Amblyrhynchus cristatus ssp. albemarlensis
|Scientific Name:||Amblyrhynchus cristatus ssp. albemarlensis|
|Species Authority:||Eibl-Eibesfeldt, 1962|
|Red List Category & Criteria:||Vulnerable B2ab(iii)c(iv) ver 3.1|
|Assessor(s):||Nelson, K., Snell, H. & Wikelski, M.|
|Reviewer(s):||Hudson, R. & Alberts, A. (Iguana Red List Authority)|
Amblyrhynchus cristatus albemarlensis is endemic to the Galápagos Islands, Ecuador. This subspecies occurs on Crossman and Tortuga islets (Isabela Island) with the population being concentrated in four major areas. Total extent of occurrence is less than 5,000 km² and area of occupancy is estimated to be less than 500 km². The main threats to the population are predation by introduced species (dogs, cats, rats and pigs) and habitat loss. The effects of El Niño also cause periodic population declines.
|Range Description:||The marine iguana occurs on the Galápagos Islands. A. c. albemarlensis is restricted to Crossman and Tortuga Islets off Isabela Island. Extent of occurrence is estimated at less than 5,000 km² and area of occupancy at less than 500 km². Average generation length is five years for females and 12 years for males.|
|FAO Marine Fishing Areas:|
Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The total population of A. c. albemarlensis is estimated at between 20,500–40,000 individuals. Recruitment appears to be zero in all subpopulations on the west and north side of Isabela (Los Cañones, Bahia Urbina, Muñeco and Punta Albermarle), probably because of introduced predators.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||A. cristatus is 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 the A. cristatus population. The main threats to A. c. albemarlensis are declining habitat quality and predation by introduced species (cats, dogs, rats and pigs).|
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 species include: further surveys for the subspecies, taxonomic research, research into factors limiting the population size, habitat and limiting factor management and control of introduced feral predators.
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. albemarlensis. The IUCN Red List of Threatened Species 2004: e.T44173A10867894.Downloaded on 25 July 2016.|
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