1. Predator Prey Interactions: Activity 1 – Learning the Rules Activity 2 – Coyotes Go Hunting Simulated Mark-Recapture: Activity 1 – Simple Mark-Recapture Activity 2 – Repeated Mark-Recapture
Week of November 26th 2018
Version Last updated: 11/27/ :38:27 PM

2. Final Field Trip: Natural History Museum
Saturday, December 1st 11 a.m.
How do diseases spread among humans, domestic animals and wild populations?
What are the implications for environmental science?
Can you find patient zero?

3. Predator-Prey Interactions – Activity 1: Learning the Rules of the Community

4. Number of hares (thousands)
Predators/prey interactions are important for:
1) Determining populations of both predators and prey;
2) Determining and maintaining community structure.
Hare
Lynx
Number of hares (thousands)

5. Mice population, survival and reproduction
In each generation, there will always be at least 10 mice on the plate.
The number of mice may be higher as determined by previous generation, but cannot be lower than 10 or higher than 100.
For example, if you end a generation with 4 mice, doubling its population would only bring you to 8. You must add 2 so that you start the next generation with 10. If doubling would result in >100 mice, only count 100.

6. Coyote population
At the beginning of each generation there must always be at least one coyote (a spoon), presumed to have arrived there by immigration.
If all your coyotes from a given generation fail to survive, or decide to emigrate, start each new generation with one coyote, presuming that it has recently migrated to the area.

7. Coyote survival and reproduction
Success:
For a coyote to survive, it must capture at least 5 mice in each generation.
For every 5 mice that a coyote catches in a given generation, the coyote will reproduce and generate 1 offspring, which will then be available to hunt at the beginning of the next generation.
Failure:
If a coyote captures 4 or fewer mice, it fails to survive, or decides to emigrate, and will not be present at the beginning of the next generation.

8. Hunting
Coyotes hunt for mice by “running” through the field. Simulate the hunt by slowly swiping a spoon across the plate once per generation, attempting to scoop up beans (mice), with no assistance from other hands, spoons, etc.
The number of beans scooped up in the spoon represent the number of mice caught by the coyote for that generation.
Example: if a generation begins with a single coyote in the community, slowly swipe one spoon across the plate one time and scoop up as many beans as possible, without any other assistance.
If there are 2 coyotes in the population, swipe two spoons sequentially.

9. Predator-Prey Interactions Activity 2 – Coyotes Go Hunting

10. Begin at generation 5, with 76 mice and 2 coyotes.1 2 3 4 5 6 7 8 9 10
Initial # mice 18 30 48 76
Initial # coyotes
# of mice caught by each coyote (#1-17) X 11 12 13 14 15 16 17
# mice captured
# mice surviving
# coyote surviving
# coyote offspring
Table 2.1. Number of mice caught by coyote, survivors and coyote population data for generations 1-10
Begin at generation 5, with 76 mice and 2 coyotes.

11. # of mice caught by each coyote (#1-17)
Generation # 11 12 13 14 15 16 17 18 19 20
Initial # mice
Initial # coyotes
# of mice caught by each coyote (#1-17) 1 2 3 4 5 6 7 8 9 10
# mice captured
# mice surviving
# coyote surviving
# coyote offspring
Table 2.2. Number of mice caught by coyote, survivors and coyote population data for generations 11-20

12. Simulated Mark-Recapture Activity 1 – Simple Mark-Recapture

13. Sampling
Population
An efficient way to accurately estimate population size with minimal effort.
Not feasible to count every individual.
Sample

14. Mark-recapture technique
Actually “capture-mark-release-recapture”.
Important when sampling mobile organisms.
Release back into natural population
Second capture
First capture

15. Place 4-6 small handfuls of light-colored beans into a paper bag.
Table 1.1. Population guess, count and calculated population estimate based on numbers of captured, marked and recaptured individuals using mark-recapture technique
Place 4-6 small handfuls of light-colored beans into a paper bag.
This represents a population of organisms.
Guess how many beans you placed in the paper bag.
Record guess.
Parameter
Value
Expression
Guess of population size = 57
= uncounted guess of total number of beans placed in bag at beginning
M =
= # of beans in first handful “captured”
n =
= # beans in second handful “captured”, regardless of color
m =
= # beans in second handful “captured” dark (= marked)
N =
= population estimate (eqn 2)
Count population size =
= actual physical count of total number of beans in bag at end
% accuracy of N =
= percent accuracy of calculated N relative to actual count of population size

16. 57 11 Take a handful of beans out of the paper bag.
Parameter
Value
Expression
Guess of population size = 57
= uncounted guess of total number of beans placed in bag at beginning
M = 11
= # of beans in first handful “captured”
n =
= # beans in second handful “captured”, regardless of color
m =
= # beans in second handful “captured” dark (= marked)
N =
= population estimate (eqn 2)
Count population size =
= actual physical count of total number of beans in bag at end
% accuracy of N =
= percent accuracy of calculated N relative to actual count of population size
Table 1.1.
Take a handful of beans out of the paper bag.
This represents your first capture (sample) of a group of organisms (M) from the population.
Count these beans and record the number as the value for M.
DO NOT return these beans to the paper bag.

