Red elderberry (Sambucus racemosa) produce the earliest berries, which are popular as food for several passerine species. In cities most numerous consumers of red berries are Black redstarts (Phoenicurus ochruros). Sometimes it is not easy for them to take berry, but with big choise birds usually fly away not hungry. Because according to Wikipedia, fruits consists on average from 88.0% water, and their dry weight includes 8.3% carbohydrates and 9.0% lipids, which is one of the highest lipid values among European fleshy fruits. Hrodna city in W Belarus, 05-07-2025 Several pictures and full story, in Belarusian, are here: https://birdwatch.by/gallery/harrier/rudakhvostki-charnushki-i-chyrvonaya-buzina Некалькі здымкаў і гісторыя рудахвостак-чарнушак і чырвонай бузіны, па-беларуску, тут: https://birdwatch.by/gallery/harrier/rudakhvostki-charnushki-i-chyrvonaya-buzina