Hummingbirds actively and aggressively defend rich sources of nectar.This food source is not limited,yet the consumption rate per individual is reduced.This might be due to__________.

A) Lotka-Volterra predator-prey relationships
B) Mutual interference and hummingbirds spending more time defending sources of nectar
C) Crowding, which tends to dampen intraspecific competition
D) Mutual interference and hummingbirds spending more time searching for sources of nectar