Nocturnal hunting by Eleonoras Falcons Falco eleonorae on their breeding and non-breeding grounds

We report on nocturnal hunting by Eleonora's Falcons in their breeding range in the Mediterranean region and in their non-breeding range in Madagascar. Hunting activity of Eleonora's Falcons near floodlights during the breeding season in western Morocco peaked 30-60 min after sunset, but continued into the early morning. Hunting activity and prey capture rates near floodlights were highest during nights with little moonlight or overcast conditions. Fifty-one percent of 73 group capture attempts were successful. Of the migratory prey species identified at the Moroccan study site (26 species), 73% belonged to species mainly migrating at night, whereas 57% of all migratory bird prey species of Eleonora's Falcon reported to date (122 species) migrate predominantly at night; suggesting that hunting near artificial light may increase the proportion of nocturnal migrant species in the diet of falcons. Sylvia and Acrocephalus were the most commonly recorded genera among prey caught after dark. Our direct observations and analysis of satellite transmitter data indicated that Eleonora's Falcons also hunted away from artificial light in Morocco, Italy, and frequently so in Madagascar. Flight activity was detected in 18% of 342 night-time locations of seven satellitetagged Eleonora's Falcons in Madagascar, at an average moon illumination of 60%. We conclude that nocturnal hunting by Eleonora's Falcons is more common than previously assumed and occurs preferably, but not exclusively, at above-average moon illumination on wintering grounds or near artificial lights during the breeding period

Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation.publishedVersio