Reassessment of the Taxonomic Status of the Cotton Mouse (Peromyscus gossypinus anastasae) on Cumberland Island, Georgia, and Implications of this Information for Conservation

Boone, J. L.
Museum of Natural History and Institute of Ecology, University of Georgia, Athens, GA

Four subspecies of cotton mice (Peromyscus gossypinus gossypinus, P. g. megacephalus, P. g. palmarius, and P. g. anastasae) were examined for genetic (14 populations, n = 379, no. loci = 44) and morphological variation (20 populations, n = 683, no. characters = 27) to assess the taxonomic validity of P. g. anastasae and the affinities of P. gossypinus on Cumberland Island.

This species is highly variable within and among populations. Polymorphic loci and heterozygosity per population averaged 40% and 10%, respectively. There was no reduction of genetic variability on the islands, but island mice were generally smaller than mainland mice. Genetic similarity among populations, averaging 0.915, was relatively low for conspecific populations.

Essentially every population was significantly different, genetically and morphologically, from all others when tested in pairwise comparisons. When all of the populations were examined simultaneously, the pairwise interpopulation differences became trivial and were not significant.

While each population was unique, no population was unusually distinct, and neither the Cumberland Island nor Amelia Island populations of P. g. anastasae were sufficiently different from other populations to warrant recognition as separate subspecies, and should be designated P. g. gossypinus. Despite this, the Cumberland Island and other populations continue to represent unique genetic stocks that deserve further study and conservation. The implications for the management and conservation of these mice are discussed.

Note: All distances, elevations, and other facts are approximate.
; Last updated 081213