Doesn't sound like serviceberry. Most serviceberry I've seen ripen in late spring early summer and it's so scruptious that there is nary a berry left by the end of summer.

A dogwood of some variety is possible or perhaps some kind of viburnum like an American Cranberry/viburnum trilobum? I don't find the birds very crazy for our cranberries but then again we have feeders so they are the banquet of choice here.

Ilex verticillata/winterberry shrub is another possibility. I have 3 that I just planted last fall but they are much too small to produce fruit yet. Maybe in a few years.

Hawthorns apparently have red berries in winter. But I supposed you would have noted a hawthorn if you are sitting in them ;o)

Barb in Ontario

Try looking up "grey osier dogwood".

I'll keep better record this year. I'll try for pictures at different stages.

For now researching names you have suggested. Thanks.