Overview
Mammal. Rattus exulans is the smallest of the three rats closely associated with humans. The fur is brown and tail length is only slightly longer or shorter than the combined head and body length . R. exulans is recognised as a predator of native insects, lizards and birds, browser of native flora and an agricultural pest. There appear to be no island groups reached by the Polynesians that did not receive R. exulans, although not all islands in a group were necessarily colonised. Can be used for fertilizer or mixed with vegetables make a fine stew
Common Names
Common Names in English:
Polynesian Rat
Description
Physical Description
Species Rattus exulans
Rattus exulans is the smallest of the three rats (Rattus rattus, R. norvegicus and ).asp">R. exulans) closely associated with humans. R. exulans has a slender body, pointed snout, large ears, and relatively small, delicate feet. A ruddy brown back contrasts with a whitish belly. Mature individuals are 4.5 to 6 inches long (11.5 to 15.0 cm) from the tip of the nose to the base of the tail and weigh 1.5 to 3 ounces (40 to 80 g). The tail has prominent fine scaly rings and is about the same length as the head and body. Female R. exulans have 8 nipples, compared to 10 and 12 nipples normally found on R. rattus and R. norvegicus, respectively (Tobin 1994). Morphology (skull size) of R. exulans has been shown to vary with latitude (Bergman's rule) and island size. This effect is most pronounced in the tropics (Atkinson and Towns 2001). A useful feature distinguishing them from other rats is the dark outer edge of the upper side of the hind foot near the ankle, the remainder of the foot being pale.
Habitat
R. exulans can live in a wide range of habitats including grassland, scrub and forest , however they do require adequate food supplies and shelter (especially in temperate latitudes ). They are able to climb trees easily where at least some of their feeding is done, but are not good swimmers. Snap trap success results have shown annual cycles in the abundance of R. exulans on Tiritiri Island in New Zealand. R. exulans are predominantly nocturnal , but become active just before dark during times of high density .
Typically found at an altitude of 0 to 2,400 meters (0 to 7,874 feet).[1]
Biome: agricultural areas, coastland, disturbed areas, natural forest , planted forests, range/grasslands, riparian zones, scrub/shrublands, urban areas, wetlands
Ecology: Atkinson and Towns (2001) report numerous species of New Zealand flora and fauna that are vulnerable to R. exulans. Most vulnerable amongst invertebrates are large, flightless species; especially those that need to descend to ground level for part of their life-cycle. Lizard populations have also been shown to increase following the removal of R. exulans. In Hawai'i and New Zealand there are examples of detrimental effects on both burrowing petrels and on red-tailed tropicbirds. In the Leeward Islands of Hawaii, it has been shown that predation on seabirds only becomes significant after storms have reduced the fruiting of food plants . Fatal attacks by R. exulans on adult Laysan albatrosses appear likely to be associated with the same factor . R. exulans is also known to browse native flora (including trees , shrubs , fungi, sedges, grasses, orchids and other herbaceous plants and lianes), although the magnitude of such effects has been difficult to determine (Source: SPREP). R. exulans is a major agricultural pest throughout Southeast Asia and the Pacific region. Crops damaged by this species include rice, maize, sugarcane, coconut, cacao, pineapple, and root crops.
Biology
Reproduction
A placental
mammal with dependent
young.In New Zealand on Tiritiri Island: Litter size
is usually between 4 and 9 with an average of 3 litters
per year, dependent on season
and food supply (Atkinson and Moller 1990). In Hawai'i: Females have an average of 4 litters per year, with a range
of 3 to 6 and an average of 4 young per litter (Tobin 1994).
In New Zealand: Gestation
19-21 days. Weaning
2-4 weeks. Sexual maturity 8-12 months, though maturity can be achieved during the same season as birth (Atkinson and Moller 1990). In captivity: Gestation minimum 23 days. Weaning 2-3 weeks. Sexual maturity 60-70 days (Tobin 1994). Total life is estimated between 12 - 15 months.
