Colombian Oldfield Mouse vs Common Eastern Wildrye

Thomasomys dispar compared with Elymus virginicus

Key Differences

• Colombian Oldfield Mouse is Data Deficient while Common Eastern Wildrye is Not Evaluated.

Taxonomic Classification

Rank	Colombian Oldfield Mouse	Common Eastern Wildrye
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Chordata (Chordates)	Magnoliophyta (Flowering Plants)
Class	Mammalia (Mammals)	Liliopsida (Monocots)
Order	Rodentia (Rodents)	Poales (Grasses)
Family	Cricetidae	Poaceae (Grass Family)
Genus	Thomasomys	Elymus
Species	Thomasomys dispar	Elymus virginicus

Conservation Status

Colombian Oldfield Mouse

DD — Data Deficient

Common Eastern Wildrye

NE — Not Evaluated

Physical Characteristics

Attribute	Colombian Oldfield Mouse	Common Eastern Wildrye
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Colombian Oldfield Mouse

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

Common Eastern Wildrye

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Range

Distributed across Denmark, Sweden, and United States.

Colombian Oldfield Mouse

<em>Thomasomys dispar</em>, commonly known as the Colombian Oldfield Mouse, is a small rodent species belonging to the genus <em>Thomasomys</em> within the family Cricetidae. This species is classified as Data Deficient, indicating that insufficient information is currently available to evaluate its conservation status with confidence. It has been documented in Colombia, where it inhabits diverse terrestrial and aquatic-adjacent environments. Members of the genus <em>Thomasomys</em> are typically associated with high-altitude Andean habitats, including páramo grasslands, shrublands, and montane forest edges, where they occupy ground-level microhabitats and burrow in soft soils. These mice are generally omnivorous, consuming seeds, plant material, and invertebrates, though specific dietary data for <em>Thomasomys dispar</em> have not been recorded. Biological traits of this species remain poorly documented in the scientific literature. The Data Deficient classification highlights the need for targeted surveys in Colombian Andean regions to determine population size, distribution, and the ecological requirements of this poorly known rodent.

Common Eastern Wildrye

<em>Elymus virginicus</em>, the common eastern wildrye, is a native North American grass in the family Poaceae, currently not evaluated by the IUCN Red List. The species is documented in Denmark, Sweden, and the United States, and typically inhabits grasslands, wetlands, forests, and cultivated lands across its range in eastern and central North America. It is a cool-season, perennial bunchgrass that typically grows in moist to mesic habitats including riverbanks, floodplain woodlands, forest understories, and moist prairies. <em>Elymus virginicus</em> is recognized by its distinctive nodding seed heads with stiff, curved awns and is among the most widely distributed wild rye grasses in North America. The species provides important ecosystem services as a native ground cover, stabilizing streambanks and riparian soils against erosion, and offering habitat and food resources for grassland birds, small mammals, and invertebrates. Common eastern wildrye is also valued in ecological restoration projects for its adaptability to a range of soil conditions and its ability to establish quickly in disturbed habitats. As a forage grass, it is moderately palatable to livestock and wildlife. Biological traits of this species remain poorly documented in the scientific literature.