Zoo air contains enough DNA to identify the animals inside

The air in a zoo is full of smells, from the fish used for feed to the manure from the grazing herbivores, but now we know it is also full of DNA from the animals living there. Two research groups have each published an independent proof-of-concept study showing that by sampling air from a local zoo, they can collect enough DNA to identify the animals nearby. This may prove to be a valuable, non-invasive tool to track biodiversity.