Genetic variability among populations of the Florida grasshopper sparrow

Genetic variability within and among the 6 known populations of the endange red Florida grasshopper sparrow (Ammodramus savannarum floridanus) was exam ined using randomly amplified polymorphic DNA (RAPDs) and microsatellites. Information from DNA profiling may provide insight into sparrow movements a nd a basis for recovery efforts. Blood samples were collected from 118 indi viduals in southcentral Florida. Distances separating populations varied fr om 4.0 to 33.3 km. Measures of allele frequencies indicated reduced heteroz ygosity (mean F-IS = 0.134). Both the RAPD and microsatellite markers indic ated little genetic differentiation among populations, except that the 2 sm allest populations showed some genetic differentiation from the other popul ations based upon the RAPD markers. Small geographic distances and interven ing unsuitable habitat do not appear to inhibit movements between populatio ns. Genetic similarities also may indicate populations that are only recent ly isolated due to habitat fragmentation.