Sigmodon ochrognathus
| Yellow-nosed Cotton Rat
(Sigmodon ochrognathus) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Myomorphi |
| Superfamily: | Muroidea |
| Family: | Cricetidae |
| Subfamily: | Sigmodontinae |
| Tribe: | Sigmodontini |
| Genus: | Sigmodon |
| Subgenus: | Sigmodon (subgenus) |
| Binomial details | |
| Sigmodon ochrognathus V. O. Bailey, 1902 | |
| Other resources | |
| Full taxonomic details at MDD | |
Description
From Hoffmesiter (1986): "A Sigmodon with a conspicuous "yellow" nose which is actually a nose ring of orangeish or ochraceous; eye ring of similar color; small to medium size; hind foot 30 mm or shorter; underparts of silvery or whitish; tail bicolor, although black all around near tip; tops of feet whitish or silvery; guard hairs, epecially on rump, long and conspicuous; ears short; skull small and not strongly arched in nasofrontal region; posterior margin of interparietal with a median notch formed by supraoccipital; palatine foramina short; no preoptic foramen (in front of optic foramen) usually; base of baculum nearly diamond-shaped and narrow."
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
| Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
|---|---|---|---|---|---|---|
| Arizona (Santa Cruz and western Cochise cos.) | Hoffmeister (1986) | males: 188–251 (n=30); females: 193–264 (n=23) | males: 80–111 (n=30); females: 81–114 (n=23) | males: 25–30 (n=30); females: 25–30 (n=23) | males: 14–19 (n=30); females: 15–18 (n=23) | |
| not reported | Ceballos (editor, 2014) | 192–243 | 85–110 | 26–30 | 16–21 | 41–133 |
| Texas | Schmidly & Bradley (2016) | 259 | 114 | 28 | 50–80, occasionally as much as 112 |
Skull
Similar species
From Hoffmesiter (1986): "S. ochrognathus differs from S. arizonae and S. hispidus in the presence of a yellow nose and eye ring; smaller size, especially the hind foot (30 mm or less). S. fulviventer differs from S. ochrognathus as follows: underparts brownish, buffy, or fulvous rather than whitish; dorsum speckled or "salt and peppery"; tops of feet buffy; tail blackish or nearly so all around."
From Schmidly & Bradley (2016): "Similar to S. hispidus but paler and with the snout distinctly orange or rusty; tail hairier and distinctly bicolor, nearly black above, grayish buff below; underparts grayish white."
References
Bailey V. 1902. Synopsis of the North American Species of Sigmodon. Proceedings of the Biological Society of Washington 15, 115.
Ceballos G, editor. 2014. Mammals of Mexico. Baltimore (MD, USA): Johns Hopkins University Press.
Hoffmeister DF. 1986. Mammals of Arizona. Tucson (AZ, USA): University of Arizona Press.
Schmidly DJ, Bradley RD. 2016. The mammals of Texas. Austin (TX, USA): University of Texas Press.