Doesn't a prime lens take tc much better then a zoom lens? I'm just thinking that 300mm seems short for birding. The only draw back I see is the lack of OS on the 300 prime lens if zooming is not a concern.
Canon 7D / 50D (40D premature death. Long Live Canon)
70-200/2.8 - 135/2.0 - 100/2.0 - 85/1.8 - 35/2.0
EX 50-500 - EX 120-300/2.8 - 18-200OS - EX 18-50/2.8 II - EX 50/1.4
TOKINA 12-24/4 (for sale1) - TAMRON 28-75/2.8, 17-50/2.8 - Samyang 8/3.5
KENKO Pro300 2XTC - 1.4XTC