Chapter 51

Question 1

Steps of Mark-recapture method

Answer 1

1) catch individuals and mark them
2) Release marked animals and allow them to mix well with the unmarked ones in the population
3) Catch individuals again - the percentage of marked individuals that were recaptured is recorded
4) solve equation (marked/? total = marked recaptured/second capture total)

Question 2

What are the assumptions of the mark-recapture method

Answer 2

-Individuals are not moving in and out of the study area
-individuals mix between captures
-No bias exists regarding which individuals are caught in each recapture
-individuals do not learn to avoid or seek out traps after being caught once
-individuals do not change their behavior attract and or deter predators or mate or die from being handled

Question 3

What 4 factors effect population size

Answer 3

birth, death, immigration, emigration

Question 4

What is demography

Answer 4

the study of statistics which illustrate the changing structure of the human population

Question 5

Things one needs to know to predict future size of popultion

Answer 5

• Age structure
  -# of individuals of each age that are likely to survive to the following year
  -# of offspring produced by females of each age
  -how many individuals of different ages immigrate and emigrate each generation
  -the average time between a mother’s first offspring and that of her daughter - generation length

Question 6

What can you infer about population size if it consists of mostly young individuals with high survival and reproductive rates

Answer 6

should increase overtime

Question 7

What can you infer about population size if it consists of mostly old individuals with low survival and reproductive rates

Answer 7

decline over time

Question 8

What does a life table show

Answer 8

the probability that an individual will survive and reproduce in any given time interval over the course of its lifetime

Question 9

What does age class refer to in a life table

Answer 9

individuals of a specific age

Question 10

Survivorship

Answer 10

the proportion of offspring that survive, on average, to a particular age

Question 11

Survivorship curve

Answer 11

a plot of the logarithm of the number of survivors versus age

Question 12

Survivorship curve: Type 1

Answer 12

High survivor ship at young age, steep decline in old age

Question 13

Survivorship curve: Type 2

Answer 13

Steady survivorship throughout lifetime

Question 14

Survivorship curve: Type 3

Answer 14

Low survivorship at a young age but high survivorship through rest of life

Question 15

Calculation of net reproductive rate

Answer 15

Net reproductive rate = Sum of all ages (survivorship at age x Fecundity at age)

Question 16

Fecundity

Answer 16

the ability to produce an abundance of offspring

Question 17

Life-History trade-offs

Answer 17

High fecundity, low survivorship vs low fecundity, high survivorship
-on a scale

Question 18

Population growth

Answer 18

a population’s change in population size (deltaN) per unit time (deltat) is a function of birthrates, death rates, immigration rates and emigration rates

Question 19

Per capita rate of increase

Answer 19

(r) is the difference between the birthrate and death rate per individual

Question 20

Density-independent factors

Answer 20

usually abiotic factors which do not depend on the population size but change birth rates and death rates
-Ex: weather patterns

Question 21

Density-dependent factors

Answer 21

Factors which depend on the population size and decrease fecundity or survivorship
-can be based on intraspecific and interspecific (predation, parasitism) interactions

Question 22

Logistical growth

Answer 22

If a population of size N is below the carrying capacity K, the population can grow at a rate proportional to (K-N)/K

Question 23

Carrying capacity

Answer 23

The upper limit of exponential growth, at which point population growth is switched to logistical growth patterns

Question 24

Exponential growth equation

Answer 24

change in population size over time = births - deaths all multiplied by population size

Question 25

Population cycles

Answer 25

• population regularly fluctuates in size
  -increase in one population causes decrease in another, then decrease in said population in turn causes decrease in initial population

Question 26

Hare-lynx cycle experiment

Answer 26

Hypothesis: predation, food availability, or both control cycle
Null Hypothesis: neither factor does
Prediction: hare population will be higher in some manipulated plots
Experimental setup: 3 plots unmanipulated, 1 plot no lynx, 2 plots extra food, 1 plot extra food no lynx
Results: Control- low density, predators excluded, higher density but not great, food added, higher density, predators excluded and food added, highest density
Conclusion: hare population are limited by predation and food

Question 27

Metapopulation

Answer 27

a collection of populations interacting via dispersal

Question 28

How do metapopulations work

Answer 28

Some subpopulations go extinct, migration restores subpopulations
-individual patches may follow exponential or logistic growth

Question 29

Age structure of developed vs developing country

Answer 29

Developed: relatively well distributed across ages, decreases at old age
Developing: high population size at young age, significant decline through middle and old age

Question 30

Population momentum

Answer 30

an inevitable increase in population size
-seen in developing countries

Question 31

What influences how populations will change over the next few decades

Answer 31

-access women have to education and reliable birth control
-economic development
-access to quality health care

Question 32

Conservation of endangered species

Answer 32

-high juvenile mortality, low adult mortality and low fecundity
-fate of population is sensitive to increases in adult mortality
- conservation focuses on protecting adults

Question 33

When are populations within a metapopulation most likely to survive

Answer 33

-have larger population size
-occupying larger geographical areas
-are closer to neighboring populations
-have higher genetically diversity