Perception Channels: tactile ; chemical
This species is rare, but is not specifically recognized under any major conservation status.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Since this species has such little direct human contact (due to their isolated habitats), they have little direct economic impact. However, due to their intense and constant consumption of insects, these shrews may have a positive effect on the farming industry by reducing the number of insect larvae and pupae that become pests (Banfield, 1974).
Positive Impacts: controls pest population
Due to their relative rarity, not much is known about specific ecosystem roles for this species. However, like many other terrestrial shrew species, Sorex dispar likely plays a large role in controlling insect populations through their foraging (DiscoverLife website, 2001).
Due to their size, these shrews forage day and night, often consuming twice their body weight in food every day. This ravenous need for food is a response to their active lifestyle and small size, which produces a large surface-area-to-volume ratio compared to larger mammals. Due to their greater heat loss, these small animals must consume a proportionally larger amount of food than larger species (Vaughn, 2000). Their foraging focuses mainly on small invertebrates and plant materials. They eat almost continuously, feeding mostly above the ground and amongst the debris (PA Game Commission website, 2001). Some of their more common foods are centipedes, beetles, and spiders, as well as flies and crickets (Richmond, 1950).
Animal Foods: insects; terrestrial non-insect arthropods
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
The range of Sorex dispar extends from Nova Scotia, Canada south through Eastern Tennessee and North Carolina (Nowak,1999). In the United States, they are found in greatest abundance throughout the Appalachian Mountain Range (PA Game Commission website, 2001).
Biogeographic Regions: nearctic (Native )
Sorex dispar has a wide tolerance for altitudinal variation, as well as different types of vegetation. They can be found in cool, damp forests, both deciduous and mixed (Nowak, 1999). However, their preferred habitats are the moist forested areas of high altitude regions. Living primarily in mountainous environments, these shrews can be found at high densities along mountain streams and amid the debris surrounding rock-slides (Whitaker and Hamilton, 1998). In these rock-slide areas, they can often be found amongst the subterranean tunnels found in the rocky crevices between boulders (DiscoverLife website, 2001).
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest ; mountains
Like many other shrews, this species is short-lived. Lifespan estimates for wild individuals rarely exceed 2 years. Other than predation, some other common causes of death include starvation, rapid temperature changes, floods, and fights with other individuals. (PA Game Commission website, 2001)
Average lifespan
Status: wild: 2 years.
Sorex dispar is often confused with its close relative Sorex fumeus, the smoky shrew. Their appearance is quite similar and their ranges may overlap in some locations. However, Sorex dispar can be distinguished by several defining characteristics, including a more slender body and longer tail (Whitaker and Hamilton, 1998). They have a long snout and small eyes, with a long and thick tail. Their length ranges from 46-100 mm. and their weight ranges between 4-6 g., with a tail length that ranges between 25-82 mm (Nowak, 1999). They have a dark grey pelage with slightly paler under parts. Their teeth are sharp, pointed and often stained (PA Game Commission website, 2001).
Range mass: 4 to 6 g.
Range length: 46 to 100 mm.
Other Physical Features: endothermic ; bilateral symmetry
To avoid predation while foraging, Sorex dispar often feed at night. Also, they tend to remain concealed under the debris of the forest floor. Also, since they are often mistaken by predators for mice, these shrews have a distinct musky odor that may serve as a deterant to predators (PA Game Commission website, 2001).
Known Predators:
The reproductive season for Sorex dispar is between April through August and they usually have several litters throughout each year. The average litter size is between four and seven, and the young are born helpless and unfurred (Nowak, 1999). They are placed quickly into a nest made of grasses and leaves, where they reumain until they are weaned. The nests are usually 10-20 cm in diameter (DiscoverLife website, 2001). Due to the rare opportunities for study of Sorex dispar, not much is known about their reproductive and behavioral development. The newborns are usually placed in a ball of vegetation directly after birth. After four or five weeks, the young are weaned and partially independent. Usually, the young spend the next several weeks foraging close to their mother before becoming completely independent (Nowak, 1999).
Average weaning age: 4-5 weeks.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Parental Investment: altricial ; female parental care
