Many years ago, Barb replaced a Bradford pear with a downy serviceberry tree, aka. shadbush. It is the native tree you see in our woods with white flowers like a Bradford pear but with smaller blossoms. In our yard it provides shade for a field of violets which the Barnharts are feeding to their voracious Regal Fritillary caterpillars, destined to repopulate our Missouri Prairie Foundation prairies with this threatened species.
This time every year we are visited by a flock of cedar waxwings which come to feast on the early ripening serviceberries. I watched as flights of 10-20 waxwings suddenly swooped in, shaking the tree branches as they gorge on the berries for 3-5 minutes, then just as suddenly take off as though they heard a starter gun. Their coordination is remarkable. It is as though they had a little earpiece where they hear an announcement, "Taking off in three, two, one, NOW"
At one time I estimated the multiple incoming flights totaled over 80 birds on the tree, jumping around like they had too much coffee. You can watch the party on this Youtube link.
A few more days and the feeding orgy will be over and they'll be eating petals and sap of shrubs and trees as well as plenty of insects during breeding season, providing extra protein for their growing young.