Two groups of researchers working independently, one based in Denmark and the other in the UK and Canada, tested whether airborne DNA could be used to detect different animal species by collecting samples at Copenhagen Zoo in Denmark and Hamerton Zoo Park in the UK.
All living organisms, including humans, leach genetic material
known as eDNA into the environment when they excrete waste, bleed, and shed skin or fur. In recent years, conservation scientists have sequenced waterborne eDNA to track certain species, such as the UK's great crested newt population
, in aquatic environments.
However, monitoring airborne eDNA was more of a challenge because it's more diluted in air than it is in water.
Their work was published in two proof-of-concept studies in the journal Current Biology on Thursday.
The team working at the Hamerton Zoo Park was able to identify DNA from 25 different species of animals, including tigers, lemurs and dingoes, said UK study
lead author Elizabeth Clare, an assistant professor at York University in Canada and a former senior lecturer at Queen Mary University of London, where she undertook the work.
"We were even able to collect eDNA from animals that were hundreds of metres away from where we were testing without a significant drop in the concentration, and even from outside sealed buildings. The animals were inside, but their DNA was escaping," Clare said in a news release.
The Copenhagen team was able to detect 49 vertebrate species, including 30 mammals.
"We were astonished when we saw the results," said Kristine Bohmann, an associate professor from the Globe Institute at the University of Copenhagen and the lead author of the Danish study
, in the statement.
"In just 40 samples, we detected 49 species spanning mammal, bird, amphibian, reptile and fish," Bohmann said. "In the Rainforest House (at the Copenhagen Zoo) we even detected the guppies in the pond, the two-toed sloth and the boa. When sampling air in just one outdoor site, we detected many of the animals with access to an outdoor enclosure in that part of the zoo, for example kea, ostrich and rhino."