What is the avifauna of Amazonian white-sand vegetation?

Abstract

White-sand vegetation (WSV) is a rare vegetation type in the Amazon basin that grows in nutrient impoverished sandy soils that occur as patches of variable size. Associated with this vegetation is bird assemblage that has not yet been fully characterized. Based on published species inventories and our own field data we compile a checklist of bird species recorded in WSV. In addition, we compared the avifauna of WSV with that found in savanna patches, another type of Amazonian open vegetation. WSV hosted a distinctive avifauna including endemic and threatened species. The number of bird species was lower in WSV compared to nearby terra firme forests, seasonally flooded forests and Amazonian savannas. Despite its low diversity, the avifauna of WSV has a distinctive species composition and makes a significant contribution to Amazonian beta diversity. At least 35 bird species can be considered as indicator species for this environment. Previously identified areas of endemism within the Amazon basin house at least one WSV indicator bird including cases of congeneric species with allopatric distributions. Seven of the WSV indicator species (20% of this avifauna) are in an IUCN threatened category, with one species Polioptila clementsi considered Critically Endangered. Their isolated distribution, small area occupied, and fragility to human-driven disturbances makes WSV one of the most threatened vegetation types in the Amazon basin. The study of WSV avifauna contributes to a better understanding of mechanisms that generate and maintain species diversity as well as of the environmental history of the most biologically diverse biome of the planet.

Comparative Phylogeography of Two Bird Species, Tachyphonus phoenicius (Thraupidae) and Polytmus theresiae (Trochilidae), Specialized in Amazonian White‐sand Vegetation

“…The high habitat specialization of WSV bird communities (Oren , Borges , , , Borges et al . ), suggests a connection between the history of the white‐sand formations and the evolution of the bird species characteristic of this habitat.…”

“…The avifauna of the two main Amazonian open vegetation habitats, savannas and WSV, are distinct in species composition, and while the savanna avifauna shares many species with other biomes, such as the Cerrado and Atlantic forest, most typical WSV bird species occur only within Amazonia (Borges , , Borges et al . ). The high habitat specialization of WSV bird communities (Oren , Borges , , , Borges et al .…”

Use of autonomous audio recordings for the rapid inventory of birds in the white-sand forests of the Peruvian Amazon

“…The number of functional white‐sand forest patches and their connectivity will likely be reduced by continuing anthropogenic pressures (Borges et al. ,b). Because they host a unique assemblage of birds not found elsewhere in Peru, protecting these white‐sand forests is crucial.…”

“…, Borges et al. ,b). Given the limited connectivity between patches of white‐sand forest, assemblages of bird species occupying these forests can vary over even a regional scale (Capurucho et al.…”

“…This low connectivity between patches renders many of these avian specialists particularly vulnerable to extinction (Borges et al. ,b), especially because patches of white‐sand forest are small and cannot support viable source populations.…”