17. Mark the organisms (beans) you just captured.
To mark these beans, simply replace them with dark-colored beans.
Release marked beans back into bag.
Shake bag to mix marked beans back into population.

18. 57 11 14 Without looking, grab a handful of beans from paper bag.
Parameter
Value
Expression
Guess of population size = 57
= uncounted guess of total number of beans placed in bag at beginning
M = 11
= # of beans in first handful “captured”
n = 14
= # beans in second handful “captured”, regardless of color
m =
= # beans in second handful “captured” dark (= marked)
N =
= population estimate (eqn 2)
Count population size =
= actual physical count of total number of beans in bag at end
% accuracy of N =
= percent accuracy of calculated N relative to actual count of population size
Table 1.1.
Without looking, grab a handful of beans from paper bag.
This is your second capture (sample) of a group of organisms (n).
Count total number of beans grabbed in this handful (regardless of color) and record the count as n.
Examine the handful of beans you gathered.
Count the number of beans that were "marked" (m) (dark-colored), record as m.
After counting, return entire sample to the paper bag (both light-colored and dark-colored beans).

19. 57 11 14 3 Examine the handful of beans you gathered.
Parameter
Value
Expression
Guess of population size = 57
= uncounted guess of total number of beans placed in bag at beginning
M = 11
= # of beans in first handful “captured”
n = 14
= # beans in second handful “captured”, regardless of color
m = 3
= # beans in second handful “captured” dark (= marked)
N =
= population estimate (eqn 2)
Count population size =
= actual physical count of total number of beans in bag at end
% accuracy of N =
= percent accuracy of calculated N relative to actual count of population size
Table 1.1.
Examine the handful of beans you gathered.
Count the number of beans that were "marked" (m) (dark-colored), record as m.
After counting, return entire sample to the paper bag (both light-colored and dark-colored beans).

20. Use Equation 2 to calculate population estimate N.
Parameter
Value
Expression
Guess of population size = 57
= uncounted guess of total number of beans placed in bag at beginning
M = 11
= # of beans in first handful “captured”
n = 14
= # beans in second handful “captured”, regardless of color
m = 3
= # beans in second handful “captured” dark (= marked)
N = 51
= population estimate (eqn 2)
Count population size =
= actual physical count of total number of beans in bag at end
% accuracy of N =
= percent accuracy of calculated N relative to actual count of population size
Table 1.1.
Use Equation 2 to calculate population estimate N.
N = (11 x 14)/3
N = 51.33
N = 51
Equation 2:
N = Mn / m
Where:
N = Population estimate
M = Number of individuals captured in first sample (and marked)
n=Total number of individuals captured in second sample
m=Number of individuals captured n second sample (n) and marked

21. 57 11 14 3 51 63 80.95 (51/63) x 100 = percent accuracy
Parameter
Value
Expression
Guess of population size = 57
= uncounted guess of total number of beans placed in bag at beginning
M = 11
= # of beans in first handful “captured”
n = 14
= # beans in second handful “captured”, regardless of color
m = 3
= # beans in second handful “captured” dark (= marked)
N = 51
= population estimate (eqn 2)
Count population size = 63
= actual physical count of total number of beans in bag at end
% accuracy of N =
80.95
= percent accuracy of calculated N relative to actual count of population size
Table 1.1.
(51/63) x 100 = percent accuracy
80.95% = percent accuracy
Count total number of beans (both light-colored and dark-colored) in the paper bag, record count.
Calculate and record percent accuracy of N relative to count of population size:
(N/count) * 100 = % accuracy

22. Table 1.2. Group data for guess of population size, calculated N, count of population and percent accuracy of N using simple mark-recapture technique
Values by Group
Table #
Parameter 1 2 3
Guess of population size N
Count of population size
% accuracy of N
Record all group data for guessing the population size, calculated N, count of population size, and percent accuracy of N for simple and repeated mark-recapture technique.

23. Simulated Mark-Recapture Activity 2 – Repeated Mark-Recapture

24. # Marked Individuals in Population (M1)
Table 2.1. Population guess and count, and calculated population estimate based on numbers captured, marked and recaptured individuals using repeated mark-recapture technique
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1=
R1= 2
M2=
C2=
R2= 3
M3=
C3=
R3= 4
M4=
C4=
R4=
Guess of population size=
382
N (calculated w/ Eq. 3)=
Count of population size=
Percent accuracy of N=
Place 4-6 small handfuls of light-colored beans in paper bag.
Do not count the beans.
Guess how many beans you placed in the paper bag.
Record guess.

25. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2=
R2= 3
M3=
C3=
R3= 4
M4=
C4=
R4=
Guess of population size=
382
N (calculated w/ Eq. 3)=
Count of population size=
Percent accuracy of N=
Take a handful of beans out of the paper bag.
This represents your first capture (sample) of a group of organisms (C1).
Count beans, record as C1 for capture 1.
DO NOT return these beans to the paper bag.

26. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2=
R2= 3
M3=
C3=
R3= 4
M4=
C4=
R4=
Guess of population size=
382
N (calculated w/ Eq. 3)=
Count of population size=
Percent accuracy of N=
Mark the organisms (beans) you captured.
Replace with dark-colored beans (# of marked individuals in population).
Record # of marked beans as M2 for capture 2.
Note that M1 for capture 1 is 0 because there were originally no marked individuals.

27. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2= 20
R2= 7 3
M3=
C3=
R3= 4
M4=
C4=
R4=
Guess of population size=
382
N (calculated w/ Eq. 3)=
Count of population size=
Percent accuracy of N=
Release marked beans bag into bag, shake to mix.
Without looking, grab a handful of beans from bag, which becomes your second capture.
Count total beans in handful (any color) and record as C2.
Examine this handful, determine # of marked (dark-colored) record R2.

28. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2= 20
R2= 7 3
M3= 30
C3= 23
R3= 5 4
M4=
C4=
R4=
Guess of population size=
382
N (calculated w/ Eq. 3)=
Count of population size=
Percent accuracy of N=
Mark unmarked beans from capture 2; return previously and newly marked to bag and mix.
NOTE M3 is now total of ALL # marked beans.
Without looking, grab a handful of beans from bag (third capture).
Count # of beans in handful (regardless of color) and record as C3.
Determine # of marked (dark-colored) record R3.

29. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2= 20
R2= 7 3
M3= 30
C3= 23
R3= 5 4
M4= 48
C4= 26
R4= 8
Guess of population size=
382
N (calculated w/ Eq. 3)=
Count of population size=
Percent accuracy of N=
Mark the unmarked beans from capture 3.
Return previously and newly marked to bag and mix; M4 = total marked beans.
Without looking, grab a handful of beans from bag (fourth capture).
Count total # of beans in handful (regardless of color) and record as C4.
Examine this handful, determine # of marked (dark-colored) record R4.

30. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2= 20
R2= 7 3
M3= 30
C3= 23
R3= 5 4
M4= 48
C4= 26
R4= 8
Guess of population size=
382
N (calculated w/ Eq. 3)=
114
Count of population size=
Percent accuracy of N=
Calculate population estimate (N) using Equation 3.
Equation 3:
M2C2+M3C3+M4C4
N =
R2+R3+R4
N = ((17x20)+(30x23)+(48x26))/(7+5+8)
N = ( )/ 20
N = 2278/20 = = 114

31. # Marked Individuals in Population (M1)
Table 2.1.
Capture #
# Marked Individuals in Population (M1)
# Captured (C1)
# Recaptured (R1) 1
M1=
C1= 17
R1= 2
M2=
C2= 20
R2= 7 3
M3= 30
C3= 23
R3= 5 4
M4= 48
C4= 26
R4= 8
Guess of population size=
382
N (calculated w/ Eq. 3)=
114
Count of population size=
125
Percent accuracy of N=
91.2%
Percent accuracy of N = (114/125) x 100
Percent accuracy of N = x 100 = 91.2%
Count actual total number of beans (both light-colored and dark-colored combined) in, record count.
Calculate percent accuracy N = (N/count) x 100.

32. Table 2.2. Comparison of class-level data of guess of population size, calculated population size (N), count of population size and accuracy of N for repeated mark-recapture
Value by Table #
Parameter 1 2 3
Guess of population size= N=
Count of population size=
Percent accuracy of N=
Record all group data for guess of population size, calculated N, count of population size, and percent accuracy of N for simple and repeated mark-recapture technique.

33. Value by Mark-Recapture Method
Table 2.3. Comparison of individual group-level data for guess of population size, calculated population size (N), count of population size and accuracy of N for simple mark-recapture versus repeated mark-recapture
Value by Mark-Recapture Method
Parameter
Simple
Repeated
Guess of population size= 57
382 N= 51
114
Count of population size= 63
125
Percent accuracy of N=
80.95
91.2
Record data for guess of population size, calculated N, count of population size, and percent accuracy of N for simple and repeated mark-recapture technique.

34. Weekly Data Sheet pages
What’s Due
Activity
Weekly Data Sheet pages
Weekly Write-Up pages P1
n/a P2
481, 485 S1
459
463 S2
467
471
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