I have decided to try my luck in 'Birds, it 'clicked' for me during this year's Easter break.
Obviously no technique for BIF yet & "making it difficult" for myself as I just sold almost all my Canon gear in March and starting out with micro4/3.
First distant shots with E-M5 & Pana 100-300 in past week not to good, E-M1 (just got one cheap - arrived today) a bit better (but gray afternoon = little contrast), so will keep trying.
Worst case scenario: if this doesn't work out => buy 7D (used to have one for 2 years), or Nikon 300s/7100/7200 & a ca. 300 zoom.
The Nikon idea: I am curious about Nikon as have been Pentax film & canon DLSR guy up until I sold my 5DIII last month.
But - as always - it's not the camera but the photographer so will see what I can achieve with current m4/3 equipment, which has proved itself great at everything else (including portraits with my old M42 super takumar).
Will check forums for technique but any pointers welcome !