I though about that yesterday whilst watching one of them feast on the cape honey suckle bush. I wanted to run in to get the camera, but I knew if I stood up, that it would fly away. And they sure did; as soon as I got up, they zoomed away! And when that happened, I had that exact same thought; now I know when they feast, so I might as well brew some coffee, get a chair, and wait for them with my camera ready!!
Oh then they might just like the tree; it is probably just a midway safe spot where they wait and look out for some yummy treats. I don't think I have enough shrubs and bushes for them to make nests in.