They are scared

The birds wait patiently for a place at the feeder, but the grackles and starlings swoop in and scare them off into the nearby trees. They hack and fight and bully their way to the seed & suet cylinder. With utter disregard, they peck, pick, gnaw at the bounty, overfilling themselves, never leaving. Then, weak in the centre, the cylinder breaks, and tumbles down into the snow and seed-husk slush. Not a bird moves. They glance at each other, the chunk of food below, back at each other. No movement.