I did more reading on ancient people who used pigeon droppings as fertilizers, just like in Cappadocia. Apparntly many other civilizations did. The ancient egyptians too used them for their crops. Studies have shown that they are rich in nitrogen.
Basically, these pigeons will go fly around in the day, eat wild seeds and berries elsewhere, go home and poo. Farmers take these nutrients and concentrate them on the soil they need to cultivate. So what these pigeons do is really just concentrating available but scattered resources.
Some modern garden composters too recommend using pigeon poo as starters. Though most warn of the fact that these poo from pigeons might contain somewhere around 26 known diseases. But hey, tell me which poo might not?