Smoky Shrew (Sorex fumeus) lives in eastern forests across North America. It feeds on insects and worms. Its conservation status is Least Concern.
Fascinating facts about the Smoky Shrew
- Only about the size of a thumb, the smoky shrew's body measures roughly 11 centimetres long, including a 4-centimetre tail, and it tips the scales at about 5 grams, barely a quarter of an ounce. Yet other surveys record an average total length of 111.4 mm and a heft of 7.6 grams, with the tail averaging 43.8 mm. This tiny mass lets the shrew slip through leaf litter and tight burrow spaces.
- Mating kicks off in late March, and females give birth by April or May, just 20 days after copulation. If they survive, they can squeeze in two more litters about a month apart, each producing two to eight pups, six on average. Gestation lasts 19-22 days and the newborns arrive blind, toothless and fur-less, weighing a mere 0.14 grams; by one month they double to 4 grams, half an adult's weight.
- In the Appalachian highlands the smoky shrew prefers cool, damp woods above 700 m, yet at its southern fringe it can be found as low as 300 m. It builds rounded nests about 5.08 cm in diameter from plant material, often tucked under forest debris, and sometimes constructs globular nests 10-15 cm across from leaf litter. By nesting in existing burrows or under debris, it avoids digging its own tunnels, while staying close to the streams it hunts along.
- A stomach-content study in North Carolina showed centipedes dominate the diet at 36.5 % by volume, followed by earthworms (19 %) and adult moths (19.5 %), with ground beetles adding another 10 %. This insect-heavy menu reflects the shrew's role as a pest controller. Though not measured in smoky shrews, close relatives in the genus Sorex have heart rates of 800-1200 beats per minute, underscoring the frantic metabolism needed to sustain constant foraging.
- Smoky shrews swap coats twice a year, a brown-yellow summer fur and a gray-white winter pelage, giving them camouflage that blends with leaf litter and snow. Their main predators include bobcats, red and gray foxes, long-eared owls, weasels, northern short-tailed shrews and timber rattlesnakes. This cryptic coloration, combined with a habit of staying hidden under debris, helps them evade a wide array of hunters across seasons.
Sources
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At a glance
RangeNorth America
HabitatEastern forests
DietInsects and worms
About the Smoky Shrew
In the damp, hidden recesses of the forest floor, the smoky shrew darts and weaves with frenetic purpose, its tiny, smoke-grey form a blur as it pursues the endless quest for insect prey. With each twitch of its whiskered snout and flick of its pointed ear, it navigates a world of intricate, hidden pathways, its very existence a testament to the boundless vitality that thrives in the shadows. As it moves, the shrew's tiny paws barely touch the ground, giving the impression of a creature almost floating across the leaf litter, driven by an insatiable hunger and an unyielding will to survive.
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