Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-10T07:25:03.738Z Has data issue: false hasContentIssue false

Rediscovery of rodents (Genus Nesoryzomys) considered extinct in the Galápagos Islands

Published online by Cambridge University Press:  24 April 2009

Darin S. Carroll
Affiliation:
Department of Biology, Angelo State University, San Angelo, TX 76909, USA. Current address: Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
Cody W. Edwards
Affiliation:
Department of Biology, Angelo State University, San Angelo, TX 76909, USA. Current address: Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The history of the endemic rodents of the Galápagos Islands began with the discovery of the first Galápagos rice rat species by Charles Darwin in 1835 and the last species was described as recently as 1980. Unfortunately, of the seven described species known to occur in the islands during the past 150 years, only two were known to be extant to 1995. Since then, two expeditions to the Galápagos Islands have been conducted to survey endemic rodent populations. The first confirmed the existence of a small endemic rice rat, Nesoryzomys fernandinae, on Fernandina, known previously only from owl pellet remains found in 1979. In 1997, an expedition to Santiago revealed a population of the larger rice rat N. swarthi, a species collected alive only once in 1906 and considered extinct in all recent literature on the Galápagos Islands. Survey efforts on Santa Cruz resulted only in the collection of introduced rodent species (Rattus rattus, R. norvegicus and Mus musculus). The extant species of native rodents in the Galápagos Islands now number four: N. narboroughi and N. fernandinae on Fernandina; N. swarthi on Santiago; and Oryzomys bauri on Santa Fe. Three species are found on islands where no introduced rodents or cats occur, whereas only one (N. swarthi) co-exists with R. rattusand M. musculus. Nesoryzomys darwini and N. indefessus on Santa Cruz and O. galapagoensis on San Cristóbal are still considered extinct. Strategies for conservation should include monitoring islands for introduced rodents and cats, development of emergency plans in the event of introductions, and captive management.

