The Wall Brown butterfly, last seen at Raw Nook Nature Reserve in 2009, was discovered by Martyn Priestley, field officer for the Low Moor and Oakenshaw Wildlife Conservation Group. Raw Nook Nature Reserve (Image: Martyn Priestley)"I looked at it in disbelief. Straight away I said, it's a Wall Brown. Urban reserve is 'gem for biodiversity'The Wall Brown’s return is particularly significant given the reserve’s location surrounded by industry in South Bradford. The Wall Brown is identifiable by its pale orange and brown colouring and distinctive pattern of black eyespots on its wings.