I've never done a survey but I imagine that 95% of the birds represented on Christmas cards in the UK are robins. I have the impression that it used to be 100%, but in recent years a few others (owls, blue tits, wrens etc) have begun to make an appearance. Today's robin came very close to me allowing this photograph and being rewarded with a few seeds we were carrying.
photo © T. Boughen Camera: Nikon P950