Courtship feeding is something of a misnomer. It describes behaviour when a male bird offers food to his mate, but it occurs most frequently when actual courtship is over. Most courtship feeding occurs during egg formation, laying and incubation and can provide a valuable source of nutrients for females. In Blue Tits, for example, males can provide up to 40% of a female’s total food intake in the period leading up to laying. With early hatching having a positive effect on the survival rates of chicks and fledglings in some species, and eggs and chicks being more vulnerable to predation than fledged young, males may use courtship feeding as a means of increasing the incubation intensity of their mates to bring forward hatching.
If you want to see courtship feeding in your garden, Robins are a great species to watch. The hen solicits food from the cock by uttering a sharp, monosyllabic call, by partly lowering her wings and then quivering excitedly. Her demeanour is, in fact, indistinguishable from a fledgling Robin soliciting food from their parents. Nearer the end of incubation, hen Robins may receive almost all of their food from their mates.