Ref. Woodall 2001 (
HBW6):
"Traditionally, the kingfishers have been grouped in a single family, the Alcedinidae, within which apparently closely related genera have been arranged to form three separate subfamilies. The results of relatively recent DNA-DNA hybridization studies, however, appear to indicate that there are wide gaps between these three groups of kingfishers, to the extent that some authors prefer to accord each of them family status, as the Alcedinidae, the Halcyonidae and the Cerylidae. At the molecular-genetic level, the last two of those seem to be more closely related to one another than either is to the Alcedinidae, which is considered to be the ancestral group.
... In addition, as already mentioned, the three separate taxonomic groups of kingfishers are generally treated as subfamilies within the family Alcedinidae: namely, the Halcyoninae, the Alcedininae and the the Cerylinae. Furthermore, morphological and behaviourial data suggest that the cerylines are closer to the alcedinines than they are to the halcyonines, and that the halcyonines are the ancestral group from which the others evolved. This discrepancy with the findings of DNA studies might be caused by some of the small alcedinine kingfishers having much quicker generation turnovers than do the larger halcyonines and cerylines, so that the latter may be older than the DNA evidence indicates.
The main divisions among the kingfishers are, therefore, well known and widely accepted. The major problem is in deciding at which level these differences should be recognized. Apart from the difficulties over whether the three subfamilies merit elevation to family rank, there are also problems at the genus level. ..."
Ref. Fry, Fry & Harris 1992 (
Kingfishers, Bee-eaters & Rollers):
"The orthodox scheme of bird classification has been turned on its head in recent years as a result of the extensive genetical studies of Charles Sibley and Jon Ahlquist and their colleagues in the USA. The Order Coraciiformes, however, has remained relatively unscathed. These are ancient perching birds, in a sense prototypes or early forebears of the songbirds, and it is now clear that the various coraciiform families are more distantly related to each other than appearances suggest. Conventionally the kingfishers, for example, have composed a single family divided into three subfamilies: the Daceloninae, Alcedininae and Cerylinae. But it is now evident that ceryline and dacelonine kingfishers diverged from one another even longer ago than did pelicans and storks, or swallows and treecreepers. The three kingfisher subfamilies should therefore be upgraded to family level, as the Dacelonidae, Alcedinidae and Cerylidae (Sibley, Ahlquist and Monroe 1988)."
Richard
