I've not seriously tried it on wild birds but here's the pup and my aunt's pet gander, Mr. G. The shots were with my 100-400mm zoom.
And a quick shot of Queen Mary 2 in Southampton yesterday. I always like photographing 'Her Madge' as she's an impressive ship (had the pleasure of a short cruise on her in 2012, she's fabulous, inside and out). The photo was taken with the 24-105mm zoom.
The one major disadvantage of this camera is that it is heavy, very heavy.