Owls eat rats, mice, shrews, and small birds. Assume that, over a period of time, an owl consumes 5,000 J of animal material. The owl loses 2,300 J in feces and owl pellets and uses 2,500 J for cellular respiration. What is the production efficiency of this owl?

Question

Quizplus · Accepted Answer

To find the production efficiency, we need to subtract the energy lost in feces and pellets and energy used in cellular respiration from the energy consumed. 
Energy consumed = 5,000 J 
Energy lost in feces and pellets = 2,300 J 
Energy used in cellular respiration = 2,500 J 
Energy available for growth and reproduction = Energy consumed - energy lost in feces and pellets and energy used in cellular respiration 
= 5,000 - 2,300 - 2,500 J 
= 1,200 J 
Production efficiency = (Energy available for growth and reproduction / Energy consumed) x 100% 
= (1,200 / 5,000) x 100% 
= 24% 
Therefore, the production efficiency of this owl is 7.4%, which is closest to option B.

Owls Eat Rats, Mice, Shrews, and Small Birds