Question

Given what you know about the Mark and Recapture estimate technique: Why would it be hard to do with a population that has absolutely huge individuals, and also extremely small individuals among the population? Why would it be of limited use to estimate a population of birds in a particular wetland, if that population of birds frequently migrates in and out of the wetland all year long?

Answer 1

Mark and Recapture technique is a method os estimating the number of a particular animal species present in an area. In this method, one sample of the animal species is marked and released to mix thoroughly with the rest of the population. A second sample is taken after some time and the estimation of the total poulation of a species is done on the basis of proportion of marked individuals in the second sample.

It is hard to use this technique for a population with very huge individuals and also extremely small individuals as it is relatively easier to mark and detect the larger ones and difficult to mark and also recapture the smaller ones

This technique is of limited use in a particular wetland with the bird population migrating in and out of the wetland all year long as there will be less recaptures . Since the marked birds will leave the wetland and new unmarked birds migrate in, there will be less recaptures than the normal equilibrium population of birds in the wetland. This will not give the right estimate of the population of the bird species.