Chapter 54.2, Problem 2R

Summary Introduction

To analyze:

The following, if the population size of an endangered bird in 2035 is to be predicted:

a. R₀, r, and G by completing the given cohort life table.

b. The expected population size (N_t) in 2035, assuming that an exponential population growth takes place and ${\text{N}}_{\text{0}}=\text{120}$

c. The population size in 2035, assuming that logistic growth takes place and $\text{K}=\text{300}$

Given:

A cohort life table is provided in Table 1, from which the above components can be calculated.

Table 1: A cohort life table representing the population of an endangered bird.

Years	Age (x)	Number of female birds (Nx)	Number of female offspring (Nx offspring)	Survivorship (lx)	Fecundity (mx)	lx m x	x l x m x
2012	0	100	0
2013	1	50	75
2014	2	40	80
2015	3	30	60

Introduction:

A cohort life table helps the researcher to investigate population size of an organism. Table 1 generally uses the group of organisms born in the similar timeframe. This table helps to estimate growth rate. It shows the number of offsprings produced at different ages, number of individuals survived each year known as survivorship, and fecundity, that is, the number of offspring born per surviving adults. This table also helps to know the generation time, reproductive rate, and an intrinsic rate of increase.