I think the characteristics and features of swallows are:

1. Characteristics of swallows

Swallows are 130 to 180 millimeters in body length, long body, small and pointed mouth, large jaw, thin wings and tail with forked wingtips long, back feathers are mostly fai-blue-black, therefore, in ancient times it was called a basilisk. Long wing tips are good at flying, the beak is short and weak with a wide cleft, typical of insectivorous birds, and the feet are short and small but the claws are strong.

2. The characteristics of swallows

Swallows are small in stature, with a scissors-shaped tail, which is conducive to rapid changes in the direction of flight; moreover, in the process of flying, swallows often encounter obstruction by air currents, and the streamlined shape of their tails can minimize resistance; its tail can also balance the body, regulate the speed, and control the lifting and lowering of the body in flight.

In addition, they often forage for food during migration, so their fat reserves are lower than other migratory birds of the same size. Breeding species in Africa often migrate in response to rainfall patterns, but the specifics are less well known, and they migrate to the north in early spring each year, and then throughout the country in the summer, and then migrate southward in flocks after breeding to winter in India, the South Sea Islands, and Australia.