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Northern Grasshopper Mouse

Onychomys leucogaster

French: Onychomys boréal / German: Nordliche Grashipfermaus / Spanish: Raton saltamontes septentrional

Taxonomy. Hydudaeus leucogaster Wied-Neuwied, 1841, Mandan village near Fort Clark, Oliver County, North Dakota, USA. Thirteen subspecies are recognized.

Subspecies and Distribution.

O. l. leucogasterWied-Neuwied, 1841 — from extreme SE Saskatchewan and S Manitoba (Canada) S to SE South Dakota and ex-NW Towa (USA).

O.l.albescensMerriam,1904—restrictedtothetypelocalityandsurroundingareasinextremeNChihuahuaState(Mexico).

O.l.arcticepsRhoads,1898—fromWyomingandSouthDakotaStoCTexasandSENewMexico(USA).

O.l.breviauritusHollister,1913—fromENebraskaandNWIowaStoC&SWOklahoma(USA).

O.l.brevicaudusMerriam,1891—SEOregon,SIdaho,extremeSWWyoming,extremeECalifornia,andNevada(USA).

O.l.fuliginosusMerriam,1890—NWArizona(USA).

O.l.fuscogriseusAnthony,1913—EWashington,EOregon,CWIdaho,NECalifornia,andextremeNWNevada(USA).

O.l.longipesMerriam,1889—SCTexas(USA)andNEMexico.

O.l.melanophrysMerriam,1889—C&SWUtahandadjacentNWArizona(USA).

O.l.missouriensisAudubon&Bachman,1851—SAlbertaandSSaskatchewan(Canada)andMontana,NWyoming,WNorthDakota,andNWSouthDakota(USA).

O.l.pallescensMerriam,1890—EUtah,W&SCColorado,NEArizona,andNW&NCNewMexico(USA).

O.l.ruidosaeStone&Rehn,1903—C&SEArizonaandC&SWNewMexico(USA)andextremeNESonoraandextremeNWChihuahuastates(Mexico).

O. l. uthaensis Goldman, 1939 — W Utah (USA).

Descriptive notes. Head—body 90-128 mm, tail 29-62 mm, ear 12-17 mm, hindfoot 17-25 mm; weight 30-60 g. The Northern Grasshopper Mouse is similar to the other two species of Onychomys but it is slightly larger in size, has a shorter tail, and is more stocky in appearance. Dorsum is pale brown to grayish or pinkish cinnamon. Tail is shorter than one-half of head-body length.

Habitat. Xeric prairies and mesquite ( Prosopis, Fabaceae) grasslands and scrubland at elevations of 152-1400 m.

Food and Feeding. Northern Grasshopper Mice are well known for their carnivorous diet, but they occasionally eat plant material. It has been hypothesized that they can regulate insect populations. They are also known to eat small mice (e.g. species of Peromyscus, Perognathus, and Microtus).

Breeding. Gestation lasts 26-47 days; apparently length depends on whether or not females are lactating when rebreeding. Litters have 3—4 young.

Activity patterns. Northern Grasshopper Mice are mainly nocturnal and active yearround. They do not hibernate.

Movements, Home range and Social organization. Courtship and mating behaviors of Northern Grasshopper Mice (circling, sniffing, grooming, etc.) are among the most complex observed in rodents. Densities generally are low (2:3 ind/ha). Individuals have large home ranges, in which they construct burrows.

Status and Conservation. Classified as Least Concern on The IUCN Red List.

Bibliography. Alvarez (1963a), Anderson (1972), Baker (1956), Egoscue (1960), Hall (1981), Horner (1968), Mc-Carty (1978), Pinter (1970), Tobén (2014c¢).