1911 Encyclopædia Britannica/Jaçaná

JAÇANÁ, the Brazilian name, according to Marcgrave, of certain birds, since found to have some allies in other parts of the world, which are also very generally called by the same appellation. They have been most frequently classed with the water-hens or rails (Rallidae), but are now recognized by many systematists as forming a separate family, Parridae,[1] whose leaning seems to be rather towards the Limicolae, as apparently first suggested by Blyth, a view which is supported by the osteological observations of Parker (Proc. Zool. Society, 1863, p. 513), though denied by A. Milne-Edwards (Ois. foss. de la France, ii. p. 110).

Pheasant-tailed Jaçaná.

The most obvious characteristic of this group of birds is the extraordinary length of their toes and claws, whereby they are enabled to walk with ease over water-lilies and other aquatic plants growing in rivers and lakes. The family has been divided into four genera—of which Parra, as now restricted, inhabits South America; Metopidius, hardly differing from it, has representatives in Africa, Madagascar and the Indian region; Hydralector, also very nearly allied to Parra, belongs to the northern portion of the Australian region; and Hydrophasianus, the most extravagant form of the whole, is found in India, Ceylon and China. In habits the jaçanás have much in common with the water-hens, but that fact is insufficient to warrant the affinity asserted to exist between the two groups; for in their osteological structure there is much difference, and the resemblance seems to be only that of analogy. The Parridae lay very peculiar eggs of a rich olive-brown colour, in most cases closely marked with dark lines, thus presenting an appearance by which they may be readily known from those of any other birds, though an approach to it is occasionally to be noticed in those of certain Limicolae, and especially of certain Charadriidae.  (A. N.) 

  1. The classic Parra is by some authors thought to have been the golden oriole (see Icterus), while others suppose it was a jay or pie. The word seems to have been imported into ornithology by Aldrovandus, but the reason which prompted Linnaeus to apply it, as he seems first to have done, to a bird of this group, cannot be satisfactorily stated.