A swallow's tail is a unique feature that distinguishes it from other bird species. The following are the characteristics of a swallow's tail:
1. Forked shape: A swallow's tail has a distinct forked shape, which means that the two tail feathers are longer than the rest.
2. Streamlined design: The tail feathers are narrow and pointed, which helps the bird to cut through the air smoothly.
3. Symmetrical appearance: A swallow's tail is symmetrical, with each half being identical in appearance.
4. Dark colouration: Swallow's tails are often dark in colour, with shades ranging from blue-black to brown.
5. Flexible movement: The tail feathers are highly flexible and can move independently of each other, allowing the bird to make sharp turns and quick manoeuvres in flight.
In summary, a swallow's tail is a unique feature that sets it apart from other birds. It has a forked shape, streamlined design, symmetrical appearance, dark colouration, and flexible movement.