Reithrodontomys megalotis (western harvest mouse)
| Class | Mammalia |
| Order | Rodentia |
| Family | Cricetidae |
| Genus | Reithrodontomys |
| Species | Reithrodontomys megalotis |
| Common | western harvest mouse |
| Diet | omnivore (seeds, insects, and plants) |
| Habitat | generalist; marshes, grasslands |
| Description | Subfamily: Neotominae Tail about equal in length to body. White belly, gray-brown or brown on dorsal. Similar to small Peromyscus. Total length ~14 cm, tail ~7 cm. Smallest of Neotominae. The genus includes five species of harvest mice in North America but only one in Oregon. |
| Skull Characteristics | Skull length ~2 cm. Longitudinal groove in incisors distinguishes from similar species. Otherwise similar to small Peromyscus. Molars as other small Neotominae: Cuspidate with 2 longitudinal rows of cusps (cp. Muridae) |
| Notes | The Neotominae are a subfamily of the Cricetidae that includes the North American mice and woodrats |