Extra eyelid of a winking bird
THE hairy petals of bogbeans (Menyanthes trifolita or bachran) flourish in damp places beneath the slopes of Mount Brandon in Kerry, and sturdy birds called dippers search rapid river courses for larvae of caddis, stonefly, crustacean and tiny fish to feed youngsters in the nest.
The birds’ football-shaped homes are usually secluded under bridges, on river banks and beneath weirs, with side entrances for security. They are always near water. One nest was seen in the boot of a car abandoned in a river in Co Tyrone; while in England, birds remained in situ as liquid concrete was sprayed during bridge repairs. The birds’ home was permanently fixed, though they were able to exit and return.
The delightful and remarkable dipper (Cinclus cinclus hibernicus) resembles a super-wren with a distinctive white breast, rounded wings and a tidy tail, flourished while perching. I have written occasionally about this little river-keeper, percher on pool rocks, earnest searcher of river beds for the aforementioned caddis — a favourite lure of trout anglers — nodding and bobbing, acknowledging the world around it with little gestures of courtesy.
A regular reader, Paul G, has sent me images of this amazing bird which walks under water and which he had last watched along the Boyne, in Meath. Indeed, my memories of dippers are from the Mattock, a tributary of that river, which marks a boundary of the archdiocese of Armagh, and of the ancient province of Ulster.
The stout-legged dipper is an internationalist, being found along fast-running streams in Eurasia and the Americas. Strong-clawed, but not web-footed, it is unique among perching birds in being able to dive and walk under water, propelled by wing power and determination, in its search for aquatic invertebrates, poking beneath rocks and in bottom mud.
This sturdy bird, from a distance, is of pied appearance with its dazzling breast, but closer scrutiny reveals head and rear body to be dark brown with grey-tinged upper-parts. When it blinks, eyelids reveal a striking white and while searching for food a third lid protects the eyes. This may be noticed when the bird is perching as the lid folds over the eye as if winking at bird watchers.
The Irish dipper has Celtic cousins in Scotland and the Isle of Man of a darker hue. Bad weather and cold winters do not deter this little plunger in its food quest. The naturalist Mark Cocker watched a bird on a freezing day re-entering ice-fringed water up to 30 times to emerge with caddis larvae, the warty cases of which it smashed off the ice with deft blows.
Dippers are sedentary and a population of around 8,000 pairs is estimated, although there has been a decline due to acidification of streams as a result of conifer plantations and water pollution from slurry. Dippers are not very melodic, making ‘chink’ and rasping ‘zit’ calls. Four to six eggs are incubated in a bulky moss and grass nest.