On 27 April 1947, the first Great Tit egg of the year was counted in the University of Oxford's 'living laboratory' at Wytham Woods. Seventy-five years later, in 2022, the year’s first Great Tit egg was counted on 28 March; almost exactly a month earlier than its predecessor from 75 years ago. The Wytham Great Tit study is the longest continuous study of an individually-marked animal population in the world. Sir David Attenborough said: ‘I am delighted to hear of the 75th anniversary of the long-term Great Tit study in Wytham Woods. One of the most striking changes is that the average Great Tit breeds three weeks earlier now than it did at the start of the study.
