ABSTRACT
We screened 44 heterologous microsatellites isolated in species of the families Threskiornithidae, Ciconiidae and Ardeidae for their use in a migratory waterbird, the white-faced ibis Plegadis chihi (Vieillot, 1817) (Threskiornithidae). Of the screened loci, 57 percent amplified successfully and 24 percent were polymorphic. In two breeding colonies from southern Brazil (N = 131) we detected 32 alleles (2-10 alleles/ locus). Average He over all loci and colonies was 0.55, and the combined probability of excluding false parents, 98 percent. There was no departure from HWE in any loci or population. Eru6 and Eru4 loci were in non-random association in the Alvorada colony, and NnNF5 and Eru5 in both populations. AMOVA analysis indicated that most of the genetic diversity was contained within populations. Structure analysis suggested a single population, and F ST value showed weak genetic structuring (F ST = 0.009, p = 0.05). The two populations are apparently connected through gene-flow. The panel of six microsatellites optimized here was sufficiently informative for characterizing the genetic diversity and structure in these natural populations of the white-faced ibis. The information generated could be useful in future studies of genetic diversity, relatedness and the mating system in Plegadis chihi and related species.