It was amusing to watch a tiny tailorbird sitting with a sparrow high up on the roof of a decrepit building in a populated neighborhood.
Tailorbird is a much smaller bird than the sparrow and had no obvious purpose of visiting the building with no trees or pot-plants in sight.
The building had more humans than insects that could interest a tailorbird!
Perhaps its purpose was to share some views on concrete structures with the stately sparrow living in the building for generations.
The tailorbird had no reason not to believe that the sparrow owned the building.
Common Tailorbird is the tiniest bird of Dhaka city although its fluffy feathers and a long tail do their best to make the bird look a little bigger than it really is.
When the bird lands on the weakest limb of a shrub without weighing it down the slightest we realise how little the bird is!
Tailorbird weighs a little less than a teaspoon of sugar. This littleness is what helps the bird survive in the concrete jungle of our city.
A few invisible insects in some roadside bush or a cluster of mealybugs on a pot-plant are enough for it to sustain for days.
The city easily has many more tailorbirds than sparrows; although it does not appear so.
We encounter sparrows often because they live in our buildings and feed in the open space around us.
Tailorbirds are seen less often because they live under cover and feed only from the foliage.
Sparrows prosper in human neighbourhoods only; but tailorbirds subsist wherever there are insects, be it Shanti Nagar or Sundarban.
Tailorbirds thrive in our villages, towns, and cities as well as in mangroves, haors, hill-forests and every other kind of wilderness.
Besides being lightweight, the tailorbird is a weak commuter of the air. It is designed for short flights between bushes, not for sustained flights in an open area.
It was not surprising for us to record in St Martin's Island some 74 species of birds; but no tailorbird. No tailorbird has the talent to take off from Teknaf and colonise the island 10 km away.
What the tailorbird lacks in flying prowess, it makes up in vocalisation. Its voice covers much greater area than its flight can.
Tailorbird has two tiny throat-sacks that inflate to act as resonant boxes when it calls loudly or sings earnestly.
Tailorbird is a remarkably articulate, loud, and persistent singer. It sings continually when separated from its mate.
It also sings loudly from bushes merely to let other tailorbirds know that the bush is occupied.
To impress his mate, the male bird sings from an exposed perch risking perilous attack by a Shikra and other hawks.
Although the tailorbird lives in lowly hedges and shrubs it has no fear of height and is quick to go to the treetop in search of insects.
From our veranda, some 20 meters above ground, we often see the tiny bird stalking insects on top branches of the trees between buildings.
With great admiration we watched the tailorbird at the treetop hanging upside down to get to the insect hiding under the leaves.
The nimbleness of tailorbird unexpectedly revealed why we humans have the common affliction called the fear of heights – unlike the tailorbird we do not have wings to break our fall when the foot falters.
Our admiration for their dexterity grew as we watched the tailorbirds make their nest.
We saw a pair of birds build a comfy nest on a single leaf of Hairy Fig, a tree widely known as 'Kaak Dumur' or 'Khoska'.
The birds rolled a leaf into a cylinder by riveting the leaf-edges together with some fibres and built a light-weight nest inside. While the leaf dangled vertically it remained alive and green.
Soon we saw a few more nests of tailorbirds, remarkably, all in the wild Khoska plants.
There was one odd nest on a strong horizontal leaf of a Khoska that did not dangle vertically like the other nests.
Was that a nest of an eccentric pair of birds or were there good reasons for building it that way?
We noticed that the Khoska plant with the odd nest was under a rickety Tamarisk tree and all the other Khoska plants with regular nests were under large leafy trees.
Like enormous umbrellas the large trees were protecting all those nests from rain except the odd horizontal one.
After a moderate rain we saw that very little rainwater entered the vertical nests, thanks to the tree cover.
The odd nest without the cover also remained quite dry because the horizontal leaf itself worked very well as an umbrella. In fact, the horizontal nest fared a little better in the rain!
Why then were all nests of the tailorbird not made under strong horizontal leaves?
Probably, because it was harder to make and less convenient to use. Perhaps such a nest is built only when suitable Khoska plants under large trees are not available.
Is it possible that the tiny tailorbird with a brain weighing 10 milligram could do all those calculations before undertaking the job of nest making?
The answer to this question has to be 'yes'. How else an ancient wild creature of the bush could thrive in a concrete jungle we created today!