Our international research team, working in the rainforest of Uganda's Kibale National Park, wondered whether the environmental DNA methods would be useful to us. We reasoned that if animal DNA was in the air, perhaps it settled and got stuck to leaves. Waxy, sticky or indented leaf surfaces might even be ideal DNA traps.
To tell which animals gave rise to the DNA in the swabs, the team sequenced a short piece of DNA, called a barcode. Barcodes are distinct for each animal, so the barcode found in the swabs could be compared to a barcode library containing all animals sampled to date. So we were surprised when the results came back from the DNA sequencer. We'd picked up over 50 species of mammals and birds and a frog, with swabs collected in just over an hour, on only 24 cotton buds.on each of the cotton buds. These species spanned a huge diversity, from the very large and endangered African elephant to a very small species of sunbird.
The high diversity of animals, coupled with the impressive animal detection rate per swab, suggests we can now collect a lot of animal DNA simply from leaves. The ease of sampling, a task we can ask anyone on our team to do quickly when they are in the forest, suggests we could use this method to track animal diversity in the park, particularly in areas that are rapidly changing., Emmanuel Opito, is studying exactly these areas in the park for his doctoral project.