Martin Jones said:
It's fine getting the correct equipment but how do you stop the b--gg--s from flying away in the time it takes to set up the equipment??
Nails. Several very small nails can be used to attach the bird's feet to a convenient perch. In the case of larger birds, small nails may not be suficient and a few self-tapping screws will come in handy.
For best results, apply a drop or two of ordinary nail varnish (which can be bought at any beauty shop) before taking your shot, as otherwise the shiny metal nail-heads can catch the light and spoil your picture. Be sure to match the colour of the nail varnish to the colour of the bird's feet: no professional photographer would use yellow nail varnish on a bird with black feet, for example.
For water birds such as ducks, grebes and swans, nails tend to be ineffective as there is seldom a sufficiently firm object into which they can be hammered. This is why the well-equipped nature photographer also carries a length of strong string. Simply take a loop around the bird's feet, measure off an appropriate length of string, and tie the other end to a brick or medium-sized rock. Toss the brick into the water at the desired disance from the camera and take your shot.
Take care to use the correct length of string for the depth of water: too long a string and the bird will often flap up into the air, exposing the string to the camera, which looks ugly. Too short a string results in the bird posing under water, which tends to look rather unnatural.
Be sure not to use the nailing-to-the-perch method with large, intelligent birds like Emus, as it can be rather dangerous. You need very large nails (which are quite expensive) and, as a number of talented young nature photographers have discovered over the years, there is some doubt as to exactly
where the hammer winds up getting shoved and by who.