Oponthoud door koude bij trekkende Kieviten Vanellus vanellus in maart 2006

The first and second decade of March 2006 were remarkably cold with minimum temperatures well below zero (Fig. 1), and deep snow cover. On 18 March Lapwings were mapped in a 2075 ha large farmland area south ofAssen (Fig. 2), resulting in atotal of2059 individuals. This is an exceptional high number for the area and it can be assumed that migrating Lapwings were forced to arrest their northbound migration at the southern boundary of an area with low temperatures. Normally Lapwings prefer open areas, but in this case densities were higher in half open areas (Table 1). In these wind-sheltered areas temperature rose more quickly during daytime, resulting in snow-free patches that were readily used by foraging Lapwings. Extrapolating for the entire province of Drenthe, there may have accumulated some 176.000 Lapwings before they took off on 20 March when temperatures rose and numbers in the study area had dropped to 186 individuals.