João Capurucho is a postdoc at the Instituto Nacional de Pesquisas da Amazônia – INPA. He is a biogeographer and ecologist with a strong focus on Amazonian birds. Here, João shares his recent work on the evolutionary history of white-sand ecosystem birds.
João Capurucho during field work in Amazonia in 2022.
Institute. Instituto Nacional de Pesquisas da Amazônia – INPA.
Academic life stage. Postdoc.
Major research themes. I am interested in biogeography and ecology, with a strong focus on Amazonian birds. My main research questions involve how landscape and climatic history since the Pleistocene (last 2.6 million years) shaped current species’ distribution and genetic diversity, and the existing threats to Amazonian biodiversity. Therefore, I am always looking into different ways to combine museum research, species’ distribution and genetic data, and information from other fields, like climatology and geology, to reconstruct the biogeographic history of bird species/populations.
Current study system. Currently, I am working as a postdoc in a different project from the one related to our recently published paper. We are studying the impact of anthropogenic fire on the bird communities of fragile seasonally flooded forests (igapós) from the Negro River basin. With this purpose, we are deploying autonomous recorders and using passive acoustic monitoring (PAM) methods in several sites that were impacted by fire in different years. Yet, I remain interested in understanding the biogeography and evolution of Amazonian birds, and thus I am pursuing different questions related to their current distribution and diversity patterns in white-sand ecosystems.
Recent JBI paper. Capurucho, J. M. G., Ashley, M. V., Cornelius, C., Borges, S. H., Ribas, C. C., & Bates, J. M. (2023). Phylogeographic and demographic patterns reveal congruent histories in seven Amazonian White-Sand ecosystems birds. Journal of Biogeography, 50, 1221– 1233. https://doi.org/10.1111/jbi.14611.
Motivation behind this paper. I have been interested in the birds inhabiting white-sand ecosystems (WSE) since I started my Master’s studies, advised by Dr. Camila Ribas and Dr. Cintia Cornelius at INPA (Manaus, Brazil). The advance of next generation DNA sequencing and new comparative phylogeographic methods stimulated us to pursue a more comprehensive analysis of species histories and diversity using these new tools. WSE are unique environments that harbor a characteristic avifauna, which we hypothesized would present a distinct biogeographic history when compared to other Amazonian birds from more well-studied habitats (e.g., terra-firme forests). We also thought that, by studying the birds and their molecules, we would improve our understanding of the Amazonian climatic and landscape histories and their impact on fragile WSE.
Field work in the Amazonian white-sand ecosystems back in 2012, to collect data that was later used in our study published at Journal of Biogeography.
Key methodologies. We studied seven species of birds that are characteristic of WSE using a DNA target-capture approach to sequence ultraconserved-elements (UCEs). We performed population structure, demographic modelling and migration surface analyses, among others, to explore genetic diversity and phylogeographic patterns within each species. Then, using a relatively recently developed method deployed in ecoevolity (http://phyletica.org/ecoevolity/), we evaluated the occurrence of shared demographic patterns among the populations of WSE birds.
Unexpected challenges. This publication was part of my PhD thesis, which I developed at University of Illinois in collaboration with the Field Museum of Natural History (Chicago, USA). There were two big challenges during these times: one was pursuing a PhD in a different country and culture, and the other was raising our daughter that was born two years before I finished Grad school. Anyway, I would do it all over again if necessary!
The sun rising at a white-sand ecosystem. We used bikes to access field sites close to the Viruá National Park, in Roraima, Brazil.
Major results. The most striking result was that, virtually, all populations that showed signals of population expansion in the recent past shared the timing of when this event happened. We show that all studied WSE birds, despite their relatively old origins (see our other publication for more details), present shallow population structure, with evidence of gene flow among populations. Similar patterns are observed in other dynamic Amazonian systems (e.g., seasonally flooded forests), but not in more stable environments (e.g., terra-firme). The oldest population split occurred 450,000 years ago, which is quite recent compared to many studied Amazonian birds from other ecosystems. We found that nine populations of WSE birds expanded demographically in the last 100,000 years, with eight of them distributed north of the Amazon River. This huge congruence in phylogeographic patterns and history shows that recent climatic and landscape history strongly affected the distribution and genetic diversity of birds inhabiting WSE.
Next steps for this research. We are currently combining ecological niche models and phylogeographic approaches to better understand the processes driving distribution and diversity patterns of WSE birds. However, the strong association of birds to WSE and their sandy soils make it hard to develop robust ENMs for these birds, due to the lack of reliable and high-quality soil data for Amazonia. We are looking into ways to overcome this issue and improve our analyses.
Typical physiognomy of a white-sand ecosystem in Central Amazonia (RDS Uatumã, Amazonas, Brazil).
If you could study any organism on Earth, what would it be? Birds, birds, birds! Isn’t it obvious?!