title: Marshes as "Mountain Tops": Genetic Analyses of the Critically Endangered São Paulo Marsh Antwren (Aves: Thamnophilidae).
abstract: Small populations of endangered species can be impacted by genetic processes such as drift and inbreeding that reduce population viability. As such, conservation genetic analyses that assess population levels of genetic variation and levels of gene flow can provide important information for managing threatened species. The São Paulo Marsh Antwren (Formicivora paludicola) is a recently-described and critically endangered bird from São Paulo State (Brazil) whose total estimated population is around 250-300 individuals, distributed in only 15 isolated marshes around São Paulo metropolitan region. We used microsatellite DNA markers to estimate the population genetic characteristics of the three largest remaining populations of this species all within 60 km of each other. We detected a high and significant genetic structure between all populations (overall FST = 0.103) which is comparable to the highest levels of differentiation ever documented for birds, (e.g., endangered birds found in isolated populations on the tops of African mountains), but also evidence for first-generation immigrants, likely from small local unsampled populations. Effective population sizes were small (between 28.8-99.9 individuals) yet there are high levels of genetic variability within populations and no evidence for inbreeding. Conservation implications of this work are that the high levels of genetic structure suggests that translocations between populations need to be carefully considered in light of possible local adaptation and that remaining populations of these birds should be managed as conservation units that contain both main populations studied here but also small outlying populations which may be a source of immigrants.
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Filho", Distrito de Rubião Júnior, s/n, CEP 18618-970, Botucatu, São Paulo, Brazil.
authors.forename: Crisley
authors.initials: C
authors.lastname: de Camargo
authors.affiliation: Department of Evolution, Ecology and Organismal Biology, Ohio State University, Columbus, Ohio 43210-1293, United States of America.
authors.forename: H Lisle
authors.initials: HL
authors.lastname: Gibbs
authors.affiliation: Departamento de Ciências Ambientais, Universidade Federal de São Carlos, Campus de Sorocaba, Rod. João Leme dos Santos, km 110, CEP 18052-780, Sorocaba, São Paulo, Brazil.
authors.forename: Mariellen C
authors.initials: MC
authors.lastname: Costa
authors.affiliation: Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana 70803, United States of America.
authors.forename: Glaucia
authors.initials: G
authors.lastname: Del-Rio
authors.affiliation: Seção de Aves, Museu de Zoologia da Universidade de São Paulo, Caixa Postal 42494, CEP 04218-970, São Paulo, São Paulo, Brazil.
authors.forename: Luís F
authors.initials: LF
authors.lastname: Silveira
authors.affiliation: Departamento de Genética, Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Filho", Distrito de Rubião Júnior, s/n, CEP 18618-970, Botucatu, São Paulo, Brazil.
authors.forename: Adriane P
authors.initials: AP
authors.lastname: Wasko
authors.affiliation: Departamento de Ciências Ambientais, Universidade Federal de São Carlos, Campus de Sorocaba, Rod. João Leme dos Santos, km 110, CEP 18052-780, Sorocaba, São Paulo, Brazil.
authors.forename: Mercival R
authors.initials: MR
authors.lastname: Francisco
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D001938:Brazil; D056727:Endangered Species; D005819:Genetic Markers; D014644:Genetic Variation; D018895:Microsatellite Repeats; D046109:Passeriformes / Q000235:genetics*; D011157:Population Dynamics; D053833:Wetlands
chemical_list: D005819:Genetic Markers