Clipperton (27176)
French Polynesia, Oceania
Site overview
KBA status: confirmed
Global KBA criteria: B1, D1a
Year of last assessment: 2012
National site name: Clipperton
Central coordinates: Latitude: 10.3038, Longitude: -109.2185
System: marine, terrestrial
Elevation (m): 0 to 29
Area of KBA (km2): 8.81057
KBA classification: Global
Legacy site: Yes
Site details
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs.
Delineation rationale: 2012-12-17 (BL Secretariat): original polygon clipped to hi-res coastline (marine areas removed) following identification in October 2012 of new marine IBA offshore this site; site area consequently changed from 1700 ha to 881 ha.
Threats
Summary of threats to biodiversity at KBA: Climate change is listed as the third greatest threat to seabirds globally (Croxall et al. 2012). It is predicted to decrease the land area of low-lying Pacific islands and cause complete inundation of some islands (IPCC 1997) leading to substantial population declines (Hatfield et al. 2012). Although no current data or predictions are available specific to this IBA climate change represents a potential threat to this site owing to the risk of future sea level rise leading to inundation, and increased frequency of storms. Invasive Alien Species represent the greatest threat to seabirds globally (Croxall et al. 2012), causing adult mortality and reduced productivity owing to egg and chick predation. Clipperton was inhabited between 1892 and 1917 introducing feral pigs. Feral pigs caused a sharp decline in the populations of masked and brown booby with only 150 and 500 respectively left in 1958 (Stager, 1964). Stager during his visit in 1958 shot all pigs present (58); this has lead to the rebuilding of the booby numbers (Pitman et al. 2005). During Pitman and others visit to Clipperton in 2000 Black rat was reported and evidence of impact on smaller breeding seabirds noted (such as Sooty Terns where only two eggs were found). Pitman and others (2005) predict the loss of smaller seabirds breeding on Clipperton due to predation in the future and a possible change to the structure of the larger bodied seabird colonies due to rat caused changes in vegetation. Polynesian Rat is ubiquitous throughout the Pacific (IUCN SSC Invasive Species Specialist Group 2012) and is assumed to be present. Polynesian Rat has been recorded predating adult seabirds as well as eggs and chicks (Kepler 1967). They have precipitated island extinctions in small-bodied, ground-nesting seabirds, but their impacts on larger or arboreal nesting seabirds appear to be lower (Atkinson 1985, Jones et al. 2008). Invasive Alien Species can potentially cause declines in seabird colonies, and ungulates can exacerbate the threat from other invasive mammals through habitat modification (Atkinson 1985, Rodríguez et al. 2006, Jones et al. 2008, Duffy 2010). Overall, invasive mammals are known to be present and are having a limiting effect on seabirds, or causing population declines.
Additional information
References: Atkinson, I. A. E. (1985) The spread of commensal species of Rattus to oceanic islands and their effect on island avifaunas. Pages 35-81 in P. J. Moors, editor. Conservation of island birds. International Council for Bird Preservation, Cambridge, United Kingdom. Croxall, J. P., Butchart, S. H. M., Lascelles, B., Stattersfield, A. J., Sullivan, B., Symes, A. and Taylor, P. (2012) Seabird conservation status, threats and priority actions: a global assessment. Bird Conservation International 22: 1-34. Duffy, D. C. (2010) Changing Seabird Management in Hawai‘i: from exploitation through management to restoration. Waterbirds 33: 193-207. Hatfield, J. S., Reynolds, M. H., Seavy, N. E. and Krause, C. M. (2012) Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise. Conservation Biology 26: 667-678. IPCC – Intergovernmental Panel On Climate Change (1997) The Regional Impacts of Climate Change. An Assessment of Vulnerability. Geneva. IUCN SSC Invasive Species Specialist Group (2012) Rattus exulans. Global Invasive Species Database. Downloaded from http://www.issg.org/database/species/ecology.asp?si=170&fr=1&sts=sss on 8th October 2012. Jones, H. P., Tershy, B. R., Zavaleta, E. S., Croll, D. A., Keitt, B. S., Finkelstein, M. E. and Howald, G. R. (2008) Severity of the effects of invasive rats on seabirds: a global review. Conservation Biology 22: 16-26. Kepler, B. (1967) Polynesian rat predation on nesting Laysan Albatrosses and other Pacific seabirds. Auk 84: 426-430. Pitman, R., Balance, L. and Bost, C. (2005) Clipperton Island: pig sty, rat hole and booby prize. Marine Ornithology, 33:193-194. Rodríguez, C., Torres, R. and Drummond, H. (2006) Eradicating introduced mammals from a forested tropical island. Biological Conservation 130: 98-105. Stager, K.E. (1964) The birds of Clipperton Island, eastern Pacific. Condor, 66: 357-371.