Bird Identification: CLOSED: Bluejay and Robin Interaction?, 3 by wingwoman

wingwoman wrote:
We currently have a Bluejay family with babies at the fledgling stage. With the neighbor's cat visiting quite often, the parents have gotten pretty noisy. The other day, we heard birdie distress sounds just before a pair of birds exploded out of the lilacs onto the lawn. A mature robin and a fledgling bluejay tumbled on the grass, and the robin moved to his tree. By that time, I'd run for my camera, and got several shots of this adorable baby and more shots of his concerned daddy as he looked on. This delightful photo op caused us to wonder this is normal behavior for robins. Our robin is damn near tame, and he comes quite close to us when we're sitting outside, so we were surprised to see this happen! Despite the fact that it gives me an excuse to share some sweet shots, I'm hoping some experienced birders can enlighten me about this aggressive behavior...