population ecology

Question 1

define populaton

Answer 1

a group of conspecifics inhabiting the same area

Question 2

define geographical range

Answer 2

the physical area that is inhabited by a population

Question 3

define clumped distribution

Answer 3

small groups that are spread throughout a habitat

Question 4

define spaced distribution

Answer 4

lone individuals spread from birthplace in search of breeding/feeding ground

Question 5

define random distribution (seeds)

Answer 5

population scattered by other factors- wind etc

Question 6

define fecundity

Answer 6

the highest potential output of of young by individuals

Question 7

define fertility

Answer 7

the actual output of young when limiting factors are considered

Question 8

what are the 5 reproductive phases? (B, JP, RP, PRP, D)

Answer 8

birth, birth phase, juvenile phase, post juvenile phase, death

Question 9

what is the longest life phase?

Answer 9

reproductive phase

Question 10

define mortality

Answer 10

number of deaths per population per time unit

Question 11

what do survivorship curves display?

Answer 11

probability of an individual reaching maximum life expectancy

Question 12

define type 1 survivorship curve (k strategist)

Answer 12

low mortality until PRP

Question 13

define type 2 survivorship curve

Answer 13

constant linear decline

Question 14

define type 3 survivorship curve (r strategist)

Answer 14

high probability of death in JP, remains constantly high throughout life

Question 15

define the life history theorem. (life events, k or r?)

Answer 15

the time at which life stages occur define what kind of strategist the animal is

Question 16

define closed population

Answer 16

one not subject to immi/emigration

Question 17

define density independent growth (fecundity)

Answer 17

unconstrained growth of a population

Question 18

define density independent factor

Answer 18

mortality is not affected by population density

Question 19

define regulation of abundance (balance of pop)

Answer 19

when population increases during breeding season, dispersal and mortality balance it

Question 20

define carrying capacity

Answer 20

stable equilibrium around which a population fluctuates

Question 21

define natality

Answer 21

the number of young born in a given time

Question 22

does population size increase linearly or logarithmically with a doubling of fecundity rates?

Answer 22

logarithmically

Question 23

define longevity

Answer 23

age at death

Question 24

which kind of strategists would you expect to find a higher number of individuals in PRP?

Answer 24

k

Question 25

how does the 50:50 birth sex ratio fluctuate as time goes on

Answer 25

more females will prevail due to male-male violence

Question 26

define ‘driven’ extinction. refer to environmental changes. why can a population not recover from it

Answer 26

a change in environment causes a decrease in pop size. too low to initiate a boom and k capacity decreases

Question 27

define ‘by chance’ extinction. why is it only prevalent in smaller pop sizes?

Answer 27

dependent on few individuals, things like simply not finding a mate can cause extinction

Question 28

define ‘genetic malfunction’ extinction. why does it occur mainly in small populations?

Answer 28

inbreeding occurs, genetic fitnesses decreases and diseases become prevalent

Question 29

define the hierarchical approach to population control- refer to levels of cause

Answer 29

pop size is determined by more than one causal factor which operates on more than one level

Question 30

what factors act on the landscape level of hierarchical causation? natural and anthropogenic

Answer 30

agriculture
succession
climate change

Question 31

what factors act on an individual level of hierarchical causation?

Answer 31

rates of feeding
presence of predators
dispersal

Question 32

define a source in the context of source-sink dynamics

Answer 32

an ideal environment that supports high fertility levels- birth rate higher than mortality

Question 33

define a sink in the context of source-sink dynamics

Answer 33

the less ideal area into which young will disperse- birth rate lower than mortality

Question 34

define metapopulation- refer to subpopulations

Answer 34

made up of many subpopulations, some acting as sources and some acting as sinks

Question 35

what % of source can sustain what % of sink

Answer 35

10%:90%

Question 36

what is the edge effect of small national reserves?

Answer 36

only species found at the edge of normal wild environments will be found in small national park due to more of it being nearer the edge

Question 37

define demographic uncertainty as a factor causing extinction

Answer 37

random events in a population such as a whole generation of males being born

Question 38

define environmental uncertainty as a factor causing extinction

Answer 38

weather causing drought

predator abundance

Question 39

define natural catastrophes as a factor causing extinction

Answer 39

short and devastating events like hurricanes

Question 40

define genetic uncertainty as a factor causing extinction

Answer 40

chance mutations occurring like susceptibility to a disease- usually only possible in small populations

Question 41

what are the 3 categories of threat to animals?

Answer 41

vulnerable
endangered
critical

Question 42

define extinction vortex

Answer 42

when multiple factors play into the extinction of a specie

Question 43

what is overshoot in the context of carrying capacity?

Answer 43

when a population produces more offspring than the ecosystem can provide

Question 44

what is die-off in the context of carrying capacity?

Answer 44

population decreases rapidly and falls below the k line

Question 45

what is oscillation in terms of carrying capacity?

Answer 45

when the population moves close to the k line- either above or below