Pic: Colin Varndell / Alamy Stock Photo
Words: Kate Risely, of the British Trust for Ornithology (BTO)
The call of a Water Rail is extremely un-bird-like, and never fails to take me by surprise! They produce a wide range of loud squealing and snorting noises, traditionally known as ‘sharming’, which brings to mind an alarmed piglet.
The birds themselves are extremely hard to see, preferring to stay hidden in thick vegetation. If you are lucky enough to get a good view, adults of this species can be recognised by the long, red bill, black and white barring on the flanks and tiny, cocked tail.
They are also surprisingly small, half the weight of a Moorhen, and very narrow-bodied. It’s worth learning the differences between Water Rails, particularly juveniles, and the other, rarer Rallidae – Spotted Crake, Little Crake and Baillon’s Crake – as views are often fleeting.
In winter, we are joined by migrant Water Rails from Scandinavia, northern Europe and even further afield; a wintering adult ringed in 1990 in Lancashire was found the following breeding season nearly 2,000 miles away in Belarus, unfortunately killed by a cat.
It seems incredible that such skulking birds can fly long distances out in the open, and in fact they are very rarely seen on migration as they are night travellers, flying under cover of darkness, and are normally safely hidden by daybreak.
Winter is the best time to see Water Rails, partly due to the larger number around, and also because birds are sometimes forced to forage in the open when the water surface is frozen solid. The BirdTrack reporting rate shows that birdwatchers are most likely to record Water Rails in November and December.
Their preferred breeding habitat is static or slow-flowing fresh water with very thick vegetation and preferably some open mud. The Bird Atlas 2007–11 distribution map shows that breeding Water Rails are patchily distributed throughout the lowlands of Britain and Ireland, with strongholds in Ireland, East Anglia and southern Scotland.
Since the first breeding atlas in 1968–72 they appear to have been lost from many breeding sites in England and Ireland, but increased in Scotland – however, these results should be interpreted with considerable caution, due to the difficulty of detecting this species on general surveys.
National population estimates for all of our breeding and wintering birds were published in 2013, including an estimate of 1,100 Water Rail territories. This figure was calculated using reports to the Rare Breeding Birds Panel, though it was flagged at the time as ‘a contender for the least reliable population estimate’!
This number was challenged by those with experience surveying Water Rails using tape playback to encourage the birds to call, who maintain that breeding Water Rails are extremely under-recorded through standard survey methods.
Playback surveys have resulted in an estimate of 800 territories in Scotland alone, and it has been suggested that the overall UK population might be in the order of 4,000 to 6,000 territories. Such wildly disparate population estimates, and the uncertainty over whether the species is increasing or declining, highlight the problems with understanding and therefore conserving such elusive birds.