BIOL 4233 Field Biology

BIOL 5533 Ecological Methods

Experiment 4: Mark-recapture sampling and removal sampling techniques

Brower et al. (1998): Units 3f and 3g

  1. Introduction
  1. Population as a unit of study
  2. Basic characteristics of populations
  3. Density
  1. estimates of relative density
  2. estimates of absolute density
  1. total counts
  2. sampling

(1)quadrat sampling

(2)mark-recapture sampling

(a)Lincoln-Peterson method

  1. N = nM/x
  2. x/n = M/N

(b)marking methods

(c)assumptions of method

(d)error measurement

(e)tests for significant differences

(3)removal sampling: Moran-Zippin method

  1. Experimental objectives
  1. Determine effect of population size on accuracy of mark-recapture method
  2. Determine effect of sample size on accuracy of mark-recapture method
  3. Determine effect of population size on accuracy of removal sampling method
  4. Determine effect of sample size on accuracy of removal sampling method
  5. Compare mark-recapture and removal sampling methods
  1. Mark-recapture sampling (lab): Lincoln-Peterson method
  1. Variables
  2. Hypotheses
  3. Protocol
  1. plastic bin containing lima bean population in a pinto bean matrix
  2. mix gently for 30 sec
  3. sample with large cup (large sampler)
  4. mark all limas in sample (marked sample), record number, then return limas to bin and mix for 30 sec
  5. recapture sample using large sampler
  6. count all limas (marked [M] and n [M + unmarked]), record, then return limas to bin and mix for 30 sec
  7. repeat steps 5 and 6 to obtain data for three replicate data sets for the large sampler
  8. repeat steps 3 through 7 using medium cup (medium sampler)
  9. repeat steps 3 through 7 using small cup (small sampler)
  1. Analysis of data
  1. variables to be analyzed (use all class data): effect of sample size on reliability of density estimate by mark-recapture
  2. statistical analyses
  1. means and standard errors
  2. 95% confidence intervals
  3. t-tests for significant differences among sample sizes
  1. Removal sampling (lab): Moran-Zippin method
  1. Protocol
  1. mix beans for 30 sec, then sample with large sampler
  2. count all limas in cup, replace pintos, but do not replace limas into bin
  3. remix for 30 sec and resample with large sampler
  4. count all limas in cup, replace pintos, but do not replace limas into bin
  5. determine population density estimate by

N = n12 / n1-n2

  1. replace all limas into bin, mix for 30 sec
  2. repeat steps 2 through 6 to obtain data for three replicate sets of data
  3. repeat steps 2 through 6 three times using medium sampler
  4. repeat steps 2 through 6 three times using small sampler
  1. Analysis of data
  1. variables to be analyzed (use all class data): effect of sample size on reliability of density estimate by mark-recapture

2statistical analyses

  1. means and standard errors
  2. 95% confidence intervals
  3. t-tests for significant differences among sample sizes

3.effect on estimates due to violation of assumptions

  1. Determination of population sizes of pillbugs using mark-recapture and removal sampling techniques

A.Mark-recapture sampling

1.determine location of three cores using randomized grid

2.using three medium sized cups as a coring devices, gently work each cup into the soil at the grid locations (three replicates)

3.count and mark all pillbugs in each core sample, record numbers

4.return all pillbugs to the population

5.after two weeks, repeat steps 1 through 3

6.determine population size ± SE using Lincoln Peterson calculations

  1. Removal sampling
  2. using the medium sized cup as a coring device, gently work the cup into the soil
  3. count all pillbugs in the sample but do not replace them into the population
  4. record number of pillbugs in sample
  5. repeat steps 1 through 3 to obtain data for two more replicate sets of data
  6. determine population size ± SE using Moran Zippin calculations

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