Invasive Species Compendium

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Datasheet

Rattus tanezumi
(Asian house rat)

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Datasheet

Rattus tanezumi (Asian house rat)

Summary

  • Last modified
  • 02 July 2019
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Natural Enemy
  • Host Animal
  • Preferred Scientific Name
  • Rattus tanezumi
  • Preferred Common Name
  • Asian house rat
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Chordata
  •       Subphylum: Vertebrata
  •         Class: Mammalia
  • Summary of Invasiveness
  • Rattus tanezumi, morphologically indistiguishable from R. rattus, is considered native from Afghanistan to China, including Indochina. It is now widely introduced across the Indo-Malayan region and is...

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Pictures

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PictureTitleCaptionCopyright
Rattus tanezumi (Asian house rat); live adult.
TitleAdult
CaptionRattus tanezumi (Asian house rat); live adult.
Copyright©Yannick Chaval/Inra-CBGP/CERoPath
Rattus tanezumi (Asian house rat); live adult.
AdultRattus tanezumi (Asian house rat); live adult.©Yannick Chaval/Inra-CBGP/CERoPath
Rattus tanezumi (Asian house rat); adult. Dead specimen. (Note scale in cm)
TitleAdult
CaptionRattus tanezumi (Asian house rat); adult. Dead specimen. (Note scale in cm)
Copyright©Yannick Chaval/Inra-CBGP/CERoPath
Rattus tanezumi (Asian house rat); adult. Dead specimen. (Note scale in cm)
AdultRattus tanezumi (Asian house rat); adult. Dead specimen. (Note scale in cm)©Yannick Chaval/Inra-CBGP/CERoPath

Identity

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Preferred Scientific Name

  • Rattus tanezumi Temminck, 1844

Preferred Common Name

  • Asian house rat

International Common Names

  • English: Asian rat; common Philippine field rat; oriental house rat; tanezumi rat

Summary of Invasiveness

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Rattus tanezumi, morphologically indistiguishable from R. rattus, is considered native from Afghanistan to China, including Indochina. It is now widely introduced across the Indo-Malayan region and is also found in South Africa and western USA. It is an opportunistic omnivore and important agricultural pest of crops such as rice, coconut, banana and maize. An integrated ecologically-based pest management approach, that considers its habitat use, population dynamics and reproduction biology, would be appropriate to manage the impact of this species.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Chordata
  •             Subphylum: Vertebrata
  •                 Class: Mammalia
  •                     Order: Rodentia
  •                         Family: Muridae
  •                             Subfamily: Murinae
  •                                 Genus: Rattus
  •                                     Species: Rattus tanezumi

Notes on Taxonomy and Nomenclature

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Rattus tanezumi is a species comprising several phylogenetic lineages of the Rattus rattus complex (Aplin et al., 2011). The R. rattus complex comprises of four mtDNA lineages that are superficially alike. Under current taxonomy, populations with a 2n = 42 karyotype (or 2n = 40 in Sri Lanka) are regarded as R. tanezumi (Musser and Carleton, 2005). These include populations associated with mtDNA Lineages II, III and IV (Aplin et al., 2011).

Description

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R. tanezumi is a medium-sized murid rodent with a tail that is the same length or longer than the head and body. It is morphometrically indistinguishable from R. rattus. adults weigh 65 to 300 g, with a body length of 114-224 mm, a tail length of 110-231 mm, a hind foot length of 30-43 mm and an ear length of 16-25 mm (Stuart et al., 2008). The dorsal fur is usually some shade of brown, but may vary in colour from dark-brown to greyish-brown or reddish-brown (Heaney et al., 1998; Aplin et al., 2003). The belly fur is usually whitish, though often with some pale yellow or orange tipping, and sometimes with grey-based fur.

