Different species of birds often stop their territorial bickering and competition to cooperatively forage together and improve one or both species’ success rate.
This cooperation can take a variety of forms. For waterbirds it is often commensal, that is, one species benefits and the other neither benefits or is harmed. A common form of commensalism is the ‘beater’-‘attendant’ relationship. The beater, let’s say a White Ibis, goes about its business using touch to find its prey in the mud. The attendant, let’s say Snowy Egret, stays close and uses their keen vision to catch any prey flushed by the feeding ibis. The Snowy Egret(s) benefit from the White Ibis’s disturbance and the White Ibis is not harmed nor benefits from the egret’s actions. They were not going to catch the runners anyway.
A case can be made that this relationship is an example of mutualism – both species benefit – if the egret(s) is also using their keen eyesight to provide the short, unwary ibis with a predator early warning system. But the mutualism tag is usually reserved for more directly mutually beneficial actions. For example, Cattle Egrets eating and ridding cattle of ticks and other parasites.
White Ibis can be paired in a relationship that is not mutually beneficial or totally harmless. Willets, for example, have been observed using ibis as beaters and then kleptoparasitizing (stealing) the ibis’s prey.
There are a lot of kleptomaniacs – sometimes called pirates – in nature. Think gulls, human beachgoers and potato chips. Kleptoparasitism is a topic for another post. Today is about no harm, no foul cooperation.