Genetic diversity and evidence of recent demographic expansion in waterbird populations from the Brazilian Pantanal

Abstract

The present study determined nuclear and mitochondrial (mtDNA) levels of genetic variability and phylogeographic patterns in breeding populations of Roseate Spoonbill (N = 57), Wood Stork (N = 89), and Jabiru Stork (N = 30), sampled in the Brazilian Pantanal. These species were selected since they are bioindicators of wetlands' health and are threatened in other parts of their distribution. As they are in close association with this ecosystem, they are appropriate for studying the effects of Pleistocene climatic changes on their demographic patterns. Levels of nuclear genetic diversity in Pantanal populations were not significantly different from those of other populations throughout the American continent, where they are considered threatened or of special concern. Reduced levels of mtDNA genetic diversity were observed in the Central American population of Jabiru Stork in comparison to the Pantanal population. Recent demographic expansion in the Pantanal was markedly evidenced by unimodal patterns of mismatch distribution and Fu's Fs neutrality test in these three species. We hypothesize that the average time of population expansion (between 30,843 and 14,233 years before present) is associated to responses of these birds' populations to paleoclimatic changes in these wetlands during the last glaciation period. We recommend special conservation efforts with the Jabiru Stork populations, a genetic monitoring program based on mtDNA, and an ecological characterization of these waterbirds species throughout their distribution range.Keywords: waterbirds, Pantanal, populations, genetic variability. Diversidade genética e evidências de expansão demográfica recente nas populações de aves aquáticas do Pantanal brasileiroResumo O presente estudo determinou níveis de variabilidade nuclear e mitocondrial (DNAmit) e padrões filogeográficos de populações reprodutivas de colhereiro (N = 57), cabeça-seca (N = 89) e tuiuiú (N = 30) do Pantanal brasileiro. Estas espécies foram selecionadas porque são bioindicadoras da integridade das áreas alagáveis e se encontram ameaça-das em outras partes da sua área de distribuição. Devido à sua estreita associação com esse tipo de ecossistema, seu estudo permite verificar os efeitos das mudanças climáticas do Pleistoceno nos seus padrões demográficos. Níveis de diversidade genética nuclear nas populações pantaneiras não diferiram significativamente dos encontrados em outras populações ao longo do continente americano onde são consideradas ameaçadas ou como de especial interesse para conservação. Níveis reduzidos de variabilidade genética DNAmit foram observados nas populações de tuiuiú da América Central, quando comparadas às populações do Pantanal. A expansão demográfica recente das três espécies no Pantanal ficou marcadamente evidenciada pelos padrões unimodais da distribuição das diferenças pareadas e pelo teste de neutralidade de Fs de Fu. Hipotetizamos que o tempo médio de expansão populacional (entre 30.843 e 14.233 anos antes do presente) está associado as respostas destas p...

Genetic structuring among populations of the great egret, Ardea alba egretta, in major Brazilian wetlands

“…According to this scenario and as observed in the present study, the intrinsic genetic diversity of equatorial great egret populations would have been maintained, while populations at more southerly latitudes would bear only part of the original variation. The pattern of past expansion found in the great egret populations is similar to that seen in breeding colonies of the wood stork, Mycteria americana , settled in the Pantanal wetland (Lopes et al ., ).…”

“…Therefore, new studies addressing species and geographical ranges that have been unexplored thus far can contribute to understand better the nature and characteristics of processes that model the genetic structure of waterbird populations. Monitoring waterbirds with a genetic approach may also provide valuable information for the establishment of management policies and protective measures for wetlands (Lopes et al, 2007). Examples of genetic monitoring for wetland conservation include the assessment of genetic variation among threatened wetland plants (Godt et al, 1995;Edwards and Sharitz, 2000), the identification of evolutionary lineages of freshwater isopods (Gouws and Stewart, 2007), the use of molecular markers to examine the stock composition of the Chinook salmon (Teel et al, 2009) and, more recently, the investigation of population structure, genetic diversity and demographic history of populations of wetland passerines (Ceresa et al, 2015).…”

Molted feathers from clay licks in Peru provide DNA for three large macaws (Ara ararauna,A. chloropterus, andA. macao)

“…Several studies have revealed the usefulness of molted feathers collected noninvasively for analyses of both mitochondrial and nuclear DNA, but amplification success rates vary considerably (Pearce et al 1997, Segelbacher 2002, Peterson et al 2003, Bush et al 2005, Horváth et al 2005, Rudnick et al 2005, Seki 2006, Hogan et al 2008). As a result, few investigators have used molted feathers as a primary source of genetic material (Segelbacher et al 2003, Lõhmus and Väli 2004, Rudnick et al 2005, Asai et al 2006, Seki 2006) and, in most studies, molted feathers are used to supplement higher quality blood or plucked‐feather samples (Duan and Fuerst 2001, Martínez‐Cruz et al 2004, Nittinger et al 2005, Hailer et al 2006, Lopes et al 2007, Banhos et al 2008).…”

A Review of the Invasive Eurasian Collared Dove and Possible Research Methods in the Future

“…However, an mtDNA study revealed slight differentiation between populations according to a historical east-west division of its distribution (Pecos River in Texas) that is currently disappearing due to the species' range expansion (Pruett et al, 2000). Lopes et al (2007) used both microsatellite loci and mitochondrial DNA analysis in wading birds in Brazilian Pantanal. They determined the genetic variability within and between populations, which is important information for assessing a population's chance of survival, by microsatellites while the demographic history of populations was revealed using mtDNA.…”