Here are some pictures of the reducing foliage. No large animals have access to our fenced yard.

Rabbits? Ground hogs? Wild pigs? I'd certainly fence it in. Where do you live?

Have you pissed off the neighbors kids recently?

We are in N. California (Bay Area). Hmm..Rabbits maybe ...as we have seen them scamper around in front yard. This is in the backyard that is fully fenced in and no other plants or trees are affected.

Ken B. Haha! That’s a thought! 😃

Rabbits, rodents. This year a bunch of my deciduous bonsai plants got heavily pruned. Clean neat cuts. In our case very likely rabbits since we also noticed rabbit poops next to the plant.

Thanks Dave! These do seem at a 45 angle. I am just surprised a little bunny could get that high :)

Bunnies would not jump over a fence. Either go through it, because it's not fine enough, or go under it. Or maybe there's a rabbit living within your fenced area. Can you show a pic of your fencing?

I have a fence that appears to have no room at all to get under it, but when my dog starts to chase bunnies it's amazing how quickly they can squeeze under it.

Can rabbits gnaw up branches that 3-4’ above the ground.

In any case, you need to wrap a protective wire mesh around the plant.

Not sure about where you live, but in New Hampshire they are releasing tons of rabbits into the wild to bring back the big birds of prey..Not in my yard, they better not.

Groundhogs can and will climb over fences. One just defoliated my newly planted mulberry they love the leaves

The best way to know exactly what it is is to face a hidden camera at it. See what triggers it. Might even be a dear.