Zoo experiments detect dozens of animals from airborne DNA

Animals are constantly shedding DNA into their environment, traces of which can then be detected in soil and water – and now, perhaps even air. Two new studies collected air samples from zoos and were able to identify a range of animals living in and around the facilities, which could eventually be used as a non-invasive way to track biodiversity.

No matter how stealthy an animal is, it’s going to leave behind some trace of its presence. Whether that’s shed skin, scales or hair, or leavings like feces or urine, DNA ends up in the environment, which can reveal a lot about the species that call an area home.

But could the same principle apply to airborne eDNA? An earlier study showed that insect eDNA could be detected in air samples, but now two independent teams have conducted similar experiments in zoos to try to pick up larger animals. And both returned surprisingly detailed analyses of the animals that live in and around the zoos.

Both studies used vacuum devices to capture samples of air from different parts of their respective zoos. One study, led by Elizabeth Clare, used vacuum pumps with sensitive filters to gather over 70 samples from around Hamerton Zoo Park in the UK. “When we analyzed the collected samples, we were able to identify DNA from 25 different species of animals, such as tigers, lemurs and dingoes, 17 of which were known zoo species,” says Clare.

The second study, led by Kristine Bohmann, used a commercial water-based vacuum and two blower fans to collect air samples from three locations in Copenhagen Zoo in Denmark. “We were astonished when we saw the results,” says Bohmann. “In just 40 samples, we detected 49 species spanning mammal, bird, amphibian, reptile and fish.