Stock proof fences: saving lemurs and littoral forests
One of the last remaining strongholds of a rare kind of Malagasy forest is being eroded. Farmers need to protect their crops to survive, but the extraction of fence wood is damaging littoral forests. Chester Zoo and Missouri Botanical Garden have partnered with Malagasy communities to protect these precious woodlands.
Forests on the edge
Littoral forest ecosystems are unique. They only grow in sandy ground close to the ocean, providing a ribbon of rare and biodiverse habitat for specific species. In Madagascar, these forests have been badly degraded by over-exploitation and human development.
Agnalazaha forest, which spans 2,745ha, is one of the largest remaining fragments of this precious littoral forest in the country and is home to many threatened species, including chameleons, bats and birds, and the Critically Endangered white-collared brown lemur (Eulemur cinereiceps).
Agnalazaha is bordered by communities of subsistence farmers. Their farms often operate within very narrow margins of viability; if they lose crops to free-ranging cattle, this can seriously impact their ability to feed themselves and their families. Farmers have taken to felling trees in Agnalazaha littoral forest, using the wood to make fence poles to protect their crops. Understandably, communities need to find ways to maintain their food supply.
While areas of Agnalazaha are highly protected, other areas are set aside for sustainable use by local people. Unfortunately, the demand for fence poles is too high, with roughly 80,000 stems being removed annually. This level of extraction degrades the forest, damaging its integrity, restricting regrowth and impacting the ecosystem.
Conservationists coming together
In 2020, Chester Zoo and Missouri Botanical Garden joined forces to help the community find a forest-friendly way of protecting their crops. Together, we successfully applied for a Darwin Initiative grant and launched a hedge-making project which ran from 2020-2024.
In that time, we helped communities install 14km of stock proof fencing. The soil conditions in the region meant the hedge plants grew slowly and had to be supplemented with temporary barbed wire fences, so Chester Zoo and Missouri Botanical Garden have committed to extend the stock-proof hedges project, now funded by Chester Zoo.
The project is designed to be self-sustaining in the long term. Chester Zoo and Missouri Botanical Garden experts work with community representatives to establish hedge-growing processes.
These include paying local zebu herders to collect zebu dung which can be used as compost, organising hedge laying training sessions for Agnalazaha community members, setting up new nurseries for the propagation of hedge plant seedlings and removing the stop-gap barbed wire fences.
Constructing living fences
The fence-laying itself is designed to boost biodiversity in the region. Firstly, farmers are encouraged to cut down and use closely-spaced stems of invasive plant species, removing them from the ecosystem.
Within this protective framework, stems of three woody plant species, alien but not invasive, can be planted. These species root easily (Gliricidia sepium; Jatropha sp. and Albizia lebbeck) and are inserted into the ground to provide a line of young trees.
Finally, between these rooted cuttings, seedlings of native trees, propagated in a local nursery, are planted to diversify and enrich the hedge and support native species.
As well as protecting the forest, the establishment of living fences will reduce annual labour undertaken by farmers in the Agnalazaha community and provide a network of corridors for small wildlife and plants. This project was acknowledged with a BIAZA award for field conservation in 2025.
Communities are key
The success of the stock proof fence project hinges on the enthusiastic participation of the main stakeholders: the people living alongside Agnalazaha forest. Work is being driven on the ground by community leaders, and we have carried out extensive surveys to monitor public opinion on the project.
Local attitudes to hedge-planting have already shifted during the initial project phase. More farmers have expressed an interest in stock proof fences, which is encouraging. Despite being a temporary measure, the installation of barbed wire fences illustrated a visible impact for crop farmers, who benefitted from protected yields.
Meanwhile, in the forest itself, researchers from the partnership are tracking changes in the ecosystem by observing key species through camera traps and audio monitoring. The goal is to reduce the number of native grown trees annually chopped down to fewer than 10,000, allowing the forest to regenerate naturally.
Page header image courtesy of Alex Dunkel (CC license)
