Genetic variability among populations of the Florida grasshopper sparrow

Genetic variability within and among the 6 known populations of the endangered Florida grasshopper sparrow. (Ammodramus savannarum floridanus) was examined using randomly amplified polymorphic DNA (RAPDs) and microsatellites. Information from DNA profiling may provide insight into sparrow movements and a basis for recovery efforts. Blood samples were collected from 118 individuals in southcentral Florida. Distances separating populations varied from 4.0 to 33.3 km. Measures of allele frequencies indicated reduced heterozygosity (mean F(IS)= 0.134). Both the RAPD and microsatellite markers indicated little genetic differentiation among populations, except that the 2 smallest populations showed some genetic differentiation from the other populations based upon the RAPD markers. Small geographic distances and intervening unsuitable habitat do not appear to inhibit movements between populations. Genetic similarities also may indicate populations that are only recently isolated due to habitat fragmentation.