Baillie, S.R., Marchant, J.H., Leech, D.I., Joys, A.C., Noble, D.G., Barimore, C., Downie, I.S., Grantham, M,J., Risely, K. & Robinson, R.A. 2009. OLD Breeding Birds in the Wider Countryside: Their conservation status 2009. British Trust for Ornithology, Thetford, Norfolk