My city's policies on keeping chickens makes it difficult to use them for their composting abilities. I'm looking for alternatives. By my understanding, chickens can take insects and weeds (two major garden problems) and creates nitrogen rich manure. As a bonus, if I provide the carbonaceous material, the chickens will do all the work of turning it for me.
Vermicomposting could be considered an alternative, although it's not necessarily exclusive with having chickens. They would probably be considered as agents in different layers of the ecosystem.
In terms of usefulness for compost, what are good alternatives to keeping chickens?