Onychomys leucogaster

Onychomys leucogaster
Conservation status
Least Concern (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Cricetidae
Genus:	Onychomys
Species:	O. leucogaster
Binomial name
Onychomys leucogaster (Wied-Neuwied, 1841)

The Northern Grasshopper Mouse, or Killer Mouse^[2] (Onychomys leucogaster), is a North American carnivorous rodent originating from the dry areas of the continent.

Background Information.

The Northern Grasshopper Mouse is found in North America, but primarily in dry areas. Their body size is relatively the size of any other rodent or mouse; on average they are 164 millimetres (6.5 in) long and approximately 35 grams (0.077 lb). The tail is most often less than 30% of the total body length, whereas other mice tend to have longer tails adding to long body lengths. The grasshopper mouse is a reddish-black/grey color with white hair on the belly. Unlike most rodents, this one has a carnivorous diet consisting of mainly small insects, other mice, and even snakes. This rodent is also nocturnal, unlike most of its kind. Throughout the night the grasshopper mouse makes high-pitched noises to claim its territory.

Habitat

The Grasshopper Mouse can be found in prairies with low grass, dry areas, and also pasture lands of the central and southwestern parts of the United States. Onychomys leucogaster have been known to associate positively with black-tailed prairie dogs, possibly due to their preference for disturbed areas, suitable habitat in the form of burrows, or food supply^[3][4][5]. The Northern Grasshopper Mouse lives in burrows underground, by either digging their own or inhabiting burrows that have been disowned. These mice have a system of multiple burrows, with each burrow serving a different function. The nest burrow is the primary area of activity during the day; since they are nocturnal they do not need to be in a burrow during the night. To keep moisture in during they day, they close up the opening. A retreat burrow serves for quick escape from predators. Its design is about ten inches into the ground at a 45-degree angle. The cache burrow is used for storing seeds. The signpost burrows are small and filled with glandular secretions that mark the boundaries of their territory. All of these burrows are found within a large area of territory.^{[citation needed]}

Reproduction

The Northern Grasshopper mouse has about two or three litters a year consisting of anywhere between two and seven young, with the average being four. They have a gestation of 32–47 days, and the young are born in either late fall or early winter, between September and February. The male gathers and provides food for the female while she is pregnant and taking of her young^[6]. The Northern Grasshopper Mouse is an altricial species; baby mice are naked with closed eyes when they are born, and approximately three grams. Both sexes reach their sexual maturity at three months, however the life span of a typical mouse living in the wild is only a few weeks to a few months.

Diseases

Susceptibility studies on Grasshopper mice from areas with plague and from those areas that have been historically free of plague by Thomas et al. (1988)^[7] showed that the animals from areas with a history of plague were more resistant to the plague bacterium Yersinia pestis than the animals from a historically plague free area and hence they were considered to be a potential alternate host for plague. Grasshopper mice have also been shown to harbor 57 species of fleas, many of which are vectors of plague^[8]. Given the abundance and diversity of fleas on the grasshopper mouse and their use of prairie dog burrows and interaction with other rodent species, they are considered to be important for the maintenance and transmission of plague in the prairie dog ecosystem ^[5][9]. They are also found frequently infected with another hemotropic intracellular pathogen Bartonella^[5] and Ying et al. 2007^[10] showed that they can acquire different strains of Bartonella from multiple rodent species.

References

1. ^ Linzey, A.V. & Timm, R. (2008). Onychomys leucogaster. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 4 August 2009. Database entry includes a brief justification of why this species is of least concern.
2. ^ "The Living Edens: Canyonlands: America's Wild West". PBS. http://www.pbs.org/edens/canyonlands/canyonlands.htm. Retrieved 2009-01-14. 
3. ^ Choate, J. R. and D. M. Terry. 1974. Observations on habitat preference of Onychomys leucogaster (Rodentia: Muridae) on the central Great Plains. Transactions of the Kansas Academy of Science 76:263-265.
4. ^ Stapp, P. 1997. Habitat selection by an insectivorous rodent: patterns and mechanisms across multiple scales. Journal of Mammalogy 78: 1128-1143.
5. ^ ^{a b c} Bala Thiagarajan. 2006. Community dynamics of rodents, fleas and plague associated with the black-tailed prairie dogs. Doctoral dissertation submitted to Kansas State University.
6. ^ Burt, W.H., R.P. Grossenheider. 1976. The Peterson Field Guide Series: A Field Guide to the Mammals. Peterson, R.A. (Ed.). Houghton Mifflin Company, Boston, p.166-67.
7. ^ Thomas, R. E., A. M. Barnes, T. J. Quan , M. L. Beard , L. G. Carter, and C. E. Hopla. 1988. Susceptibility to Yersinia pestis in the northern grasshopper mouse (Onychomys leucogaster). Journal of Wildlife Diseases 24:327–33.
8. ^ 6) Thomas, R. E. 1988. A review of flea collection records from Onychomys leucogaster with observations on the role of grasshopper mice in the epizoology of wild rodent plague. Great Basin Naturalist 48: 83-95.
9. ^ Gage, K. L., and M. Y. Kosoy. 2005. Natural history of the plague: perspectives from more than a century of research. Annual Review of Entomology 50:505 - 528.
10. ^ Ying, B., M. Kosoy, J. F. Cully, T. Bala, C. Ray, AND S. Collinge. 2007. Acquisition of non-specific Bartonella strains by the northern grasshopper mouse (Onychomys leucogaster). FEMS Micro. Ecol. 61 (3): 438–448.

External links

• The Mammals of Texas - Online Edition Entry
• Worsley School file
• Entry on E'Nature.com
• Entry on America Zoo.com