Farmland practices are driving bird population decline across Europe

Abstract

Declines in European bird populations are reported for decades but the direct effect of major anthropogenic pressures on such declines remains unquantified. Causal relationships between pressures and bird population responses are difficult to identify as pressures interact at different spatial scales and responses vary among species. Here, we uncover direct relationships between population time-series of 170 common bird species, monitored at more than 20,000 sites in 28 European countries, over 37 y, and four widespread anthropogenic pressures: agricultural intensification, change in forest cover, urbanisation and temperature change over the last decades. We quantify the influence of each pressure on population time-series and its importance relative to other pressures, and we identify traits of most affected species. We find that agricultural intensification, in particular pesticides and fertiliser use, is the main pressure for most bird population declines, especially for invertebrate feeders. Responses to changes in forest cover, urbanisation and temperature are more species-specific. Specifically, forest cover is associated with a positive effect and growing urbanisation with a negative effect on population dynamics, while temperature change has an effect on the dynamics of a large number of bird populations, the magnitude and direction of which depend on species' thermal preferences. Our results not only confirm the pervasive and strong effects of anthropogenic pressures on common breeding birds, but quantify the relative strength of these effects stressing the urgent need for transformative changes in the way of inhabiting the world in European countries, if bird populations shall have a chance of recovering.

Agriculture and hot temperatures interactively erode the nest success of habitat generalist birds across the United States

“…Our results highlight the vulnerability of birds nesting in agricultural settings to temperature extremes and may offer insight into mechanisms underlying North American bird declines ( 30 ). They also align with recent findings from Europe suggesting that climate change may be causing larger population declines in generalist, farmland-associated birds compared with specialist, woodland-associated species ( 31 ). Maintaining forest patches in anthropogenic landscapes may thus increase avian resilience to extreme climatic events ( 32 ).…”

Effects of human depopulation and warming climate on bird populations in Japan

“…The expansion and intensification of agriculture to support an increasing global population has been a major threat to global biodiversity over the past few centuries, and this trend is expected to continue into the 21st century (Leclère et al., 2020; Tilman et al., 2017; Rigal et al., 2023). In contrast to the global trend of human population growth, 61 countries or areas are projected to lose more than 1% of their population between 2022 and 2050 (United Nations, 2022).…”

Land‐use intensity influences European tetrapod food webs

“…The decline in local tetrapod richness in Atlantic croplands is a cause for concern. This region shows by far the largest proportion of intensive croplands (60%, Figure S3.3), which may have contributed to this decline, given that the generalization of intensive agriculture has contributed, for example, to the decline of birds in Europe (Rigal et al., 2023). Besides, we observed a decrease of omnivory and an increase of trophic chain lengths in response to higher land management intensity in cities and peri‐urban areas, partly explaining the unexpected general trends for these two facets.…”