6.
5.
4.
3.
If a hawk eats 30% of the weasel population, weasels eat 30% of the mouse population, and
mice eat 20% of the wheat plants, calculate the total numbers of each organism that exist in
this ecosystem.
a. Start by finding how many weasels there are to support the one hawk
i. # of weasels eaten / .3 =
total weasels
ii.
total weasels x # of mice needed / .3=
total mice
iii. total mice x # of wheat plants needed / .2 = total wheat plants
Weasels
Mice
Wheat Plants
Organism per Trophic Level
Organism
Total Number
1,003
b. Secondary consumers -
why,
c. Primary consumers -
d. Producers -
3,345
16,729
Given the amount of energy each organism stores in its tissues, and the number of organisms
needed to support one hawk for one year, calculate the amount of energy stored by each
trophic level.
a. Top-level predators -
Ova
0.3 x x = 120, 450 kJ / (400)
=301,125 x 301.125 10.3
t
lalable to the
only
Draw an energy/biomass pyramid to summarize your calculations.
mungo
Based on your calculations, how many more wheat plants would be needed to feed 5 more
hawks?
n
