Fig. 1
From: Foraging for high caloric anthropogenic prey is energetically costly
Map of the study system and habitat use (a) Overview of the study area, latitude and longitude are indicated on the x and y axis in UTM zone 31 (× 10.000), breeding colony is indicated with an asterix (615,201.4 E, 5873649 N). Foraging areas of category urban which contain refuse are indicated in dark grey. Another source of human waste is the closest waste treatment center to the colony, indicated with a circle. Foraging area of category marine with main prey fishery discards are North Sea and Wadden Sea. Foraging areas of category intertidal are indicated in the dashed area, but herring gulls also forage in the Wadden Sea on intertidal mudflats indicated in light grey. Terrestrial foraging areas are found on Texel and the mainland and are indicated in grey. b Space use of all the herring gulls used in the study (n = 17) during chick care in breeding seasons of 2013–2016, expressed in total time spent in minutes per square kilometer