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Monomoy NWR

Site Facts

Country, State, Province/Region:

USA, Chatham, Massachusetts

Relative Location:

North East Atlantic Coast of United States, islands located off the "elbow" of Cape Cod


41˚ 36'N, 69˚ 59'W


Regional Site

Basis for Designation:

Highest one day shorebird count ~21,000


3077 ha. (7604 acres)



Human Population within 100km:

7,000 year-round to 15,000 in peak summer season

Site Owner/Steward:

U.S. Fish & Wildlife Service


Matthew D. Hillman
Refuge Manager
Monomoy National Wildlife Refuge


Sand stretches for eight miles off the elbow of Cape Cod, forming the barrier islands of North Monomoy, South Monomoy and Minimoy. Here, among the varied habitats of oceans, dunes, freshwater ponds, mudflats, salt and freshwater marshes, lies the 7,604-acre Monomoy National Wildlife Refuge. The refuge provides important resting, nesting and feeding habitat for a wide variety of migratory birds including, to date, 40 species of shorebirds.

The fall shorebird migration route originates in the Arctic and eastern Canada and heads south, taking them along an “outer coast” flyway that covers the whole outer Cape from Provincetown to Chatham and west to the towns of Brewster and Harwich. Most of the shorebirds within the local area get funneled toward the Monomoy system that also includes South Beach which is also located in Chatham.

The barrier islands are constantly changing, but the dynamics of the area seem to be beneficial to shorebirds. Sand, eroding and drifting from the outer beaches of Cape Cod, is the foundation of the island refuge. Here, on the edge of the vast Atlantic, storms, high winds, tide and surf endlessly change terrain and shore. Yet in this apparently unstable world, a remarkable array of lasting habitats and niches have evolved, in which shorebirds thrive.


  • 1944 Designated a National Wildlife Refuge, administered by the United States Fish and Wildlife Service
  • 1970 Designated a National Wilderness Area
  • 1999 Designated a Western Hemispheric Shorebird Reserve Network (WHSRN) Regional Site
  • 2001 Designated an Important Bird Area (IBA)

Land Use

Adjacent lands and harbors continue to grow in population and use. Recreational boating, fishing, birding and beach use continue as growing activities within the refuge boundaries. Commercial fishing activities are also conducted within the refuge boundary and immediately adjacent to the boundary.

Habitat Protection

As part of the National Wildlife Refuge System, the lands are protected by all laws and regulations associated with powers of the Fish and Wildlife Service, the Endangered Species Act and the Migratory Bird Treaty Act. Monomoy Refuge also provides additional protection by creating seasonal closures in high shorebird use areas.


Impacts by adjacent recreational and commercial activities can disturb roosting, nesting, feeding and migrating shorebirds. In addition, there are impacts caused by marine debris (plastics and styrofoam), land-based, (fertilizer, pesticides and effluent from septic systems that have been associated with high nitrogen and E. coli) and marine-based (oils and other petroleum products) pollutants.

Management Priorities

A restoration project was initiated on the Refuge in 1996 that increased the diversity and abundance of beach nesting birds. Monomoy was established to perpetuate the natural diversity and abundance of wildlife on the refuge. The site also needs to maintain its character of wilderness and ensure that quality, wildlife-dependent activities are available to visitors using the Refuge.

Ecology & Conservation

Habitat Description
Monomoy was formed through deposition of the eroding glacial deposits of Outer Cape Cod and is continually reshaped by winds and waves and shifting sands. The lands are in constant motion with ever changing island and mudflat configurations, with narrow beaches, dunes, estuarine marsh, freshwater marsh, and a wide intertidal sand and mud flats.


Species that use the site

Maximum count: 2000-2005

Black-bellied Plover 4,000
American Golden-Plover *
Wilson’s Plover *
Semipalmated Plover 4,800
Piping Plover 100
Killdeer 50
American Oystercatcher 195
Greater Yellowlegs 350
Lesser Yellowlegs 220
Solitary Sandpiper *
Willet 225
Spotted Sandpiper *
Upland Sandpiper *
Whimbrel 700
Hudsonian Godwit 80
Marbled Godwit *
Bar-tailed Godwit *
Ruddy Turnstone 350
Red Knot 1,600
Sanderling 4,000
Semipalmated Sandpiper 5,500
Western Sandpiper *
Least Sandpiper 900
White-rumped Sandpiper 400
Baird’s Sandpiper *
Pectoral Sandpiper *
Dunlin 3,400
Stilt Sandpiper *
Buff-breasted Sandpiper *
Short-billed Dowitcher 4,200
Long-billed Dowitcher *
Wil;son's Snipe *
Wilson’s Phalarope *
Red-necked Phalarope *
Red Phalarope *
Ruff *
Rufous-necked Sandpiper *
Little Stint *
Curlew Sandpiper *
Eurasian Curlew *
* Present in the last 5 years but in small numbers
(data collected by B. Nikula, W. Harrington and USFWS Staff)

Special thanks to Blair Nikula who has conducted continuous shorebird surveys since 1973.

Special Information

The best time to visit for shorebird viewing is from mid-summer through late fall. Different species peak at different times through this period. Shorebird abundance is greatest during late July and early August, while diversity is greatest during late August and early September.

Monomoy has the largest Common Tern colony on the Atlantic Coast with over 9000 nesting pair. The Refuge has Black Skimmers and the Federally endangered Roseate Terns which nest in small numbers. There is approximately 40 breeding landbirds such as Common Yellow-throat, Savannah Sparrow and Horned Lark as well as a healthy breeding population of nesting Saltmarsh Sharp-tailed Sparrows. The Refuge has consistent nesting of American Oystercatcher, Willet and the Federally threatened Piping Plover. There are numerous nesting colonial waders, such as; Great Egret, Snowy Egret, Glossy Ibis and Black-Crowned Night-Heron.

The Refuge has large staging flocks of American Oystercatcher and Roseate Terns during fall migration.

Large winter congregations of Common Eider and Long-tailed Ducks are present, with mixed flocks of scoters, mergansers and American Black Ducks. Many Alcid species are present just off-shore. The Refuge also has the only state nesting record for the Ruddy Duck.

Good fall hawk migration with large numbers of Cooper’s Hawk, Sharp-shinned Hawk, Peregrine Falcon and Merlin.

The refuge has one of the largest Gray Seal haul-out sites in New England with over 7000 seals. In the late summer and early fall harbor seals return, and in the winter, occasional arctic seals journey to the refuge.

Monomoy National Wildlife Refuge

From May 1 - October 1 Ferry Services are available to transport people to the Refuge for wildlife dependant activities.

Birding Trips to the Refuge can be found through two organizations.

Bird Sightings:

Virtual Birding at Monomoy for 35 species:

Contact Us

Matthew D. Hillman
Refuge Manager
Monomoy National Wildlife Refuge
Wikis Way, Morris Island
Chatham, MA 02633