Genetic variability of Conopophaga lineata (Conopophagidae) (Wied-Neuwied, 1831) in Atlantic Forest fragments

Abstract

Forest fragmentation affects bird populations in many ways, modifying the composition of communities and favouring open country species. The Atlantic Forest is considered one of the most important biomes in the world, due to its great biodiversity, accelerated rates of deforestation, and high endemism. Despite these characteristics, few studies have evaluated the effects of forest fragmentation in the genetic structure of Atlantic forest bird populations. So, this study aims to verify the effects of forest fragmentation in the genetic population structure of Conopophaga lineata, through RAPD markers. To achieve this goal, 89 C. lineata individuals were captured in nine Atlantic Forest fragments in Minas Gerais State. The RAPD data indicate that forest fragmentation has not affected the genetic variation of C. lineata populations (Mann-Whitney U = 3.50; p = 0.11). Great part of the genetic variability of this species is found within populations and it was not observed a correlation between genetic and geographic distance (Mantel test t = 0.6250; p = 073). UPGMA analyses did not show defined clades and all branches showed low statistical support. The low population differentiation observed in this species can be due to a high gene flow among populations or a recent fragmentation. Thus, the current diversity status of C. lineata populations indicates that this species is not significantly affected by fragmentation. However, more genetic studies are essential to improve conservation strategies of Brazilian Atlantic Forest birds.Keywords: RAPD, passeriformes, birds. Variabilidade genética de Conopophaga lineata (Conopophagidae) em fragmentos florestais da Mata Atlântica ResumoA fragmentação florestal afeta populações de aves de muitas maneiras, modificando a composição das comunidades e favorecendo espécies de áreas abertas. A Mata Atlântica é considerada um dos biomas mais importantes do mundo, devido à sua grande biodiversidade, aos altos níveis endemismo e de desmatamento. Apesar destas características, poucos estudos avaliaram os efeitos da fragmentação florestal na estrutura genética de populações de aves desse ecossistema. Dessa forma, este estudo visa verificar os efeitos da fragmentação florestal na variabilidade genética de Conopophaga lineata, através de marcadores RAPD. Assim, foram capturados 89 indivíduos de C. lineata em nove fragmentos florestais da Mata Atlântica do Estado de Minas Gerais. Os dados de RAPD indicam que a fragmentação florestal não afetou a variabilidade genética de Conopophaga lineata (Mann-Whitney U = 3,50; p = 0,11). Grande parte da variabilidade dessa espécie se encontra dentro das populações e não foi observada correlação entre a distân-cia geográfica e a distância genética (Teste de Mantel t = 0,6250; p = 0.73). A análise UPGMA não mostrou clados definidos e todos os ramos apresentaram baixo suporte estatístico. A reduzida diferenciação populacional observada nessa espécie pode ser devida a intenso fluxo gênico entre as populações ou à recente fragmentação na região. Assim...

Population structuring of the endemic black-cheeked gnateater, Conopophaga melanops melanops (Vieillot, 1818) (Aves, Conopophagidae), in the Brazilian Atlantic Forest

“…Bates et al (1999) and Bates (2000) also found substantial levels of genetic differentiation among Amazonian passerine populations in a continuous forest at a local scale (sites 200 km apart), which were explained by the sedentary nature of the studied species. On the other hand, Dantas et al (2007) did not find significant genetic structuring in the congener Conopophaga lineata (Wied, 1831) in semideciduous Atlantic Forest fragments of Minas Gerais State, even when RAPD markers were applied to populations that were more than 600 km apart. Likewise, McDonald (2003) found relatively low levels of genetic differentiation between two populations of Long-tailed Manakin, Chiroxiphia linearis (Bonparte, 1838), in Costa Rica, between a mid-elevation (1,300 m) and a sea-level site separated by 115 km, using microsatellite markers.…”

Bird movement in a fragmented Atlantic Forest landscape

“…Even though apparently low, this value suggests that, in general, there is a lot of gene flow in the forest fragments studied. Support for this statement comes from genetic analyses indicating that populations of Conopophaga lineata from Atlantic Forest have not been effected by fragmentation (Dantas et al 2007). This result is important if we consider that isolated populations may suffer from inbreeding depression (Ralls et al 1986;Primack 1993).…”