[Source: CNN]

Dr. Mrinalini Watsa, a researcher at San Diego Zoo Wildlife Alliance in California, scoops up soil from a fresh paw print made by Rakan.

Rakan is a 4-year-old male Sumatran tiger who lives at the San Diego Zoo Safari Park, and secures it in a specimen jar.

Back in her lab, Watsa analyzes the sample using a small electrophoresis device that’s connected to a smartphone. Jackpot. She’s able to detect Rakan’s DNA in the soil.

The proof of concept experiment is part of her work adapting existing genome-sequencing technology so it can be easily used to detect individual tigers in the wild using their DNA. Watsa hopes the application will make it easier to track Rakan’s wild counterparts in Sumatra, Indonesia’s biggest island, and tiger populations across the rest of Asia.

“Now, instead of saying we’ve seen about 40 prints in this 3-kilometer-square (1.8-mile-square) area, actually you can see those 40 prints come down to four tigers and that gives us so much more power in terms of how we go about counting them,” she said in the latest episode of CNN Original Series “This Is Life with Lisa Ling.”

All living organisms, including humans, shed genetic material into the environment when they excrete waste, bleed, or shed skin or fur.

Conservation scientists are increasingly making use of this environmental DNA — whether it’s in soil, water, snow or even air — to gather information about particular species or ecosystems.

It can alert scientists to the effects of the climate crisis or the existence of harmful pathogens, and help them track animal populations.