Levels of an energy pyramid 

The energy pyramid is made up of several bars. The order of these bars is based on who feeds on whom. Each bar has a different level to represent the four main levels of the energy pyramid are follows:

Level 1: Producers 

• Level 1 comprises producers and the energy available within them. They are found at the base of an energy pyramid.
• Most producers are autotrophs, organisms that synthesize their food from abiotic materials. Plant areas can manufacture their food by photosynthesis. Plants and algae are included in level 1.
• Plants and algae have chlorophyll pigment inside the chloroplasts. Chlorophyll can absorb light energy.
• Few autotrophs do not obtain their energy from the sun directly but from the soil, they get energy. Such autotrophs are earthworms and mushrooms.

Level 2: Primary Consumer

• The second level is comprised of primary consumers, which are those organisms or animals that feed on the producers. 
• Primary consumers are usually herbivores (an animal that feeds on plant material). They depend only on the plant for their survival and nourishment.
• Plant get their energy from the sun then plants pass the energy to the primary consumers. This facilitates the transfer of solar energy from one tropic level to another.
• Primary consumers have physiological and anatomical features that make them adapt to a plant diet. For example, they have wide flat teeth for grinding and gut flora (bacteria and protozoans) that help cellulosic material digestion. Examples of herbivores are goats, cattle, horses, etc.

Level 3: Secondary Consumers

• Secondary consumers are located on the third level of the energy pyramid. Secondary consumers feed on primary consumers. They are commonly known as carnivores (organisms that eat another animal).
• Secondary consumers have anatomical and physiological features that make them adapt to an animal diet.
•  Carnivores or secondary consumers depend on primary consumers. Without primary consumers, they wouldn’t have anything to eat and hence not exist.
• At this level, the energy that gets to the primary consumers from the producers is now transmitted to secondary consumers. This facilitates the smooth flow of energy for effective use.
• Examples of secondary consumer animals are foxes, spiders, etc.

Level 4: Tertiary Consumers 

• The last level of the energy pyramid is comprised of tertiary consumers. Tertiary consumers are also known as secondary carnivores that feed on both primary and secondary consumers.
• The energy level of the ecosystem is finished at this level.
• Usually, the energy that the plant does not utilize goes back to the environment, which includes the atmosphere, soil, and water bodies.
• It is vitally important that all the different level of the energy pyramid get sufficient energy as required to ensure the earth remain stable.
• Tertiary consumers include leopards, hawks, etc.