There is an interaction between mated birds as they greet each other. I had never really thought about it until witnessing the ritual. And in general it’s…a kiss hello.
Here, a male Anhinga returns to the nest. The female (soft brown neck feathers) greets him by rubbing and grabbing his beak. The same ritual, plus resting on each others shoulder, holds true for Egrets and Herons.
The old ‘Honey I’m Home’.