Whether you're a bird person or not, this is stunning! Not to detract from the sheer magic of it, but in practical terms, how MANY trips would a bird have to make with that tiny quantity of mid/clay it could carry? (and how far from the nest is the source?)
If you take the construction of a circular bowl in your stride as instinctive, how the heck does the bird come up with the windbreak/entrance design that shields the eggs/chicks from the elements and at what point in fashioning the bowl do they start to construct it?
Even if you think you could build this...
Try it without using your hands!
And now...stop to consider this:
Where did the knowledge to do this come from?
TRULY THERE HAS TO BE A