Conserving these Old World primates could help save Africa’s tropical forests, says study

The Red colobus, a rare group of imperilled monkeys spread across Africa, are primary indicators of biodiversity decline in the continent’s tropical forests. Conserving them could hold the keys to protecting these forests, a new study by an international team of scientists stated on April 30, 2024.

Declining populations of red colobus “forewarn the fate of other large-bodied terrestrial vertebrates across African tropical forests and portend a bleak future for Africa’s biodiversity if a business-as-usual approach is followed,” a statement by New York-based Wildlife Conservation Society, which is part of the research, noted. 

The scientists — from almost 20 institutions in the United States, Europe, and Africa — urged peers, civil society, local communities, funding agencies and other stakeholders “to invest in red colobus conservation efforts to help protect Africa’s tropical forests and biodiversity, mitigate the impacts of climate change, and improve food security and public health”.

Investing in and conserving the red colobus species “could have cascading net positive impacts on African tropical forest health in the face of a growing biodiversity crisis”, they added.

They called for all red colobus to be provided legal protections and their inclusion as priority conservation species in national laws and international treaties.

Other recommendations made included greater investment in the creation and management of protected areas for red colobus monkeys, providing support to and engaging with communities that live in close proximity to these primates, carrying out surveys to estimate the exact populations of these monkeys and creating awareness about their conservation value.

From Senegal to Zanzibar

Red colobus monkeys are one of two major simian groups globally. Colobines are primarily leaf-eaters, as compared to the cercopithecines, which are omnivores and thus include animals in their diet as well.

Colobines, which also include the langurs of south and south east Asia besides Africa’s colobus (olive and black-and-white besides red) monkeys, need to exercise a tremendous amount of choice in the kinds of plant materials they feed on or the way they process such materials, one of India’s top primatologists Anindya Sinha told Down To Earth recently.

Read Frans de Waal showed non-human species are more complex than they are given credit for: Anindya Sinha

Their cognitive abilities in this regard were fascinating, he had added. Cercopithecine species, including the macaques of south and southeast Asia, and the mangabeys, mandrills, drills and baboons of Africa, on the other hand are socially more complex. That is because they are largely generalists in terms of their omnivorous diets, Sinha had added.

“In Africa, the 17 red colobus species (18 taxa if you count one species with two subspecies) range widely from Senegal in the west to the Zanzibar Archipelago in the east. One of the most imperilled and understudied primate groups, all 18 taxa are threatened with extinction and 14 of the 18 taxa are listed as Endangered or Critically Endangered on the Red List of Threatened Species maintained by the IUCN,” the WCS statement noted. 

According to WCS research scientist and a co-author of the study Fiona Maisels, “Red colobus are among the first mammal species to vanish from African forests, because they are large-bodied—providing a lot of meat with a single shot—and because they tend to look with interest at the hunter, rather than fleeing sensibly like most other monkeys.”

She added: “They (Red colobus) often form large, noisy groups that are easy for a hunter to find compared with many of the smaller monkey species. The result can be that a perfectly good forest can swiftly be rendered red-colobus free within just a few years of hunting starting within it. Many of our priority action areas are in fact applicable to conservation of a wide range of species, and, indeed, of landscape protection as a whole.”

To conserve African tropical forests, invest in the protection of its most endangered group of monkeys, red colobus was published in Conservation Letters on April 30, 2024.