A food chain is a sequence describing how different animals eat each other, showing the order in which living things depend on each other for food. A food chain is a diagram showing how energy is transferred between different organisms in an ecosystem, starting with a plant and ending with an animal. Organisms include both plants and animals.
Eating food is how we get our energy. Without consuming calories and nutrition, we could not survive. The food chain shows how living things get their food. For example, some animals will only feed on plants, while others will eat other animals.
The food chain has four different categories of organisms: producers, consumers, prey, and predators.
Top Ten Food Chain Facts
- Food chains usually start with producers. Producers are organisms that make their food. Examples of producers include plants, phytoplankton, and plant-like organisms such as algae. Other organisms eat these producers, which starts the food chain.
- Some producers, such as plants, create their food using energy they absorb from the sun. This process is called photosynthesis. Other producers make their food using chemical energy, but most producers depend on sunlight for their food.
- The energy passed along a food chain from one organism eating another is generated by producers, as they can transform inorganic compounds into organic compounds, the foundation for all life on Earth.
- Organisms that eat producers are referred to as consumers. There are three consumer types: herbivores, carnivores, and omnivores. For example, herbivores only eat plants, carnivores only eat animals, and omnivores can eat plants and animals. In addition, some animals hunt live prey to eat, and others exclusively eat dead animals; these are called scavengers.
- Examples of carnivores include lions, tigers, sharks, and eagles. Examples of herbivores include cows, sheep, rabbits, zebras, antelope, and giraffes. Examples of omnivores include humans, bears, pigs, and dogs. Finally, examples of scavengers include raccoons, hyenas, and vultures.
- Another type of organism plays a vital role in the food chain. These are decomposers that break down decaying organic matter to create soil. Plants absorb nutrients from the ground, which begins the process again, so many ecosystems would not exist without decomposers. There are over 100,000 types of decomposers, including bacteria, fungi, and worms.
- Food chains can be long or short, depending on the environment in which they exist. If a food chain is too long, the energy passed to the end of the chain will be of less value to the animal, as some energy is lost at each stage of the food chain.
- The concept of the food chain was first suggested by a scientist and philosopher called Al-Jahiz in the 10th century. Charles Elton popularised his ideas in a book he published in 1927, which also suggested the idea of the food web. A food web visualizes the links between all the food chains in a particular area.
- Some of the most unusual food chains in the world are the diet of the Brazilian maned wolf, which feed primarily on plants and fruit, and the Blue Whale. The blue whale is the largest animal in the world, yet it feeds exclusively on krill, a tiny sea creature similar to a small shrimp.
- Humans are positioned at the end of the food chain, as humans eat plants and animals and have no natural predators.
What is a Primary Consumer in a Food Chain?
Primary consumers are organisms that eat the producers. Producers are at the top of the food chain. These are always plants, like grass. Plants get energy from the sun by making their food through photosynthesis. Primary consumers are herbivores, which means that they are creatures that eat only plants.
Primary consumers tend to be smaller, and there are many of them. There are more primary consumers than prey. Energy is lost through food at each level of the food chain. About 50% of the energy in food is lost at each level when an organism is eaten, so it is less efficient to be prey or predator in the food chain. There is plenty of food to go around for primary consumers due to many producers and the fact that there are more producers than consumers.
Take a look at the primary consumer examples below.
Primary Consumer Examples
Here are some examples of primary consumers:
- Grasshoppers – eat grass and are eaten by shrews. Owls then eat the shrews.
- Mosquitoes – eat algae in ponds and are eaten by dragonflies. Fish eat the dragonflies, and then raccoons eat the fish.
- Zooplankton – they eat phytoplankton in the ocean. Phytoplankton is microscopic plants that live in the water. Zooplankton is then eaten by fish, which seals and sharks eat.
What are the prey and the predator in a food chain?
Above the producer is the consumer, and above the consumer is the prey, followed by the predator. So, first, the prey eats the consumer, then the predator eats the prey.
Prey can be herbivores (creatures that eat only plants) or carnivores (creatures that mainly eat meat), or omnivores (animals that eat both plants and meats). Depending on the food chain, any of these might be the last ones on the top. The animal at the top of the food chain is a predator who eats meat as a carnivore or an omnivore. The predator at the very top of the food chain that nothing else eats is called an apex predator.
An apex predator has no natural predators. Other animals may sometimes eat the young and old of these species, but they usually die due to disease, hunger, or aging. They also have competition with humans because humans tend to get rid of the top predators so that they can be the only ones with access to the prey. Sometimes the habitats of apex predators are destroyed by humans, too, such as through deforestation. You can read more about different types of habitat loss here.
Energy Transfer in the Food Chain
While a food chain is made up of many different forms of life, from trees and plants to insects, mammals, and fish, the energy that travels through the food chain is called energy transfer in the food chain. Energy is first taken in by the ‘producer,’ which is often trees or plants, who gather their energy from water and sunlight. Then, this same energy is passed through each link in the food chain when animals eat or consume something in the part of the chain before themselves. This energy transfer continues until the end of the food chain.
Energy Transfer In Action
Primary consumers like the Giant African Land Snail (Achatina Fulica) will eat primary producers like leaves and plants. The Land Snail will then take energy from the plants it eats; in time, this primary producer may be eaten by a secondary consumer such as a bird or mammal, and the flow of energy will continue.
Energy Loss
Roughly 90% of the available energy is lost during energy transfer in the food chain. Only 10% of available energy is transferred up to the next level. The rest of the energy is passed out of the food chain in several different ways:
- It is used as heat energy
- It is used for life processes (movement)
- Animal and plant waste
Since energy is lost as energy transfer in the food chain takes place. There is a natural limit to the number of links and levels in an ecosystem. It also means that those animals higher in the chain must take in more food and energy to stay healthy.
Food Chain Examples
There are many examples of food chains from different ecosystems. Here is an example of a food chain where the grass is the producer, rabbits are the primary consumer, foxes are the prey, and bears are the predators.
Another example of a food chain is:
- Plant (producer) → Caterpillar (primary consumer) → Mouse (prey) → Wolf (predator)
In the above example, the plant is at the bottom of the food chain as the producer. The caterpillar consumes the plant. The mouse then eats the caterpillar before the mouse finally becomes the prey of the predator: the wolf.
