Like it or not, mirrorless is where the majority of the industry is headed (or has already arrived). And while that means you will eventually have to upgrade your camera bodies, the situation with lenses is a bit murkier, particularly since they generally have much longer useful lifespans and there are many adapters available. This interesting video takes a look at an extremely challenging situation for bird photographers, offers some great tips, and shows you how adapted lenses rise to the challenge.
Coming to you from Jan Wegener, this excellent video will show you some useful tips for a challenging bird photography situation and discuss the performance of adapted lenses on the EOS R5 in that situation. I agree with Wegener regarding the performance of adapted lenses. Though I have a few RF lenses, I am still using many of my older EF lenses, particularly those that are too expensive to replace or that simply don't have mirrorless equivalents. After having worked this way for over a year, I can confidently say that the image quality is just as good while autofocus performance has actually been better, with my hit rate having gone up with every lens. Check out the video above for the full rundown from Wegener.