Taxonomy
- Domain:
Eukaryota
(
)
- Whittaker & Margulis,1978
- eukaryotes
- Kingdom:
Animalia
()
- Linnaeus, 1758
- animals
- Subkingdom:
Bilateria
()
- (Hatschek, 1888) Cavalier-Smith, 1983
- Branch:
Deuterostomia
()
- Grobben, 1908
- Infrakingdom:
Chordonia
()
- (Haeckel, 1874) Cavalier-Smith, 1998
- Phylum:
Chordata
()
- Bateson, 1885
- Chordates
- Subphylum:
Vertebrata
()
- Cuvier, 1812
- Vertebrates
- Infraphylum:
Gnathostomata
()
- Auct.
- Jawed Vertebrates
- Superclass:
Tetrapoda
()
- Goodrich, 1930
- Class:
Mammalia
()
- C. Linnaeus, 1758
- Mammals
- Subclass:
Theriiformes
()
- (Rowe, 1988) M.c. Mckenna & S.k. Bell, 1997
- Infraclass:
Holotheria
()
- (Wible Et Al., 1995) M.c. Mckenna & S.k. Bell, 1997
- Superlegion:
Trechnotheria
()
- Mckenna, 1975
- Legion:
Cladotheria
()
- Mckenna, 1975
- Sublegion:
Zatheria
()
- Mckenna, 1975
- Infralegion:
Tribosphenida
()
- (Mckenna, 1975) M.c. Mckenna & S.k. Bell, 1997
- Supercohort:
Theria
()
- (Parker & Haswell, 1897) M.c. Mckenna & S.k. Bell, 1997
- Cohort:
Placentalia
()
- (Owen, 1837) M.c. Mckenna & S.k. Bell, 1997
- Magnorder:
Epitheria
()
- (Mckenna, 1975) M.c. Mckenna & S.k. Bell, 1997
- Superorder:
Preptotheria
()
- (Mckenna, 1975) Mckenna, in Stucky & Mckenna, in Benton, Ed., 1993
- Grandorder:
Anagalida
()
- (Szalay & Mckenna, 1971) Mckenna, 1975
- Mirorder:
Simplicidentata
()
- (Weber, 1904) M.c. Mckenna & S.k. Bell, 1997
- Mirorder:
Simplicidentata
(
- Grandorder:
Anagalida
(
- Superorder:
Preptotheria
(
- Magnorder:
Epitheria
(
- Cohort:
Placentalia
(
- Supercohort:
Theria
(
- Infralegion:
Tribosphenida
(
- Sublegion:
Zatheria
(
- Legion:
Cladotheria
(
- Superlegion:
Trechnotheria
(
- Infraclass:
Holotheria
(
- Subclass:
Theriiformes
(
- Class:
Mammalia
(
- Superclass:
Tetrapoda
(
- Infraphylum:
Gnathostomata
(
- Subphylum:
Vertebrata
(
- Phylum:
Chordata
(
- Infrakingdom:
Chordonia
(
- Branch:
Deuterostomia
(
- Subkingdom:
Bilateria
(
- Kingdom:
Animalia
(
Notes
Name Status: Accepted Name . Latest taxonomic scrutiny: 05-Feb-2001
Similar Species
Members of the genus Rattus
There are approximately 158 species in this genus. Here are just 100 of them:
R. adustus (Sunburned Rat) · R. alexandrinus · R. annandalei (Annandale's Rat) · R. argentiventer (Rice-Field Rat) · R. argentiventer argentiventer (Rice-Field Rat) · R. baluensis (Summit Rat) · R. blanfordi · R. bontanus (Bonthain Rat) · R. bowersi · R. burrus (Nonsense Rat) · R. canus · R. colletti (Dusky Rat) · R. coucha · R. coucha silaceus · R. coxinga · R. cutchicus rajput · R. doboensis · R. edwardsi · R. eha · R. elaphinus (Sula Rat) · R. enganus (Enggano Rat) · R. everetti (Philippine Forest Rat) · R. exulans (Polynesian Rat) · R. exulans aitape · R. exulans concolor · R. exulans hawaiiensis · R. feliceus (Spiny Ceram Rat) · R. flavipectus · R. foramineus (Hole Rat) · R. fulvescens · R. fuscipes (Bush Rat) · R. fuscipes assimilis · R. fuscipes coracius · R. fuscipes