Similar to insectivores, the indirect effects of raptors might be equally or more important than
their direct effects, but more studies are needed, especially in agricultural and urban ecosystems where these effects can have economic value. We know little about the impacts of avian grazing (Figure 2d), but substantial declines in formerly numerous species, such as Aleutian Canada geese Branta canadensis leucopareia, could have top-down effects on plants [54]. Although we are becoming increasingly aware of the importance of nutrient deposition by seabirds and of carcass disposal by scavengers, there is a pressing need for further ecological studies, especially to estimate the consequences of the rapid and recent declines in these groups