Wildlife with an amateur observer
My workplace overlooks the River Ilen and, over the years, I’ve been fortunate to see some wonderful wildlife along its banks. Through constant sightings, I’ve gotten to know a lot of the birds and animals as individuals, watching them feeding, breeding and rearing their young over the decades.
However, there is one aquatic bird that I’ve only seen twice in all the years – the dipper. So it was a cause of great excitement to see one recently, bobbing up and down on the riverbank opposite.
I’ve seen the dipper once before on the Ilen, further upriver near Ballyhilty Bridge. This is a bird that favours fast moving water so I was not surprised to see it hunting in the tumbling waters around the bridge. And now we’ve identified another Ilen-side hunting ground of this aquatic bird, which is fortunately right outside the building where I work.
The dipper is a distinctive bird and so it’s very easy to identify. It is present in most counties in Ireland, however, it’s rarely seen.
Like the wren, the dipper has a jaunty tail-cocked posture but it’s slightly bigger in size than the robin. It has extremely strong legs which look like those of a starling while its beak is similar to that of a thrush in both colour and size.
Its upperparts are a rich, plain-chocolate brown verging on black. The wings and tail look short in proportion to its plump body. But by far its most noticeable feature is the large, white ‘bib’ that extends across the throat and down to the belly.
There is some variety in the ‘white-throated’ dippers of Europe. The British dipper has a chestnut band at the base of its white bib. This band is slightly narrower in the dippers in Ireland while it’s not present at all on the breasts of Continental birds. This, along with other slight variations, gives us a sub-species of dipper in Ireland - the ‘hibernicus’ – which is also found in the Hebrides and the Isle of Man.
With its white bib and bobbing movement, the dipper flits close to the water over fast-flowing streams and rivers, alighting onto a boulder when it needs to feed. From this perch, it plunges into the stream, walking along its bed to hunt aquatic prey.
From its lookout on the boulder, the dipper hunts for food, often beneath the surface but sometimes just up to its ‘waist’ in the shallows. It’s extraordinary to see this diminutive bird hold its own against a strong current.
To submerge itself, the dipper may jump straight into the water or gradually walk deeper into the stream. Once below the surface, it hunts on foot. This is where the bird’s stout legs and powerful claws serve a vital purpose as they hold the bird’s buoyant body down on the bed of the stream. It is also believed that the shape of the dipper’s body actually makes the water passing over it press the bird to the bottom.
Underwater, the wings are used like fins, used both for propulsion and to keep balanced in strong currents. Sometimes dippers swim for some distances.
Most underwater animals form part of the dipper’s diet at some stage. Favourite items include caddisfly and water beetle larvae, worms and small shellfish as well as freshwater shrimp and tadpoles.
Hard to See
The bobbing of the dipper, alongside its white bib, provide surprisingly good camouflage against the background of broken white water. This is important as hunting in the open is a risky business and leaves the birds vulnerable to predation.
As the dipper bobs and dips its tail, it also blinks, using its so-called ‘third eyelid’. This is a white membrane (the nictitating membrane) which moves from one side of the eye to the other, not up and down like a normal eyelid. This works like a windscreen wiper in a car, wiping the surface of the eye clean. And, because it’s white when it’s closed, it is also effective in increasing the bird’s camouflage against the tumbling water it hunts in.
Under water, this eye membrane becomes transparent and, it is thought, protects the dipper’s eye from bits of grit that might be floating in the water. It does not affect its submarine vision.
Thanks to its effective camouflage, the dipper is a bird that is uncommonly seen. It tends to stick ‘close to home’ in its habitat. It establishes a territory on a suitable river or stream and rarely strays far from it. So the best way to get a chance to observe a dipper is to keep an eye out in such a preferred habitat, generally close to fast-flowing bodies of water.
In flight, the dipper is fast and low and makes frequent ‘zit-zit-zit’ calls, generally over its own stretch of water. However it will fly inland, if sufficiently alarmed.
The origin of its English name is obvious as it is constantly ‘dipping’ in motion. Its name in Irish – ‘gabha dubh’ – means ‘blacksmith’, a reference to its white bib or perhaps its black back. Older English names include the ‘water ouzel’ or ‘water blackbird’ and this theme also emerges in its alternative Irish name – ‘lon abhann’ – meaning ‘river blackbird’.
The dipper was once believed to be the female kingfisher. How these two so differently-hued birds could be mistaken is a mystery. However, as aquatic birds, they do share habitats and some hunting techniques and both fly low over the water.
In Victorian Britain, the dipper was persecuted as it was mistakenly believed to feed off the eggs of salmon and trout. Many hundreds of dippers were killed by over-zealous gamekeepers as a result.
In nineteenth-century Ireland, a sighting of a number of dippers was believed to foretell the arrival of a malignant disease in the area. The skin of a dipper, when worn on the stomach, was said to be a cure for indigestion.
In modern times, seeing a dipper is a cause for celebration and we certainly enjoyed our recent observation. However, it’s even more tempting to look out at the river these days which may not aid productivity at work!