Question

analyzing energy transfer
if the grass contains 100,000 kcal of energy, how much energy will a fox obtain from eating a bird?
10,000 kcal
1,000 kcal
100 kcal
10 kcal

Explanation:

Step1: Recall energy - transfer rule

Only about 10% of the energy is transferred from one trophic level to the next.

Step2: Calculate energy at primary - consumer level

If grass (producer) has 100,000 kcal, primary consumer gets $100000\times0.1 = 10000$ kcal.

Step3: Calculate energy at secondary - consumer level

Secondary consumer (bird) gets $10000\times0.1=1000$ kcal.

Step4: Calculate energy obtained by fox

Fox (tertiary consumer) gets $1000\times0.1 = 100$ kcal from eating the bird.

Answer:

100 kcal