What is a forked tail?

A forked tail is a tail that is split into two parts. It is common in birds, where the two halves of the tail can be used to steer or balance during flight. In some cases, the fork may be very slight and only noticeable when the tail is spread out, while in other cases it may be more pronounced, with the two halves of the tail separated by a gap. It is also sometimes referred to as a "swallow tail".