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ISSN 2307-8235 (online)
IUCN 2008: T1086A3222951
Amblyrhynchus cristatus, Fernandina Marine Iguana
Assessment by: Nelson, K., Snell, H. & Wikelski, M.
View on www.iucnredlist.org
Citation: Nelson, K., Snell, H. & Wikelski, M. 2004. Amblyrhynchus cristatus. The IUCN Red List of
Threatened Species 2004: e.T1086A3222951.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
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THE IUCN RED LIST OF THREATENED SPECIES™
Taxonomy
Kingdom
Phylum
Class
Order
Family
Animalia
Chordata
Reptilia
Squamata
Iguanidae
Taxon Name: Amblyrhynchus cristatus Bell, 1825
Infra-specific Taxa Assessed:
• Amblyrhynchus cristatus ssp. albemarlensis
• Amblyrhynchus cristatus ssp. cristatus
• Amblyrhynchus cristatus ssp. hassi
• Amblyrhynchus cristatus ssp. mertensi
• Amblyrhynchus cristatus ssp. nanus
• Amblyrhynchus cristatus ssp. sielmanni
• Amblyrhynchus cristatus ssp. venustissimus
Common Name(s):
• English:
• French:
• Spanish:
Fernandina Marine Iguana, Galapagos Marine Iguana, Galápagos Marine Iguana, Marine
Iguana, Sea Iguana
Amblyrhynche à crête, Iguane marin
Iguana Marina
Assessment Information
Red List Category & Criteria:
Vulnerable B2ac(iv) ver 3.1
Year Published:
2004
Date Assessed:
April 30, 2004
Annotations:
Needs Updating
Justification:
The marine iguana Amblyrhynchus cristatus is endemic to the Galápagos Islands, Ecuador. The
population occurs as ten subpopulations on separate islands in the range. Total extent of occurrence is
less than 5,000 km² and area of occupancy is estimated to be less than 500 km². Total population size is
unknown, however, El Niño effects are known to cause periodic declines in population (at least 85%
mortality). In addition to this, the population is threatened by pollution (e.g., oil spills) and predation by
exotic species on the islands.
Previously Published Red List Assessments
1996 – Vulnerable (VU)
1994 – Rare (R)
1990 – Rare (R)
1988 – Rare (R)
1986 – Rare (R)
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
1
Geographic Range
Range Description:
The marine iguana occurs on the Galápagos Islands of Baltra, Daphne, Darwin, Marchena, Pinzon,
Rabida, Santa Fe, Seymor, Sin Nombre and Wolf. Extent of occurrence is estimated at less than 5,000
km² and area of occupancy at less than 500 km². Average generation length is 5 years for females and 12
years for males.
Country Occurrence:
Native: Ecuador (Galápagos)
FAO Marine Fishing Areas:
Native: Pacific - southeast
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
2
Population
The global population size is currently unknown. Although the island subpopulations listed below are
currently classified as A. cristatus, there has been no attempt to evaluate these subpopulations for
subspecific status (i.e., they may not all be A. cristatus). Seven of these islands with supposed A.
cristatus subpopulations have never been surveyed or studied. Numbers of iguanas in each of the
subpopulations are estimated at:
Marchena = 4,000–10,000; Rabida = 1,000–2,000; Santa Fe = 15,000–30,000; Baltra = unknown; Daphne
= unknown; Darwin = unknown; Pinzon = unknown; Seymor = 300? Sin Nombre = unknown; Wolf =
unknown.
Current Population Trend: Unknown
Habitat and Ecology (see Appendix for additional information)
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.
Systems: Terrestrial, Marine
Threats (see Appendix for additional information)
El Niño causes periodic dramatic (> 85%) mortality. The 2001 "Jessica" oil spill had a particularly severe
immediate effect on the Santa Fe subpopulation, comparable to the 85% mortality caused by el Niño
events. Introduced predators may be having a negative effect on the Baltra subpopulation.
