The Relationships of the Flamingos as Indicated by the Egg-White Proteins and Hemoglobins

Abstract

The living species of flamingos form a small, easily defined group of three genera, Phoenicopterus, Phoeniconaius, and Phoenicopawus. Phoenicopterus is usually divided into three forms, considered to be species by some authors while others treat them as races of the Greater Flamingo, Phoenicopterw Tuber. These are P. T. Tuber of the New World tropics and subtropics, P. r. chilen&.s of temperate South America, and P. T. roseus (= antiquorum) of the Old World. The Lesser Flamingo; Phoeniconaius minor, occurs in Africa and India and Phoenicoparrus an&us and P. jamesi are confined to the Andes in Peru, Argentina, and Chile. These four (or six) living species are the survivors of a long and well-documented lineage extending at least to the early Tertiary and possibly into the Cretaceous. In spite of this unusually good fossil record the relationships of the flamingos to other groups of birds have been difficult to determine beyond doubt. A large body of evidence, mainly anatomical, suggests an alliance to the Ciconiiformes (herons, storks, ibises), but the bill and feet, development of the young, the voice, and the mallophagan parasites have been interpreted as indicating an origin from the Anseriformes ( ducks, geese). The question is, are the flamingos most closely related to the herons and storks and merely convergent to the anseriform birds in certain characters or were they derived from the ducks and geese and later converged toward the ciconiiform birds? A third possibility is that they were derived from some other group and are similar to both geese and herons only by convergence. In this paper we will review various opinions about the classification of the flamingos, the fossil history, and the anatomical, behavioral, and other evidence which has been presented. We will then present some new data from our studies of the egg-white proteins and hemoglobins of birds which bear upon this problem.