Southeastern Beach Mouse
Peromyscus polionotus niveiventris
The Southeastern Beach Mouse is a federally threatened coastal mouse found only in dune habitat along Florida's Atlantic coast.
The Southeastern Beach Mouse is a pale coastal subspecies of the oldfield mouse. Its light coat, white belly, and partly white tail help it blend into Atlantic beach sand.
It lives in primary dunes, secondary dunes, and nearby scrub where sea oats and other native plants provide food and cover. Its limited range makes every remaining dune system important.
Habitat:
Beaches and Dunes, Scrub and Dry Prairie
Area / Range:
Central Florida, South Florida, Atlantic Coast
Diet:
Eats seeds and fruits from sea oats and other dune plants, along with insects and other small invertebrates. It also stores food in burrows.
Behavior:
Primarily nocturnal. It digs burrows in loose dune sand and forages under cover of darkness. Breeding can occur throughout the year when food is available, with activity often peaking during cooler months.
Night, Dusk, Dawn
Active Times:
Best time to see:
Rarely seen. Look only from established paths at dusk or dawn in protected Atlantic dune habitat
Florida Native Status:
Native Florida subspecies
Conservation Status:
Federally Threatened and listed in Florida as Federally-designated Threatened. Habitat loss, storms, dune disturbance, artificial lighting, free-roaming cats, and fragmented populations remain major threats.
Safety Level:
Low Risk
Safety Information:
Harmless to people and pets. Do not handle, trap, feed, or disturb beach mice or their burrows. Keep cats indoors and stay off protected dunes.
Benefits to Property:
Moves and caches native dune seeds, contributing to plant regeneration and a functioning coastal food web. Healthy mouse habitat also supports stable, vegetated dunes.
Property Concerns:
Coastal construction, vegetation clearing, pesticide use, outdoor lighting, and pet predation can harm this protected subspecies. Projects within occupied habitat may require agency review and permits.
Fun Fact:
Beach mice use multiple burrows for shelter, food storage, and escape. Their pale coloring is a local adaptation to bright coastal sand.
Wildlife Laws:
The Southeastern Beach Mouse is protected under the federal Endangered Species Act and Florida's Endangered and Threatened Species Rule. It is illegal to harm, capture, possess, or destroy occupied habitat without required authorization.
Identification:
Adults average about 5.3 to 5.5 inches in total length. The back is light brown to gray, the forehead is buff, and the belly is white. The tail is short and distinctly pale.
Large dark eyes and rounded ears reflect its nocturnal habits. Location is important because Florida has several closely related beach mouse subspecies.