Hispid Cotton Rat

Description:

These little rodents were spotted on the trails at the St. Marks Lighthouse. Most were this color, but there were a few black ones as well. They look more like large hamsters than rats, as their tails were not ratlike. I referred to them as river rats, but have no idea what they really are. A moderately large, robust rat with pattern of last two lower molars S-shaped; tail shorter than head and body, sparsely haired, the annulations and scales clearly visible; ears relatively small and blackish or grayish; pelage coarse and grizzled, the black guard hairs rather stiff (hispid); hind foot with six plantar tubercles and with three middle toes longer than outer two; upperparts grizzled brown; underparts grayish white or buff. External measurements average: total length, 270 mm; tail, 110 mm; hind foot, 31 mm. Weight, 80-150 g.

Habitat:

St. Marks is known for its brackish waters and freshwater pools. These little guys (and gals) were seen next to the fresh water pools eating the vegetation. Normally this rat inhabits tall-grass areas where such grasses as bluestem (Andropogon), cordgrass (Spartina), or sedges (Carex) offer both freedom of movement under a protective canopy and an adequate food supply. In such situations, their runways form a network of interconnecting travelways about 5-8 cm wide. In western Texas, where grassy ground cover is not available, the rats live in dens at the bases of small, low clumps of mesquite in otherwise nearly barren terrain, much after the fashion of white-throated wood rats. Between these two extremes are several types of habitat that may support small populations of cotton rats. Preferred sites are old fields, natural prairie, unmolested rights-of-way for roads and railroads, and other places not subject to flooding and where the vegetation grows rank and tall.

Notes:

They didn't seem to be too fearful of humans and this one stayed on the trail even while we walked past. http://www.nsrl.ttu.edu/tmot1/sigmhisp.h...