New York mammals

Norway Rat in New York

Rattus norvegicus

Introduced to New York

New York's Rattus norvegicus records are of an introduced species; it does not occur here as a wild native population.

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.

Live Norway rat beside shallow waterBrown rat crossing stones in a streamNorway rat feeding in short vegetationBrown rat standing beside rocks in an urban parkLive Norway rat walking through debris beside human structures
Photo: Charles J. Sharp · CC BY-SA 4.0Live Norway rat beside shallow waterPhoto: Sciadopitys from UK · CC BY-SA 2.0Brown rat crossing stones in a streamPhoto: AnemoneProjectors (talk) · CC BY-SA 2.0Norway rat feeding in short vegetationPhoto: Chuck Homler d/b/a Focus On Wildlife · CC BY-SA 4.0Brown rat standing beside rocks in an urban parkPhoto: Steve Milsom · CC0Live Norway rat walking through debris beside human structures

Norway Rat in New York, by the numbers

Common in New York 8th most recorded of 102 mammals logged in New York

2,454 occurrence records
2,318 with iNaturalist photos
Jul 9, 2026 Last seen in New York

Records from 2000–2026.

2,454 total records count every New York occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 300; the monthly chart covers the 2,439 records with a full observation date.

When to look for the Norway Rat in New York

Most sightings fall in April to October.

2,439 New York occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly New York records (table)
MonthRecords
January135
February127
March173
April251
May261
June196
July220
August260
September294
October230
November149
December143

Monthly norway rat occurrence records (iNaturalist and GBIF) in New York, 2000–2026.

Seasonality

Year-round in New York, with recorded sightings peaking in April–October.

Occurrence map

Where Norway Rat has been recorded in New York

300 records mapped · zoom and drag to explore

299 New York records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Long Island 130
Gateway National Recreation Area 12
Hudson River Park 9
Calder Ecology Center 2
Manhattan State Psychiatric Center 2
Niagara River corridor 1
Northampton Beach Campground 1
Long Beach Bay Tidal Wetlands Area 1

Protected places with the most norway rat 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 New York

CountyRecords
New York County 1,631
Kings County 349
Queens County 129
Bronx County 85
Suffolk County 65
Tompkins County 33
Nassau County 29
Westchester County 19
Erie County 10
Rensselaer County 9
Monroe County 8
Ulster County 8
31 other counties 79

The complete county distribution, spread across 43 New York counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

New York’s Norway-rat records are concentrated in dense urban settings, especially waterfront, rail, market, and refuse-handling corridors in New York City and Buffalo. They are most likely to be noticed after dark; observation records strongly favor places people visit and do not measure infestation levels.

Reports are spread through the year without a strong seasonal peak. Winter weather shifts activity toward sheltered structures and tunnels, while mild nights bring more surface movement.

Occurrence data from iNaturalist and GBIF.

Live Norway rat beside shallow water
Full species profile Norway Rat Rattus norvegicus Size 15–28 cm5.9–11 in Weight 140–500 g0.3–1.1 lb Lifespan Up to 3.8 yr View the full profile

More mammals in New York 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"