Explanation of Indicator
Given its status as a state endangered species and its dependence on a high quality coastal habitat, the beach mouse is important as an indirect indicator of the state’s coastal environmental health and the declining abundance of beach mice habitat. Optimal habitat for this species consists of primary and secondary dunes and scrub dunes. Development of the dune habitat is generally accompanied by a decline in beach mice populations, either as a direct result of habitat loss or indirectly as a result of predation or increased competition with house mice. Minimum effective habitat range necessary for the long-term survival of beach mouse populations has not been determined.
Changes in beach mice range are a direct indicator of the physical availability and quality of suitable habitat. As impacts associated with development increase, beach mice populations and ranges decrease.
Data Characteristics
SOURCE
The contact for southeastern beach mice data is Jeff Gore at the Florida Game and Fresh Water Fish Commission, 3911 Highway 2321, Panama City, Florida 32409, or at (904) 265-3677. Additional data on the Anastasia Island beach mouse can be obtained from Philip Frank at the Florida Game and Fresh Water Fish Commission, 2796 Overseas Highway, Suite 213, Marathon, Florida, 33050, or at (305) 289-2365. Additional data on the southeastern beach mouse can be obtained from Mark Robson at the Florida Game and Fresh Water Fish Commission, 551 North Military Trail, West Palm Beach, Florida, 33415, or at (407) 640-6100.
ACQUISITION
The data can be obtained in hard copy format at no cost.
COLLECTION
The data are being updated in 1995 and will continue to be updated on a five-year basis.
Data Limitations
The data are limited in that it is difficult to obtain reliable figures due to the characteristics of the species. The niche of the beach mouse in coastal ecosystems is not well understood at this time; however, experts recognize this species as a significant component of the coastal strand and dune community. Additionally, this indicator reflects linear kilometers (km) of habitat occupied. Variations in habitat width are not accounted for; therefore, all sections of habitat should not be assumed to be of equivalent quality. Data on the habitat of the southeastern beach mouse are figures for total limit of distribution and include both unoccupied and unsuitable stretches of habitat. Because data are collected every five years, an immediate response to conditions and trends is not reflected by the data. Regardless of the data limitations, the best available measure of beach mouse status is given by linear kilometers of habitat occupied.
This indicator is useful in that it can determine successes and failures in protecting the state’s remaining coastal strand and dune habitats. Only historic data are available at this time, however, so this indicator should be used as a benchmark until additional data are available.
Data Analysis
Based on the 1990 data, the Choctawhatchee beach mouse (Peromyscus polinotus allophrys) presently inhabits about 6.5 km of beach dunes at Topsail Hill and 9.4 km on Shell Island. The Perdido Key beach mouse (Peromyscus polinotus trissyllepsis) is the most endangered of the five subspecies of beach mice listed as endangered by the United States government; it presently occupies 11 km of habitat on Gulf Islands National Seashore. The St. Andrew beach mouse (Peromyscus polinotus peninsularis) inhabits an 8 km strip of high dunes at the north end of St. Joseph Peninsula State Park and in a small, unquantified patch of habitat on Crooked Island East in Bay County. The Anastasia Island beach mouse (Peromyscus polinotus phasma) presently inhabits 13 km of habitat on Anastasia Island. The threatened southeastern beach mouse (Peromyscus polinotus niveiventris) has been documented on 200 km of shoreline, from Ponce Inlet south to Ft. Pierce Inlet State Recreational Area.