The cattle egret and grazing cattle in close association, is a classic example of 

The association of cattle egret and grazing cattle is a classic example of commensalism. The egrets always forage close to where the cattle are grazing because the cattle, as they move, stir up and flush out insects from the vegetation that otherwise might be difficult for the egrets to find and catch. Egret is thus benefitted, and cattle are neither benefitted nor harmed (neutral).