Mercury Consumption by Songbirds

We can confidently say that the increase in mercury found in songbirds when eating spiders is due to biomagnification. This is the concept that consumers on higher trophic levels will consume more “magnified” amounts of trace elements, as their food also consumes other food rather than producing it. The reason that this happens is that when an organism consumes trace elements, or any substance that its body isn’t familiar with, the organism will hold much of that substance in its body and will have a hard time excreting it. Over time the substance builds up even though all of the “normal” waste is excreted. When the higher trophic level predators come and eat these organisms with elevated mercury, they will consume a large amount of mercury at once and will also not process it well, holding it in their bodies. This effect is why toxins tend to build up in larger amounts at the top of food chains