What do rainforest birds eat?
This question that has has puzzled ornithologists for years. Despite technological advances, the diets of most rainforest birds remain very poorly known. Conveniently, technology for sequencing DNA is evolving rapidly: as of just 2014, we can use “metabarcoding” to sequence DNA in bird feces to understand what birds eat. The idea is that each species has a unique “DNA barcode”, a region of the mitochondrial CO1 gene. This gene is only a few hundred base pairs long (the whole genome of a species is typically millions of base pairs), so even if DNA is degraded as it passes through a birds’ gut, much of the barcode region remains in tact, allowing us to identify what birds have eaten.
Understanding the diets of tropical birds is highly applicable to conservation science. For example, if we sample in both primary and degraded rainforest, we can address critical questions like:
-Are bird species with specialized diets more vulnerable to rainforest degradation?
-Do hotter and drier conditions (those often seen under climate change) change the diets of birds in a negative way?
-When forest patches become smaller and more isolated, does that affect the diets of birds?
-If managing a landscape to maximize biodiversity, what types of trees are most beneficial to arthropods and the birds that consume them?
In addition to focused studies in Central Africa, our broad ambition is to address the bird diet issue with multiple collaborators from across tropical rainforests. We believe that if we can look at these patterns from a “pantropical” framework, we’ll be in a strong position to understand whether those questions we address can be generalized across the world – to all rainforest types.
This project began as a collaboration between geneticist Andreanna Welch and BI’s Luke L. Powell at the Smithsonian Conservation Biology Institute. We currently have collaborators that are collecting samples from across the globe (see map below). We welcome other collaborators – especially those working in areas with poor coverage such as the Upper Guinea Forests of Africa, New Guinea and Madagascar. Please email BiodiversityInitiative@gmail.com for more information.