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 2,600 J for cellular respiration. What is the production efficiency of this owl?

Question

Quizplus · Accepted Answer

Production efficiency is calculated as (net secondary production / assimilation of primary production) x 100%.

Assimilation of primary production = 5,000 J (amount consumed) 
Net secondary production = 5,000 J - 2,300 J - 2,600 J = 1,100 J (energy available for growth and reproduction)

Production efficiency = (1,100 J / 5,000 J) x 100% = 0.22 x 100% = 22%

Therefore, the production efficiency of this owl is 22%, which is closest to choice C (4%).

Owls Eat Rats, Mice, Shrews, and Small Birds