A little about my back deck setup (skip if you already read it in my Bird thread).
More is not necessarily better. After learning the hard way, I have decided against using a teleconverter with the 5DIII + 600L telephoto. I missed shots of squirrel skirmishes because the 600L + 1.4x TC (effective 820mm) got me too close. Sometimes I need a wider field of view to get everything in the shot or to follow fast moving critter action. I do keep the 1.4x and 2x TC's on a nearby table "just in case."
I think the Douglas's squirrels and some of the birds, like the pileated woodpeckers, are habituating to my presence. They have gotten close enough for full frame shots with the 1DxII + 100-400L II telephoto zoom, which I keep within arm's reach.
There was squirrel action once again in my backyard Monday afternoon (
4-13-2020). A Douglas's and an eastern gray were on my back fence. I set up for another squirrel skirmish, but the two kept a respective distance from each other.
I tracked the Douglas's squirrel to a tree in a neighbor's yard. Later I heard at least two Douglas's squirrels calling from that area. One, which I have named Michael, came to my yard and climbed high up one of my Douglas's firs, where he perched for a while.
A squirrel can travel among the the four Douglas's firs in my backyard without having to come down to the ground. Michael descended the tree closest to the back deck, enabling me to get closeups with the 1DxII + 100-400L II telephoto zoom.
He also explored the area under the tree beneath the deck.
Michael climbed up my back fence and traversed those of my neighbors, heading south toward Pine Ridge Park. He had nearly reached the park when I saw him last. It will be interesting to see if he returns to my back yard tomorrow.