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 8th most recorded of 62 mammals logged in Delaware

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

Records from 2000–2026.

247 total records count every Delaware occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 238; the monthly chart covers the 238 records with a full observation date.

When to look for the Muskrat in Delaware

Most sightings fall in April to June.

238 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
January7
February5
March28
April60
May54
June40
July25
August8
September3
October1
November3
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

238 records mapped · zoom and drag to explore

238 Delaware records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Lums Pond State Park 3
Saint Jones Reserve 2
Fort Delaware State Park 2
Augustine Wildlife Area 1
Abbotts Pond 1
Ted Harvey Wildlife Area 1
First State National Historical Park 1
Killens Pond State Park 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 116
Sussex County 86
New Castle County 31
Other localities 14

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

Muskrat range map (all 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: