Attributes / relations provided by
♦ ¹del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
♦ ²J. Dierschke (2002) Food preferences of Shorelarks Eremophila alpestris, Snow Buntings Plectrophenax nivalis and Twites Carduelis flavirostris wintering in the Wadden Sea: Seeds of plants from lower salt marsh communities are preferred, with insects less important., Bird Study, 49:3, 263-269