“…The role of citizens has been noted in a variety of subjects, from astronomy to zoology (Raddick and Szalay, 2010;Dickinson et al, 2010;Wiersma, 2010;Muller et al, 2015;Rossiter et al, 2015). Citizens have also already contributed greatly to mapping activities, including, for example, to major programmes such as bird species distribution mapping (Dickinson et al, 2010;Wiersma, 2010) and to the pioneering production of national land cover datasets such as the first land utilisation survey of the UK in the 1930s (Parece and Campbell, 2015).…”