Lecture 15

Question 1

organism size and population density

Answer 1

1. In general, population density declines with increasing organism size (exceptions)
2. same for plants but different underlying processes

Question 2

factors that influence rarity

Answer 2

1. geographic range of species (extreme vs restricted)
2. habitat tolerance (broad vs narrow)
3. local population size (large vs small)

Question 3

International Union for the Conservation of Nature

(IUCN) levels

Answer 3

1. extinct (X)
2. extirpated - Canada (XT)
3. endangered (E)
4. threatened (T)
5. special concern (SC)
6. not at risk (NAR)

Question 4

special concern (SC)

Answer 4

particularly sensitive to human activities or natural events

Question 5

threatened (T)

Answer 5

likely to become endangered if limiting factors are not reversed

Question 6

endangered (E)

Answer 6

at immediate risk of extirpation or extinction

Question 7

extirpated (XT)

Answer 7

no longer exists Canada, but does elsewhere

Question 8

extinct (X)

Answer 8

no longer exists anywhere in the word

Question 9

factors that influence population structure

Answer 9

1. Mortality/survival rates
2. Age distribution
3. Sex ratios
4. Dispersal

Question 10

patterns of survival

Answer 10

Patterns of survival and mortality among individuals in population are a fundamental descriptor of population

Question 11

life tables

Answer 11

bookkeeping device to track births and deaths in populations, from which to estimate survival.

Question 12

3 ways to estimate patterns of survival

Answer 12

1. cohort life table
2. static life table
3. age distribution

Question 13

cohort life table

Answer 13

identify individuals born at same time and keep records from birth (easy to interpret data, but often difficult to collect)

Question 14

static life table

Answer 14

record age at death of large number of individuals over narrow window in time (requires accurate estimate of age at death)

Question 15

age distribution life table

Answer 15

calculate difference in proportion of individuals in each age class (assumes differences in numbers from one age class to next due to mortality, and population size stable)

Question 16

type 1 survivorship curve

Answer 16

high survival of young - most large vertebrates, annual plants, rotifers, humans

Question 17

type 2 survivorship curve

Answer 17

constant rates of survival - birds, robins, sparrows, water snake, lizards

Question 18

type 3 survivorship curve

Answer 18

low survival of young - fish, trees, other plants

Question 19

importance of age distribution

Answer 19

1. reflects history of survival, reproduction, and growth
   potential
2. make predictions about future of population (understand species stability)
3. climate problems

Question 20

sex ratio

Answer 20

relative frequency of each sex type in a population; can change depending on relative fitness of different sexes (most species 1:1)