The deer density in my area is pretty low but lots of buck sign. I find everywhere I put cameras it is after dark and I was convinced they bed on river ridges. However I have two huge islands in the river (easy to cross over) and when walking through there are major game trails.

Do bucks prefer islands to hills, etc for beds?

he's gonna prefer the most hidden and secluded place. whether it be an island, a briar thicket.

They could be on the island. The downside from the deers perspective is that you feel confined. The plus side is that a predator can't follow your scent through the water.

I guess the only way to find out is to set up where I think they may be coming off the island. They are either there or on the ridge slope I am guess but it is hard to determine. They alway pop in and out of the slopes but I am not sure where their bedroom is because it is always after dark.