We isolated 11 polymorphic microsatellite loci for wood stork ( Mycteria americana ). Polymerase chain reaction (PCR) primers and conditions are described for the amplification of five dinucleotide, one trinucleotide and five tetranucleotide microsatellite loci. The PCR primers were tested on two wood stork populations, Fazenda Ipiranga, Mato Grosso, Brazil ( n = 11) and Tamiami West, Everglades, Florida, USA ( n = 20). The primers yielded two to four alleles per locus, an observed heterozygosity of 0.0 -0.727 and a polymorphic information content of 0.048 -0.604. The low level of polymorphism for these markers is consistent with previous studies of this species.

ABSTRACT. The wood stork (Mycteria americana) is a colonial wading bird that inhabits the Neotropical region from the southeastern United States (US) to northern Argentina. The species is considered to be endangered in the US due to degradation of its foraging and breeding habitat. In other parts of its range, such as in the Brazilian Pantanal region, breeding populations of this species appear to be stable. We compared the levels of genetic variability and population structuring of the US and the Pantanal breeding populations using mitochondrial DNA (mtDNA) control region 1910-1922 (2011) Mitochondrial DNA diversity of wood storks sequences. Twenty-seven haplotypes were identified among 88 wood stork samples collected from eight breeding colonies in the US and eight in the Pantanal. Patterns indicative of heteroplasmy were observed in 35.3% of the mtDNA sequences that were examined. Significantly higher levels of haplotype diversity were observed in the Pantanal samples compared to those from the US, suggesting that during the last century, demographic declines or a recent evolutionary bottleneck reduced the levels of mtDNA variability of the US population. Analyses of genetic structuring revealed non-significant genetic differentiation between these regions, indicating that either the populations were only recently separated or that gene flow continues to occur at low levels. Haplotype network analysis indicated low current levels of gene flow between populations that were closely related in the past.