Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, June 01, 2006

The Nature of long curved beaks

Straw-necked Ibis
The colourful and attractive Straw-necked Ibis* is a "wader", really. That is, it is a swamp bird by nature, with a long pointed beak, designed for poking into the mud, in search of worms and grubs. However, Australia is a dry country, so this bird has adapted to living away from swamps and the water's edge, and is known as the farmer's friend.
* Incidentally, it gets its name from the long stiff feathers on its neck and chest, which are said to resemble straws.

These birds still breed in colonies (as do many swamp birds), but they now fly out to farmers paddocks, and clean up huge numbers of invasive pests, such as Grasshoppers ("Locusts") and curl grubs, which live under the soil and eat the roots of crops.

What are they doing in Canberra? Well, as you will see from the photo, this bird (one of a small flock) was on the lush green lawns which happen to be surrounding the Australian War Memorial, a place seemingly immune to the watering restrictions which are in place in the rest of Canberra (and most of the rest of the country). Lush green lawns are a sign of frequent watering, which means that the soil is soft enough to allow these birds to probe with their beaks, deep into the soil, in search of grubs.



When they are not promenading around on the lawns of our National Institutions, these birds are capable of flying vast distances, across the dry country, in search of the next occasional flood. They are beautiful fliers, as may be understood from the photo at left. Long straight wings transform this slightly ungainly bird (on land) into a true, long-distance flying machine. Their wing shape is similar to that of the totally unrelated Pelican, which is another bird which makes huge pilgrimages in search of the next flooded inland river system.

Both birds are capable of appearing, in the "desert", when the next flood is coming down along the inland river systems, from far north Queensland, such as in the periodic flooding of Lake Eyre. So flights of several thousand kilometers are well within the capability of this bird (and the Pelican). Quite how the Ibises of Canberra know that there might be a flood headed for Lake Eyre is one of those mysteries of meteorology which scientists have yet to unravel. But it is true, when Lake Eyre, or other inland river systems flood, Ibises, Pelicans and many other swamp birds ("waders") and waterbirds which normally reside on the East Coast of Australia, will suddenly appear in the previously totally dry landscape, in huge numbers, to take advantage of the bounty of Nature, when water arrives in the previously dry riverbeds of the red interior of Australia. So, it helps to have wings built like this, which are perfect for gliding on wind currents, to assist with huge, long distance flights.

2 comments:

Miss Eagle said...

Denis, is the Straw-Necked Ibis a different beastie from the one I am used to seeing in North Queensland. He doesn't look as tall or sleek in that photo. All Ibis's are known a George in our family because when Shelley was a toddler in Bowen, NQ, we used to visit family friends who always had one or two ibis foraging in the backyard. Old Family Friend used to tell Shelley that his name was George. So ibis after ibis is still George the Ibis. At my home at Bluewater just north of Townsville, I would get lots and lots of course.

Denis Wilson said...

Hi Miss Eagle.

I approve of "family names". eg, George the Ibis. This one was in reasonably long grass (not long, long grass, but it does make his legs look a bit "stocky", I agree.
The other, more common Ibis is the nasty, messy White Ibis (much given to hanging around rubbish dumps, and also near food outlets, in parks, and at Taronga Zoo. It has a white body, and black head and tail.
There is a smaller, more dainty Glossy Ibis, but it is all dark, with a prominent "oily tinge" to its feathers (as does this bird, on its wings). But that Ibis has no white on it, at all.
So you choose - same species, just when on dirt, or mud beside a lake, it might look 2 inches taller. Or if dirty white, with a black head, it would have been the White Ibis. Glossy Ibis, possible, in FNQ, but smaller.
Just call it George, anyway.
I liked the flying shot - so more more elegant when flying than on the ground. You often see large flocks of them, circling around to gain height, then heading off in a big "V" formation, when moving from one area to another. Great fliers.