Soaring into the skies above the Chevin and the fields below Farnley Hall, the male skylark shows impressive levels of stamina. It belts out a seemingly non-stop song in its almost vertical ascent to heights of up to 300 metres, alerting potential mates and rivals alike, and inspiring one of Britain's most-loved pieces of music. This crested bird can be hard to spot up there, and unfortunately a change in farming practices in the 1970's has resulted in numbers plummeting.