The water rail, western water rail or European water rail (Rallus aquaticus) is a bird of the rail family which breeds in well-vegetated wetlands across Europe, Asia and North Africa. Northern and eastern populations are migratory, but this species is a permanent resident in the warmer parts of its breeding range. The adult is long, and, like other rails, has a body that is flattened laterally, allowing it easier passage through the reed beds it inhabits. It has mainly brown upperparts and blue-grey underparts, black barring on the flanks, long toes, a short tail and a long reddish bill. Immature birds are generally similar in appearance to the adults, but the blue-grey in the plumage is replaced by buff. The downy chicks are black, as with all rails. The former subspecies R. indicus has distinctive markings and a call that is very different from the pig-like squeal of the western races, and is now usually split as a separate species, the brown-cheeked rail.

The water rail breeds in reed beds and other marshy sites with tall, dense vegetation, building its nest a little above the water level from whatever plants are available nearby. The off-white, blotched eggs are incubated mainly by the female, and the precocial downy chicks hatch in 19–22 days. The female will defend her eggs and brood against intruders, or move them to another location if they are discovered. This species can breed after its first year, and it normally raises two clutches in each season. Water rails are omnivorous, feeding mainly on invertebrates during summer and berries or plant stems towards winter. They are territorial even after breeding, and will aggressively defend feeding areas in winter.

These rails are vulnerable to flooding or freezing conditions, loss of habitat and predation by mammals and large birds. The introduced American mink has exterminated some island populations, but overall the species' huge range and large numbers mean that it is not considered to be threatened.

Taxonomy

The rails are a bird family comprising around 150 species. Although the origins of the group are lost in antiquity, the largest number of species and the most primitive forms are found in the Old World, suggesting that this family originated there. However, the genus Rallus, the group of long-billed reed bed specialists to which the water rail belongs, arose in the New World. Its Old World members, the water, African and Madagascar rails, form a superspecies, and are thought to have evolved from a single invasion from across the Atlantic. and by Eleazar Albin in 1731.

The former subspecies R. a. indicus has very different vocalisations from the water rail, and it was considered to be a separate species in early works. It was restored as a full species R. indicus, by Pamela Rasmussen in her Birds of South Asia (2005). Her treatment has gained acceptance, and is followed in Birds of Malaysia and Singapore (2010). A 2010 study of molecular phylogeny further supported the possibility of specific status for R. indicus, which is estimated to have diverged from the Western forms around 534,000 years ago.

The nest is made from whatever wetland vegetation is available and built mostly by the male, usually in a single day. It is raised or more above the level of the marsh, and is sometimes constructed on clumps of roots, tree stumps or similar support. It may be built up higher if the marsh waters start to rise. The nest is across and about high. It is well hidden and approached by narrow tracks.

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Cited texts

  • Ageing and sexing by Javier Blasco-Zumeta & Gerd-Michael Heinze (PDF, 5.2 MB)