In the Saône Valley, the study was carried out from 2009 to 2014. Mowing was postponed each year from July 2009. Bird breeding in 2009 was considered as the reference before the experiment. We accepted the risk of relying on a single survey in 2009 to derive baseline data as the reference point before the start of the experiment as the weather conditions were normal (neither drought nor spring flood). After mowing manipulation however, the breeding conditions of meadow birds were affected by a severe drought during the spring 2011, and by heavy rainfall and late flooding in 2013. The control areas however can determine the impacts of weather vs. management. In 2013 however, we decided to discard from the analysis two manipulated study sites which have been exceptionally flooded until the end of May.