The diverse order Gruiformes contains about 12 bird families with, on first sight, little in common.
Traditionally, a number of wading and terrestrial bird families that did not seem to belong to any other order were classified together as Gruiformes. These included the large land-based bustards, the very large cranes, the relatively small and secretive water-loving crakes and rails, and the small, plump buttonquail (all families with a wide distribution and a dozen or more member species), as well as a variety of very small families, several of them containing just a single species.
On first sight, the Gruiformes seem to have little in common with one another. They are morphologically diverse and the relationships between them are obscure. Recent DNA analysis, however, indicates that most Gruiformes are in fact more closely related to one another than they are to any other birds and the taxonomical revolution of the late 20th century has left the order surprisingly intact.
DNA work has led to three main changes: buttonquail are now treated as an independent order (Turniciformes); the unusual Plains Wanderer is now classed as a charadriiform, and some (but not all) authorities raise the Rallidae to ordinal status.
- Order GRUIFORMES
- Sibley, C. G., and J. Ahlquist. 1990. Phylogeny and classification of birds. Yale University Press, New Haven, Conn.
- Taxonomic recommendations for British birds. Ibis (2002), 144, 707–710. Alan g. Knox, Martin Collinson, Andreas J. Helbig, David T. Parkin & George Sangster