Since leeches suck the blood of many animals, researchers are now turning to them as survey tools, according to Mongabay.
An international team of researchers collected 750 leeches from the genus Haemadipsa from various areas of southern Asia to assess the diversity of mammals on which they fed. As it reports in Systematics and Biodiversity, the team led by the American Museum of Natural History's Mark Siddall amplified and sequenced vertebrate-specific 16S rRNA from within the leech bloodmeals. Through this, they identified one avian order and a number of mammalian ones, including — Carnivora, Primates, and Rodentia — among the leech meals. They also noted no clear preference among the leeches for feeding on particular animals.
This, the researchers say, confirmed previous work done using camera traps, and also highlighted the ability of the approach to study animals within the leeches' range.
"[W]e can determine what mammals are in a protected area without hunting, without trapping, without the use of scat or hair samples, and especially without camera traps—all of which are problematic methods," Siddall says in a statement. "Instead, by sequencing the host DNA that remains inside of terrestrial jungle leeches for months after feeding, we can out-perform all other methods of biodiversity monitoring."