CHAPTER 26 Terrestrial Small Mammals James G. Dickson’ US Forest Service Southern Reseurch Station, Nclcogdoches, TX A variety of terrestrial small mam- species on higher trophic levels. As mals with diverse size, form, geo- such, small mammals play a substan- graphic range, and ecological niche tial role in system energetics and inhabit southern forests. Some are nutrient cycling. Also, small mam- highly specialized for their environ- mals can be important vectors of dis- ment, such as the semi-aquatic eases, such as tularemia, lyme dis- species or fossorial species, such as ease, and hantavirus, which can moles. Some, such as the cotton rat, infect humans, livestock, and other are widely distributed throughout species of wildlife. A number of dif- the region and others highly restrictive in their range and ferent species inhabit and function in southern forests. habitat. Because of their secretive and often nocturnal In this chapter I cover shrews and moles (Insectivores), nature, most small mammals are not apparent to the casu- and small terrestrial rodents. al observer, but they are prominent in southern forests. Terrestrial small mammals are integral and impor- INSECTIVORES tant components of southern forest systems. They func- tion as consumers of primary productivity. They con- Shrews are the smallest mammal, weighing less than an sume, distribute, and disperse plant seed, including ounce. These Insectivores are very active with a high acorns. They consume large quantities of insects and metabolism and voracious appetite. Their main diet is other arthropods. Also, their subterranean activities aer- insects; other invertebrates such as earthworms, sowbugs, ate soils and they function in dispersing mycorrhizal and snails; and larger vertebrates. They use burrows of fungi spores within forests (Maser et al. 1978). other small mammals and construct burrows of their own. Small mammals are primary prey for many mam- They have a long snout, poor sight and sense of smell, but mals, birds, and reptiles and sustain many vertebrate keen hearing and tactile sense. Owls are among shrew Turrent Address: School of Forestry, Louisiana Tech University. Ruston. LA 350 TERRESTRIAL SMALL MAMMALS 351 Small rodents, such as this woodrat, are important components of southern forest systems. They consume primary produc- tivity, and disperse plants and fungi (J. Dickson). Small mammals are primary prey for many mammals, birds, and reptiles, and sustain many vertebrate species on a higher trophic level (OK Dept. Wildlife). predators; shrew skulls show up regularly in owl pellets. larly grasses such as bluestem, bermudagrass, and Several species are found in southern forests. Johnson grass (Schmidly 1983). It has been document- The southeastern shrew is found throughout the ed, apparently in appropriate habitat, in different stand South except the western extremity and along the south- types (Tables 1,2,3). em coastal area (Hall 198 1). Some specimens have been The water shrew occurs along the Appalachian captured in dry woods, but most have been taken from Mountains from Virginia to northern Georgia (Hall marshy habitat to moist woods (Sealander and Heidt 198 1). Appropriately named (S. ynfustris), it occupies 1990). They have been documented in some young moist habitat along pond, stream, and marsh edges. brushy stands (Table 2) and in some mature stands, par- Range of the long-tailed shrew is similar to that of the ticularly in hardwood stands on moist sites (Table 3). water shrew. The short-tailed shrew, originally recognized as 1 The smoky shrew occurs in the mountainous central species (Blarina brevicauda), recently has been split part of the region from central Kentucky to western into 3 species: B. brevicaudu in the northeastern part of Virainiab and southerly to northeastern Georgia and the region, B. carolinensis through the southern portion western South Carolina (Hall 1981). The pygmy shrew of the South, and B. hylophaga in the midwestern U.S. occurs along the eastern mountains from northern extending into eastern Oklahoma and northwestern Virginia to northern Georgia. The swamp short-tailed Arkansas. Blarina spp. occur regularly throughout the shrew has been identified along coastal Virginia and region. Typical habitat of these species is moist woods North Carolina. (Sealander and Heidt 1990). They are very abundant Moles, somewhat larger than shrews, are another species in the South, commonly inhabiting many differ- Insectivore. They construct extensive tunnels in which ent stand types at different stages of stand development rhey live and are well adapted for their subtermnean from the young brushy stage to maturity (Tables I .3.3). existence and lor digging. Their legs are short and