Wildlife Clinic

Species

American pygmy shrew

Sorex hoyi

One of the smallest mammals in North America, weighing about as much as a coin.

At a glance

Size
Body about 5 to 6 cm; tail about 2.5 to 3 cm
Weight
About 2 to 4 g
Habitat
Forests, clearings, bogs and grassy edges; in Georgia, mainly the north
Diet
Insects and their larvae, spiders and other small invertebrates
Active
Day and night, all year
Shelter
Runways under leaf litter, logs and moss
Lifespan
Usually a year or so
Rabies vector
No

Identification

Key marks
Tiny; reddish-brown to greyish-brown back and paler belly; long, narrow snout; tail shorter than the body
Told apart from
Masked shrew, which looks very similar; the two are reliably told apart only by their teeth
Told apart from
Least shrew, which has a very short tail
Where to look
Seldom seen; forest leaf litter and grassy edges

Behaviour

The American pygmy shrew is one of the lightest mammals in the world, a little heavier than a dime. It lives in the leaf litter and under logs, feeding almost constantly on tiny insects and spiders, and does not hibernate.

It is rarely seen and was once thought to be very rare; better survey methods have shown it is more widespread than people assumed, though still seldom common anywhere.

Why they matter

A mammal this small is at the very edge of what warm-blooded life can manage. Pygmy shrews show how much energy a small body needs and how finely an animal can be tuned to find enough food to survive.

Reproduction and lifecycle

Breeding — late spring and summer
Litter — usually three to eight young
Lifespan — about a year
Much of this species' breeding biology is not well recorded.

Living around people

  • Leaving logs and leaf litter in woodland keeps their habitat.
  • Uncovered buckets, pits and window wells can trap tiny mammals like this one.

Misconceptions

  • The smallest mammals are always babies. Pygmy shrews are fully grown at a few grams.
  • Rare means absent. Pygmy shrews are simply hard to find.

Related species

  • Masked shrew
  • Smoky shrew
  • Least shrew

Seasonal activity

When this species is breeding, and when there are nests on the ground. Mowing during the shaded months is how most nests are found.

Breeding and active nests by month for this species
JanFebMarAprMayJunJulAugSepOctNovDec
BreedingJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
Active nestsJan: noFeb: noMar: noApr: noMay: noJun: noJul: noAug: noSep: noOct: noNov: noDec: no
NotesActive under leaves and snowActiveActiveBreeding beginsLitters bornYoung leave the nestBreeding continuesYoung disperseActiveActiveActive in cold weatherActive under leaves and snow

Where it lives

Recorded in 42 states and provinces. Each one links to the other animals there, and to the rehabilitators licensed for them.

If you found one

Answer a few questions and you will get a specific answer for what you are looking at.

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