SREL Reprint #2405

Low levels of genetic variability in North American populations of the wood stork (Mycteria americana)

Ronald A. Van Den Bussche1, Stephanie A. Harmon1, Robert J. Baker2, A. Lawrence Bryan, Jr.3,
James A. Rodgers, Jr.4, Michael J. Harris5, and I. Lehr Brisbin, Jr.3

1Department of Zoology and Oklahoma Cooperative Fish and Wildlife Research Unit,
Oklahoma State University, Stillwater, Oklahoma 74078, USA
2Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409, USA
3Savannah River Ecology Laboratory, Aiken, South Carolina 29802, USA
4Wildlife Research Laboratory, Florida Game and Fresh Water Fish Commission, Gainesville, Florida 32601, USA
5Georgia Department of Natural Resources, Social Circle, Georgia 30025, USA

Abstract: The breeding population of Wood Storks (Mycteria americana) in the southeastern United States has declined since the 1930s, resulting in the listing of all United States populations of the species as endangered in 1984. We assessed genetic structure within and among nine colonies of Wood Storks from Georgia and Florida. Levels of band sharing based on multilocus oligonucleotide DNA fingerprinting of individuals from seven colonies ranged from 58% among nests within the same tree to approximately 55% within the same colony. Levels of band sharing were similar to those reported for other populations of birds that have experienced drastic reductions in population size. A more thorough analysis of four polymorphic microsatellite loci for 136 individuals from nine colonies indicated low levels of allelic diversity and low genetic divergence among colonies. Genetic differentiation (FST = 0.015) was similar to levels detected from allozymes for 15 colonies of Wood Storks in Florida (FST = 0.019). These data, together with demographic studies of these populations, indicated high levels of gene flow among colonies (Nm = 16.4). In agreement with previous studies, we recommend that all colonies of Wood Storks in the southeastern United States be managed on a regional basis as a single interbreeding population. Similar genetic surveys of the disjunct breeding populations of Wood Storks in South America and Central America would be beneficial in understanding the total genetic differentiation in the species.

SREL Reprint #2405

Van Den Bussche, R.A., S.A. Harmon, R.J. Baker, A.L. Bryan, Jr., J.A. Rodgers, Jr., M.J. Harris, and I.L. Brisbin, Jr. 1999. Low levels of genetic variability in North American populations of the wood stork (Mycteria americana). The Auk 116:1083-1092.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).