I used to get my bat guano from the mine shafts where i grew up. Did this affect the ecosystem down there? Was i stealing sources of nutrition for the critters down below? I didn't think anything down there wanted to eat that poop except my plants
you're lucky you had a local source - ultimately those bats live in a mine shaft so that ecosystem was totally fucked a long time ago, but the guano is definitely helping to re-balance any toxicity caused by the mining. Guano mining is something that can be done responsibly and in a sustainable way, but buying off the locals and giving them a bulldozer is the current norm.
Back when I lived in Florida I would collect the dried cow patties and crumble them into compost/top dress with them, that was probably the best natural fertilizer I've used. In fact, the agrarian civilization of the Indus valley worshiped cows because cows plowed their fields in off seasons, provided milk, and provided fertilizer and fuel from their poop.
Why we don't use cow poop, I'll never know. you can order it by the freight car full, and it makes much, much happier plants than guano.