Past Influences On Biodiversity In Madagascar
July 25, 2012

Past Influences On Biodiversity In Madagascar

Brett Smith for - Your Universe Online

While human activity is usually identified as the primary threat to biodiversity through the loss of species, a new study published in the journal Proceedings of the Natural Academy of Sciences (PNAS) focused on identifying pre-human causes of pressures that threaten endangered species.

The latest research focused on Madagascar, which is world-renowned for its biodiversity and has been plagued by deforestation and the destruction of natural habitats. Despite the prevailing sentiment that habitat loss is caused mainly by human activities and population growth, the recent study by an international research group questions the idea that the corruption of tropical ecosystems is primarily the fault of civilization. The study, which was led by Lounès Chickhi, a leader at the Instituto Gulbenkian de Ciência in Portugal, partially reassesses impact of local communities on their environment.

In their study, the research team looked to find the cause for the population losses suffered by the golden-crowned sifaka that predates human arrival on the island. Their examination of aerial and satellite photographs of the Daraina region, where the sifaka lives, showed that the region´s habitat has remained fairly unchanged over the last 60 years, excluding any strong effect of humans on the environment.

Analysis of the photographs along with historical and paleontological records, suggests that the present-day open habitats of Daraina are a result of pre-human climate change. The study specifically identified the Holocene droughts, which happened between 10,000 and 4,000 years ago, as a possible cause of the deforestation and subsequent loss of the tree-dwelling Golden crown sifakas.

The team also focused on primate´s genome, which holds clues to major population reduction or expansion events within the genetic data.

The study is notable for its look at a reoccurring and controversial question in conservation biology: what role and significance do human activities have in the changes in ecosystems and natural habitats?

Chickhi stressed that although the study results point the finger primarily at nature for the deforestation in northern Madagascar, humans still have a responsibility in protecting the environment.

"There is no doubt that humans have played a major role in driving several Malagasy species to extinction, since their arrival on the island,” said Chickhi.

“Although our findings relate to a specific region in Madagascar, they shine the spotlight on how important it is that conservation projects account for regional differences. The presence of humans, we have demonstrated, may not be the only cause for loss of biodiversity. It is risky to alienate local communities by excluding them from their territories, rather that bringing them on as precious allies to help conservationists find local answers for sustainable resource management".

Extensive conservation efforts might be necessary to maintain or grow the sifaka population. Currently, officials plan to tar the main road, which passes directly through the habitat of these lemurs. Increased poaching and mining in the region, could also threaten the local sifakas and their habitat. Environmentalists stress that these developments mean that conservation efforts needs to be maintained or strengthened.

The golden-crowned sifaka is one of the most threatened animals in Madagascar. The IUCN recently recommended that it be included in their Red List as critically endangered.