Consumer (food chain)

Consumers are typically viewed as predatory animals such as meat-eaters. However, herbivorous animals and parasitic fungi are also consumers. To be a consumer, an organism does not necessarily need to be carnivorous; it could only eat plants (producers), in which case it would be located in the first level of the food chain above the producers. Some carnivorous plants, like the Venus flytrap, are classified as both a producer and a consumer. Consumers are therefore anything that eats; hence the word consume which means to eat.

Levels of the food chain

Within an ecological food chain, consumers are categorized into primary consumers, secondary consumers, and tertiary consumers.

• Primary consumers are herbivores, feeding on plants or algae. Caterpillars, insects, grasshoppers, termites and hummingbirds are all examples of primary consumers because they only eat autotrophs (plants). There are certain primary consumers that are called specialists because they only eat one type of producers. An example is the koala, because it feeds only on eucalyptus leaves. Primary consumers that feed on many kinds of plants are called generalists.
• Secondary consumers are small/medium-sized carnivores that prey on herbivorous animals. Omnivores, which feed on both plants and animals, can be considered as being both primary and secondary consumers.
• Tertiary consumers, which are sometimes also known as apex predators, are hypercarnivorous or omnivorous animals usually at the top of food chains, capable of feeding on both secondary consumers and primary consumers. Tertiary consumers are usually the largest, strongest and most aggressive animal in the local environment. Both secondary and tertiary consumers must hunt for their food, so they are collectively referred to as predators. Humans are an example of a tertiary consumer.