Lecture 2b- Methods in Mammology

Question 1

What are the two types of counts that determine animal density?

Answer 1

Total counts and incomplete counts

Question 2

How does ‘distance sampling’ work?

Answer 2

It estimates the ‘detection function’

Question 3

Key assumptions of distance sampling

Answer 3

All animals at distance 0 are detected
Animals detected at original location
Distances measured accurately

Question 4

How can animals be counted when using a distance sampling method?

Answer 4

Spotlights, night vision and thermal imaging

Question 5

How does ‘radiotracking’ work?

Answer 5

An animal is fitted with a radio tracker

Question 6

How much should a transmitter and collar weigh for radio tracking?

Answer 6

1-3% of body mass

Question 7

What are the key assumptions of capture-mark-recapture?

Answer 7

Catching has no impact
Animals are random sample
Marking has no impact
Animals equally likely to be re trapped
Marks not lost

Question 8

What is the equation for the Peterson method to work out population size?

Answer 8

Population size (n) = (1st sample (caught and marked) X 2nd sample) / 2nd sample marked

Question 9

Why are computer simulation models used?

Answer 9

Cheap, enable researchers to investigate possible changes quickly