Here's me seagull.
This was taken with a 300mm. Messing or not Bubby is spot on.
I do spot meter for this sort of photo, but I also find it is important to have the sun behind me, so it is shining on the bird, rather than silhoetting it.
My prefered birding lens is my Sigma 150-500 if I cannot be sure a prime is going to be long enough.