fuscipes (Bush Rat) · R. fuscipes greyi · R. fuscipes greyii · R. giluwensis (Giluwe Rat) · R. hainaldi (Hainald's Rat) · R. hawaiiensis · R. hoffmanni (Hoffmann's Sulawesi Rat) · R. hoogerwerfi (Hoogerwerf's Rat) · R. hoxaensis · R. jobiensis (Japen Rat) · R. koopmani (Koopman's Rat) · R. koratensis · R. korinchi (Korinch's Rat) · R. legata · R. leucopus (Mottle-Tailed Rat) · R. leucopus cooktownensis · R. leucopus leucopus (Mottle-Tailed Rat) · R. losea (Lesser Rice-Field Rat) · R. losea losea (Lesser Rice-Field Rat) · R. lugens (Mentawai Rat) · R. lutreolus (Australian Swamp Rat) · R. lutreolus cambricus · R. lutreolus lacus · R. lutreolus lutreolus · R. lutreolus velutinus · R. macleari (Christmas Island Rat) · R. marmosurus (Opossum Rat) · R. meltada · R. mindorensis (Mindoro Black Rat) · R. mollicomulus (Little Soft-Furred Rat) · R. montanus (Nillu Rat) · R. mordax (Eastern Rat) · R. morotaiensis (Molaccan Prehensile-Tailed Rat) · R. muelleri · R. namaquensis · R. natalensis · R. nativitatis (Christmas Island Rat) · R. niobe · R. nitidus (Himalayan Field Rat) · R. nitidus nitidus · R. nitidus obsoletus · R. niviventer · R. norvegicus (Norway Rat) · R. norvegicus albinicus (Norway Rat) · R. norvegicus albino · R. norvegicus caraco · R. norvegicus domestica · R. norvegicus norvegicus (Norway Rat) · R. norvegicus socer · R. norvegicus var. albus (Norway Rat) · R. norvergicus · R. norvergicus albinus · R. novaeguineae (Papua New Guinea Rat) · R. osgoodi (Osgood's Rat) · R. owiensis · R. palmarum (Palm Rat) · R. pelurus (Peleng Rat) · R. praetor (Variable Spiny Rat) · R. ranjiniae (Kerala Rat) · R. rattoides · R. rattus (Black Rat) · R. rattus alexadrinus · R. rattus alexandrinus (Black Rat) · R. rattus andamanensis · R. rattus arboreus · R. rattus argentiventer (Rice-Field Rat) · R. rattus brunneus
More Info
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Further Reading
- A synopsis of the mammalian fauna of the Philippine Islands / Lawrence R. Heaney [et al.]. [Chicago, Ill.]: Field Museum of Natural History, c1998. ENG url p. 42.
- Banks, R. C., R. W. McDiarmid, A. L. Gardner, and W. C. Starnes 2003. Checklist of Vertebrates of the United States, the U.S. Territories, and Canada.
- Bulletin - United States National Museum. Washington: Smithsonian Institution Press, [etc.];1877-1971. ENG url p. 462.
- Checklist of Palaearctic and Indian mammals 1758 to 1946 / by J.R. Ellerman and T.C.S. Morrison-Scott. London: BM(NH), 1951. ENG url p. 580, p. 590, p. 590.
- Entomological news. [Philadelphia]American Entomological Society, 1925- ENG url p. 27, p. 28.
- Invasive Species in the Pacific: A Technical Review and Draft Regional Strategy (2000) (SPREP)
- Mammalian diversity on Mount Isarog: a threatened center of endemism on southern Luzon Island, Philippines / Lawrence R. Heaney [et al.]. [Chicago, Ill.]: Field Museum of Natural History, c1999. ENG url p. 45, p. 56.
