Hello and welcome to the site. My wife and I started birding some eight years ago; we had the idea of using a small camera to photograph any birds we couldn't identify, this idea seems to have a life of its own as I have just bought my second DSLR and a 500 mm f4 p Nikon manual focus lens, to go with my 300 mm f4 AF-S. The photographs I have taken so far are mostly at local sites in and around Lancashire, with some of the rarities we have twitched.  With the lenses mentioned above we have a D70 and a D200 with TC14E and TC20E Teleconverters which have both been modified for use on either lens (see links for details). We have a Manfrotto 393 Gimbal Head on a Manfrotto tripod for the 500mm lens but use the 300mm with the 1.4 telecoverter hand held.  If forced to use high ISO we use "Neat Image" to clean up the photographs - sometimes this works very well but other times not so well, but worth a try nevertheless.