Exploringnature.orgEnergy flows through an ecosystem as the animals eat plants or other animals in a complex food web. The source of all energy comes from the green plants which change sunlight into food through the process of photosynthesis. Some energy is lost each time an animal eats. Energy is lost as heat, as the predator uses its muscles to chase its prey (and often doesn't even catch it). Energy is lost because not all of the prey can be digested and some material is passed as waste. Some energy is used for growth and reproduction, while some is simply used to fuel the animal's everyday activities. This means that one lynx has to eat a lot of snowshoe hares to maintain its energy, reproduce and grow. Every snowshoe hare must eat a lot of grass and plants to maintain its energy, reproduce and grow. Because there is energy lost at each level of the food chain, it takes a lot of plants to feed one large predator found at the end of the food chain. Each part of this food chain is a trophic level and has a name. The plants that make their own food, using water, sunlight and carbon dioxide (photosynthesis), are called producers. The animals (insects, mice, chipmunks, squirrels, rabbits, deer, etc.) that eat the plants are primary consumers. If they eat only plants, they are called herbivores. The animals (spiders, birds, snakes, weasels, etc.) that eat the primary consumers are the secondary consumers. If they eat both plants and meat, they are called omnivores. If they eat only meat, they are called carnivores. The animals (fox, coyotes, eagles, owls, hawks, etc.) that eat the secondary consumers are tertiary consumers. The living things that eat and recycle dead animals and plants are called the decomposers or detritivores. These include insects, bacteria, mushrooms and other fungi. At each trophic level, energy is lost as heat.Food Webs & Trophic LevelsSolar energy from the SunProducers(1st Trophic Level)Primary Consumers(2nd Trophic Level)HerbivoresSecondaryConsumers(3rd Trophic Level)CarnivoresTertiary Consumers(4th Trophic Level)CarnivoresHeatHeatHeatHeatHeatHeatHeatHeatvoleshort-tailed weaselbarredowlgreen plantsDecomposers or Detritivoresinsects, bacteria & fungi
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