Girton Birdwatch - February 2008
Some time ago I mentioned the Water Rail, dead unfortunately, found by Jenny Knights near the electricity pylons down Fairway. If you are not familiar with this bird, or if you've never seen one in the wild, that would not be too surprising for they have a reputation for great secrecy and elusiveness. Recently, however, Jenny has had the good fortune to observe not one but two of these attractive birds, on separate occasions, relatively close to the village. Their preferred habitat is marshes, swamps, bogs and reedy lake margins and I usually make the trip to Fowlmere to try and catch a glimpse of them, but Jenny saw one near the boggy/pond area by the Barhill roundabout and another crossing Park Lane near the brook in Histon. I suppose the Water rail resembles a slimmed down version of a Moorhen but it has a much longer, more delicate, curved red bill lacking the Moorhen's yellow tip, with which it has been known to skewer other small birds. Its breast, face and throat are slate-grey, its flanks are barred, while its upper parts are dark brown with black streaks. It is white under the tail and this flash of white is often all that is seen of it as it vanishes into the reeds, darting from one piece of cover to another, using a high-stepping walk which has been likened to that of a nervous mouse. Given that the Water rail figures among our top ten most elusive birds it is surprisingly noisy and its presence, especially in winter, may be betrayed by a cacophony of highly un-birdlike noises emanating from its favourite reed beds; these distinctive calls, most often heard at dawn and dusk, are a mixture of squeals, grunts and groaning screams variously described as being like 'squealing piglets', 'between a purring cat and croaking frog', a 'grubbing hedgehog', 'the purring of a contented squirrel' and even 'an animal in mortal agony'.
It is a bird which has suffered over the last 30 years through loss of its wetland habitat although, given its secrecy and other obstacles to an accurate census, there are those who think that the present population estimate of fewer than 2000 pairs is a serious underestimate.
Water rails are in Britain throughout the year, although they are migratory. If given the choice, they prefer to use their long, powerful legs to escape danger rather than their short, rounded wings, and their flight appears to be weak, an impression exacerbated by their limply dangling legs. However, this impression is misleading as the birds are capable of long journeys on the wing. Many Water rails move into this country for the winter from the Netherlands, Belgium and southern Scandinavia, while others summer in northern and central Europe, even crossing such mountain systems as the Alps. However, Jenny Knights' 'dead sighting' confirms that although the Water rail's rapidly beating wings can carry it for long distances it is not really suited for high flight, and during the course of its migratory flights collisions with overhead wires and North sea oil rigs are by no means uncommon.
You might have noticed more Long tailed tits than usual around your garden this autumn and winter, and a relative dearth of Blue tits. The culprit appears to have been the wettest May-July weather since records began. It was also a wonderfully warm April - people who took their holidays then were very lucky - and tits started breeding a week or two earlier than normal for England. Most tits had young in the nest during May, and with the terribly wet weather that month both young and parents experienced real problems. Not only were nests waterlogged and chicks drowned but parent birds found it extremely difficult to find food; caterpillars and other insects were simply washed away. The only tit to have a good breeding season was the Long tailed which breeds earlier and which managed to take advantage of the warmer April. Their chicks were fledged and active when the worst of the weather arrived and although they also suffered, they were better equipped to forage for the existing food. Fortunately the effect should not be long-lasting and should not affect breeding numbers next spring. Large numbers of young tits are produced each year - as those of you who find the activity of Sparrowhawks 'hoovering up' the surplus so distressing will be aware - and those which survived should quickly replenish numbers. Moreover, it appears that Cambridge probably didn't do so badly weather-wise as some other parts of the country.