Trophic Pyramid
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To the left is a video of the trophic pyramid for a Bald Eagle's ecosystem. Now you may ask, what is a trophic pyramid? Well, the exact definition is a graphical representation designed to show the biomass productivity at each trophic level in a given ecosystem. In other words, it is a graph that shows the energy level in any given ecosystem. The ecosystem of the Bald Eagle are lakes, rivers, coastal bays, and marshes. The producers are the first level and they contain the most energy. Grass is the producer of this pyramid. The second level is the grasshopper and they are the primary consumers. The next level is the secondary consumer and in my case, they are frogs. The highest level is the tertiary consumer and they contain the least amount of energy because they do not produce their own food. Eagles are the tertiary consumers of their ecosystem because they are a top predator.
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Food Web
To the left is an image of the Bald Eagle's food web in a freshwater marsh ecosystem. A food web is a system of interlocking and interdependent food chains. In other words, a food web is a representation of food chains that belong in the same ecosystem and help each other. The Bald Eagle is on the top of the food web because it is a top predator. Since Eagles are on the top of the food web, they tend to have the most risk to be exposed to toxic chemicals in the environment due to chemicals from the lower levels of the food web. The levels in a trophic pyramid are much like the arrows in a food chain. There are still primary, secondary, and tertiary consumers. Energy is still transferred between the organisms, starting from the bottom of the web to the top.
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Limiting Factors & Carrying Capacity
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Limiting factors are things that prevent a population from growing. Some limiting factors that Eagles faced were land development, hunting, and pesticides. Land development in the 19th century is the main reason why Eagles became extinct because their shelters were being destroyed. Hunting became a trend due to new advancements in firearms. Eagles were targeted for their sharp talons and feathers. In the 1960s a pesticide called DDT was introduced and caused a large decline of the Eagles' population. Carrying capacity is the maximum population of a species that the environment can sustain. Factors that can determine the carrying capacity of an environment are food supply, water supply, and habitat/shelter. Eagles are on top of the food web in their environment, however they still compete with other consumers for food. Eagles compete with other large birds, like hawks, for smaller animals like snakes. When people first started to expand in the West, land development was happening and Eagles lost a lot of their shelter creating a decline in Eagles. Eagles typically live near bodies of water so water supply isn't that big of a factor.
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