Distribution

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According to Aplin et al. (2011), the natural range for Lineages II and IV of R. tanezumi extends from eastern India through Myanmar, northern Laos and Vietnam, southern China and Taiwan, but populations are now widely distributed across the Indo-Malayan region, including the Philippines. Those associated with Lineage II also occur in Japan, Sri Lanka, Papua New Guinea, South Africa, and western USA. The range for Lineage III includes the Himalayan foothills of Pakistan and Nepal (Aplin et al., 2011).

Musser and Carleton (2005) report that R. tanezumi is also native to Afghanistan, Bangladesh, Bhutan, Cambodia, Korea and Thailand and is introduced in Indonesia, Malaysia, Philippines, Fiji and Papua New Guinea. According to Musser and Carleton (2005), the native status of R. tanezumi in Japan and Taiwan is unknown. However, Aplin et al. (2011) suggest that Lineage II rats (R. tanezumi) occurred naturally on Taiwan and dispersed to Japan during the late Holocene.

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

AfghanistanPresentNativeMusser and Carleton, 2005
BangladeshPresentNativeMusser and Carleton, 2005
BhutanPresentNativeMusser and Carleton, 2005
CambodiaPresentNativeMusser and Carleton, 2005
ChinaPresentNativeMusser and Carleton, 2005; Aplin et al., 2011
IndiaPresentNativeMusser and Carleton, 2005; Aplin et al., 2011
IndonesiaPresentIntroducedMusser and Carleton, 2005
JapanPresentIntroducedMusser and Carleton, 2005; Aplin et al., 2011Absent from Japanese fossil records until the late Holocene
Korea, DPRPresentNativeMusser and Carleton, 2005
Korea, Republic ofPresentNativeMusser and Carleton, 2005
LaosPresentNativeMusser and Carleton, 2005; Aplin et al., 2011
MalaysiaPresentIntroducedMusser and Carleton, 2005Most likely introduced to the Malay Peninsula
MyanmarPresentNativeAplin et al., 2011
NepalPresentNativeMusser and Carleton, 2005; Aplin et al., 2011; Adhikari et al., 2018
PakistanPresentNativeAplin et al., 2011
PhilippinesPresentIntroducedMusser and Carleton, 2005; Aplin et al., 2011
Sri LankaPresentIntroducedAplin et al., 2011
TaiwanPresentNativeMusser and Carleton, 2005; Aplin et al., 2011Likely that Lineage II rats occurred naturally on Taiwan
ThailandPresentNativeMusser and Carleton, 2005
VietnamPresentNativeAplin et al., 2011

Africa

South AfricaPresentIntroducedAplin et al., 2011

North America

USAPresentIntroducedAplin et al., 2011Western USA

Oceania

FijiPresentIntroducedMusser and Carleton, 2005
Papua New GuineaPresentIntroducedMusser and Carleton, 2005; Aplin et al., 2011

Habitat

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R. tanezumi are most often associated with commensal and agricultural habitat, but they may also occur in forest (Aplin et al., 2011).

Habitat List

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CategorySub-CategoryHabitatPresenceStatus
Terrestrial
Terrestrial – ManagedCultivated / agricultural land Present, no further details Harmful (pest or invasive)
Cultivated / agricultural land Present, no further details Natural
Disturbed areas Present, no further details Harmful (pest or invasive)
Disturbed areas Present, no further details Natural
Terrestrial ‑ Natural / Semi-naturalNatural forests Present, no further details Harmful (pest or invasive)
Natural forests Present, no further details Natural

Hosts/Species Affected

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R. tanezumi is an opportunistic omnivore and considered an important agricultural pest of rice, coconut, banana, and maize. Rice is the main diet of R. tanezumi during the ripening to harvest stages of rice (Htwe and Singleton, 2014).

Biology and Ecology

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Reproductive Biology

In rice-based agro-ecosystems, the reproductive activity of R. tanezumi peaks during the ripening stages of the crop (Marges, 1972; Stuart et al., 2015). The breeding season may also be extended where the rice crops are asynchronous or where there are alternative food crops available. The mean litter size ranges from 3.2 (marsh habitat) to 9.7 (rice field) (Alfonso et al., 1985).

