Least Shrew
Cryptotis parva
Description & Range:
Least shrews are small, measuring 2 ¾ to 3 ⅝ in in length, with a short tail. They have dense, short hair that is a grayish light brown in the summer and darker reddish brown in the winter on their backs, and a light gray underneath. Their tail is also bicolored, with a darker brown on top and lighter underside. Like most other shrew species, they have small ears concealed in their fur, tiny eyes, and a long snout.
The geographic range of the least shrew extends along the east coast from New York south to Florida, and as far west as Texas and South Dakota. They are also present in Central America, ranging from Mexico to Panama.
Habitat:
Least shrews prefer open fields or meadows with tall grasses and scattered brush. They are also commonly found in saltwater marsh habitat along the Atlantic Coast, and have been associated with saltmarsh grasses.
Diet:
Least shrews are insectivores, eating primarily insect larvae and centipedes. Occasionally, they will eat snails, spiders, crickets, fungi, or green plants. Once they have identified their prey, they will immobilize it by attacking its joints so it cannot escape. Least shrews fuel their high metabolism by eating 60 to 100% of their body weight every day.
Reproduction:
Mating is a process that occurs within the nest and can take up to three days. Females will attract nearby males by stopping the release of pheromones from their scent glands, causing males to investigate by sniffing the anal and ear glands. If a female is receptive, she will allow the male to mount her. The most aggressive males will be able to mate first, and will remain protective over the female after mating is complete. The mating season lasts from February to November, and reproduction can occur multiple times during this period. Females give birth to 2 to 7 young per litter.
Sounds:
Least shrews make a variety of chirps, squeaks, clicks, and other high frequency sounds that are typically inaudible to humans. They often make these noises to help echolocate within their underground burrows.
Behavior:
Least shrews are active for up to 11 hours each day, peaking at night and slowing down during extreme heat or cold. Most of their time is spent hunting and hiding from predators. They are very social compared to other species of shrews, and can form nesting colonies of several individuals. They cooperatively share food, dig tunnels, and build small, round nests made of plant matter within this tunnel system.
Sources:
Peterson Field Guide to Mammals of North America, Fourth Edition
https://animaldiversity.org/accounts/Cryptotis_parva/
https://www.nrs.fs.usda.gov/pubs/jrnl/2007/nrs_2007_laerm_004.pdf
https://dwr.virginia.gov/wildlife/information/least-shrew/
