This is what my setup for bird photography soon...
400mm f5,6 L prime lens with Better Beamer flash extender. 'L' is for luxury!
The white lens is Canon Trademark for long telephoto. Compare with Nikon's and other brand black lenses.
My setup now, Tamron 70-300mm f4-5.6
The white thing is Tamron 1.4x TC (Teleconverter)
A flurry of birds.
2 hours ago