The genus Sarothrura (Aves, Rallidae). Bulletin of the AMNH ; v. 143, article 1
New York : [American Museum of Natural History]
"The small rails comprising the genus Sarothrura form a well-marked group, for which a subfamily, the Sarothrurinae has been proposed. They are familiarly known as flufftails, from the fluffy decomposed tail. There are nine species, seven in Africa, two in Malagasy. 2. Except in S. ayresi, differences in color between the sexes are striking, although there is no difference in size. The male is predominantly black, each species with its characteristic pattern of white or buffy spots or streaks, and with a chestnut head. The female is predominantly black or brown, each species again with its characteristic pattern. Exceptions to the foregoing are that the female of pulchra has the male-like character of a chestnut head; whereas both sexes of watersi are brown, patterning is no more than vestigial, and confined to the female. In rufa, lugens, and boehmi the tail is black; in the other species there is a varying amount of chestnut. In some species at least, molt of the primaries is alternate so that the power of flight is never lost. 3. So far as they are known, the eggs are invariably white, and the nest is usually domed over to conceal them. In some species, at least, despite the color dimorphism, both sexes apparently incubate the eggs. The chicks are clothed in black down, and in some species they have pale markings on the bill, which may serve to emphasize signal movements employed in obtaining food from adults. Immature birds are uniform blackish, with the exception of pulchra, which has some patterning. The immature plumage is quickly replaced by a patterned adult dress, the change perhaps usually starting at an age of only about six weeks. 4. Sarothrura pulchra and elegans are forest and thicket dwellers. The others, including the Malagasy species, insularis and watersi, inhabit swamps or grasslands. Sarothrura affinis has a montane distribution, fragmented under existing climatic conditions. Sarothrura ayresi is probably confined to Ethiopia and to South Africa, although it has not been certainly recorded in the latter area since 1901. It may be represented ecologically in the intervening area by boehmi. No difference in habitat between rufa and lugens has been established. They appear to compete with each other, rufa being in most localities the more successful. 5. In southern Africa at least, breeding is predominantly in the rains. But the scanty data for insularis of Malagasy suggest that it breeds before the rains. There is strong evidence that boehmi is absent from southern Africa in the dry season, which lasts some seven months. In common with another rail, Crex egregia, its habitat is liable to be burnt out. No other Sarothrura is considered to have any regular, long-range movement. 6. Because of its secretiveness, very little, indeed, is known about Sarothrura behavior. But probably all the species have striking song calls during the breeding season. Those of the African species, except ayresi, have been tape recorded by Keith, and a special and pioneer feature of the present paper, so far as African ornithology is concerned, are sonograms of these calls. 7. Subspeciation is lacking in boehmi, ayresi (notwithstanding its fragmented distribution), insularis, and watersi. Color variation is rather slight, except in the female of pulchra. This species also shows a marked tendency to small size, mainly in southern Cameroun, and possibly a manifestation of Bergmann's Rule. There is, however, an inexplicable and striking contrast in size with northern Cameroun birds, and also in the color of the females. Sarothrura rufa also shows a tendency to small size in southern Cameroun and adjacent areas, but is unknown in northern Cameroun. Sarothrura lynesi is regarded as a subspecies of lugens. It only differs in being smaller -- curiously in the colder part of the range of the species. Only two subspecies of affinis are formally recognized, but probably two more will eventually have to be. This involves the collecting of topotypical material of S. affinis antonii, the type of which was destroyed in the troubles in Hungary in 1956. 8. Sarothrura pulchra and rufa are much the best represented species in museum collections, ayresi and watersi, the worst. In general, this is also a reflection of the state of knowledge of these species in life. The only specimens from Ethiopia are 26 of ayresi and one of rufa; from Somalia, one of elegans. Males preponderate over females in collections in a ratio of more than two to one. 9. In the section on phylogeny the species are placed in four groups: (1) pulchra and elegans; (2) rufa, lugens, and boehmi; (3) affinis and insularis; (4) ayresi and watersi. The first two (the pulchra and rufa groups) form the two extremes. The pulchra group is thought to be the most recently evolved and the most advanced. But for the red in the tail, as in the pulchra group, the affinis group could be merged with the rufa group. Sarothrura affinis and insularis form a superspecies. Sarothrura affinis stock may have colonized Malagasy in a colder, wetter regime. The resultant insularis is a successful species, able to exist even at sea level. Sarothrura ayresi and watersi seem less closely related to each other than are affinis and insularis. The early extinction of watersi may be predicted, although ayresi may still be holding its own in Ethiopia"--P. 74-75.
84 p. : ill. (some col.), maps ; 27 cm.
Includes bibliographical references (p. 80-84).
Includes bibliographical references (p. 80-84).