Fig. 4

Intake rate by red knots in the Wadden Sea (a) and at Banc d’Arguin (b) predicted on the basis of estimates of food abundance using grid-sampling. The two maps are to scale, and each square represents one sampling location. The potential intake rate of ash-free dry flesh mass (AFDM_flesh) was calculated by an experimentally tested diet choice model. Calculations were based on mollusc species making up at least 1% of the red knot’s diet (Table 1). Differences in mean digestive capacity between the tagged Wadden Sea and Banc d’Arguin red knots were considered