Conservation Actions (see Appendix for additional information)
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 of the islands, taxonomic
and genetic research, and monitoring of the population.
The seven marine iguana subspecies described to date have been based on morphology. The taxonomic
status of the ten subpopulations of A. cristatus is unclear. Taxonomic/genetic research is recommended
for the different island subpopulations to establish whether any of them should be reclassified.
Additionally, the status of seven of the ten subpopulations is unknown. Populations on different islands
face different threats and should be included in future surveys.
Credits
Assessor(s):
Nelson, K., Snell, H. & Wikelski, M.
Reviewer(s):
Hudson, R. & Alberts, A. (Iguana Red List Authority)
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
3
Bibliography
Baillie, J. and Groombridge, B. (eds). 1996. 1996 IUCN Red List of Threatened Animals. pp. 378.
International Union for Conservation of Nature, Gland, Switzerland.
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.
Groombridge, B. (ed.). 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and
Cambridge, UK.
IUCN. 1990. IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.
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.
IUCN Conservation Monitoring Centre. 1986. 1986 IUCN Red List of Threatened Animals. IUCN, Gland,
Switzerland and Cambridge, UK.
IUCN Conservation Monitoring Centre. 1988. IUCN Red List of Threatened Animals. IUCN, Gland,
Switzerland and Cambridge, UK.
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
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
4
reproductive strategies. Animal Behaviour 52: 581-596.
Citation
Nelson, K., Snell, H. & Wikelski, M. 2004. Amblyrhynchus cristatus. The IUCN Red List of Threatened
Species 2004: e.T1086A3222951. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
Disclaimer
To make use of this information, please check the Terms of Use.
External Resources
For Images and External Links to Additional Information, please see the Red List website.
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
5
Appendix
Habitats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Habitat
Season
Suitability
Major
Importance?
9. Marine Neritic -> 9.1. Marine Neritic - Pelagic
-
Suitable
-
10. Marine Oceanic -> 10.1. Marine Oceanic - Epipelagic (0-200m)
-
Suitable
-
12. Marine Intertidal -> 12.1. Marine Intertidal - Rocky Shoreline
-
Suitable
-
12. Marine Intertidal -> 12.4. Marine Intertidal - Mud Flats and Salt Flats
-
Suitable
-
Threats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Threat
Timing
Scope
Severity
Impact Score
8. Invasive & other problematic species & genes ->
8.1. Invasive non-native/alien species -> 8.1.1.
Unspecified species
Ongoing
-
-
-
Stresses:
2. Species Stresses -> 2.1. Species mortality
Ongoing
-
Stresses:
2. Species Stresses -> 2.1. Species mortality
Ongoing
-
Stresses:
1. Ecosystem stresses -> 1.2. Ecosystem degradation
9. Pollution -> 9.2. Industrial & military effluents ->
9.2.1. Oil spills
11. Climate change & severe weather -> 11.4. Storms
& flooding
-
-
-
-
Conservation Actions in Place
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Actions in Place
In-Place Land/Water Protection and Management
Occur in at least one PA: Yes
In-Place Education
Included in international legislation: Yes
Subject to any international management/trade controls: Yes
Research Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
6
Research Needed
1. Research -> 1.1. Taxonomy
1. Research -> 1.2. Population size, distribution & trends
3. Monitoring -> 3.1. Population trends
© The IUCN Red List of Threatened Species: Amblyrhynchus cristatus – published in 2004.
http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1086A3222951.en
7
The IUCN Red List Partnership
The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species
Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership. The IUCN
Red List Partners are: BirdLife International; Botanic Gardens Conservation International; Conservation
International; Microsoft; NatureServe; Royal Botanic Gardens, Kew; Sapienza University of Rome; Texas
A&M University; Wildscreen; and Zoological Society of London.
THE IUCN RED LIST OF THREATENED SPECIES™