The dwarf shrew is one of the smallest mammals on Earth and among the least-recorded in Colorado. Open occurrence databases hold just 133 Colorado records for it, nearly all from museum specimens and survey trapping rather than field photographs.
A shrew of high rock
Weighing as little as two grams, less than a penny, the dwarf shrew lives among broken rock high in Colorado’s mountains, from montane forest up through subalpine talus and alpine tundra. It threads the gaps between stones after insects, spiders, and other small invertebrates. The scattered records reflect that hidden life: Fremont, Boulder, and Larimer counties lead, spanning the rocky slopes of the Front Range and the southern mountains where the right cold, stony ground exists.
Recorded mostly in summer, active all year
Colorado records cluster in late summer, but that is a trapping-season pattern, not a sign the animal disappears in winter. Shrews cannot hibernate, since their metabolism runs too hot, so the dwarf shrew stays active beneath the snow and rockfall through the cold months while the biologists who document it are away from the high country.
Status in Colorado
NatureServe ranks the dwarf shrew S2, imperiled, in Colorado, and it is native to the state. That ranking reflects both a genuinely patchy, high-elevation distribution and how rarely such a tiny animal is ever caught.
Full species profile
