2) How Is Population size Estimated ?

Question 1

Census ?

Answer 1

-counting every single individual in a population

Question 2

Census limitations ?

Answer 2

1) large enough animals
2) Area not too big
3) slow moving
4) sessile
5) stationary

Question 3

Census method ?

Answer 3

1) Aerial photography

2) Helicopters

Question 4

Quadrant method formula?

Answer 4

N= numbers in sample X size of whole habitat / size of quadrant

Question 5

Quadrant method?

Answer 5

1) measure size of total area
2) use a wooden frame of known diameters as quadrant
3) quadrants should be distributed at random
4) count individuals in each quadrant

Question 6

Quadrant method precautions ?

Answer 6

1) size , shape and area of quadrant must remain constant
2) quadrants must be randomly selected
3) Count the number of individuals in each quadrant

Question 7

Why is random sampling important ?

Answer 7

• sample as many quadrants of the total area as possible to achieve a true reflection of the distribution

Question 8

Mark and recapture method used for ?

Answer 8

1) mobile animals (butterfly)

2) not easily visible (🐠)

Question 9

Mark and recapture method ?

Answer 9

1) Mark out a well-defined area
2) Capture as many individuals as possible and mark them
3) release the marked individuals back in the environment
4) Allow time to mix thoroughly with other individuals
5) Recapture as many individuals as possible
6) count marked and unmarked

Question 10

Mark and recapture formula?

Answer 10

P=MxC/R

P=estimated population
M=total number of marked animals
C=total number of animals caught in 2nd sample
R=total number of animals in 2nd sample

Question 11

Mark and recapture precautions?

Answer 11

• only a short time should pass between samplings
• sampling should be repeated several times
• marking must not damage individual or affect its movement of behavior
• marked animal must mix freely
• no emigration or immigration