Amblyrhynchus cristatus ssp. mertensi
|Scientific Name:||Amblyrhynchus cristatus ssp. mertensi|
|Species Authority:||Eibl-Eibesfeldt, 1962|
|Red List Category & Criteria:||Endangered A2ce; C2b ver 3.1|
|Assessor(s):||Nelson, K., Snell, H. & Wikelski, M.|
|Reviewer(s):||Hudson, R. & Alberts, A. (Iguana Red List Authority)|
The marine iguana Amblyrhynchus cristatus is endemic to the Galápagos Islands, Ecuador. A. c. mertensi is found on San Cristobal and Santiago Islands. Extent of occurrence is estimated at less than 100 km² and area of occupancy at less than 10 km². San Cristobal Island was the site of a shipwreck in January 2001, which spilled diesel oil/bunker fuel along the southwest coast of the island.
Although A. c. mertensi is found on two different islands, the population is low on Santiago and unknown (but probably low) on San Cristobal. The 2001 oil spill is likely to have caused high (around 60%) mortality to the San Cristobal population, based on the location of the spill and its effects on other nearby islands (Santa Fe). feral dogs and cats associated with the human population pose an ongoing threat for marine iguanas on San Cristobal.
|Range Description:||A. c. mertensi occurs on San Cristobal and Santiago Islands. Extent of occurrence is estimated at less than 1000 km² and area of occupancy at less than 10 km².|
|FAO Marine Fishing Areas:|
Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Average generation length is five years for females and 12 years for males. The total population is not known.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The world's only marine lizard species. Adults and juveniles occur on rocky coast and intertidal zones. Adult females can be found nesting up to 2 km inland and adult males can be found in marine waters, up to depths of 20 m.|
|Major Threat(s):||El Niño causes periodic dramatic (> 85%) mortality in A. cristatus. In 2000 extensive habitat contamination occurred after an oil spill. The population declined as a result of this spill. A. c. mertensi is also inder threat from predation by introduced species.|
A. cristatus is included on CITES Appendix II. It is under "Special Law" in the Galápagos and occurs in three protected areas: Galápagos National Park and National Marine Reserve; Galápagos Islands Man and Biosphere Reserve (UNESCO); and Galápagos Islands World Heritage Site.
Conservation actions recommended for the subspecies include: further surveys for the subspecies, taxonomic and limiting factor research, public education, control of introduced predators on the island, and monitoring of the population and habitat.
Carpenter, C. 1966. The marine iguana of the Galápagos Islands, its behavior and ecology. Proceedings of the California Academy of Sciences 34(6): 329-376.
IUCN. 1994. Iguanidae and Varanidae Conservation Assessment and Management Plan (CAMP) Taxon Reports. IUCN Conservation Breeding Specialist Group.
IUCN. 2004. 2004 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 23 November 2004.
Kruuk, H. and Snell, H. 1981. Prey selection by feral dogs from a population of marine iguanas (Amblyrhynchus cristatus). Journal of Applied Ecology 18: 197-204.
Laurie, A. 1981. Marine iguana census. Unpublished document.
Laurie, A. 1983. Marine iguanas in the Galápagos. Oryx 17: 18-25.
Laurie, A. 1987. Marine iguana project to continue. Noticas de Galápagos 45: 19-22.
Laurie, A. and Brown, D. 1990a. Population biology of marine iguanas (Amblyrhynchus cristatus). I. Changes infecundity related to a population crash. Journal of Animal Ecology. 59: 515-528.
Laurie, A. and Brown, D. 1990b. Changes in annual survival rates and the effects of size, sex, age and fecundity in a population crash. Journal of Animal Ecology 59: 529-544.
Laurie, A. and Brown, D. 1990c. Population biology of marine iguanas (Amblyrhynchus cristatus). III. Factors affecting survival. Journal of Animal Ecology. 59: 545-568.
Merlen, G. 1984. The 1982-83 El Niño: Some of its consequences for Galápagos wildlife. Noticas de Galápagos 41: 8-15.
Rassmann, K., Tautz, D., Trillmich, F. and Gliddon, C. 1997. The microevolution of the Galápagos marine iguana Amblyrhynchus cristatus assessed by nuclear and mitochondrial genetic analyses. Molecular Ecology 6: 437-452.
Trillmich, K. 1983. The mating system of the Marine Iguana (Amblyrhynchus cristatus). Z. Tierpsychology 63: 141-172.
Wikelski, M. and Trillmich, F. 1997. Body size and sexual size dimorphism in marine iguanas fluctuate as a result of opposing natural and sexual selection: an island comparison. Evolution 51(3): 922-936.
Wikelski, M., Carborne, C. and Trillmich, F. 1996. Lekking in marine iguanas: female grouping and male reproductive strategies. Animal Behaviour 52: 581-596.
|Citation:||Nelson, K., Snell, H. & Wikelski, M. 2004. Amblyrhynchus cristatus ssp. mertensi. The IUCN Red List of Threatened Species 2004: e.T44176A10856296.Downloaded on 29 August 2016.|