Practicals

Question 1

What does Practical 1 involve?

Answer 1

Estimating population size - mark & recapture

AKA how many maggots are in a plastic pot

Question 2

Practical 1: What are the 3 methods?

Answer 2

1. Surface count
2. Lincoln index
3. Sampling the habitat
   Compare all 3 estimates to the actual number (final thing counted)

Question 3

Practical 1: What is the methods for mark and recapture of the maggots & Lincoln Index?

Answer 3

1. Capture -> M (30)
2. Mark with a marker pen
3. Release (put back in pot and stir)
4. Recapture -> R and n (30)
5. Input the numbers into the Lincoln index equation and calculate number

Question 4

Practical 1: How is the habitat going to be sampled?

Answer 4

• Maggots will be in vermiculite
• Take 15 spoonfuls and count number of maggots -> mean number of maggots per spoonful (x)
• How many spoonfuls of vermiculite in the pot (y)
• xy = ?

Question 5

Practical 1: What are the assumptions of the Lincoln index (mark & recapture)?

Answer 5

1. Marking must not affect the animal
2. The mark must last the investigation
3. The marked animals must be completely mixed before the next sampling
4. The likelihood of capture must not vary with age
5. There should be no immigration or emigration
6. There should be no births or deaths during the investigation
7. Recapture rates should be high enough -> use the Bailey Correction