -> 6.1. Recreational activities
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.2. Species disturbance

8. Invasive and other problematic species, genes & diseases -> 8.1. Invasive non-native/alien species/diseases -> 8.1.2. Named species [ Felis catus ]
♦ timing:Past, Unlikely to Return    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.2. Competition

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
3. Monitoring -> 3.1. Population trends

♦  Pets/display animals, horticulture
 International : ✓ 

Bibliography [top]

Armstrong, B.L. and Murphy, J.B. 1979. The natural history of Mexican rattlesnakes. University of Kansas Museum Natural History, Special Publications 1(5): 1-88.

Avila-Villegas, H. 2005. Aspectos ecológicos de la serpiente de cascabel de la Isla Santa Catalina Crotalus catalinensis, Golfo de California, México. Tesis de Maestría. Centro de Investigaciones Biológicas del Noroeste.

Avila-Villegas, H. 2007. Crotalus catalinensis (Santa Catalina Island Rattlesnake). Winter activity. Herpetological Review 37(4): 476.

Avila-Villegas, H., Martins, M. and Arnaud, G. 2007. Feeding ecology of the endemic rattleless rattlesnake, Crotalus catalinensis, of Isla Santa Catalina, Gulf of California, Mexico. Copeia 2007(1): 80-84.

Avila-Villegas, H., Tejas, A., Torres, F. and Arnaud, G. 2005. Crotalus catalinensis (Santa Catalina Island Rattlesnake). Diet and mortality. Herpetological Review 36(3): 323.

Avila-Villegas, H., Venegas-Barrera, C.S. and Arnaud, G. 2004. Crotalus catalinensis (Santa Catalina Island Rattleless Rattlesnake). Diet. Herpetological Review 35(1): 60.

Beaman, K.R. and Wong, N. 2001. Crotalus catalinensis. Catalogue of American Amphibians and Reptiles 733: 1-4.

Campbell, J.A. and Lamar, W.W. 1989. The Venomous Reptiles of Latin America. Cornell University Press, Ithaca, New York.

Campbell, J.A. and Lamar, W.W. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock, Ithaca, New York and London, UK.

Cliff, F.S. 1954. Snakes on the islands in the Gulf of California, Mexico. Transactions of the San Diego Society of Natural History 9: 67-98.

Diario Oficial de la Federación. 1994. NORMA Oficial Mexicana NOM-059-ECOL-1994, que determina las especies y subespecies de flora y fauna silvestres terrestres y acuáticas en peligro de extinción, amenazadas, raras y las sujetas a protección especial, y que establece especificaciones para su : .

Diario Oficial de la Federación. 2002. Norma Oficial Mexicana NOM-059-SEMARNAT-2001, Protección ambiental-Especies nativas de México de flora y fauna silvestres-Categorías de riesgo y especificaciones para su inclusión, exclusión o cambio-Lista de especies en riesgo, 6 de marzo de 2002.

Dodd Jr., C.K. 1984. Status, conservation and management. In: R.A. Seigel, J.T. Collins and S.S. Novak (eds) Snakes: Ecology and Evolutionary Biology, pp. 478-513. McGraw Hill, New York.

Foote, R. and MacMahon, J.H. 1977. Electrophoretic studies of rattlesnake (Crotalus and Sistrurus) venom: taxonomic implications. Comparative Biochemistry and Physiology 57B: 235-241.

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, Berkeley and Los Angeles, California.

IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: (Accessed: 12th September 2007).

Klauber, L.M. 1972. Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind. Second edition. University of California Press, Berkeley, California.

Mellink, E. 1995. The potential effect of commercialization of reptiles from Mexico’s Baja California Peninsula and its associated islands. Herpetological Natural History 3(1): 95-99.

Nogales, M., Martín, A., Tershy, B.R., Donlan, J., Veitch, D., Puerta, N., Wood, B. and Alonso, J. 2004. A review of feral cat eradication on islands. Conservation Biology 18(2): 310-319.

Stille, B. 1987. Dorsal scale microdermatoglyphics and rattlesnake (Crotalus and Sistrurus) phylogeny (Reptilia: Viperidae: Crotalinae). Herpetologica 43: 98-104.

Wood, B., Tershey, B.R., Hermosillo, M.A., Donlan, C.J., Sanchez, J.A., Keitt, B.S., Croll, D.A., Howard, G.R. and Biavaschi, N. 2002. Removing cats from islands in north-west México. In: C.R. Veitch and M.N. Clout (eds.) Turning the tide: the eradication of invasive species, pp. 374-380. IUCN SSC Invasive Species Specialist Group, IUCN, Gland, Switzerland and Cambridge, UK.

Citation: Avila Villegas, H., Frost, D.R. & Arnaud, G. 2007. Crotalus catalinensis. In: . The IUCN Red List of Threatened Species 2007: e.T64314A12764544. . Downloaded on 23 June 2018.
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