query: How large is the water rail?
passage: Water rail
The 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 23–28cm (9–11in) 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.
passage: Water ball
A water ball or water walking ball is a large inflatable sphere that allows a person inside it to walk across the surface of a body of water. The giant ball is usually two metres in diameter and has a zippered entrance to allow for easy entry and exit. The water ball is similar to the zorb, also referred as Human Hamster Ball, but it has only one layer and is designed for water travel rather than down-hill rolling. In the United Kingdom, the balls have been used at swimming pools, marinas and lakes in an effort to keep children fit.