(Synaptomys cooperi helaletes)
The size of this species is medium with a total length from 119-135 mm and a weight of 26-36 grams. The upper incisors are longitudinally grooved.The upper parts are mixed black, gray, and yellowish brown, giving a grizzled cinnamon brown appearance. The underside is grayish white or grayish cream. The feet are brownish black, brighter than Synaptomys cooperi stonei. This species breeds throughout the year, but there are peaks in the spring and fall with usually 3-4 litters of 1-8 young being produced per year. This species is native. This species is active all year and at all times of the day. They are gregarious and the home range is normally less than 1/2 acre. They utilize surface and subsurface tunnels as well as nests above and below the ground.
It was originally collected only from the Great Dismal Swamp, but several populations have recently been found well beyond the Dismal Swamp boundaries, including three populations 15 to 22 miles west of Suffolk Escarpment. This species is most common in open areas in the Dismal Swamp, in which the principle vegetation is cane (Arundionaria gigantea), softstem rush (Juncus effusus), sedges, grasses and herbaceous forbs.
The winter food is unknown. They consume a wide variety of leafy and grassy material.