I feel wiki on Black Kite is very accurate https://en.wikipedia.org/wiki/Black_Kite :
The Black Kite (Milvus migrans) is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors. It is thought to be the world's most abundant species of acciptrid, although some populations have experienced dramatic declines or fluctuations. Current global population estimates run up to 6 million individuals. Unlike others of the group, Black Kites are opportunistic hunters and are more likely to scavenge. They spend a lot of time soaring and gliding in thermals in search of food.