Most birds use their tails for balance and steering while flying. Some use them to show off and attract mates.
For birds that can't fly, the tail could just be for balance while running like with the ostrich.
The Gray African Red Tail
dove tail.
Grebes are small water birds similar to ducks. They do have a tail, but it is very short and stubby and not obvious when you look at these birds.
Yes
flight feathers
the function of a tail is to lift its body and to increase the speed of flight
Their wings and tail
the tail has flight feathers and the flight feathers help a bird to fly.
the tail of birds is really useful during their flight and hence is the 5th limb
A birds tail swerves its body left and right. It also has drag.
Yes, birds fly if they have salt on their tails. I put some salt on the end of my bird's tail. She flew to the cage and the salt fell off.
The Uropygial gland is found near the base of the tail of birds.