One of the largest cityfinches, the Comoros staghorn-bird (Molochavis comoroensis) is restricted to the Comoros islands where it is one of the most common non-seabirds in residence. The species is unique in building colonies directly on the ground with subterranean chambers. Staghorn cities are built at the bases of large trees and consist of a series of domed mud/clay structures aboveground connected by a series of underground tunnels amongst the roots of the tree. Such colonies generally contain about 10-30 adult birds.

    The quail-like warbirds spend most of their time on the ground, their extraordinary beaks imposing a hefty aerodynamic penalty. They are incapable of feeding themselves and must be tended to by serfs and returning scouts. Their natural enemies on the islands include large lizards, tenrec-like mammals and predatory seabirds. When threatened, the warbirds retreat tailfirst into the entrances, leaving their formidable beaks protruding.