Here are some of the visitors to the bird feeder this spring. I used a Nikon D810 with a Nikkor 200-500MM - F5.6 with a 1.7 tele-extender. This works out to be an 850MM lens.
I saw two cardinals fighting the other day. They were flying vertically off the ground face to face and flapping until one decided he had enough and disengaged and landed a few feet off. I guess hormones and mating season will do that.
Nice pics. I see the same birds in my yard too.