Using archived television video footage to quantify phenology responses to climate change

Predicting how the timing of cyclic life‐history events, such as leafing and flowering, respond to climate change is of paramount importance due to the cascading impacts of vegetation phenology on species and ecosystem fitness. However, progress of this field is hampered by the relative scarcity, and geographic and phylogenetic bias, of long‐term phenology datasets.
By taking advantage of archived television video footage, we here developed an innovative tool using previously unexploited records to build long‐term datasets of phenological responses. To demonstrate the potential of this method, we worked with broadcast archives of sport events and focus on one of the most famous professional road cycling races world‐wide, the Tour of Flanders.
After viewing >200 hr of film, we compiled 523 individual × year observations of leaf‐out and flowering of 46 individual trees and shrubs visible in four decades (1981–2016) of video footage. We detect surprisingly strong advances in the timin...