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Marsh Rice Rat

Oryzomys palustris

The marsh rice rat is a grayish-brown rodent with a long tail. It lives in tidal marshes near the Chesapeake Bay in Delaware, Maryland and Virginia.

Appearance:

• Long, slender body
• Coarse, grayish-brown fur with some blackish hairs
• Scaly tail that is usually longer than the head and body (about 7 inches long)
• Belly, feet and underside of tail are light grayish or whitish
• Grows to about 5 inches long and weighs less than 3 ounces

Habitat:

• Lives in tidal marshes and swamps
• Prefers areas with plenty of grasses and sedges
• Semi-aquatic, meaning it spends time both on the land and in the water
• Mostly nocturnal

Range:

• Found throughout the Delmarva Peninsula and within the coastal plain in Maryland and Virginia

Feeding:

• An opportunistic feeder, meaning it eats whatever is available
• Foods include insects, snails, fishes, bird eggs and fiddler crabs as well as grasses, sedges and aquatic plants

Predators:

• Owls are a major predator
• Other predators may include hawks, minks, weasels, raccoons, foxes and snakes
• Will often dive underwater when threatened

Reproduction and Life Cycle:

• Breeds several times between March-October
• Females can produce several litters of 3-5 young each year
• Builds a softball-sized nest of woven grasses and sedges in hidden areas above the high-tide mark
• Gestationperiod lasts about 25 days
• Young are born blind and helpless
• By early in their second week of life, young open their eyes and are able to eat solid food
• Females reach sexual maturity within six weeks of age
• Usually does not live longer than one year

Other Facts:

• A skilled swimmer that is able to dive more than 30 feet deep and swim across nearly 1,000-foot stretches of water

Sources and Additional Information:

• Wildlife Information: Marsh Rice Rat – Virginia Department of Game & Inland Fisheries
• North American Mammals: Oryzomys palustris – Smithsonian National Museum of Natural History
• Oryzomys palustris – Discover Life in America

Places:

• Smithsonian Environmental Research Center – Edgewater, Maryland
• Parkers Creek Watershed Nature Preserve – Prince Frederick, Maryland
• Eastern Neck National Wildlife Refuge – Rock Hall, Maryland
• Chesapeake Bay Environmental Center – Grasonville, Maryland
• Blackwater National Wildlife Refuge – Cambridge, Maryland
• Janes Island State Park – Crisfield, Maryland
• Mason Neck National Wildlife Refuge – Lorton, Virginia
• York River State Park – Williamsburg, Virginia
• Dutch Gap Conservation Area – Chesterfield, Virginia
• Hoffler Creek Wildlife Preserve – Portsmouth, Virginia