Twinkle, twinkle, little star,
Now we all know what you are!
for I have found out how the bird does its sewing.
Some months ago Mr. G. A. Pinto, a very keen ornithologist, informed me
that a tailor-bird built regularly every year in the verandah in front of
his drawing-room window. He told me that he had never thought of watching
the stitching operation, and was much surprised when I informed him that,
so far as I knew, no one had ever observed the complete process. He said
that as the bird would undoubtedly begin building shortly, he would
follow the whole process from the other side of the window. He was as
good as his word. It is thanks to his patient watching that I am in a
position to pen this article. Towards the end of May the hen tailor-bird
began “prospecting” for a likely site, for the hen alone works at the
nest, and selected a _Dracæna_ plant on the left-hand side of the
entrance to the verandah. One of the leaves of the plant was so curved
that its terminal half was parallel with the ground. Upon this she
commenced operations. The first thing she did was to make with her sharp
little beak a number of punctures along each edge of the leaf. In this
particular case the punctures took the form of longitudinal slits, owing
to the fact that the veins of the _Dracæna_ leaf run longitudinally. In
leaves of different texture the punctures take other shapes. Having thus
prepared the leaf, she disappeared for a little and returned with a
strand of cobweb. One end of this she wound round the narrow part of the
leaf that separated one of the punctures from the edge; having done this,
she carried the loose end of the strand across the under surface of the
leaf to a puncture on the opposite side, where she attached it to the
leaf and thus drew the edges a little way together. She then proceeded to
connect most of the other punctures with those opposite to them, so that
the leaf took the form of a tunnel converging to a point. The under
surface of the leaf formed the roof and sides of the tunnel or arch.
There was no floor to this, since the edges of the leaf did not meet
below, the gap between them being bridged by strands of cobweb. This was
a full day’s work for the little bird, and more than sufficient to
disqualify her for membership in any trade union.
She next went on to line with cotton this _cul-de-sac_ which she had made
in the leaf. She, of course, commenced by filling the tip, and the weight
of the lining soon caused the hitherto horizontal leaf to hang downwards,
so that it eventually became almost vertical, with the tip pointing
towards the ground. When lining the nest the bird made a number of
punctures in the leaf, through which she poked the lining with her beak,
the object of this being to keep the lining _in situ._ It was Mr. Pinto
who first called my attention to these punctures in the body of the leaf.
He informed me that he had never seen a tailor-bird’s nest in which the
lining did not thus project through holes in the leaf, and that when
searching for such nests he always looked out for this. My subsequent
observations have tended to confirm his statement.
All this time the edges of the leaf that formed the nest had been held
together by the thinnest strands of cobweb, and it is a mystery how these
can have stood the strain. However, before the lining was completed, the
bird proceeded to strengthen them by connecting the punctures on opposite
edges of the leaf with threads of cotton. Her _modus operandi_ was to
push one end of a thread through a puncture on one edge and the other end
through a puncture on the opposite edge of the leaf. The cotton used is
soft and frays easily, so that that part of it which is forced through a
tiny aperture issues as a fluffy knob, which looks like a knot and is
usually taken for such. As a matter of fact, the bird makes no knots; she
merely forces a portion of the cotton strand through a puncture, and the
silicon which enters into the composition of the leaf catches the soft,
minute strands of the cotton and prevents them from slipping.
Every one must have noticed how brittle a dead leaf is. This brittleness
is due to the silicon which is deposited in the epidermis of the leaf.
When the leaf is green the silicon is not so obvious; it is nevertheless
there. Some leaves take up more silicon than others; grasses, for
example, contain so much that many will cut one’s hand if roughly
plucked. I imagine that the tailor-bird usually selects for her nest a
leaf or leaves in which there is plenty of silicon. Thus the bird does
not make a knot as is popularly supposed, nor is there any necessity for
her to do so. Sometimes the connecting threads of cotton are sufficiently
long to admit of their being passed to and fro, in which case the bird
utilises the full length.
I may mention that when the nest, the building of which I have attempted
to describe, was about three parts finished, Mr. Pinto noticed that the
bird had ceased to work at it. He was surprised and disappointed. He then
discovered that the little builder was at work on a _Dracæna_ plant on
the right-hand side of the entrance to the verandah, not two yards
distant from the first nest. He was much astonished at the strange
behaviour of the bird, and still more so when, the next day, she had
resumed work at her first nest, which she completed, leaving the second
unfinished at the stage when the punctures had been made and the edges of
the leaf drawn together by strands of cobweb. Presently an explanation of
the bird’s unusual behaviour occurred to him. His dog which, ordinarily,
is chained up at one end of the verandah, was, on the day the tailor-bird
left her first nest, fastened up in the middle of the verandah, so that
the bird while working at her nest would be within its reach. She
evidently objected to this, so began a new nest; but next day, when the
dog had been removed, she returned to her more advanced nursery. This
accident of chaining up the dog for one day in the middle of the verandah
was particularly fortunate, for it enabled me to examine carefully a nest
in an early state of construction.
This account must, I fear, close with a tragedy. When the little cobbler
had been sitting on her eggs for about ten days one of the garden coolies
broke them, out of mischief, and thought he had done a clever thing. He
is now a sadder if not a wiser rascal!