2d- Monitoring populations

Question 1

What can the presence, absence or abundance of indicator species give information on?

Answer 1

Environmental qualities, such as the presence of a pollutant

Question 2

What can be used to monitor an ecosystem?

Answer 2

Susceptible or favoured species (indicator species)

Question 3

What indicates that a species is susceptible to some factor in the environment?

Answer 3

Absence or reduced population

Question 4

What indicates that a species is favoured by the conditions?

Answer 4

Abundance or increased population

Question 5

What is the mark and recapture technique used to estimate?

Answer 5

Population size

Question 6

In the mark and recapture equation what do the following represent:

i) M
ii) C
iii) R
iv) N

Answer 6

i) M= number of the population that has been captured, marked and then released
ii) C= number in the second sample that is captured
iii) R= number in the second sample who were also captured the first time
iv) N= total population

Question 7

What three things does the mark and recapture method assume?

Answer 7

1. that all individuals have an equal chance of capture
2. that there is no immigration or emigration
3. that individuals that are marked and released can mix fully and randomly with the
   total population

Question 8

What are five examples of marking animals?

Answer 8

• banding
• tagging
• surgical implantation
• painting
• hair clipping

Question 9

What must the method of marking and subsequent observation ensure?

Answer 9

That there is minimal impact on the study species