There are a few wild blueberry plants growing in a section of my
lawn. I am wondering how they got there.

I have lived here for 20 years and would have noticed them if they
were here all along. As I understand it, blueberries spread mainly by
rhizomes. This area is isolated by a paved driveway and a concrete
walk. There are a lot of wild blueberries in my region, but none
around my property.

Since the berries are at the base of a tree, a friend suggested that
perhaps a bird ate some berries and later perched on this tree and
"did his business", leaving some berry seeds on the ground by the
tree..

Is it possible that blueberry seeds (or any seeds for that matter)
could pass through a digestive system and still germinate?