New collaborative inventory of biodiversity at the Mas du Petit Saint-Jean

From 10 to 12 April 2026, the Tour du Valat organised a new naturalist inventory at the Mas du Petit Saint-Jean, showcase of the Institute’s agroecological activities since 2016. On this occasion, around a hundred participants – amateur naturalists and experienced specialists alike –, from the Tour du Valat as well as several partner organisations across the country, came together to help improve our knowledge of the site’s biodiversity. 

Working together to study biodiversity

This inventory weekend is part of a long-term initiative to monitor biodiversity linked to the agroecological practices implemented on the domain. It serves two purposes: to improve our knowledge of the species present on the estate – particularly those essential to agriculture, such as pollinators, field plants and soil microfauna – and to demonstrate, in concrete terms, the positive effects of agroecological practices on biodiversity.

More than just generating scientific data, this inventory campaign helped to connect naturalists and promote knowledge-sharing. The friendly atmosphere during field trips and meals also encouraged exchanges between professionals and volunteers, creating a dynamic of knowledge transfer and collaboration.

The data collected is incorporated into the ‘Rewilding farms’ network, thereby contributing to the comparative monitoring of biodiversity trends in agricultural environments.

Le Mas du Petit Saint-Jean in figures 76 hectares of natural habitats: marshes, montilles, sansouïres, pine forest 5 semi-permanent ponds to provide a habitat for amphibians and European pond turtles 22 nesting boxes installed for passerines, rollers and birds of prey 30 bat boxes mounted on posts to accommodate bats in the vineyards, where they play a role in controlling grapevine moths 5 hectares of vines 800 metres of fruit hedges 3 hectares of pear and sorb trees in agroforestry systems dedicated to timber production 4 hectares of orchard meadows combining almond, olive, pistachio, pomegranate and persimmon trees, which also provide fodder (mown) and are grazed in winter

Inventories conducted throughout the site, both day and night

The teams conducted a variety of surveys across the entire site, employing protocols tailored to different taxonomic groups: direct observations, night-time insect inventories (with the use of lights on white sheets), bird song monitoring, as well as specific capture and identification methods using various non-lethal traps.

This collaborative effort has significantly enriched local knowledge, notably with the observation of two species not previously recorded on the site:

• the European red-rumped swallow (Cecropis rufula) ;
• the Sawfly Orchid (O. Tenthredinifera subsp. neglecta.), a species of orchid never before observed in the Gard.

Under-documented taxonomic groups

The 2026 edition also provided an opportunity to further study taxonomic groups that had previously been less explored on the site. Lichens, for example, were the focus of particular attention, with seven new species identified. Fish surveys also were conducted, notably through angling campaigns. Finally, numerous observations of insects and arachnids, which often require meticulous identification using a binocular magnifying glass, will be added to the inventories over the coming months.

These results complement the existing data and contribute to a better understanding of the diversity of habitats present within the Mas du Petit Saint-Jean.

Outlook

Following the success of this latest edition, a third participatory inventory campaign is already being planned for June 2027. This will enable us to continue improving the scientific monitoring of the site and to consolidate long-term observations on the interactions between agricultural practices and biodiversity.