Every spring, on three occasions, more than 2,000 bird watchers go on a bird counting campaign. They do not have a choice of observation place that is always the same, nor the hours, days and duration of observation (5 minutes). They observe and compile the results of their meetings by hearing and seeing. On this strict protocol certified ornithologists Bird Protection League (LPO) and National Museum of Natural History (MNHN) to ensure a serious scientific observation of bird evolution in France. And the result is not good. In three decades, 123 most common species globally have lost a third of their numbers.
The situation is different depending on the habitat of the species. The situation is improving for forest birds, but it is significantly worsening for those living with people in towns and villages, and especially for those who specialize in the agricultural environment. In addition, birds that need special ecological conditions, mainly because of their diet, are more endangered than “generalists” who adapt to less demanding living conditions and a more varied diet. “The main reason for the decline is the reduction of available resources, whether it is food or favorable habitats for shelter, breeding or feeding,” details of Caroline Moussy, in charge of overseeing Stolac in the LPO. A total of 32 species are expanding, 43 others are declining, and the rest are stable.
Birds benefit from changes in forest management
Therefore, there are fewer birds in the city. Overall, the workforce fell by 28% in thirty years. LPO explains this decline by transforming buildings and renovating facades that offer fewer cavities for species that also suffer from declining insect and seed stocks, especially in winter. Very generalist species like the forest pigeon, which has doubled in number in 19 years, or big tits (+ 9%), on the other hand, are doing very well. “And this is bad news because it reveals the increasing banalization of habitats, loss of diversity and standardization of fauna.”, Explains Benoît Fontaine, a researcher who follows the MNHN program. Among the losers are swallow chimneys (-23%) and barns (-25%), European gold (-31%).
The decline in numbers is evident for agricultural environments (dark brown) and built (ocher) while GPs (yellow) are doing well. © Stoc
After falling significantly, the forest bird population seems to have stopped its decline, even though the balance has remained negative for thirty years with a decline of 10% in number. Black woodpecker, pitcher’s nursery spreads as black grouse or peony decays. Ornithologists explain the recent improvement in the situation by changing forestry practices. More and more operators are abandoning clean felling for “garden” forestry techniques where, in particular, abandoning dead wood to enrich the litter and preserve aging that favors insect populations increases the ability to find a rich and varied diet. But climate change can also affect birds. So the three-legged belt has seen their numbers explode by 79% in nineteen years, probably because this species loves high temperatures and so can increase its range. Her close cousin, the crested jerk, shrinks by 44% as she prefers colder temperatures and therefore goes north, gradually leaving French territory.
Agriculture on the dock
Agriculture is mainly blamed for the overall decline in numbers. Field- and meadow-dependent species suffer from increasing plot size, hedge plucking, significant use of pesticides and chemical fertilizers – which drastically reduces the insect populations from which birds live. Food – and early mowing of meadows. All this cocktail explains the 30% drop since 1989. Red and gray partridges have thus decreased by a third, and the emblem of Stolac, the meadow, has fallen by 60% since 2001. “The impact of this intensive agriculture is particularly visible on birds and clearly shows the urgency of establishing a new common agricultural policy (CAP) that really preserves biodiversity,” notes Alain Bougrain-Dubourg, president of the LPO. The French part of the CAP is being completed, and the direction taken seems not to be favorable for birds as major supporters of more environmentally friendly agriculture left the debate table on Friday 28 May.
Stoc is now reaching the age at which he shows his real usefulness. Thirty years of tracking allow us to draw long-term trends. The participation program is therefore being expanded by monitoring mountain species since 2014 living in certain conditions and winter monitoring to better understand the status of year-round bird populations in France.