Delaware mammals

Muskrat in Delaware

Ondatra zibethicus

Native to Delaware S5 Secure in Delaware

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

Muskrats resting on a floating log in open waterMuskrat swimming head-on through calm waterLive muskrat sitting on a grassy bank at the water edgeTwo muskrats at a grassy water edgeMuskrat swimming with a long narrow tail trailing behind
Photo: Ken Clark · CC-BYMuskrats resting on a floating log in open waterPhoto: Svetlana Tsarakhova · CC0Muskrat swimming head-on through calm waterPhoto: Robert McLeod · CC0Live muskrat sitting on a grassy bank at the water edgePhoto: Dan Vickers · CC-BYTwo muskrats at a grassy water edgePhoto: Lukas Zangl · CC-BYMuskrat swimming with a long narrow tail trailing behind

Muskrat in Delaware, by the numbers

Common in Delaware 6th most recorded of 62 mammals logged in Delaware

242 occurrence records
241 with iNaturalist photos
Jul 2, 2026 Last seen in Delaware

Records from 2000–2026.

242 total records count every Delaware occurrence from GBIF and iNaturalist; the monthly chart covers the 241 records with a full observation date.

When to look for the Muskrat in Delaware

Most sightings fall in April to June.

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

Monthly Delaware records (table)
MonthRecords
January8
February6
March27
April58
May55
June43
July26
August6
September3
October1
November4
December4

Monthly muskrat occurrence records (iNaturalist and GBIF) in Delaware, 2000–2026.

Seasonality

Year-round in Delaware, with recorded sightings peaking in April–June.

Occurrence map

Where Muskrat has been recorded in Delaware

242 records mapped · zoom and drag to explore

242 Delaware records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Lums Pond State Park 3
Fort Delaware State Park 2
Saint Jones Reserve 2
Augustine Wildlife Area 1
Woodland Beach Wildlife Area 1
Ingram Pond 1
First State National Historical Park 1
Abbotts Pond 1

Protected places with the most muskrat 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 Delaware

CountyRecords
Kent County 119
Sussex County 88
New Castle County 31
Other localities 4

The complete county distribution, spread across 3 Delaware counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Muskrats inhabit Delaware’s freshwater and brackish marshes, ponds, and slow creeks. Refuge impoundments at Bombay Hook and Prime Hook are strong viewing areas: scan emergent vegetation for a low-swimming animal, narrow V-shaped wake, or dome-shaped lodge.

They occur year-round, with records strongest from April through June. Early morning and evening offer the best chance of surface activity; observation totals emphasize accessible boardwalks and wildlife drives.

Occurrence data from iNaturalist and GBIF.

Muskrat in other states

Muskrats resting on a floating log in open water
Full species profile Muskrat Ondatra zibethicus Size 25–36 cm9.8–14.2 in Weight 0.6–2 kg1.3–4.4 lb Lifespan 3 yr View the full profile

More mammals in Delaware in the atlas

Data & sources

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