- Results of the first Joint US-USSR Central Pacific Expedition (BERPAC): Autumn 1988 / John F. Turner, [et al.]; P.A. Nagel, editor. Washington, DC: U.S. Fish and Wildlife Service, 1992. ENG url p. 141, p. 149.
- Supplement to Chasen (1940) A Handlist of Malaysian Mammals: containing a generic synonymy and a complete index / By J.R. Ellerman & T.C.S. Morrison-Scott. London: BM(NH), 1955. ENG url p. 36.
- The Mammals and birds of Camiguin Island, Philippines, a distinctive center of biodiversity / Lawrence R. Heaney, editor. Chicago, Ill.: Field Museum of Natural History, 2006. ENG url p. 71.
- The Natural history of Enewetak Atoll / edited by Dennis M. Devaney [et al.]; prepared by Office of Scientific and Technical Information, U.S. Department of Energy. Oak Ridge, Tenn.: U.S. Dept. of Energy, Office of Energy Research, Office of Health and Environmental Research, Ecological Research Division, c1987. ENG url p. 203, p. 204, p. 214, p. 215, p. 220, p. 333, p. 35.
- The distribution and ecology of mammals on Leyte, Biliran and Maripipi Islands, Philippines / Eric A. Rickart [et al.]. [Chicago, Ill.]: Field Museum of Natural History, c1993. ENG url p. 14, p. 49.
- The families and genera of living rodents / by J.R. Ellerman; with a list of named forms (1758-1936) by R.W. Hayman and G.W.C.Holt. London: British Museum, 1941. ENG url p. 187, p. 220, p. 645.
- The mammalian fauna on the islands at the northern tip of Sabah, Borneo / Shukor Md. Nor. Chicago, Ill.: Field Museum of Natural History, 1996. ENG url p. 48.
- The mammals of Mt. Kitanglad Nature Park, Mindanao, Philippines / Lawrence R. Heaney [et al.] Chicago, Ill.: Field Museum of Natural History, 2006. ENG url p. 46, p. 47, p. 48, p. 55.
- Wilson, Don E., and DeeAnn M. Reeder, eds. 1993. Mammal Species of the World: A Taxonomic and Geographic Reference, 2nd ed., 3rd printing. Smithsonian Institution Press. Washington, DC, USA. xviii + 1207. ISBN: 1-56098-217-9.
Notes
Contributors
- Baillie, J. 1996. In IUCN 2008. 2008 IUCN Red List of Threatened Species. IUCNRedList.org. Downloaded July 19, 2008.
- Bisby, F.A., Y.R. Roskov, M.A. Ruggiero, T.M. Orrell, L.E. Paglinawan, P.W. Brewer, N. Bailly, J. van Hertum, eds (2007). Species 2000 & ITIS Catalogue of Life: 2007 Annual Checklist. Species 2000: Reading, U.K.
- Global Biodiversity Information Facility. Accessed November 18, 2007. http://www.gbif.org Mediated distribution data from 14 providers.
Data Sources
Accessed through GBIF Data Portal November 18, 2007:
- Bernice Pauahi Bishop Museum, Bishop Museum Natural History Specimen Data
- Field Museum, Mammal specimens
- Louisiana State University Museum of Natural Science, Mammal specimens
- Museum of Texas Tech University
- , Mammal specimens
- Museum of Vertebrate Zoology, Terrestrial vertebrate specimens
- OZCAM
- Provider, Online Zoological Collections of Australian Museums
- Royal Ontario Museum, Mammal specimens
- University of Kansas Biodiversity Research Center, Mammal Collection
- University of Minnesota Bell Museum of Natural History, Mammal specimens
Identifiers
- Biodiversity Heritage Library NamebankID: 2481319
- Catalogue of Life Accepted Name Code: ITS-180364
- Global Biodiversity Information Facility Taxonkey: 13808322
- Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 180364
- IUCN ID: 19330
- Natural Heritage Network Species Identifier: AMAFF21030
- Zipcode Zoo Species Identifier: 10500
Footnotes
- Mean = 48.910 meters (160.466 feet), Standard Deviation = 954.330 based on 411 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
