How can I know for SURE these wild berries are edible?

Contact your county’s Agricultural Agency. They will know. If you can, bring in a sample to them. Or you could look to identify them online by matching up a photo.

Or pick a few and take them to your local farmer’s market or food coop (or gardening center).

Blueberries and blackberries are pretty easy to ID.

If the birds are eating them, that is also a clue (but not a foolproof) one that they are edible.

Around here there are almost no blueberries, or wild blackberries left for eating. The birds get all of them that aren’t netted.

Are the birds and other critters eating them?

Try to see if there’s a Botany dept. at a local college. Find out the Prof. name and give them a call. Email them a photo of the berries in Qs or bring in a sample if they need it.

@rojo

I just noticed these bushes and most of the berries are gone. I will have to keep an eye out for the birds next year I guess :O( .

QED. Net them next year when the blossoms appear.

It was too helpful, just not appropriate. That’s why I flagged it.