Question

12. Complete the following life table of lizards data. Calculate R0 for this species, and comment on the growth of this population

Age	Number Alive	Lx	Bx	LxBx
0	1150		0
1	980		0.09
2	432		3.01
3	116		4.15
4	51		4.9
5	6		6.5

Answer 1

Subpart1

Step 1:

Lx is the probability of the animal surviving to age x.

The formula by which we can calculate Lx is

Lx= number of alive individual at age x / number of alive individual at age 0.

Step 2:

Bx is the estimation of female offspring born to a mother at age x. (In the table value is given)

Step 3:

Calculation of LxBx gives us the basic reproductive rate at age x.

Step 4

So the table may now be completed:

Age	Number of alive	Lx	Bx	LxBx
0	1150	1150/1150=1	0	0
1	980	980/1150=0.85	0.09	0.76
2	432	432/1150=0.375	3.01	1.128
3	116	116/1150=0.1	4.15	0.415
4	51	51/1150=0.044	4.9	0.215
5	6	6/1150=0.005	6.5	0.032

Subpart 2:

Basic Reproductive rate (R0)= LxBx

So here R0= (0+0.76+1.128+0.415+0.215+0.032) = 2.55

Subpart 3:

The growth of the population follows type III survivorship curve. As the age increases the number of individuals decreases sharply.