Question

energy that is captured by producers moves through the trophic levels of the food web. which organism is in a trophic level that obtains a smaller proportion of this energy than the proportion at the wading bird’s level?
a. bald eagle
b. benthic invertebrate
c. zooplankton
d. bivalve
image courtesy of the united states geological survey

Explanation:

In a food web, energy decreases as it moves up trophic levels (only ~10% transferred per level). The wading bird (Herbivorous Duck? Wait, the diagram has Herbivorous Ducks, and Bald Eagle is a higher trophic level than the wading bird (since eagles eat ducks or other organisms in the web). Benthic invertebrates, zooplankton, and bivalves are lower or same/slightly higher but not higher than the eagle. So Bald Eagle is at a higher trophic level than the wading bird, so it gets a smaller proportion of energy (since energy decreases up levels). The other options (benthic invertebrate, zooplankton, bivalve) are at lower or same trophic levels as the wading bird's level or lower, so they would have more energy proportion than the eagle (and less than? Wait, no: the question is which has a smaller proportion than the wading bird's level. So higher trophic level than wading bird. Bald Eagle is a top predator, so its trophic level is higher than the wading bird (which eats producers or primary consumers). So energy at eagle's level is less than at wading bird's. The other options are lower (benthic invertebrate, zooplankton, bivalve are primary or secondary consumers, wading bird might be secondary or tertiary, but eagle is quaternary or higher). So Bald Eagle is in a higher trophic level, so smaller energy proportion.

Answer:

A. bald eagle