Genetic status of the wood stork (Mycteria americana) from the southeastern United States and the Brazilian Pantanal as revealed by mitochondrial DNA analysis

Abstract

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.

Genetic differentiation and historical demography of wood stork populations in Brazilian wetlands: Implications for the conservation of the species and associated ecosystems

“…Wood stork breeding colonies in the Amapá and Pantanal wetlands have moderate microsatellite diversity (Table 1). within the range observed in jabiru storks (Jabiru mycteria) in the Brazilian Pantanal (Lopes et al, 2011), Oriental storks (Ciconia boyciana) in China (Huang & Zhou, 2011) and white storks (Ciconia ciconia) in Europe (Shephard, Galbusera, Hellemans, Jusic, & Akhandaf, 2009;Shephard, Ogden, Tryjanowski, Olsson, & Galbusera, 2013). Storks therefore appear to conform to the trend of low to moderate nuclear genetic diversity described for waterbirds (mean He: 0.44 to 0.83; see Table S1 in Eo, Doyle, & DeWoody, 2011).…”

“…Alleles were scored using the MegaBACE Fragment Profiler® v1.2 (GE Healthcare, Piscataway, NY, USA). A subset of samples was amplified at a fragment of the mitochondrial Control Region (mtDNA CR) following Lopes et al (). Sequencing was performed in ABI Prism 3700/3730 machines using the Big‐Dye Terminator Cycle kit (Perkin Elmer, Walthan, MA, USA).…”

“…Sequences were aligned and visually verified using CodonCode Aligner v2.0.5 (CodonCode Corporation) and BioEdit 7.0.9 (Hall, ). Coding fragments were trimmed out from all sequences, and further analyses were carried out with 237‐bp fragments of untranslated mtDNA CR, in contrast to a previous study (Lopes et al, ) that also included translated fragments.…”

“…Previous studies based on only one type of molecular marker found low levels of genetic structure between wood stork breeding colonies located in the Brazilian Pantanal (Del Lama, Lopes, & Del Lama, 2002;Lopes, Rocha, & Del Lama, 2004;Lopes et al, 2006Lopes et al, , 2011Rocha, Del Lama, & de Regitano, 2004). In agreement, the results of genetic estimation, assignment tests, Bayesian clustering and coalescent models performed in the present study support continuing gene flow between wood stork colonies within the Pantanal as well as among those settled within the Amapá wetlands.…”

“…Samples were amplified by polymerase chain reaction (PCR) at nine species-specific microsatellites (Table S2) (Hall, 1999). Coding fragments were trimmed out from all sequences, and further analyses were carried out with 237-bp fragments of untranslated mtDNA CR, in contrast to a previous study (Lopes et al, 2011) that also included translated fragments.…”