Charlotte has been in charge of the nature department at the Courmettes centre for almost three years. She coordinates the monitoring and study of populations of the Hermit, an endangered species of butterly found on the estate.
Due to its decline in recent years, the Hermit moth is a target species of the National Action Plan (PNA) for butterflies. In 2021, a regional version of this plan was approved in the Provence-Alpes-Côte d’Azur region, leading to a study of the Hermit moth at Les Courmettes. This study is divided into two parts: monitoring the caterpillar in spring and the adult in summer.
Could you tell us about the work that A Rocha France is doing with the Hermit?
The caterpillar is monitored between May and June at two sites in Les Courmettes. The aim is to confirm the presence of the caterpillar at these sites and to identify the host plants used by the species. As with many butterflies (e.g. the Diana), the decline of the host plant contributes to the decline of the species. Caterpillars do not like light, so field sessions usually take place between 11 p.m. and 1 a.m. Once a week, a few volunteers brave the night to crawl a few dozen meters with headlamps. They inspect every tuft of grass, looking for brown and gray caterpillars. These field sessions to search for individuals according to a protocol are called surveys.
Our research is not often successful, but we persevere despite the rarity of these observations. If you don’t know what to do next spring, come and join us! We are in great need of help and, above all, extra eyes.
The monitoring of the imago (adult butterfly) takes place between July and August. Here, the main objective is to determine the distribution of the Hermit moth population on the estate, estimate the size of this population, and monitor its evolution over time. We also seek to estimate the minimum dispersal capacity (i.e., the ability of an individual to move within a landscape) and the average lifespan of adults of the species.
To do this, we follow a Capture-Mark-Recapture (CMR) protocol for five weeks from the first sighting of Hermit beetles in the season. Using entomological nets, we capture the adults, mark them with a felt-tip pen, and then release them. Marking is done using colored dots—red for units and blue for tens—applied to different areas of the hind wing, so that each Hermit crab has its own identification number. This allows us to track the history of all individuals that are recaptured. At the end of the protocol, we can analyze the data collected and estimate the size of the population. By cross-referencing this data with that from previous years, we can track the evolution of the species at Les Courmettes.
In parallel with this monitoring, we carry out so-called “non-protocoled” surveys, i.e., outside the monitored sites, in areas favorable to the species. These observations enable us to find other sub-populations of Hermites on the estate and estimate the distances traveled by tagged individuals around the monitored sites. Since 2023, thanks to the Global Conservation Fund, we have also started a genetic study of the species.
A Rocha France’s work with the Hermit is therefore primarily scientific. We seek to better understand the species at the local level—as many studies have been conducted in laboratories or in other countries—in order to better protect it and adapt our management of the site to favor the species. The various monitoring programs allow us to gain expertise locally, as we are the only ones studying the Hermit Crab in the Provence-Alpes-Côte d’Azur region.
How is this work related to the Global Conservation Fund ?
A Rocha International created the Global Conservation Fund (GCF) to provide financial support for conservation projects within the A Rocha family. In 2023, we submitted the Hermit project because we wanted to develop a genetic study and learn more about the species in the region. The GCF funded the fieldwork part of the genetic study, covering the labor and mileage costs involved in collecting genetic samples and conducting surveys outside Les Courmettes. Thanks to this, we have discovered a new population of Hermite and collected 30 genetic samples to date.
The GCF also enabled us to purchase new entomological nets and cover the labor costs associated with other aspects of the study (caterpillar monitoring, imago CMR, etc.). We are now seeking new grants that will enable us to continue the ongoing study and move on to the next stage with the analysis of the genetic samples collected.
Why did you choose to get involved in conservation work?
One of A Rocha’s missions is to preserve life. In France, this translates into scientific studies, public awareness campaigns, and site management measures. I believe that one of A Rocha France’s strengths is having a team of scientists who dedicate their time to implementing these actions. Even though the organization is not entirely devoted to science, it can gain scientific recognition through the fruits of its labor and carve out a place for itself in a world that is often not very open to Christians. It can also get involved in its local area and contribute directly to its development by interacting with the public and local, and even national, institutions.
A Rocha’s mission and its development in France generate opportunities that I find unique and wonderful for witnessing, marveling, and learning. Through my work, I am fortunate to be able to combine my personal convictions and passions, meet people from all walks of life, and take concrete action for nature.
How can we support you in this work?
Much of the scientific work carried out by A Rocha France is not very attractive. The work can be long and repetitive. It involves rigorous data collection over several years to better understand biodiversity and contribute to large national databases. However, this monitoring work is necessary and useful in preparation for any conservation action, as it is difficult to protect nature without knowing about it. To give you an idea, a dataset is considered to be of interest after five years of study. This monitoring requires a lot of time and therefore a certain budget.
If you would like to support our actions, you can do so in two ways: by giving your time and/or by supporting us financially. Donations can be used to fund the work of the salaried scientific team, to provide technical equipment, or to invest in services, such as genetic analysis, which contribute to a better understanding of nature in order to protect it more effectively.