S-carboxy keratins from waterfowl feather were prepared and studied in regard to effect of preparation, individual and intraspecific variation. These results were then expanded in in an extensive intraordinal study of the waterfowl using polyacrylamide gel electrophoresis (PAGE) to compare representatives of approximately 40 genera in regard to intra- and intertribal variation. The PAGE was supplemented by double diffusion and immunoelectrophoresis using antisera to SCM—keratins of Anas. The resultant patterns, especially in PAGE were useful in testing a number of taxonomic hypotheses and demonstrated the conservative nature of these proteins. The basic ordinal structure of the waterfowl was supported but specific questions, especially to the relations of a number of monotypic or intermediate genera and a proposal regarding the sea ducks, were addressed. In almost all cases the placement of such taxa were resolved.
The PAGE data were used to test a number of published proposed phylogenies of the waterfowl.
SCM-keratins of feathers are a complex of similar sized monomers with great immunological similarity. The data presented here are discussed in regard to waterfowl systematics and the use of electrophoretic data to test systematic theory.