I should think the odds of this stack occurring naturally is very high! Perhaps this bird will be able to stay there, maybe not, but who knows? When Linda and I were wed, our families gave us 6 months at the most before we split up; and yet several decades have gone by and we are still looking forward to another 6 months. Sometimes, the seemingly impossible comes true, just like the situation of the Jews when they returned from exile to build the temple. Nehemiah says...Neh 4:1-6 But it happened that when Sanballat heard that we were building the wall, he was angry, and took great indignation, and mocked the Jews.
2 He spoke before his brothers and the army of Samaria, and said, What are these feeble Jews doing? will they fortify themselves? will they sacrifice? will they make an end in a day? will they revive the stones out of the heaps of rubbish, seeing they are burned?
3 Now Tobiah the Ammonite was by him, and he said, Even that which they are building, if a fox go up, he shall break down their stone wall.
4 Hear, our God; for we are despised: and turn back their reproach on their own head, and give them up for a spoil in a land of captivity;
5 and don't cover their iniquity, and don't let their sin be blotted out from before you; for they have provoked you to anger before the builders.
6 So we built the wall; and all the wall was joined together to half the height of it: for the people had a mind to work. WEB
The wall just didn't happen, there had to be plenty of faith and hard work. Sure there were obstacles both physical and psychological, but so what, life is full of them. Faith combined with hard work quite often yields success. And who knows, perhaps the stones in the above picture will still look like that in 6 months, but I think a little superglue would help!