In exchange for the fruit they eat, frugivorous birds distribute plant seeds and help with plant propagation. This co-evolved mutualism benefits both birds and plants: Birds access energy-rich berries and in exchange they scatter undigested seeds (plus some great fertilizer) in their droppings. Passing through a bird’s digestive system also aids in seed germination by scarifying the seed’s hard outer coating.
This seed dispersal service means birds play a crucial role in building and maintaining their own habitats. Researchers are looking at how frugivorous birds might contribute to ecosystem restoration of fragmented landscapes, and trying to better understand seed dispersal networks in natural and urban environments. They also warn of a potential seed dispersal crisis due to habitat loss and environmental change.