This weekend, we’re counting the birds for science — editing

It is the largest scientific operation for French citizens. This weekend is the 11th edition of the Garden Bird Observatory’s official census. Any citizen can participate: all you have to do is Register online, add contact details from his observation-place, his garden, his balcony, or his favorite field, and then count for an hour, using a card showing the most common species, the number of individuals perched on the branches of bushes or placed on the railing.

During the previous wintering operation in January 2022, 24,048 budding ornithologists participated, painting a fairly complete picture of France’s bird populations, and even of the health status of France’s ecosystems and biodiversity.

Birds are very popular among the public, and people love to watch them. Enthusiastic is Marjorie Poetvin, facilitator and reviewer at the Garden Bird Observatory. Within ten years, the number of participants had increased tenfold, from 3,000 to nearly 30,000 today. Launched in 2012, this system developed under the supervision of the League for the Protection of Birds (LPO), the National Museum of Natural History (MNHN) and the French Office for Biodiversity (OFB), is based on citizen observations, carried out all year round and spread throughout France. , in order to measure the occurrence and abundance of common bird species.

Increased presence in winter

The results of the ten-year report, presented on Tuesday in the Jardin des Plantes (5th arrondissement), show two trends, contradictory at first glance: in winter, 49% of species increase over ten years, while in spring, during the second count that occurs during the season Reproduction, 41% of species are in decline.

This winter trend isn’t necessarily a positive thingMarjorie Poitevin analyzes, These are mostly migratory birds, who come from northern and eastern Europe to take refuge with us.” Previously, these birds fed in the countryside, but today, “Intensive farming causes these populations to retreat from towns and gardens, where they often find more food and nutrients.”Also adds Alain Bogren-Duborg, President of the LPO.

The increase in birds in winter is also explained by the milder temperatures, which leads to a better survival rate of individuals and a redrawing of the migration map: “Under the influence of global warming, the wintering conditions of some species have changed, Marjorie Poitvin notes. Birds like the black-capped warbler have a much shorter distance to travel and stay close to their breeding grounds in the spring.”

This also applies to white storks, whose mortality rate during the first migration is close to 75%. “There are more than 1,000 little storks who stay with us and do not migrate. These are all animals that will not give up during migration,” Alain Bogren Dubourg explains.

When birds disappear, biodiversity vanishes.

After winter, the number of birds seen in gardens decreases. “Our concern is that these are ‘domestic’ birds, nesting on our lands.”, says Alain Bogren Dubourg. Less than 46% for the common swift and European goldfinch, and less than 17% for the blue swift … “Retreat is dangerous, LPO chief gets upset, Especially because when birds disappear, so does biodiversity.”

considered as an indicator of biodiversity. “Birds are among the species at the top of the food chain, because we have quite a few large mammals in France. The occurrence of birds therefore indicates the quality of the ecosystem,” Benoit Fontaine, ornithologist at MNHN and OFB.

At the origin of the degradation of ecosystems, professionals distinguish three main factors: intensive farming and widespread use of pesticides and pesticides; artificial “vertical or horizontal”Which deprives birds of their nesting places and global warming. Under tiles for example, the characteristic nesting space, temperatures rise rapidly Chicks are exposed to frightening heat that may reach 40 degrees Celsius. They throw themselves into the void without feathers. The brilliant Alain Bogren Dubourg.

Citizen science, an “unusual tool”

While OFB work published in 2021 and data from the International Union for Conservation of Nature (IUCN) document the decline of birds in France, citizen contributions are essential, with ongoing feedback, and in many areas. “If we can say that we have lost 30% of birds in agricultural settings since 2000, it is also thanks to data from participatory science,” thought Benoit Fontaine.

Participatory science was criticized ten years ago by a part of the scientific community that it was impossible for them to do real science using data collected by ordinary citizens, and participatory science is now recognized. “It is an exceptional tool for large-scale, long-term, high-volume data collection”As Benoit Fontaine says.

More and more work being done by CNRS or MNHN “It can only be done with the contribution of participatory science. In the case of birds, there are not enough biologists and ornithologists to make an inventory,” Alain Bougrin Dubourg says: For the head of the LPO, the French’s enthusiasm for bird watching in the gardens is proof of that “Communion between citizens and science for the common good of nature.”