Merton distinguishes two types of opinion leadership&colon; monomorphic and polymorphic. Thus, Skil transforms polymorphic high order functions into monomorphic first order C functions. Both sexes are monomorphic in plumage colouration. "Trypanosoma evansi", although monomorphic in most cases, can be pleomorphic in some strains. Typically, aposematic species experience strong selection favoring monomorphic populations. Todies are generally a sexually monomorphic genus. The manucodes and paradise-crow, which are socially monogamous, are sexually monomorphic. Horned puffins are monomorphic (the male and female exhibit the same plumage coloration). This applies to both sexes of "Pica pica", which carries similar monomorphic plumage. Worm-eating warblers are sexually monomorphic. They are sexually monomorphic, with thick reddish coats. As a genetically monomorphic clone, it slowly propagated throughout much of Eurasia. Auks are monomorphic (males and females are similar in appearance). Ghost ants are monomorphic and the thorax is spineless. Juvenile convict cichlids are monomorphic until they reach sexual maturity.