Monitoring animals and ecosystems has historically been considered scut work. Tedious and boring, researchers (usually newbie PhD students) must sit quietly and note the presence of species over the course of many hours. Yet, this is changing. Teams in recent years have found that they can collect DNA from water in aquatic ecosystems to work out which species are around. Known as environmental DNA (eDNA) monitoring, researchers have tried this in terrestrial environments by looking for DNA traces in permafrost, snow and soil but nothing has proved particularly effective. Now a team is revealing that they have found a way to gather eDNA out of thin air.
The researchers behind this new work collected air samples at multiple locations within a British zoo using a pump that moved air through a flexible tube to filters with tiny holes in them. The pump gently ran collected air past the filters for 30 minutes. After this was done, the filters were brought back to the lab for DNA analysis. What they found was pretty impressive.
Not only did the team pick up evidence of eDNA from every animal kept at the zoo but their technology also revealed that cows, pigs and chickens were there too. Given that none of these animals were actually kept at the zoo, the researchers concluded that much of this domesticated animal eDNA was coming from the food being given to the tigers and dingoes at the facility. Squirrel, duck and hedgehog eDNA turned up too which the researchers assume must be coming from these animals living on the zoo's grounds. All told, these findings look set to revolutionise the way in which zoologists conduct their field work. You can read more in The Economist article that I wrote on this here.