Climate

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ClimateStatusDescriptionRemark
Af - Tropical rainforest climate > 60mm precipitation per month
Am - Tropical monsoon climate Tropical monsoon climate ( < 60mm precipitation driest month but > (100 - [total annual precipitation(mm}/25]))
Aw - Tropical wet and dry savanna climate < 60mm precipitation driest month (in winter) and < (100 - [total annual precipitation{mm}/25])
BW - Desert climate < 430mm annual precipitation
BS - Steppe climate > 430mm and < 860mm annual precipitation
Cw - Warm temperate climate with dry winter Warm temperate climate with dry winter (Warm average temp. > 10°C, Cold average temp. > 0°C, dry winters)
Cf - Warm temperate climate, wet all year Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year
Dwa - Hot summer continental climate Hot summer continental climate (Warm average temp. > 10°C, coldest month < 0°C, dry winters, warmest month average temp. > 22°C)
Dfa - Hot summer continental climate Hot summer continental climate (Warm average temp. > 10°C, coldest month < 0°C, wet all year, warmest month average temp. > 22°C)

Latitude/Altitude Ranges

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Latitude North (°N)Latitude South (°S)Altitude Lower (m)Altitude Upper (m)
45 35 0 2000

Means of Movement and Dispersal

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In rice fields, an established population of R. tanezumi is restricted to a home range of 0.45-1.3 ha depending on sex and crop stage (Alfonso et al., 1985; Singleton, 2003).

Impact Summary

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CategoryImpact
Economic/livelihood Negative

Economic Impact

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R. tanezumi is a pest of rice, coconut, banana and maize, and is considered the most serious rodent pest in rice fields within Luzon and Visayas in the Philippines.

Risk and Impact Factors

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  • Negatively impacts agriculture
Impact mechanisms
  • Herbivory/grazing/browsing

Prevention and Control

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Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

When developing management strategies for R. tanezumi, an integrated ecologically-based pest management approach (EBRM: Singleton et al., 1999) should be developed that incorporates knowledge of its habitat use, population dynamics and breeding biology. Coordinated community action is recommended.

Control

Cultural Control and Sanitary Measures

Traditional methods of control include community rat campaigns that use trapping, hunting or flushing out rat burrows, and field sanitation. In rice-based systems, food availability may be reduced by synchronous cropping, minimizing grain spillage, ploughing immediately after harvest, and an extended fallow (Stuart et al., 2012; Htwe and Singleton, 2014). Rodent-proofing of storage facilities can be highly successful where feasible. This should be accompanied by sanitation such as removing potential food, water and shelter to make the habitat less attractive to rats. In coconut plantations, trunk banding with metal or plastic sheets may be used.

Chemical Control

Rodenticides are a popular method of rat control, but should be used as part of an integrated management approach. Acute and delayed acting toxicants are available for rodent management. Careful assessment of the infestation, appropriate placement and maintenance of bait as well as measures to protect non-target species are recommended.

In rice-based agro-ecosystems, baits placed within rice fields are likely to be more attractive and more readily accepted during the tillering stage of the rice crop because food availability is low and pest rodents move into the rice field from the surrounding habitats during this time. When rice plants enter the reproductive stage, the acceptability of rodenticide bait is expected to decline.

Monitoring and Surveillance

Rodent damage to rice crops generally occurs towards the centre of the crop and is not readily visible until damage is greater than 10%. Monitoring of active rodent burrows along irrigation banks and around villages provides a coarse measure of population density.

References

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Adhikari P, Han S, Kim Y, Kim T, Thapa TB, Subedi N, Kunwar A, Banjade M, Oh H, 2018. New record of the Oriental house rat, Rattus tanezumi, in Nepal inferred from mitochondrial Cytochrome B gene sequences. Mitochondrial DNA Part B: Resources, 3(1), 386-390.

