Part 2

Question 1

What are the four ways that population is measured?

Answer 1

1. Census
2. Sample
3. Relative Abundance
4. Mark-Recapture

Question 2

What are the four primary population parameters?

Answer 2

(BIDE)
Birth
Immigration
Death
Emigration

Question 3

How does the sampling method differ from the census method for measuring population?

Answer 3

The census method is a measure of the total number of individuals in a population, while the sample method is a measure of the number of individuals within a distinct area within a population.

Question 4

Which formula relates the measurement taken from a population sample to the population as a whole? What do the variables represent?

Answer 4

N=C/aB where N is the estimated number of individuals within a population, C is the number of species counted in the sample, a is the proportion of the total area sampled, and B is the probability of correct detection.

Question 5

The method of Mark-Recapture in determining population density which relates the ratio of the number of re-caught tagged individuals over the total number of individuals caught in a second sample to the ratio of previously tagged individuals in a first sample over the total population is known as?

Answer 5

The Lincoln-Peterson Method.

Question 6

What are the major assumptions of the Mark-Recapture method?

Answer 6

1. Marks remain visible between captures.
2. Marked and unmarked animals are equally likely to be caught.
3. No immigration or emigration
4. The catch-able population has been identified.

Question 7

Define semelparous

Answer 7

Reproduces once in a life-time

Question 8

Define Iteroparous

Answer 8

Reproduces multiple times in a life-time

Question 9

What is demography and what are its primary and secondary goals?

Answer 9

Demography is the statistical study of populations and their age structures as well as density and vital statistics (birth and death rates). The primary goal of demography is to project population growth, and its secondary goal is to determine sensitive and important ages.

Question 10

What is a cohort and how does it relate to life-tables?

Answer 10

A cohort is a group of individuals all born roughly at the same time. A life table measures the mortality rates of a cohort as it relates to their age groups.

Question 11

How is survivorship (Ix) calculated?

Answer 11

By dividing the number of individuals currently alive in an age group by the number of individuals that were alive at the beginning of their cohort.

Question 12

How is mortality for an age group calculated?

Answer 12

By dividing the total number of fatalities between the measured age group and the next age group after by the total number of individuals originally within the age group. (a_x-a_(x+1))/a_x)

Question 13

What is the measurement m_x?

Answer 13

The fertility schedule for a cohort i.e. the number of females produced per female in age class x.

Question 14

How is the net reproductive rate R_0 calculated?

Answer 14

It is the number of daughters produced in generation t+1 divided by the number of daughters produced in generation t. Or the sum of all l_x*m_x for a cohort.

Question 15

Define the mean length of a generation.

Answer 15

The average time between the birth of a female to the birth of her average offspring.

Question 16

Calculate population size after six time steps using the following data:

K = 1600
r = 0.07

N_0 = 1333

Answer 16

Nt = K / {1+([K-N0]/N0)e-rt}

N6 = 1600 / 1+([1600-1333]/1333)e-0.07*6

N6 = 1414

Question 17

Define Gause’s competitive exclusion principle.

Answer 17

Two species with the same primary limiting resource cannot coexist in the same place at the same time.

Question 18

What are the growth rate equations for two species 1 & 2 in the Lotka-Volterra model?

Answer 18

dN1/dt = r1N1 [(K1-N1-aN2)/K1]
dN2/dt = r2N2 [(K2-N2-βN1)/K2]

Question 19

What are the 5 basic assumptions of the LV predation model?

Answer 19

a. encounters are assumed to occur at random in a homogeneous environment.
b. predators are specialists.
c. predator and prey populations are closed.
d. no self-limitation in the prey population.
e. predators have a type-1 functional response.

Question 20

Define functional response.

Answer 20

the change in the per capita killing rate with changes in prey density.

Question 21

What is the Allee effect?

Answer 21

Population growth is low at low individual numbers.