My daily morning walks witness a ritual that continues throughout the year. As soon as I step out of the house in our colony, I am greeted by twittering calls overhead. Without even looking up, I know it’s the resident colony of house swifts (Apus affinis), approximately thirty in number, wishing me a very good morning. If you look up at the sky and see a small blackish bird with narrow, streamlined wings and white on its back (visible only when the bird twists and turns in flight), you are looking at the house swift. House swifts (or little swifts as they are also called) are small, agile birds with extremely short legs. Their scientific name is derived from the Greek word apous which means ‘without feet’. House swifts are resident birds and can be seen throughout the year in most parts of India.
Flying often with the swift, you may see another small bird. This bird, the swallow, unlike the swift, has broad triangular wings. The wings of swifts are held mostly at right angles to the body when in flight, whereas in the case of swallows the wings are held at a slight angle to the body in flight.
Among the most commonly seen swallows in India is the red-rumped swallow (Cecropis daurica). While the red-rumped swallow appears dark coloured in silhouette, it is actually bluish-black with a reddish colour on its rump (or back). This swallow is a resident in many parts of India, but in south India it is only a winter visitor.
Though swifts and swallows actually belong to different bird families, they have a lot in common. The most amazing facet of swifts and swallows is how they hunt. Both these birds are agile fliers and are skilled at feeding on insects while they are in flight. The bills of these birds are small, yet flattened, so they can devour small insects as they fly, often very high up in the sky. I often wonder whether there is any life so high up in the sky, but the presence of swifts and swallows, appearing as only as dots in the sky above, is a clear sign that there is food to be had for these birds, even at that height!
The other behaviour of swifts and swallows that never ceases to amaze me is the amount of time they spend flying and foraging. While swallows may occasionally be seen resting on electric or telephone wires (often hundreds of them lined up together), you will hardly ever see swifts sitting, at least during the day.
Both these bird species can be seen tirelessly foraging for insects all day long. Don’t they get tired? I have often wondered. Why don’t they rest once in a while? Is the energy they get from the insects they eat in flight sufficient for them to forage in this manner? Well, the birds seem to be flourishing, so obviously they have worked out the energy economics of being aerial predators and balancing the lack of competition at that height versus the degree of difficulty of preying on insects in flight.
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