Leeches used to track rare wildlife

Leeches, slimy, bloodsucking and altogether unsettling, these slippery suckers have been used in medicine for literally thousands of years to help with wounds and clotting problems. When an “excess of blood” was diagnosed in the past leeches were placed on the patient’s skin to drain small amounts. Later it was realised that leeches could be used to help remove excess blood from a wound or after surgery and that the enzyme they secreted to keep blood flowing had healing properties. They are still used for treatment all around the world, and are especially handy for reattaching lost fingers. 

Now they have yet another valuable property. They are being used to track endangered species in Vietnam. The forests of Vietnam are rapidly disappearing but still contain hard-to-find animals. A research team from the University of Copenhagen, Denmark noted that leeches hold traces of blood from the animals they feed off for up to four months after. Taking samples from 25 leeches native to an area of the Vietnamese forest, the research team identified the DNA of a striped rabbit, a muntjac, a rare badger and a rare goat. The DNA establishes the presence of the animals and opens up possibilities for further tracking and conservation of their forest habitat. 

Did you know?

Leeches are not the only live organisms used for medicinal purposes. Maggots are also used to treat open wounds as they remove dead tissue and kill bacteria.

Glossary 

Muntjac

The oldest known species of deer, they first appeared 15-35 million years ago. They have been introduced all over the world but the present-day species is native to South Asia.