I have two DSLR's and three long lenses, 90 - 210 does not auto stop down so a pain to use, 400 fixed so hard to find the wild life, and a 18 - 270 which is so slow to focus you could make a cup of coffee while waiting, however it does depend what wild life you want to capture, I found a wood peckers nest, and I set up the 400 mm a fair distance away on a tripod aimed at where the birds were likely to land, sat in a stool with a cable release and waited for them to visit, speed was not required.
Again garden pond irises were being regular visited by bees, so tripod 400 mm lens and extension bellows as would not focus close up, and again waited with a cable release.
Birds in flight are hard, and a lens able to capture enough light to freeze motion is going to cost a lot of money, I have tried to capture a fox, seen it many times, but only once got a photo actually with a rabbit as well in its mouth, I was sitting having a cup of tea next to a picture window, and it actually stopped and looked in at us. But it was a one off, sat same place drinking tea many times, never saw the fox on that track again.
Movement is hard, with a long lens, some times you are lucky, but in the main you need a tripod, so in the main it is a waiting game. Even then it does not always work, I knew a steam train was due, so positioned myself on a bridge worked out with the Diesels where was best place and what speed and aperture I needed, the Diesels were doing around 30 MPH, when the steam came it was doing around 70 MPH speed set to slow.
Some times tripods don't work, useless on a narrow boat, engine vibration comes through the tripod, your body will absorb them. I have found in the main the 400 mm lens rarely used, at distance the haze means the photo is not crisp enough, and swapping a lens means chance of dust on sensor, I try not to ever take the lens off on my Nikon only swap lenses with the Pentax which already has dust on sensor.
But main thing is what wild life, bee, fox, red kite are all wild life, but each needs a different method.