The document outlines the 041 mark-recapture method used by wildlife biologists for estimating animal populations. It details the procedure of trapping and marking animals, followed by a second trapping to calculate population estimates using the Petersen-Lincoln estimator. Materials for the experiment include white and red beads, and the document provides specific steps for conducting the experiment and recording data.

1. 041 MARK-RECAPTURE METHOD
FOR POPULATION STUDY
This technique is used to simulate a population estimate by wildlife
biologists in the field. The first step is to trap a random sample of
animals of the species being studied. These animals are then marked in
some manner appropriate to the species and released. Then the next step
is to do another trapping. Some of the animals captured may have been
marked from the first sample. Using a simple ratio, a quick population estimate,
Petersen-Lincoln estimator of population size can be made as follows:
N = Population estimate
M = Number of individuals captured in first sample & marked
n = Number of individuals captured in second sample
m = Number of (n) that were already marked
Assuming that the marked proportion in the sample is equal to the marked
proportion in the population suggests that
N/M = n/m
To solve for (N) we re-arrange the formula:
N = nM/m

2. MATERIALS REQUIRED
White Beads (around 5-6 handfuls)
Red Beads (around 1-2 handfuls
Small paper bags
White Beads Black Beads paper bags
NOTE: Red beans such as Rajma and light coloured beans
can also be used to simulate this experiment

3. PROCEDURE
Put 5-6 handfuls of white beads into a bag. Do not count them.
Pick out a handful of these beans and count them (do not return them to the
sack). This is the first trapping sample (M). Record answer [M = ___ ]
To mark these beans merely replace them with colored beans (red). Now
release these marked individuals (beads) back into the population (bag). The
replaced white beads are set aside and never returned to the bag again.
They were replaced (marked).
Shake the bag and without looking into the bag grab another handful of beads.
This represents the second trapping sample (n). Count them and record the
answer. [n = ___ ]
How many of the beads in the second trapping sample were already marked
(red beads)? This is the (m) value. Count them and record the answer.
Return this trapping sample (white and red) to the bag. [m = ____ ]
Now use the equation to calculate the population estimate (N). [N = ____ ]

4. FOR EXAMPLE:
M =16
n= 20
m= 4
Hence N= 16 x 20 /4 = 80
SECOND CAPTURE
n =20
M =4
FIRST CAPTURE
(M) =16
DISPERSE