The study looked at wildlife populations in northern Republic of Congo over a mosaic of land-use types, including a national park, a community-managed reserve, and various logging concessions. It found that core protected areas - coupled with strong anti-poaching efforts - are critical for maintaining populations of forest elephants, western lowland gorillas, and chimpanzees.
The region, known as the Ndoki-Likouala Conservation Landscape, is considered one of the most important sites in Central Africa for all three species. The Wildlife Conservation Society has been working in the landscape since 1991 and helped establish Nouabalé-Ndoki National Park in 1993.
The study appears in the April 23rd edition of the journal PLoS One. The authors found that protected areas remain a key component of the landscape for all three species. Chimpanzees and elephants are particularly sensitive to human disturbance outside the Nouabalé-Ndoki National Park, and the park plays a major role in their distribution.
In fact Nouabalé-Ndoki National Park may be one of the most important sites for chimpanzees in the Congo Basin with some of the highest densities recorded in Central Africa.
The study also found that logging concessions that have wildlife management in place, including protection of key habitats and anti-poaching patrols, can support important populations of elephants and gorillas.
However, the authors warn that logging concessions are only of conservation value if there are strict anti-poaching measures in place, and if they are close to protected areas free of human disturbance. As evidence, the study showed the results of surveys in a logging concession without any anti-poaching measures or wildlife management where abundance of all three species was very low.
"Protected areas free of human disturbance, logging, or roads remain key to the protection of great apes and elephants," said WCS researcher Emma Stokes, the study's lead author. "Landscape conservation should focus on protected areas surrounded by other land-use types that also have wildlife management in place."
The forests of the Congo Basin are one of the last remaining tropical wildernesses and a top priority for biodiversity conservation.
Commercial logging is prevalent throughout much of the Congo Basin, with over 30 percent of native forest allocated to logging concessions compared to only 12 percent under protection. More than 50 percent of the current range of western gorillas and chimpanzees is estimated to lie in active logging concessions.
"This study shows that landscape-wide conservation can work in Central Africa - provided there are the resources and political will to save wildlife over large areas," said James Deutsch, Director of the Wildlife Conservation Society's Africa programs.
"Conservation on this scale is difficult and expensive, but absolutely necessary if we hope to save viable populations of elephants and great apes. At the same time, the government's capacity to follow up and take legal action against poachers should be strengthened and is a key to maintaining the protection of the forests and their wildlife."
The authors estimated elephant and great ape density using distance-sampling surveys of elephant dung piles and great ape nests.
Authors include Wildlife Conservation Society researchers Emma Stokes, Samantha Strindberg, Parfait Bakabana, Paul Elkan, Fortuné Iyenguet, Bola Madzoke, Guy Aíme Malanda, Franck Ouakabadio and Hugo Rainey; Brice Mowawa of the Ministre de l'Economie Forestičre, Republic of Congo; and Calixte Makoumbou, formerly with WCS Congo Program.
The surveys presented in this paper were made possible through generous funding from the U.S. Agency for International Development Central Africa Regional Program for the Environment (CARPE) and U.S. Fish and Wildlife Service Great Ape Conservation Fund.
Donations in support of helping save wildlife and wild places, can be made at www.wcs.org/donation