Southeastern beach mouse
Peromyscus polionotus niveiventris
Overall vulnerability:
Conservation status:
Federally ThreatenedGeneral Information
Very little is known about the life history of the Southeastern beach mouse, a subspecies of the small old-field mouse, endemic to the dunes of Florida’s Atlantic coast. The beach mouse can reach a length of 5 inches and has grayish-brown back and white belly. The Southeastern beach mouse is dependent on dune habitat for food and shelter, burrowing under dune vegetation and eating a diet of insects, seeds and fruit. The species is monogamous and has the fast-reproductive cycle common of small mammals. Breeding season typically occurs during the early winter months but can continue year-round in optimal food and climate conditions.
Habitat Requirements
The Southeastern beach mouse relies exclusively on sand dune habitat on the Atlantic coast of the Florida peninsula from between Volusia and Martin counties.
Habitats:
Habitat area:
- 2,491 hectares within Florida (modeled)
- 1,477 hectares (59%) is located on public lands
Habitat impacted by up to 3 meters sea level rise:
Climate Impacts
As a coastal endemic subspecies, the Southeastern beach mouse faces substantial threats related to climate change. First, sea level rise is a grave impending threat to the beach mouse’s island habitat. Additionally, this species faces many of the same existing threats common to coastal or island species: habitat loss and degradation from coastal development, barriers to migration, habitat disturbance from recreational use and high mortality from non-native predators. These existing threats are likely to be magnified by the increasingly severe storm events and shifting conditions of a changing climate.
More information about general climate impacts to species in Florida.
Vulnerability Assessment(s)
The overall vulnerability level was based on the following assessment(s):
Standardized Index of Vulnerability and Value Assessment
Vulnerability: Highly vulnerableThe primary factors contributing to vulnerability of the Southeastern beach mouse are sea level rise, presence of barriers, habitat fragmentation, runoff and storm surge, and alterations to biotic interactions and disturbance regimes. Biotic interactions include increased depredation by feral cats. This species is already extirpated from non-protected lands.
Adaptation Strategies
- Conservation of existing beach habitat will allow the beach mouse the best chance of recovering and maintaining a healthy population as climate change begins to accelerate. This includes controlling existing stressors, such as reducing populations of non-native predators.
- As sea level rise may eventually become too great a threat for the Southeastern beach mouse in its current habitat, developing and maintaining a captive breeding population is a strategy to consider for this coastal endemic subspecies.