# It has been established that 1 kg of tit mass (second-order consumers) contains 4000 kcal of energy, and the efficiency of photosynthesis

It has been established that 1 kg of tit mass (second-order consumers) contains 4000 kcal of energy, and the efficiency of photosynthesis in the forest is 1%. What is the maximum number of these birds with an average weight of 20 g that can feed in a community on the surface of which 2 x 10 ^ 7 kcal of solar energy is supplied?

1) Let’s make a diagram of the food chain:
foliage -> insects – > tits.
2) Let’s calculate how much solar energy is used in the process of photosynthesis:
2 • 107 kcal – 100% x kcal – 1% x = 2 • 105 kcal.
3) Let’s calculate how much energy is contained in the body of one tit:
1 kg (1000 g) contains 4000 kcal 20 g – x kcal x = 80 kcal.
4) According to Lindemann’s rule, when moving from one trophic level to another, 10% of the energy of the previous level is lost, that is, insects will receive 200,000 kcal from the foliage: 10 = 20,000 kcal, and tits – 2000 kcal.
5) Let’s calculate how many tits can feed in this community:
2000 kcal: 80 kcal = 25.