Do you mind me asking what lens you have used? I am considering doing a bit of gentle birding sometime but wonder how much dosh I need to save...
I was using a Nikkor 500mm f4 AF-S II, plus I had the 1.4TC fitted.
If that is a bit more than your budget, the Nikkor 300mm f4 AF-S is a superb lens, which will take the 1.4TC giving you a 420mm f5.6, or the 1.7TC giving you a 510mm f6.7 (If you look in my gallery there are some shots using the 300mm f4 and 1.4 & 1.7TC )
Very nice. There's been a couple of them chattering away in next doors garden for a few weeks but I've been unable to get close enough for a decent shot. I tried again today and was amazed when about fifty of them (plus Redwings I think) took off and 'swarmed' me. They seem to be laying claim to the apples on the trees.
You could try putting some apples out for them, pierce a hole through the apple and put it on a thin stem.
The problem is if you spook one the lot go up, best is to spot where they are feeding, get into position, stand still and wait for them to return