07/11/2024
WHO TAUGHT THE TAILOR BIRD HOW TO SEW A NEST AND TIE KNOTS WITH SPIDER SILK?
The Indian tailor bird uses spider silk to sew the nest together! How could it possibly learn how to do that? After making a cup of living leaves, still on their stems, the bird holds some spider silk in its bill, pierces the leaf, and draws the silk through it. It finishes by tying a knot at the end of the silk. Can you tie a knot in a thread from a spider web? You can't do it? Then how can a little bird do it? Repeating the operation many times, the nest gradually takes shape as the two leaves are sewn together. Both the weaverbirds of Africa and the icterids of Latin America go a step further-and actually weave their nests. They make a fabric of grasses as they interlace the weft spears in and out of the parallel warp blades. The result is grass cloth! The fibers used are long creepers, thin rootlets, grasses, reeds, or strips torn from broad leaves, such as the banana.
In order to weave their nests, these birds need to know two complicated skills: weaving and knotting. Without a knot, the initial woven part will immediately come undone. If you were a bird, how would you tie a knot in a stem? Here is how the bird does it: First it flies with a long piece to a tree branch where it wants to make its nest. Then it holds part of it down on the branch with one foot. Next, with its beak it passes the end around the branch, threading it through the other, and pulls it tight. A series of half hitches are then tied at the end of this knotted end. By now, are you becoming confused? The bird isn't.
The bird then begins threading one strip beneath another that runs across it diagonally or at right angles. This is not easy work, but the bird persists. It never gives up. After each threading, the strip is pulled tight. If the strip is long enough, the bird will reverse direction of weaving and loop the strip back and interweave it parallel with itself. This looping-back procedure adds to the strength of the nest.
The result is woven nests which dangle from the tips of branches. These nests are not only single rental units, but also apartment complexes! Many of them have separate rooms in them-all carefully woven together.
"It's really nothing at all; just a product of random evolution," someone will say. Well, then, try making an apartment house out of woven grass! If you cannot do it, how do you think that tiny bird ever figure out the process???
