The common kestrel is a generalist predator. However, it also shows significant within-species variation in food habits, such as local specialisations on given prey (e.g. voles in northern or lizards in southern Europe) or even individual food preferences. This chapter illustrates the factors that affect the diet composition of kestrels, their foraging strategies and the processes of food competition, including kleptoparasitism. It also explores the last-generation techniques, such as stable isotope analyses and accelerometer-GPS loggers, that would enable the limits of classic methods used to study the feeding ecology of kestrels to be overcome.