NOVA

(gentle music) Look at the size of this scat. This is one that was dropped last night. And just by coincidence, there's a cow pat here in front of the rhino heap. So you can really get a sense of how massive these animals are. And they're just roaming in and out of the village here and everyone seems to be getting along. Just imagine the size of the bum that this dropped out of. (dramatic music) These are just single scats. I'm after the mother lobe. (dramatic music) Coming across fresh scat in the wild is a golden opportunity for scatologist like me, even if it's not for my research. Collecting samples for other scientists can help their studies. Some of this rhino poo may even be used to help save the greater one horned rhinoceros. So this large pile of scat here is a latrine site used by a few different rhinos. They communicate to the other animals in their population via the chemicals in these scats. They communicate social status and reproductive status and who's in the neighborhood. It's like a feces book for rhinos. (dramatic music) But this social platform also attracts ruthless killers. A fresh poop pile is a message to poachers that rhinos visit here. They're killed for their horns, which are smuggled out of the country and used for luxury goods or in traditional medicine in parts of Asia. Scientists have figured out a way to protect the rhinos by using their scat for forensics. They collect scat in the wild and extract DNA which goes into a database. When a dead rhino is found or a rhino horn confiscated from criminals, authorities can match its DNA with DNA in the database to locate where it came from. The DNA evidence can be used to convict poachers and to know where to concentrate police efforts. In the 1900s, they faced extinction. Now there are over 2,600 greater one-horned rhinoceros in a san. Perhaps this scat will go towards saving one more. Just using my GPS here to get a geolocation for this sample. The trends help rhinos communicate. And now they may also protect these superb packidons from extinction. That's a good poop story. (gentle music)