Shea, shea everywhere, but no insects left to eat
Imagine that you have just travelled across the Saharan desert non-stop from Europe, and you need a place to rest your weary wings and grab an insect or two to refuel. Historically, you would have found great spots in the more northern sub-Sahara region, which would have provided diverse parkland habitats for migratory birds.
However, increasing agricultural and climate pressures have dramatically altered the landscape.
In particular, these habitats have become much more intensive agricultural landscapes, with increased use of tractors, fewer trees and greater pesticide use. However, while many trees are being cut down to make way for crops, one species in particular, the shea tree (Vitellaria paradoxa), is protected and retained in the parkland landscape.
At first glance, the protection of shea trees, could seem like a straight-forward win-win for birds and local livelihoods. But the reality is far more complex.
Shea butter: not just a moisturiser
Let’s take a step back. Many of us have heard of shea butter, but few know of its origins in sub-Saharan Africa. Shea trees grow in 21 countries across the Sudan-Guinea zone, where the nuts are collected by women and often hand-processed into the butter. While shea is perhaps most familiar for its cosmetic uses, over 90% of the $120 million dollar export crop actually goes to the confectionery industry and three-quarters of the total crop is retained for traditional uses.
Like the more controversial palm oil, shea butter can be used as a ‘cocoa butter equivalent’ which in the EU can constitute up to 5% of a chocolate bar. Despite the increasing demand, shea trees are not generally cultivated. Instead the nuts are collected from trees that grow naturally among farms in the landscape. Shea is also integral to local livelihoods as the primary edible oil for 80 million people and a crucial source of income for 18.4 million women, supporting education and family food budgets.
But not all trees are equal in the eyes of birds
While the link between the loss of habitat diversity in wintering grounds and the population decline of migrating birds has long been discussed, little is known about how birds actually use trees in these landscapes.
Shea trees persist in the agricultural landscapes of the parklands. Photo: Jane Stout
In a study funded by Vogelbescherming Nederland (VBN, BirdLife in the Netherlands) through the BirdLife project Living on the Edge, renowned ornithologists Leo Zwarts and Eddy Wymenga investigated the shea-zone habitat use of declining migratory birds like the Willow Warbler and Tree Pipit. They travelled throughout the region, carefully cataloguing bird densities in different trees along large transects of land.
What they observed was surprising: migratory birds appeared to avoid shea trees, instead showing a preference for thorny acacia species thought to be rich in insects. Increasingly, the evidence suggests that the simplified shea parklands, now being created in many areas by removing other species of trees and shrubs, are failing to provide suitable habitat for migratory birds. And it may not just be the birds that are suffering.
BirdLife has commissioned research to investigate insect pollinators in the shea parklands, also thought to suffer from a loss of habitat diversity. A decline in their population has serious implications for yields of insect-pollinated crops, including shea.
Working towards a ‘bird, bee and butter-friendly’ strategy
Diverse parkland landscapes provide a number of other services and resources for farmers, such as fuelwood, shade, erosion prevention and non-timber forest products. Therefore, BirdLife will work with local communities in Northern Ghana and Southern Burkina Faso to identify a ‘bird, bee and butter-friendly’ strategy which will restore diversity in the parklands and secure local communities’ livelihoods.
BirdLife is also working with the Global Shea Alliance (GSA), a non-profit industry association that aims to drive a competitive and sustainable shea industry worldwide, and is currently seeking to enhance its ecological and economic sustainability. BirdLife will be speaking at the GSA Annual Conference in Accra this year, raising awareness of how sustainable shea production can benefit both people and biodiversity.
The ‘Trees, bees & birds’ project is funded by the UK Government’s Darwin Initiative. More information about the project can be found on their website.
Stichting BirdLife Europe gratefully acknowledges financial support from the European Commission. All content and opinions expressed on these pages are solely those of Stichting BirdLife Europe.