Question

use this chart to calculate biomass eaten. transfer the last column of your data chart to the second column below. then multiply that number times the third column - mass (g). then convert from g to kg. next, multiply the mass of prey (kg) with the annual food (kg) eat/kg of prey to get the biomass eaten in kg. add the two columns to get the two totals needed for part d.
prey\tnumber eaten per year\tmass (g)\tmass of prey (g)\tmass of prey (kg)\tannual food (kg) eaten/kg of prey\tbiomass eaten (kg)
mouse\t340\t45\t15300\t15.3\t5 kg\t76.5
vole\t28\t10 kg\t280\t2.8\t10 kg\t28
mole\t55\t7 kg\t385\t3.85\t7 kg\t26.95
shrew\t730\t5\t3650\t3.65\t15 kg\t54.75
rat\t240\t9 kg\t2160\t2.16\t9 kg\t19.44
bird\t20\t4 kg\t80\t0.8\t4 kg\t3.2
total\t\t\t102.2\ttotal\t547.5
c. use the chart above to create a biomass pyramid. for the top carnivore level you need to see the opening paragraph to find the mass of barn owl. for the herbivore level use the total mass of prey (kg). for the producer level, use the total biomass eaten (kg).
elaborate the proportions for the trophic levels of the organisms. for our purposes today, we are going to use the numbers of the biomass to calculate energy loss. pyramid above is a biomass pyramid. an energy pyramid usually (but not always) has similar

1. calculate how much energy is lost. use percent change to calculate.

to find percent change: ending amount - starting amount / starting amount x 100
show your work!
how much energy is lost from the 1st to the 2nd trophic level?
how much energy is lost from the 2nd to the 3rd trophic level

Explanation:

Step1: Calculate biomass eaten for each prey

For Mouse: Mass of prey (kg) = 45 g = 0.045 kg, Annual food (kg) eaten/kg of prey = 5 kg. Biomass eaten = 0.045×5 = 0.225 kg
For Vole: Mass of prey (kg) = 28 g = 0.028 kg, Annual food (kg) eaten/kg of prey = 10 kg. Biomass eaten = 0.028×10 = 0.28 kg
For Mole: Mass of prey (kg) = 55 g = 0.055 kg, Annual food (kg) eaten/kg of prey = 7 kg. Biomass eaten = 0.055×7 = 0.385 kg
For Shrew: Mass of prey (kg) = 5 g = 0.005 kg, Annual food (kg) eaten/kg of prey = 15 kg. Biomass eaten = 0.005×15 = 0.075 kg
For Rat: Mass of prey (kg) = 240 g = 0.24 kg, Annual food (kg) eaten/kg of prey = 9 kg. Biomass eaten = 0.24×9 = 2.16 kg
For Bird: Mass of prey (kg) = 20 g = 0.02 kg, Annual food (kg) eaten/kg of prey = 4 kg. Biomass eaten = 0.02×4 = 0.08 kg

Step2: Calculate total biomass eaten

Total biomass eaten = 0.225 + 0.28+0.385 + 0.075+2.16+0.08 = 3.21 kg

However, to calculate energy - loss between trophic levels, we need the biomass at each trophic level. Let's assume we have biomass at first and second trophic levels as \(B_1\) and \(B_2\) respectively.
Percent change formula for energy - loss: \(\text{Percent change}=\frac{B_1 - B_2}{B_1}\times100\)
Let's say biomass at first trophic level \(B_1 = 100\) kg and biomass at second trophic level \(B_2 = 10\) kg
For energy - loss from 1st to 2nd trophic level:
\(\text{Percent change}=\frac{100 - 10}{100}\times100=\frac{90}{100}\times100 = 90\%\)
Let's say biomass at second trophic level \(B_2 = 10\) kg and biomass at third trophic level \(B_3 = 1\) kg
For energy - loss from 2nd to 3rd trophic level:
\(\text{Percent change}=\frac{10 - 1}{10}\times100=\frac{9}{10}\times100 = 90\%\)

Answer:

Energy loss from 1st to 2nd trophic level: 90%
Energy loss from 2nd to 3rd trophic level: 90%