Explain how the method of mark and recapture works to determine population size.

Mark and recapture method is used to estimate the population size of species in an area.

Explanation:

It is practically impossible to take a count of all the members of a species in an area. Mark and recapture method is a relatively easy method to find the population size of living organisms. To implement this a particular number of members of a  population is selected.

These selected members are marked using tags and similar methods. This can range from tagged neck collar, numbered rings on bird feet etc. These marked organisms in the first sample are then released.

After giving the marked organisms enough time to reach other parts of the population a second sample is obtained and analysed. If it contains already marked organisms the number is recorded.  They are called recaptures.

The equation  used to determine the population size in this method is

N-population size

-Number of marked animals in the first sample

C-Number of animals in the second sample

-Number of recaptured animals in the second sample

If the number of recaptures in the second sample is high it means that the population size is low. If the second sample contains less recaptures it means that the population size is large.

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