title: Adaptation to ephemeral habitat may overcome natural barriers and severe habitat fragmentation in a fire-dependent species, the Bachman's Sparrow (Peucaea aestivalis).
abstract: Bachman's Sparrow (Peucaea aestivalis) is a fire-dependent species that has undergone range-wide population declines in recent decades. We examined genetic diversity in Bachman's Sparrows to determine whether natural barriers have led to distinct population units and to assess the effect of anthropogenic habitat loss and fragmentation. Genetic diversity was examined across the geographic range by genotyping 226 individuals at 18 microsatellite loci and sequencing 48 individuals at mitochondrial and nuclear genes. Multiple analyses consistently demonstrated little genetic structure and high levels of genetic variation, suggesting that populations are panmictic. Based on these genetic data, separate management units/subspecies designations or translocations to promote gene flow among fragmented populations do not appear to be necessary. Panmixia in Bachman's Sparrow may be a consequence of an historical range expansion and retraction. Alternatively, high vagility in Bachman's Sparrow may be an adaptation to the ephemeral, fire-mediated habitat that this species prefers. In recent times, high vagility also appears to have offset inbreeding and loss of genetic diversity in highly fragmented habitat.
authors.affiliation: School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America.
authors.forename: Blain
authors.initials: B
authors.lastname: Cerame
authors.affiliation: Tall Timbers Research Station and Land Conservancy, Tallahassee, Florida, United States of America.
authors.forename: James A
authors.initials: JA
authors.lastname: Cox
authors.affiliation: Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.
authors.forename: Robb T
authors.initials: RT
authors.lastname: Brumfield
authors.affiliation: Archbold Biological Station, Venus, Florida, United States of America.
authors.forename: James W
authors.initials: JW
authors.lastname: Tucker
authors.affiliation: School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America.
authors.forename: Sabrina S
authors.initials: SS
authors.lastname: Taylor
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000818:Animals; D017753:Ecosystem; D005390:Fires; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D006702:Homing Behavior; D008928:Mitochondria / Q000201:enzymology; D009245:NADH Dehydrogenase / Q000235:genetics; D011336:Probability; D018401:Sample Size; D015144:Southeastern United States; D046370:Sparrows / Q000235:genetics* / Q000502:physiology*
chemical_list: D009245:NADH Dehydrogenase