The effect of climate change on avian offspring production: A global meta-analysis

Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to repro- ductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young

Village modernization may contribute more to farmland bird declines than agricultural intensification

The central tenet of European farmland ecology is that agricultural intensification during the 20th century was largely responsible for dramatic declines in species abundances. However, during this time, human rural settlements were also undergoing radical changes through modernization, with undocumented biodiversity impacts in this important wildlife habitat. We performed the first ever large-scale study to disentangle the impact of these simultaneous processes on farmland bird diversity in 104 Polish villages. We show that modernized villages and their surrounding agricultural fields had 50-60% fewer birds than those in and around comparable older villages. The relative contribution of modernization versus agricultural intensification to predicted bird declines was 88% versus 12% for bird communities in villages and 56% versus 44% in surrounding croplands, with considerable variation among ecological species subgroups. These results challenge our current understanding of agricultural ecosystem ecology and how best to implement conservation measures costing billions of euros annually

Constant and seasonal drivers of bird communities in a wind farm: implications for conservation

Background. One of the most difficult challenges for conservation biology is to reconcile growing human demands for resources with the rising need for protecting nature. Wind farms producing renewable energy have been recognised to be a threat for birds, but clear directives for environmental planning are still missing. Methods. Point counts were performed to study the relationship between eight environmental variables and bird populations in different parts of a year on the largest Polish wind farm between March 2011 and February 2013. Variables potentially related to species richness (Chao 1 estimator) and the abundance of the entire bird community as well as five selected farmland species were analysed with the use of generalized linear mixed models. Results. Some associations between the studied variables and bird populations were season/year specific, while others had a constant direction (positive or negative) across seasons and/or years. The latter were distance to the nearest turbine, field size, number of wind turbines, proximity of settlements and water bodies. Spatial autocorrelation and counting time were significantly correlated with bird population estimates but the directions of these relationships varied among seasons and years. Associations between abundance of individual species and environmental variables were species-specific. Conclusions. The results demonstrated a constant negative relationship between wind turbine proximity and bird numbers. Other environmental variables, such as field size, proximity of settlements and water bodies that also had constant associations with bird populations across seasons may be taken into account when minimizing adverse effects of wind farm development on birds or choosing optimal locations of new turbines

Patchy versus. linear non-cropped habitats in farmland. Which is better for nesting success of Red-backed Shrike Lanius collurio?

The survival rate of Red-backed Shrike Lanius collurio nests in western Poland was higher when they nested in bushes aggregated in patches, rather than linear formations

Spatial and thematic bias in the scientific literature on farmland birds across the globe

The global biodiversity crisis and constantly growing human impact on the natural environment call for more evidence where conservation actions are the most urgent. As the agricultural lands are under increased pressure of growing human food needs here the literature survey on farmland bird conservation (FBC) was conducted to reveal geographical distribution in research intensity, the topics addressed and to identify potential drivers for the worldwide scientific effort. The Scopus database search has revealed 2290 papers dedicated to FBC from the period 1990-2020. The distribution was spatially uneven with most papers published in Western Europe and North America. Scientific collaboration was also spatially biased in favor of countries located close to each other and having high scientific capacity. The analysis also revealed 139 terms representing main topics raised in FBC research. The number of FBC papers per country was positively correlated with Gross Domestic Production (GDP), the total number of scientific papers, and number of threatened species, and negatively with the GDP from agricultural production, whereas it was not related to area of agricultural lands or bird species richness. Spatial and thematic biases in studies of farmland birds may have important consequences since uneven scientific evidence constrains development of proper conservation solutions and limits their implementation. We conclude that research on FBC should be globally coordinated and flexible enough to undertake burning conservation problems adjusted to regional differences in agriculture, socio-economy, and bird diversity