Scientists from Australia and Papua New Guinea are using a new technique to discover which mammals species live in some of the world's most remote forests.

Key points: Scientists collect DNA from leeches, dung beetles, mosquitos

Scientists collect DNA from leeches, dung beetles, mosquitos Their diet can reveal the number and range of wildlife in isolated and threatened places

Their diet can reveal the number and range of wildlife in isolated and threatened places Collection can be done by villagers in remote areas who have knowledge about the animals

The researchers, from the University of Papua New Guinea and James Cook University, are not observing the mammals themselves, they are analysing the DNA of the insects which feed on their blood.

Scientists will collect DNA from leeches and other "surrogates" to see what their diet can reveal about the number and range of wildlife in isolated and threatened places.

Mark Ziembicki, a senior research fellow at James Cook University, is working on the pilot study.

"One of the techniques that's been recently developed is to look at using surrogates for what's in the forest," he said.

"For example leeches and dung beetles and mosquitoes all feed on what's in the forest.

"So rather than actually sample for the animals themselves, we're sampling for the leeches and those sort of animals to see whether we can use them to determine what's in the forest."

Dr Mark Ziembicki collecting samples near Port Moresby. ( ABC News: Eric Tlozek )

Dr Ziembicki said the method could be of particular use in a rugged and undeveloped country like PNG.

"Papua New Guinea has these extraordinary natural wonders and from a scientific perspective we know very little about it," he said.

"Part of the reason is because it's a really difficult place to work.

"The topography is challenging, the rainforest is really dense and thick, so it's really hard to find a lot of the animals in the forest."

But insects like leeches are doing the hard work already, collecting DNA from the mammals they are feeding on.

"So rather than directly observing the animals themselves, we're using these proxies if you like, or sending out little robots to collect the samples for us, in a way," Dr Ziembicki said.

The collection method is simple — find the leeches and put them in ethanol for later analysis in a laboratory. ( Pixabay )

Saving a forest 'requires knowing what you're saving'

The collection method is simple — find the leeches and put them in ethanol for later analysis in a laboratory.

Gabriel Porolak, from the University of Papua New Guinea, said collection could be done by villagers in remote areas, who already have a lot of traditional knowledge about the animals of the bush.

"There are some elusive species out there which they don't know, and this technique will help them to know what they are missing or what they think is not there anymore is still there," he said.

A Huon tree kangaroo in the Sarawaged mountains. ( Supplied: Mark Ziembicki )

Mr Porolak said the research was timely, because Papua New Guineans were beginning to notice their own increasing impact on the forest.

"It has always been a part of their life, but because of increased human population it's gotten out of hand, so there's more demand for land and for forest products," he said.

"They're using it in a non-sustainable way, so the direction for conservation is to help them keep on using it, but in a more sustainable manner."

Mr Porolak hopes this research will help conservation efforts around PNG.

"In terms of conservation you can't just save a forest, you have to know what you're saving," he said.

"So knowing what's out there helps to leverage your claim for pledging your land for conservation."

The pilot study will run for several months and will hopefully lead to a full research project that surveys many different forests across Papua New Guinea.