“…For example when the Cuckoo has evolved seemingly perfect egg mimicry with host eggs, the host can respond by evolving more intricate surface patterns on their eggs like a form of "signatures" which make the eggs more difficult to mimic (Davies, 2000). Furthermore, the host may evolve a lower intraclutch variation and a higher interclutch variation in egg appearance (Davies and Brooke, 1989b;Øien et al, 1995;Soler and Møller, 1996;Stokke et al, 2002;Vikan et al, 2010Vikan et al, , 2011. Low intraclutch variation will make it easier for hosts to recognize foreign eggs (Stokke et al, 1999) while high interclutch variation will make it more difficult for parasites to mimic the eggs of the host species (Davies and Brooke, 1989b).…”