Hazel growing beside Oak

[Jackdaw]

Does anyone have any knowledge of why, within my woodland, a high percentage of Oak standards seem to have Hazel growing within a foot of their trunks ?.
I've noticed this over time but only today did it get my mind wondering .
Possibly, because to the Ash crisis , my attention to detail of the surroundings woodland has been heightened, or maybe I was just daydreaming as usual.
My only real conclusion would be that the fluffy greys had something to do with it, maybe preferring their lunch in an Oak tree and occasionally discarding a rouge Hazel nut.
I would guess of all the Oaks in the 15 acre woodland, (maybe around 200), 1 in 10 have Hazel growing right beside.
Is it just me or is this something of a common phenomenon.

[splodger]

it's quite common / not unusual to have hazel growing near / on other trees - birds are the main culprit actually - i have often seen jays dropping their nuts down a big crack

[coppiceer]

It seems to be squirrels in my wood. They take a hazelnut cluster up into a tree, eat the ones that they find palatable and throw the rest out of the tree. Often one of the discarded ones will germinate in the leaf litter at the base of the tree.