The food chains or Trophic chains they are the cycle of transmission of energy and matter that involves the different species of a biological community, in which each one feeds on the previous ones and serves as sustenance for the next ones. For example: phytoplankton serves as food for crustaceans, bees subsist on floral nectar.
Each link in this food chain it is called the trophic level and determines the relationship of each species with those that are higher or lower in the cycle: predators and prey respectively.
However, this cycle feeds back when large predators die and provide food for scavengers and decomposing microorganisms that transform their remains and, ultimately, turn them into fertilizer for plant life.
rungs of the food chain
Broadly speaking, every food chain is made up of the following rungs:
- Producer organisms. Usually photosynthetic, they are autotrophic plant beings, which take advantage of water, sunlight and soil nutrients.
- Herbivores or exploiters. Animals that feed on vegetation or its fruits.
- decomposers. Animals that “recycle” organic matter, decomposing it and returning it to its original state, for use by producing organisms. Fungi, bacteria, insects and scavengers make up the bulk of this step.
- small predators. Animals that prey on small herbivores or feed on young and eggs, or decomposers.
- large predators. Large carnivores, which survive by feeding on herbivores and other predators.
Fragility of food chains
The usual problems of food chains take place when the disappearance of some intermediate link occurs, which leads to the disorderly proliferation of inferior species and, consequently, to unfair competition that leads to the extinction of other species, as the biological balance deteriorates. loses and the entropy of the system increases.
The same thing happens when a lower rung becomes extinct and the immediately higher species suffer from the decrease in their nutrient quota, having to look for it elsewhere or also succumbing to population decline.
Many green initiatives They try to make visible the impact of human activities and mass extinctions on food chains, to show that they are never isolated events and that, eventually, everything has consequences for the order of nature.
examples of food chains
- The phytoplankton (vegetable) that lives in the oceans serves as food for malacostraceous crustaceans (krill), in turn eaten by small fish. These, once again, are preyed upon by slightly larger fish, such as sardines, frequent food for larger predators such as barracuda. However, upon death, these large and aggressive fish are decomposed by scavengers and the cycle restarts.
- The rabbits of the prairies they eat the plants and grasses, they are predated by pumas, foxes and other mammals carnivores medium size. And when they die, they provide food for carrion birds such as vultures.
- The fleshy leaf plants they are parasitized by the caterpillars of butterflies, which in turn feed various small birds, which are hunted by snakes and wildcats, whose bodies, again, will be decomposed by bacteria and fungi.
- Many flying insects Like the locust, they eat the leaves of the plants, but the insectivorous toads eat them and are preyed upon by rodents such as the mongoose. And these are devoured by snakes.
- The marine zooplankton and krill serve as food for whales, which catch them by the ton with their long baleen to filter the water. These are depredated by man, and much of their organic matter returns to the sea as waste and is food for zooplankton.
- The meat of dead animals serves as an incubator and immediate food for the fly larvae, which in a short time will become imagos. They will then be predated by spiders, also victims of other larger spiders, which serve as food for different spider birds, finally predated by hunting snakes such as rattlesnakes.
- The grass feeds the goats, favorite victims of jaguars and other similar felines, which when dying provide food for bacteria and fungi, which nourish the initial grass again.
- The bark of many trees provides food for parasitic fungi, food in turn for small rodents, which are hunted by birds of prey such as the owl or the barn owl.
- The waves that hit the stones push the marine phytoplankton to bivalve colonies such as mussels, which devour them. These, in turn, are preyed upon by crabs and the latter by seagulls that hunt them with pecks.
- the famous dung beetles They feed on the remains of the feces of higher animals. At the same time they are predated by insectivorous lizards and lizards, which are the food of quadrupedal mammals such as coyotes. The man kills them with bullets.
- The bees They subsist on floral nectar, but are preyed upon by small birds, whose eggs feed nocturnal rodents such as the opossum. This, however, is hunted by snakes and birds of prey.
- Back in the sea, small molluscs like squid they are predated mainly by medium-sized fish, which in turn provide food for seals and marine mammals, finally hunted by the voracious orca whales.
- In the microscopic world, decaying organic matter supports plants. bacteria, which give the same to protozoa (such as free-living amoebas) and these to certain nematodes (worms), which in turn provide sustenance to larger nematodes.
- The butterflies they eat floral or fruit nectar, but are food for predatory insects such as the ferocious praying mantis. This is also devoured by insectivorous bats, which when they die return nutrients to the soil to feed the flower or fruit plants.
- The large herbivores Like the zebra, they feed on wild grasses and bushes, but are predated by crocodiles when they are about to drink water. No one preys on these, but time is responsible for converting them into organic matter to nourish wild herbs and weeds.
- The Earthworms They feed on decomposing organic matter that they get from the earth itself. They are food for small birds, which extract them with pecks, and which in turn are victims of feline hunters, such as the wild cat. These, when dying, return to the earth the organic matter that will feed new worms.
- The corn Harvested by man, it is fed to free-range chickens, whose eggs are stolen and eaten by weasels. These are hunted by snakes, and these are killed by the hand of man.
- Many aquatic spiders they are dedicated to hunting larvae or pupae of other insects, but they serve as prey for fish that lie in wait for them underwater. These are predated by the Kingfisher bird, which in turn feeds on birds of prey such as the sparrowhawk.
- The wood worms they feed on the bark of dead trees and are eaten by long-billed birds. These lay new ones that some snakes devour, and these in turn eggs that other rodents can eat. Finally, the cycle will end with a larger predator, such as the eagle.
- The ticks they inhabit the fur of mammals (they feed on blood) and are fed by symbiotic birds that clean the fur of these large mammals, such as buffalo. It feeds on herbs, but is preyed upon by large cats such as the tiger.