Climate change affects the duration of the reproductive season in birds

Summary 1. The duration of the reproductive season may depend on the duration of the growing season, with recent amelioration in spring temperatures allowing earlier start of reproduction. Earlier start of reproduction may allow a longer breeding season because of more broods a longer interval between broods for multi‐brooded species. 2. We analysed extensive long‐term data sets on timing of breeding in 20 species of birds from Denmark, based on...