Sounds evocative

Greenfingers recently posted a piece called Call of the Wild extolling the virtues of the sound of the redshank and asking his readers if they have 'any iconic wildlife sounds that convey the same sense of place?

Sounds are such an important contributor to atmosphere that its so difficult to pick one above others.  The redshank's familiar call has been the backing track to so many brilliant days on the coast over the years that its right up there on my own list of favourites.  But, I have to say that the curlew would top that for me.  If ever there is a sound that invokes open wild places, from summer moorland to winter shore, then this is surely it - the emblematic bird of the Northumberland National Park and rightly so.

However, I have a sneaky favourite - one bird whose sound I always love to hear when it arrives in numbers on the coastal flats of Lindisfarne and Budle Bay - the wigeon.  Its whistle, floating on the wind on a cold winters day takes some beating - and its a bonny sight into the bargain.

I have a weird sort of brain whereby a sound can trigger a precise memory of exactly where I was when I heard it.  One such sound that still brings back a vivid and wonderful memory, from many years ago now, of  5am on silent misty moors between Weardale and Teesdale is this one... the black grouse. Imagine a spooky silence and tricky shadows broken only by this sound, with the birds invisible somewhere in the murk and you've got it.

But before I get carried away completely and start mentioning kittiwakes echoing off the Cullernose cliffs just one more as I admit to a soft spot for a charismatic little bird whose sound encapsulates the best of mature deciduous woodlands. The sound of the wood warbler (nice recording here - scroll down to the last on the list) tootling its plaintive little whistle before shaking itself to bits is ten out of ten.

Bent-billed Curlew

I watched a curlew feeding on the tidal flats at Budle Bay at the weekend. When the bird withdrew its bill, I thought I had a new species for a moment .......

..until the protruding worm wriggled before being swallowed.

After the bird poked its bill into the mud, I watched as it moved its head from side to side and front to back. It was clearly 'feeling' for food and therefore must have some sort of sensitivity in the bill tip. In fact, if it is able to detect a soft-bodied worm, it must be very sensitive indeed.

Reading around to find out more about the design of the bill, I discovered that it is full of sensory organs located in small pits in the bill structure (as are other waders such as snipe for example). This prompted me to go and root about in the garage for a curlew skull that I collected from a dead bird and cleaned up some years ago.

If you look closely at the tip of the bill (and note that this is the underlying bone structure without the bill sheath that overlies this), you can see lots of small holes - presumably the location of these sensory structures.

The common perception of a bird's beak as hard, dead material probably derives from the painful experience of a budgie peck. In reality, the bill of the curlew is a delicate and complex structure.

Later, the bird wandered off into the distance and beyond my compact camera range. As I followed it in the telescope it found a small crab, picked it up by one leg and shook it vigorously. The leg broke off - as it is designed to do (there is a line of weakness designed-in as a predator escape mechanism). The curlew discarded the leg and picked up the crab again by another and did the same. Although I couldn't be sure, it looked like all were similarly treated until the hapless, and by now, legless, decapod was swallowed. A neat trick, but was that learned or inherited behaviour? Somebody somewhere must know....