Supply chain shocks
At the foot of nature’s food chains is a primary producer, an autotrophic organism that creates complex compounds from substances present in its surroundings using energy from light (photosynthesis) or chemical reaction (chemical synthesis). In turn these organisms are eaten by animals, “consumers”, which in turn will be eaten by other higher level animal consumers. And eventually at the top of the food chain is an apex predator, an animal on which no other animals prey.
There are many food chains in nature. All share the linkage dependency of the higher levels for the activity outputs of the lower levels. Predators only exist if they have prey to feed on.