Massachusetts mammals

Masked Shrew in Massachusetts

Sorex cinereus

Native to Massachusetts S5 Secure in Massachusetts

Not listed as nonindigenous in Massachusetts by USGS NAS; native to its Massachusetts range.

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

LC – Least Concern

Widespread and abundant; not at risk.

Sorex cinereus, Harwich, Chatham, Ontario, Canada 1Sorex cinereus, Harwich, Chatham, Ontario, Canada 2Sorex cinereus, Harwich, Chatham, Ontario, Canada 3Sorex cinereus, Harwich, Chatham, Ontario, Canada 4Sorex cinereus, Billings National Historical Park, Woodstock, Vermont, USA 1Masked Shrew (Sorex cinereus)
Photo: rpoort · CC BY 4.0Sorex cinereus, Harwich, Chatham, Ontario, Canada 1Photo: rpoort · CC BY 4.0Sorex cinereus, Harwich, Chatham, Ontario, Canada 2Photo: rpoort · CC BY 4.0Sorex cinereus, Harwich, Chatham, Ontario, Canada 3Photo: rpoort · CC BY 4.0Sorex cinereus, Harwich, Chatham, Ontario, Canada 4Photo: er-birds · CC BY 4.0Sorex cinereus, Billings National Historical Park, Woodstock, Vermont, USA 1Photo: Sean Frey · CC BY 4.0Masked Shrew (Sorex cinereus)

Masked Shrew in Massachusetts, by the numbers

Occasional in Massachusetts 42nd most recorded of 93 mammals logged in Massachusetts

140 occurrence records
56 with iNaturalist photos
May 15, 2026 Last seen in Massachusetts

Records from 2000–2026.

140 total records count every Massachusetts occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 139; the monthly chart covers the 137 records with a full observation date.

When to look for the Masked Shrew in Massachusetts

Most sightings fall in April.

137 Massachusetts occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly Massachusetts records (table)
MonthRecords
January1
February0
March7
April45
May23
June19
July8
August10
September11
October9
November4
December0

Monthly masked shrew occurrence records (iNaturalist and GBIF) in Massachusetts, 2000–2026.

Seasonality

Year-round in Massachusetts, with recorded sightings peaking in April.

Occurrence map

Where Masked Shrew has been recorded in Massachusetts

139 records mapped · zoom and drag to explore

134 Massachusetts records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Hy-Crest Ranches, Inc. 6
Burrage Pond Wildlife Management Area 4
Camp Edwards Wildlife Management Area 2
Cape Cod National Seashore 2

Protected places with the most masked shrew sightings, from the USGS Protected Areas Database plus named mountain ranges, good spots to look, not a full breakdown, so they don't sum to the total.

Where it's recorded in Massachusetts

CountyRecords
Barnstable County 56
Worcester County 28
Middlesex County 20
Plymouth County 12
Essex County 9
Bristol County 3
Franklin County 2
Hampshire County 2
Norfolk County 1
Other localities 7

The complete county distribution, spread across 9 Massachusetts counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

The cinereus shrew, also called the masked shrew, is one of the smallest mammals in Massachusetts, and its metabolism runs so fast it has to hunt insects and other invertebrates almost around the clock rather than settling into a clear day or night pattern. Barnstable County holds the most records, 56, and named sites from Burrage Pond Wildlife Management Area to Cape Cod National Seashore offer the cool, moist ground this shrew burrows through.

Records spike sharply in April after a nearly empty winter, likely reflecting the start of breeding-season movement as much as any change in how often people are out looking. NatureServe ranks the species S5, secure, in Massachusetts, and it’s found across nearly every wooded and wetland habitat the state offers despite rarely being seen.

Occurrence data from iNaturalist and GBIF.

Sorex cinereus, Harwich, Chatham, Ontario, Canada 1
Full species profile Masked Shrew Sorex cinereus Size 6.9 cm2.7 in Weight 5 g0.2 oz Lifespan Up to 2.5 yr View the full profile

More mammals in Massachusetts in the atlas

Data & sources

The data and visualizations on this page draw on these open sources:

  • GBIFCC-BY 4.0occurrence records behind the range map, elevation, and record counts
  • iNaturalistCC0 / CC-BY / CC-BY-SAobservations, photos, and audio recordings
  • NatureServe ExplorerCC-BYthe state conservation rank
  • IUCN Red Listattributed factthe global conservation status
  • USGS NASpublic domainnative / introduced status
  • Natural Earthpublic domainthe relief basemap
  • USFSpublic domainnational-forest boundaries
  • USGS Protected Areas Databasepublic domainthe named parks, forests, and refuges behind "notable places to look"