Seaside Sparrows (Ammodramus maritimus) along the Gulf of Mexico are currently recognized as four subspecies, including taxa in Florida (A. m. juncicola and A. m. peninsulae) and southern Texas (Ammodramus m. sennetti), plus a widespread taxon between them (A. m. fisheri). We examined population genetic structure of this “Gulf Coast” clade using microsatellite and mtDNA data. Results of Bayesian analyses (Structure, GeneLand) of microsatellite data from nine locations do not entirely align with current subspecific taxonomy. Ammodramus m. sennetti from southern Texas is significantly differentiated from all other populations, but we found evidence of an admixture zone with A. m. fisheri near Corpus Christi. The two subspecies along the northern Gulf Coast of Florida are significantly differentiated from both A. m. sennetti and A. m. fisheri, but are not distinct from each other. We found a weak signal of isolation by distance within A. m. fisheri, indicating this population is not entirely panmictic throughout its range. Although continued conservation concern is warranted for all populations along the Gulf Coast, A. m. fisheri appears to be more secure than the far smaller populations in south Texas and the northern Florida Gulf Coast. In particular, the most genetically distinct populations, those in Texas south of Corpus Christi, occupy unique habitats within a very small geographic range.
School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, Louisiana, 70803, United States of America;School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, Louisiana, 70803, United States of America;School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, Louisiana, 70803, United States of America;Mississippi State University - Coastal Research and Extension Center, Grand Bay National Estuarine Research Reserve, Moss Point, Mississippi, 39562, United States of America;Department of Biology, Austin Peay State University, Clarksville, Tennessee, 37040, United States of America;School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, Louisiana, 70803, United States of America
Recommended Citation:
Stefan Woltmann,Philip C. Stouffer,Christine M. Bergeon Burns,et al. Population Genetics of Seaside Sparrow (Ammodramus maritimus) Subspecies along the Gulf of Mexico[J]. PLOS ONE,2014-01-01,9(11)