E herbivores are called primary consumers 3 rd

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heterotrophs that feed directly on autotrophs (i.e. herbivores) are called primary consumers. 3 rd trophic level: secondary consumers Heterotrophs who feed exclusively on primary consumers. In other words, some carnivores. 4 th trophic level: tertiary consumers Heterotrophs that feed only on secondary consumers i.e. carnivores who eat other carnivores. Usually, tertiary consumers are found at the top of the food Omnivores: heterotrophs that can feed at any trophic level. Detrivores: wastes and dead organisms (detritus) from all trophic levels consumed by organisms called deterivores (or decomposers). Detrivores break down organic matter into simpler nutrients allowing these to be recycled in the ecosystem. Food webs and thermodynamics: Why are there so many producers and so few tertiary consumers? The 2 nd law of thermodynamics limits the efficiency of energy transfer from one trophic level to another. At best it is 10%. The rest is used by the organisms in the lower level and is ultimately lost as waste heat. Organisms that feed at lower trophic levels have access to more of the primary production than do those at higher levels. Earth can sustain more herbivores than top carnivores. Eating more grains and vegetables, and less meat, might be a way of increasing the food supply.
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