According to this article in the journal Ecology (full article only available through library subscriptions to the journal), the fruit of the common juniper (Juniperus communis) and red cedar (Juniperus virginiana) are important food sources for red squirrels, as well as a number of birds. The article is about seed dispersal: while the birds eat the fruit whole, and "disperse" the seeds later, the squirrels scrape off the fruit and just eat the seed inside--hence the noise of the operation.
I stayed for several minutes watching, and moving up slowly, a squirrel gobbling the seeds like there was no tomorrow. It would tear off a laden branch tip, hold it in its front paws and just demolish it, cast it aside and tear off another. I finally got close enough to shift it: it let loose one scold, and then just moved down into the tree a little and continued to dine.
Grapes were great this year too, and this squirrel was within paw's reach of a great many ripe, sweet (much sweeter now, after a few frosts) wild grapes, but ignored them in favour of the red cedar berries. Takes all kinds.