Keeping Up with Insect Pollinators in Paris

SIMPLE SUMMARY: The city of Paris is a dense and highly urbanized capital. However, it has many green spaces, some of which are managed to promote biodiversity. Among the wildlife that can be found in the city, insect pollinators are of great interest because of their pollination services. But what diversity of pollinators can we expect in such an artificial environment? In order to learn more about the species present, we carried out standardized inventories in Parisian green spaces for two consecutive years, over the course of the seasons. We identified 118 species of wild bees and 37 species of hoverflies, some of which had never been observed in Paris before. In particular, we observed relatively high proportions of parasitic and specialist bee species, which are generally uncommon in cities. The greatest diversity was observed in ecologically managed green spaces, suggesting that such approaches effectively support insect communities. Paris is home to many species of pollinators, forming assemblages that shift throughout the seasons. This is evidence that dense metropolises should not be overlooked when it comes to protecting biodiversity. ABSTRACT: There is growing interest in urban pollinator communities, although they may be subject to biotic homogenization in densely artificial landscapes. Paris (France) is one of the densest cities in the world, yet over the years many insect pollinator species have been reported there. We conducted in-depth surveys of Parisian green spaces for two years, in order to improve our knowledge of these assemblages. We explored several types of green spaces, monitoring pollinators throughout their activity season. We listed 118 species of wild bees and 37 species of hoverflies, updating pre-existing lists with 32 additional species. Bee assemblages showed functional diversity with 18.5% parasitic species and 17.7% oligolectic species. We also found several bee and hoverfly species under special conservation status. Over the study period, we observed seasonal succession of species, with diversified phenological niches. The greatest taxonomic and functional diversity was found in green spaces combining several habitats with ecological management. Despite its very dense urbanism, Paris is home to diverse pollinator communities. As a result, nearly half of the wild bee species of the wider Ile-de-France administrative region can be found within the city. This highlights the need to also consider dense urban environments in insect pollinator conservation strategies.