Originally Posted by
rpcrowe
If you desire to go the Canon road, I would recommend a crop camera such as the 7DII (or even the 7D) and either a third party 150-200mm to 500-600mm zoom lens or the Canon 100-400mm f/4.5-5.6L IS II lens. The Canon lens is far more expensive than the third party issues but, it is smaller in size and lighter in weight. The Canon 100-400 II lens is remarkably friendly to hand holding because of its great image stabilization combined with relatively light weight. However "light weight" is a relative concept...
OTOH, a used Canon 400mm f/5.6L lens has gone down in price (perhaps because of the 100-400 II) and a combination of Canon 7D plus the 400mm f/5.6L lens could be purchased for around $1,200 USD or so. I have also used the 300mm f/4L IS lens and while 300mm is a bit short for most birding, this lens is very TC friendly which results in a 420mm f/5.6 lens with the addition of a 1.4x TC. This prices of this lens have also taken a slight dip.