I am very new to photography compared to others responding. Started when I retired at the end of 2008 and borrowed my wifes Canon Rebel her first digital in 2009 and her canon pocket camera and went to Alaska in 2009. I explored a lot of photography types and styles, macro, 4x5 large format film, studio portraits, light painting and on and on.
I was a hunter, fisherman, backpacker, bike rider, xc and dh skier etc. and love the outdoors.
The camera that got me hooked on wildlife was the D300s, and the camera that got me hooked on birds including birds in flight was the Nikon D4s, that was my first introduction into high frame rates, fast focus, low light high ISO capability even up to 12,800. It was a great camera and along with Sigma 150-600 sport and Tamron 150-600 G2 that got me into the world of VR/IS and very portable hand held bird chasing photography.
D500 was a great bird photography body and D850 had a D500 built in. D6 was a souped up D4s.
Number 1 is:
For a birder and bird ID photographer where subjects are unpredictable all sizes, all terrain, weather, habitat and light but seldom closer than 20 feet the Z9 (about fW 4.0 and up now at fw 5.0) and Z800 mm have been my dream come true.