Conservationists tracking wild peccaries in Brazil say they made an unexpected find -- ancient cave drawings made thousands of years ago by hunter-gatherers.

Researchers from the Wildlife Conservation Society and a local partner NGO, Instituto Quinta do Sol, made the discoveries while tracking wildlife and gathering environmental data in forests that link Brazil's Pantanal and Cerrado regions, a release from the New York headquarters of WCS said Thursday.

"Our work with the Wildlife Conservation Society focuses on promoting sustainable land use practices that help protect important wildlife species and the wild places where they live," Alexine Keuroghlian, a researcher with WCS's Brazil Program, said. "Since we often work in remote locations, we sometimes make surprising discoveries, in this case, one that appears to be important for our understanding of human cultural history in the region."

After the discovery, Keuroghlian contacted archaeologist Rodrigo Luis Simas de Aguiar, a regional specialist in cave drawings, who determined they were made between 10,000 years and 4,000 years ago by hunter-gatherer societies that either occupied the caves or used them specifically for their artistic activities.

The drawings depict an assemblage of animals including armadillos, deer, large cats, birds, and reptiles, as well as human-like figures and geometric symbols.

"These discoveries of cave drawings emphasize the importance of protecting the Cerrado and Pantanal ecosystems, both for their cultural and natural heritage," Julie Kunen, Director of WCS's Latin America and the Caribbean Program, said.