Alfonso PJ, Fieldler LA, Sumangil JP, 1985. Rodent ecology, population dynamics and behaviour. In: Rodent Biology and Control (with special reference to the Philippines), [ed. by Sanchez FF, Benigno EA]. Los Baños, Philippines: The National Crop Protection Center. 25-47.

Aplin K, Brown P, Jacob J, Krebs C, Singleton G, 2003. Field methods for rodent studies in Asia and the Indo-Pacific. MN100. Canberra, Australia: ACIAR.

Aplin KP, Suzuki H, Chinen AA, Chesser RT, ten Have J, Donnellan SC, Austin J, Frost A, Gonzalez JP, Herbreteau V, et al, 2011. Multiple Geographic Origins of Commensalism and Complex Dispersal History of Black Rats. Plos One, 6(11), e26357. doi: https://doi.org/10.1371/journal.pone.0026357

Heaney LR, Balete DS, Dolar ML, Alcala AC, Dans ATL, Gonzalez PC, Ingle NR, Lepiten MV, Oliver WLR, Ong PS, et al, 1998. A synopsis of the mammalian fauna of the Philippine Islands. Fieldiana Zoology new series, 88, 1-61.

Htwe NM, Singleton GR, 2014. Is quantity or quality of food influencing the reproduction of rice-field rats in the Philippines?. Wildlife Research, 41(1), 56-63. http://www.publish.csiro.au/nid/145/aid/112.htm doi: 10.1071/WR13108

Marges BE, 1972. Reproduction and seasonal abundance of the ricefield rat (Rattus rattus mindanensis Mearns) at Siniloan, Laguna. Los Baños, Philippines: University of the Philippines.

Musser G, Carleton M, Superfamily Muroidea. In: Mammal species of the world: a taxonomic and geographic reference, 3rd ed, [ed. by Wilson DE, Reeder DA]. Baltimore, USA: The John Hopkins University Press. 894-1531.

Singleton GR, 2003. Impacts of rodents on rice production in Asia. In: IRRI Discussion Paper Series No. 45 . Los Baños, Philippines: IRRI.30 pp.

Singleton GR, Leirs H, Hinds LA, Zhang Z, 1999. Ecologically-based management of rodent pests - Re-evaluating our approach to an old problem. In: Ecologically-based Management of Rodent Pests, [ed. by Singleton G, Hinds L, Leirs H, Zhang Z]. Canberra, Australia: Australian Centre for International Agricultural Research (ACIAR). 17-29.

Stuart AM, Prescott CV, Singleton GR, 2008. Biology and management of rodent communities in complex agroecosystems - Lowlands. In: Philippine rats: ecology and management, [ed. by Joshi RC, Singleton GR, Sebastian LS]. Science City of Muñoz, Nueva Ecija, Philippines: Philippine Rice Research Institute. 37-56.

Stuart, A. M., Prescott, C. V., Singleton, G. R., 2012. Natal nest locations of the Asian house rat (Rattus tanezumi) in lowland rice-coconut cropping systems: a coconut penthouse or rice bunds with water frontage?. Wildlife Research, 39(6), 496-502. http://www.publish.csiro.au/nid/145/aid/112.htm doi: 10.1071/WR11197

Stuart, A. M., Singleton, G. R., Prescott, C. V., 2015. Population ecology of the Asian house rat (Rattus tanezumi) in complex lowland agroecosystems in the Philippines. Wildlife Research, 42(2), 165-175. http://www.publish.csiro.au/nid/145/aid/112.htm

Contributors

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08/07/16 Original text by:

Alexander M Stuart, International Rice Research Institute, Los Baños, Philippines

Grant R Singleton, International Rice Research Institute, Los Baños, Philippines

Jens Jacob, Federal Research Centre for Cultivated Plants, Julius Kühn-Institut, Münster, Germany

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