Betsileo people, Namoly Valley

Central Highland, Madagascar

Credit: Google earth. Landsat/ Copernicus, Data SIO, NOAA, U.S. Navy, NGA, GEBCO.
Maxar Technologies. CNES / Airbus

Unpredictable and decreased rainfall trends and higher temperatures are negatively affecting livelihoods of Betsileo people in Namoly Valley, who reported several changes in wild fauna and crops species. Changed frequency of cyclones and rainy season duration have dramatically reduced irrigated rice yields. Climate change impacts are aggravated by land use change and social-cultural changes.

madagascar map


The Betsileo people are the third-largest ethnic group in Madagascar, and around 3,800 are living in Namoly Valley since the 19th century. Agro-pastoral communities specializing in zebu herding and irrigated rice cultivation but also relying heavily on gathering of wild edible plants and freshwater fish.

Man - Ico

Take care of the rice nurseries and work in home gardens and other crops.

Woman - Ico

Take care of zebus, prepare the rice fields, but also exchange and trade remove goods, hunting/gathering and fishing activities.

Mapa Madagascar

Credit: Vincent Porcher


Ico Campo

Irrigated lowland and rainfed rice cultivation. Highland home garden including cassava and corn field.

Herding - Ico

Zebu livestock.

Ico Maiz

>200 wild plant species in their daily diet.


Credit: Vincent Porcher

Subtropical highland


Changes in the climate

Thermomether - Ico
20 °C avg.

Temperatures have been climbing since the 1950’s with a total average increase of 0.8ºC/year.

Water - Ico

1,600mm/year, with significant seasonal variations. Monsoon season from mid October to end of March.

Decreased rainfall trend of 17,5 mm/decade since 1970s’. More frequent droughts during the dry season. Monsoon season is shorter and more intense.


Changes in the territory

Ico Montañas

Rice paddy fields and home gardens, traditional rice varieties are placed on the bottom of the valley.

The population increase has led to changes in the agricultural system, leading to the proliferation of irrigated rice fields on hilltops and the introduction of new rice crop varieties.

Icono Rio

Floodplains areas for traditional rice and pastures for zebus.

Sibiloi National Park: the protected area has restricted access to communal lands and limited grazing and hunting of endangered species, such as cheetahs and leopards.

Icono Árboles

Wood, water, and wild edible plants.

Introduction of allochthonous fish species in 1980 by government decision.


The Betsileo people have a deep knowledge of bioclimatic processes and their links land change are rooted in their traditional rice-growing system and traditional beliefs. Their insights demonstrate how climate change, land use change, and progressive change in their society and cultural norms are interconnected.

Drivers of change

Madagascar - Bolas


Extreme weather shapes

Credit: Vincent Porcher

Extreme weather shapes local production systems
The intensification of cyclones destroys crops and infrastructures, while increasing drought makes it impossible to irrigate rice throughout the year, forcing local populations to adapt their production systems.

Adapting land use

Credit: Vincent Porcher

Adapting land use for local needs
Changing climatic conditions and population growth have led to an increased food demand. Traditional long-cycle rice varieties are progressively abandoned in favour of shorter-cycle varieties in paddy rice terraces, which is rapidly altering the landscape covering most of the hills and reducing the tree cover.

The decline of traditional customs

Credit: Vincent Porcher

The decline of traditional customs
As a result of globalization and growing poverty due to reduced crop yield, young generations are moving out of their villages looking for work, and thus gradually abandoning traditional livelihoods.


Adaptations of local communities
In response to the irrigation problem linked to more frequent droughts, the Betsileo have modified their agricultural system both by changing the type of rice field to those requiring less irrigation and by choosing short-cycle rice varieties. In addition, many farmers are abandoning irrigated rice production and converting their plots to rainfed crops such as cassava and sweet potatoes, which are new staple foods.

A culturally grounded view of change 
The Betsileo perceive many climate-related changes, most often as part of long chains of complex physical and ecological processes that also involve spiritual entities. The Betsileo people explain changes in the climate system as the result of local bioclimatic processes, but also as the direct consequence of a failure to respect traditions and intertwined spiritual processes.


The Betsileo perceive climate change as the result of different factors, both bioclimatic and spiritual. Consequently, they are adapting both technically by modifying their production systems and in terms of their magico-religious systems by modifying their rituals and adopting new ones. It is therefore essential to take a holistic approach when considering local perceptions.


Betsileo knowledge is key to identify, understand and develop strategies to adapt to climate change. Many Betsileo people already work as tourist guides in Andringitra National Park. Biodiversity conservation and adaptation to local climate change will benefit greatly from the co-production of knowledge between local people, researchers, and conservation NGOs.

Credit: Vincent Porcher


Vincent Porcher