Country diary: metamorphosis in a museum tower

Oxford University Museum: For 70 years, researchers have been watching ‘particularly hideous’ young swifts turn into long-winged angels

This glorious structure is a place rich in history. As we walked through the galleries our guide paused to show us the great oak door behind which Bishop Wilberforce confronted “Darwin’s bulldog”, Thomas Huxley, in their famous debate on evolution. We, however, were intent on a more modest fraction of the building’s past. For it was here in 1947 that the ecologists Elizabeth and David Lack noticed how breeding swifts were vanishing into air vents in the roof’s slate-covered tower.