Population Studies

Question 1

Mark-recapture method

Answer 1

p=m*c/r

Question 2

To get scientifically reliable results(few things).

Answer 2

There should be a short period of time between the first and second captures so that population size would not be affected. Sampling should be repeated many times so that the average population can be calculated. The mark placed on the individuals should not harm them in any way and shouldn’t affect their movement or behaviour. The marked animals must mix with the rest of the population well before the next sample is taken. No immigration or emigration is allowed.

Question 3

What is “Carrying Capacity, and what happens to a population when carrying
capacity is reached?

Answer 3

Carrying capacity is the total number of individuals of a population that an
environment can sustain without being damaged.
When carrying capacity is reached, environmental resistance causes the birth rate to
decrease and the death rate to increase. An equilibrium is reached.

Question 4

What are the differences between the two types of competition?

Answer 4

Intraspecific Competition: ie competition between individuals of the same species. two male hippos fighting:
Stronger individuals survive to breed
Interspecific Competition: ie competition between different species.
eg. Lion and hyena fighting for prey

Question 5

Why is random sampling important?

Answer 5

Each member of a population must have an
equal chance of being selected. If not random then the selection is not “fair”.

Question 6

Why is territoriality beneficial to populations?

Answer 6

The advantages of territoriality include: only the fittest males will mate(strong, healthy offspring will be produced with a great chance of survival),
population size is regulated (little or no immigration), food supplies and shelters are
not depleted (because population size is regulated).

Question 7

What is territoriality?

Answer 7

Territoriality is a social behavioural mechanism whereby a group or family
aggressively protects its habitat and resources (food, space and mates).

Question 8

What is a territory?

Answer 8

A territory is an area selected by a male and defended against other males of the
same species.

Question 9

What is a ‘density-dependent factor’?

Answer 9

Density-dependent
factors are generally biotic factors that regulate population size and help keep it
stable.regulate population size when the population is dense (high).
Population size is directly proportional to the mortality rate with regards to these
factors.