Type
Research Article
Copyright
Copyright © Fauna and Flora International 2000

References

Allen, J.A. (1892) On a small collection of mammals from the Galápagos Islands, collected by Baur, Dr G.. Bulletin of the American Museum of Natural History, 4, 4750.Google Scholar
Balmford, A., Mace, G.M. & Leader-Williams, N. (1996) Designing the ark: setting priorities for captive breeding. Conservation Biology, 10, 719727.CrossRefGoogle Scholar
de Beaufort, F. (1963) Les cricétinés de Galépagos. Valeur dugenre Nesoryzomys. Mammalia, 27, 338340.Google Scholar
Brosset, A. (1963) Statut actuel des mammiferes des lies Galápagos. Mammalia, 27, 323338.Google Scholar
Cabrera, A. (1961) Catalogo de los mamiferos de America del Sur. Revista del Museo Argentino de Ciencieas Naturales ‘Bernardino Rivadavia’. Ciencias Zoologicas, 4, 309732.Google Scholar
Clark, D.A. (1984) Native land mammals. In Key Environments: Galápagos (ed. Perry, R.), pp. 225231. Pergamon, Oxford.Google Scholar
Clark, D.B. (1980) Population ecology of an endemic Neotropical island rodent: Oryzomys bauri of Santa Fe Island, Galápagos, Ecuador. journal of Animal Ecology, 49, 185198.CrossRefGoogle Scholar
Corbet, G.B. & Hill, J.E. (1980) A World List of Mammalian Species. British Museum (Natural History), London.Google Scholar
Corbet, G.B. & Hill, J.E. (1986) A World list of Mammalian Species, 2nd edn.British Museum (Natural History), London.Google Scholar
Dowler, R.C. & Carroll, D.S. (1996) The endemic rodents of Isla Fernandina: population status and conservation issues. Noticias de Galápagos, 57, 813.Google Scholar
Ebenhard, T. (1988) Introduced birds and mammals and their ecological effect. Swedish Wildlife Research, 13, 1107.Google Scholar
Ellerman, J.R. (1941) The Families and Genera of Living Rodents, vol. 2. British Museum (Natural History), London.Google Scholar
Gardner, A.L. & Patton, J.L. (1976) Karyotypic variation in oryzomyine rodents (Cricetinae) with comments on chromosomal evolution in the Neotropical cricetine complex. Occasional Papers of the Museum of Zoology, Louisiana State University, 49, 148.Google Scholar
Heller, E. (1904) Mammals of the Galápagos archipelago, exclusive of the Cetacea. Proceedings of the California Academy of Sciences, 3, 233251.Google Scholar
Hutterer, R. & Hirsch, U. (1980) Ein neuer Nesoryzomys von der Insel Fernandina, Galápagos. Bonner Zoologische Beiträge, 30, 276283.Google Scholar
Hutterer, R. & Oromí, P. (1993) La rata gigante de la Isla Santa Cruz, Galápagos: algunos datos y problemas. Resultados Cientificos del Proyecto Galápagos, Patrimonio de la Humanidad, Museo de Ciencias Naturales, Tenerife (TFMC), 4, 6376.Google Scholar
Iucn (1996) 1996 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland.Google Scholar
Key, G. & Munoz Heredia, E. (1994) Distribution and current status of rodents in the Galápagos. Noticias de Galápagos, 53, 2125.Google Scholar
Musser, G.G. & Carleton, M.D. (1993) Family Muridae. In Mammal Species of the World. A Taxonomic and Geographic Reference (eds Wilson, D. E. and Reeder, D. M.), pp. 501755. Smithsonian Institution Press, Washington, DC.Google Scholar
Niethammer, J. (1964) Contribution á la connaissance des mammiféres terrestres de L'ile Indefatigable (á Santa Cruz), Galápagos. Résultats de l'expédition allemande aux Galápagos 1962/63, No. VIII. Mammalia, 28, 593606.CrossRefGoogle Scholar
Nowak, R.M. (1999) Walker's Mammals of the World, 6th edn.The Johns Hopkins University Press, London.CrossRefGoogle Scholar
Orr, R.T. (1938) A new rodent of the genus Nesoryzomys from the Galápagos Islands. Proceedings of the California Academy of Sciences, Ser. 4, 23, 303306.Google Scholar
Orr, R.T. (1966) Evolutionary aspects of the mammalian fauna of the Galápagos. In The Galapagos (ed. Bowman, R. I.), pp. 276281. University of California, Berkeley, CA.Google Scholar
Osgood, W.H. (1929) A new rodent from the Galápagos Islands. Field Museum of Natural History, Zoological Series, 17, 2124.Google Scholar
Patton, J.L. & Hafner, M.S. (1983) Biosystematics of the native rodents of the Galápagos archipelago, Ecuador. In Patterns of Evolution in Galápagos Organisms (eds Bowman, R. I., Berson, M. and Leviton, A. E.), pp. 539568. AAAS Pacific Division, San Francisco, CA.Google Scholar
Patton, J.L., Yang, S.Y. & Myers, P. (1975) Genetic and morphologic divergence among introduced rat populations (Rattus rattus) of the Galápagos archipelago, Ecuador. Systematic Zoology, 24, 296310.CrossRefGoogle Scholar
Peterson, R.L. (1966) Recent mammal records from the Galápagos Islands. Mammalia, 30, 441445.CrossRefGoogle Scholar
Steadman, D.W. (1981) Vertebrate fossils in lava tubes in the Galápagos Islands, abstract. Proceedings of the 8th International Congress of Speleology, Vols. I and II, pp. 549550.Google Scholar
Steadman, D.W. & Ray, C.E. (1982) The relationships of Megaoryzomys curioi, an extinct cricetine rodent (Muroidea: Muridae) from the Galápagos Islands, Ecuador. Smithsonian Contributions to Paleontology, 51, 123.Google Scholar
Steadman, D.W., Stafford, T.W. Jr, Donahue, D.J. & Jull, A.J.T. (1991) Chronology of Holocene vertebrate extinction in the Galápagos Islands. Quaternary Research, 36, 126133.CrossRefGoogle Scholar
Steadman, D.W. & Zousmer, S. (1988) Galapagos: Discovery on Darwin's Islands. Smithsonian Institution Press, Washington, DC.Google Scholar
Thomas, O. (1899) Descriptions of new Neotropical mammals. Annals and Magazine of Natural History, Ser. 7, 4, 278288.CrossRefGoogle Scholar
Trillmich, F. (1986) The future of the Fernandina rice rats: extinction or captive breeding? Noticias de Galápagos, 44, 1516.Google Scholar
Waterhouse, G.R. (1839) The Zoology of the Voyage of HMS Beagle, under the Command of Captain Fitzroy, R. N., During the Years 1832 to 1836. Part 2. Mammalia. Smith, Elder and Co., London.Google Scholar
Wilson, D.E. & Reeder, D.M. (1993) Mammal Species of the World. A Taxonomic and Geographic Reference. Smithsonian Institution Press, Washington, DC.Google Scholar