m4/3 and wildlife action photography

Hi,

I'm lucky enough that my family has an oceanfront cabin where I routinely see eagles fishing, whales jumping, seals doing their thing - even a walrus a time or two a year.

I'm on shore, so I'd need something within a minimum 250-300mm equivalent zoom (i.e. the pana 14-140 would be fine).

My question is that these things (eagle fishing, whale jumping, etc.) happen so fast. Has m4/3 moved to the point where I could actually take decent in-focus shots of these sorts of things? Or are DSLRs still king by a wide margin for these sorts of things (I'm fine if they're still king - it's by how much taht I'm interested in?

Looking mostly at the pana bodies - OMD is way outta my price range.