pow- The least shrew is distributed throughout [he South. erful and placement facilitates digging. Their eyes and It is gregarious, often with several occupying the same ears are vestigial and they have a short almost hairless nest during winter. It is not a woodland species. but is tail ilowery 1974). Three moles occupy southern associated with dense herbaceous vegetation, particu- lorests. The most common and l’ound throughout is the 352 T ERRESTRIAL SMALL MAMMALS Table 1. Relative abundancea of captures of terrestrial small mammals in 1 -year-old stands in the South Standb Cotton White- Golden Hispid Short- Least South- Eastern Marsh House Eastern Mouse footed Mouse Cotton tailed shrew eastern Harvest Rice Mouse Woodrat Mouse Rat shrewc shrew Mouse Rat I. Pine Plant.-GA 1 2 4 3 2. Pine Plant.-MS 4 f 5 3 2 3. Pine regen.-MS 1 2 3 4. Bottomland 1 2 3 a1 =hlghest abundance, 2=2nd highest, etc. Wtation: 1. Atkeson and Johnson 1979; 2. Perkins et al. 1989; 3. Wolfe and Lohoefener 1963; 4. Dickson et al. unpubl. data “Blarina spp. Table 2. Relative abundancea of captures of terrestrial small mammals in young brushy stands (3-6 years old) in the South. Standb Cotton White- Golden Hispid Short- Least South- Eastern Marsh House Eastern Eastern Other Mouse footed Mouse Cotton tailed shrew eastern Harvest Rice Mouse Woodrat Chipmunk Mouse Rat Shrewc Shrew Mouse Rat 1, Pine Stand-SC 3 1 4 2 2. Pine Plant.-SC 3 1 2 3. Pine Plant.-NC 9 3 1 6 3 8 2 7 5 4. Pine Plant.-GA 2 1 3 4 5. Pine Stand-MS 1 2 4 3 6 5 6. Pine Plant.-MS 4 1 5 2 3 7. Pine Plant-TX 3 1 2d 4 5a 8. Bottoml. Hardw.-TX 2 1 5 36 4 6 9. Right-of-way-TN 3 2 4 5 1’ 10. Right-of-way-TN 2 f 4 5 3’ =l=highest abundance, 2=2nd highest, etc. Titation: 1.2. Mengak et al. 1989; 3. Mitchell et al. 1995; 4. Atkeson and Johnson 1979; 5. Wolf and Lohoefener 1983; 6. Perkins et al. 1989; 7. Fleet and Dickson 1964: 8. Dickson et al. unpubl. data; 9.10. Johnson et al. 1979. c131arina spp. dFulvous harvest mouse BBlack Rat ‘Pine vole eastern mole. Of more limited range in the eastern noted for storing food in chambers in burrows which it mountains is the hairy-tailed mole and in the eastern constructs. It often frequents areas with some type of mountains and along the eastern coast into Florida is the physical structure such as down logs, exposed tree star-nosed mole. Moles feed on a variety of inverte- roots, rock outcrops, rock piles, and log piles. brates in the soil and occasionally plants. They are Chipmunks are active during the day and seasonally found in a variety of open and forested habitats; usual- undergo periods of torpor during winter. During winter ly in sandy to loamy soil in which they can tunnel easi- they awake periodically to feed on their food cache or ly; they usually do not occupy heavy clay or very rocky forage aboveground. Foods include buds, fruits and soils (Sealander and Heidt 1990). berries, grain, mushrooms, insects, and small verte- brates and their young or eggs. Acorns and hickory nuts RODENTS are frequently stored items (Lowery 1974). Chipmunks are commonly captured in mature hardwood and pine The eastern chipmunk occurs generally in the central stands in Tennessee (Table 3), and appear to be wide- and northwest portion of the region and is mostly absent spread and common in upland stands in the northern from the coastal plain (Hall 1981). It is named and central portion of the South. TERRESTRIAL SMALL MAMMALS 353 Table 3. Relative abundancea of captures of terrestrial small mammals in mature stands in the South. Standb Cotton White- Golden Hispid Short- Least South- Eastern Marsh House Eastern Eastern Other Mouse footed Mouse Cotton tailed shrew eastern Harvest Rice Mouse Woodrat Chipmunk Mouse Rat Shrew Shrew Mouse Rat 1. Pocosin-NC 2 6 1 4 3 5” 2. Laurel oak floodplain-GA 1 2 3 7 5 4 68 3. LongleaWslash-MS 1 3 4 2 4 4 4. Bayhead-MS I 3 6 4 4 2 6 5.. Pine-hardw.-MS 1 6. Pine-hardw.-TX 2 4 3 1 7. Streamside zone-TX 1 5 6 4 3” 2 8. Bottoml. Hardw.-TX 1 4 3 5e 2 5’ 9. Oak-hickory-TN 3 2 1 IO. Pine-TN 3 5 1 2 49 11. Oak-hickory-TN 1 3 2 12. Chestnut-oak-TN 1 2 13. Pine-TN 1 3 4 2 al=highest abundance, 2=&d highest, etc. bCitation: 1. Mitchell et al. 1995; 2. Boyd 1976; 3.4. Wolfe and Lohoefener 1983; 5. Perkins et al. 1989; 6. Fleet and Dickson 1984; 7. Dickson and Williamson 1988; 8. Dickson et al. unpubl. data; 9.10. Johnson et al. 1979; 11.12.13. Dueser and Shugart 1978; cBlarina spp. %outhern bog lemming EFulvous harvest mouse ‘Marsh rice rat spine vole Range of the 13-lined ground squirrel, common 3 species of pocket gophers (colonial, Sherman’s, throughout the central western U.S., extends only into Cumberland Island) each with limited range along the western edge of the region (NW Arkansas, NE coastal Georgia.