Butterflies in the Landes de Gascogne: “The primary cause of species disappearance is the destruction of natural habitats and wetlands”
The summer of 2021-2022 and its severe droughts caused a decline in butterfly flights and numbers. The following two years, a few more were found. But in the long run, the rhopalocera face many threats to their survival.
Does the Landes de Gascogne massif have any particular characteristics of interest to butterflies?
Yes, absolutely. The Landes de Gascogne region contains a wide diversity of species, which remains exceptional in 2025, despite the disappearance and decline of certain populations. What makes this region so strong is its microclimate, the presence of wetlands, lagoons, and woodlands, all refuges for butterflies.
What are the main threats hovering over their wings?
The primary cause of their disappearance is the destruction of natural habitats and wetlands. This is due to construction and crop drainage. Changes in grassland management, which will involve more frequent mowing, shorter forestry routes, or even slash-and-burn in the mountains, also have impacts. The second threat is, of course, climate change, which will weaken vulnerable species. And, of course, extreme events also have an effect on mortality. Afterwards, if the species is abundant, it can survive thanks to genetics, because it will adapt. It is still necessary to restore as much land as possible for this reproduction to take place...
An ecological issue compatible with the challenges of forestry as practiced in the Landes de Gascogne?
It is important to know that thanks to pine forestry, we have preserved habitats in this massif, conducive to the reproduction of certain species. This means that when we cut down a plot and replant it, we move the soil and force the butterflies to go elsewhere... They cannot take refuge very far away. Hence the urgent need to have a preserved plot right next door. Hence the need to design forestry in the Landes de Gascogne with a mosaic of pines of different ages.
How do you listen to foresters?
Frankly, we are seeing a real awareness of biodiversity on their part, particularly with the action of the Landes de Gascogne Regional National Park since 2021. Action which has allowed us to talk, to exchange, to set up programs together to better understand biodiversity and generate respectful and economically viable production routes.
Are you worried about other threats?
Yes, clearly. The one conveyed by the legal obligation to clear brush (OLD) implemented in the fight against forest fire risk. The fact is that outside of natural environments, the areas affected by the OLD are ideal breeding grounds for butterflies. The firebreak role of certain natural habitats has also not been sufficiently taken into account.
What advice can you give to individuals to make their garden a paradise for butterflies?
They can be invited to leave a small, unmowed or very sparsely mowed area where wildflowers can grow. By leaving this space and letting time do its work, they can contribute in their own way to preserving biodiversity...
