Wurdemann's Sitting on Its Nest:
The Great Herons are extremely diligent when raising young. Both parents share the duties equally. Observation shows that the only time the sitting parent lifts up off the eggs is to stretch and rearrange the twigs in the nest, then settle back on them. When the mate arrives, it in turn does the same. I imagine the reason besides incubating the eggs with warmth is also that it serves to keep the eggs protected against marauding species in the colony. The routine is quite amazing really and kind of rest before the feeding storm begins.