In a population of about 50 walruses with 30 fertile females

In a population of about 50 walruses with 30 fertile females, only 4 males are mating, due to strong male-male competition. Suppose that you need to provide data for conservation efforts and are asked to calculate the effective population size (N_e). What would be your best estimate?

Solution

Answer :

Effective population size can be calculated by using the formula

Ne = 4Nm Nf / Nm + Nf

Where,

Ne = Effective population size

Nm = number of breeding males

Nf = number of breeding females

So,

Ne = 4Nm Nf / Nm + Nf

      = 4 X 4 X 30 / 4 + 30

      = 480/34

Ne = 14