A critically endangered elephant species has been photographed by researchers for the first time in South Sudan, significantly expanding the known range of the animal. But even in these remote central African forests, it faces threats from illegal logging and from war.

Smaller than savannah elephants, the forest elephants roam tropical forests and were photographed by cameras tied to trees in Western Equatoria state, a lush area near Congo and the Central African Republic.

"This is by far the most northerly herd of forest elephants that anyone has seen in Africa," Adrian Garside, co-leader of the study by Fauna & Flora International, told Associated Press.

Forest elephant populations declined by 60 percent between 2002 and 2011, while losing 30 percent of their range in West and Central Africa, according to a 2013 study published in scientific journal PLOS ONE.

The forest elephant has straighter tusks than its cousins and more rounded ears and head.

The remotely activated cameras, set up over 3,000 square miles (7,770 sq. kilometers) of the state, also captured images of African golden cat, red river hog, giant pangolin, and water chevrotain, which is like a small deer, all previously unrecorded in South Sudan, the group said.

Over six months, the cameras captured more than 20,000 wildlife images. Chimpanzee, leopard, hyena, and bongo antelope were also spotted.

"We are proving that there are expanses of habitat that is sort of pristine and unexplored, which is a very hopeful sign," Garside said.

In other countries, forest elephants are under intense poaching pressure, said said DeeAnn Reeder, co-leader of the new study and a biology professor at Pennsylvania's Bucknell University.

She said the greater threat in Western Equatoria is habitat loss.

"There's illegal logging happening in Western Equatoria now, and it's pretty much unchecked," Reeder said.

South Sudan's war has led to more poaching of elephants for meat and ivory. Over 50 percent of elephants in South Sudan fitted with radio tracking collars before the war have been poached since fighting broke out two years ago, Paul Elkan of the Wildlife Conservation Society told AP.

Western Equatoria was mostly peaceful during the conflict but skirmishes broke out there between rebels and army this week.