Fig. 1From: Colour-ring wear and loss effects in citizen science mark-resighting studiesStudy area map of the Netherlands showing all locations where the Eurasian oystercatcher has been ringed (a), in addition to the two colour-ring types considered in this analysis including barcode style rings (b) and two-letter engraved colour-rings (c). Both colour-ring schemes contain a small colour-ring with no inscription (b, c). b Jeroen Onrust, c Andrew AllenBack to article page