The distance to the closest nest correlated highly with the number of nests within a radius of 3 m in both years (Spearman correlations: 1997: rS = -0.543, N = 28, P = 0.003; 2005: rS = -0.611, N = 118, P < 0.001); therefore we report only one of these measures (nests within 3 m) as an estimate of nest density