Mark Release Recapture

Question 1

How to calculate population size?

Answer 1

No in 1st sample x no in 2nd sample / no marked in 2nd
= population size

Question 2

What are the assumptions made?

Answer 2

• no births/deaths
• no migration - immigration or emigration

Question 3

How can organisms be marked?

Answer 3

• leg rings (birds)
• electronic tags
• non-toxic nail varnish
• fur clipping

Question 4

What are the ethics?

Answer 4

• important that animals not harmed
• not disadvantages by their marking, e.g. more easily caught by predators, prevented from finding food