Chapter 9 Population Distribution & Abundance

Question 1

Mountain tops and river basins are considered to be _________ boundaries, while countries and parks are considered to be _________ boundaries to populations.

Answer 1

natural

artificial

Question 2

Which of the following would be areas where population biology would inform decision making?

Answer 2

response to epidemics

pest control

wildlife management

Question 3

Which of the following are considered to be characteristics of populations?

Answer 3

density

spacing

growth rate

Question 4

There are limits to how much organisms can compensate for ______ variation.

Answer 4

environmental

Question 5

The environmental limits of a species are considered to be the species’ ______.

Answer 5

niche

Question 6

A population is defined as ______.

Answer 6

members of a species living in a defined area

Question 7

The difference between the realized and the fundamental niche is the additional requirement of
________ factors as part of the definition of the
________ niche.

Answer 7

biotic

realized niche

Question 8

The greatest threat to biological diversity and integrity of the biosphere is the growth of ______ populations.

Answer 8

human population

Question 9

The number of individuals per unit area is known as ______.

Answer 9

density

Question 10

Behavioral, physiological, and anatomical characteristics interact with the ______ to influence the geographical distribution of populations.

Answer 10

environment

Question 11

To an ecologist, niche summarizes the environmental characteristics that influence the ______, ______, and ______ of a species.

Answer 11

growth

survival

reproduction

Question 12

Through which of the following factors may climate be indirectly influencing the distributions of kangaroo species?

Answer 12

water supply

food production

habitat

Question 13

The difference between Grinnel’s niche concept and that of Elton was the inclusion of ______ factors in Elton’s definition.

Answer 13

abiotic

Question 14

Match the kangaroo species to its biome. This match will reflect the factors that control their distribution.

Eastern Grey -
Western Grey -
Red -

Answer 14

Temperate and tropical forests

Mediterranean wood- and shrub land

Savannah and desert

Question 15

The presence of tiger beetles on southern mountain tops can be explained by climate change associated with ______. (Select all that apply.)

Answer 15

glacial retreat

global warming

Question 16

Schultz found that measurements of water loss, metabolic rates and temperature preferences _________ between the populations of C. longilabris.

Answer 16

were similar

Question 17

Precipitation may be ______ influencing the distribution of kangaroos through other factors such as food production, habitat, and even pathogens or parasites.

Answer 17

indirectly

Question 18

The climate found at higher elevations is most similar to that of ______.

Answer 18

boreal forests

Question 19

Even though they have a similar distribution, locally, E. frutescens and E. farinosa differ in the ______ they are found in.

Answer 19

microclimates

Question 20

The movement of tiger beetles northward and to higher elevations as a result of climatic warming is supported by evidence from ____________.

Answer 20

the fossil record

Question 21

The larvae of Balanus are found at ______ levels of the intertidal zone compared to Chthamalus.

Answer 21

similar

Question 22

Schultz found that for the tiger beetle C. longilabris, metabolic rates were ______ and preferred temperatures ______ than for other species of tiger beetles.

Answer 22

higher; lower

Question 23

Variation in leaf pubescence (“hairiness”) of Encelia species varied in relationship to ______ along the gradient that Ehleringer and Clark studied.

Answer 23

moisture

Question 24

In response to competitive interactions in the experiments by Connell and in nature, the spatial distribution of Chthamalus can be considered to be a ______ niche.

Answer 24

realized niche

Question 25

The difference in pubescence between E. farinosa and E. frutescens results in ______ by E. frutescens in order to prevent overheating.

Answer 25

greater transpiration

Question 26

When talking about the distributions of organisms, "large-scale" versus "small-scale" refers to ______ change relative to the size of the organism.

Answer 26

environmental

Question 27

Connell found that the upper limits to the distributions of the intertidal barnacles are determined by susceptibility to ______.

Answer 27

dessication

Question 28

Animals living near watering holes would be an example of a ______ distribution.

Answer 28

clumped

Question 29

On a mountain slope, where environmental change occurs quickly with changes in elevation, a "small-scale process" would be a ______ land area than an area where environmental change was more gradual.

Answer 29

smaller

Question 30

Attraction between individuals would produce a more ______ distribution.

Answer 30

clumped

Question 31

Match the distribution pattern to its description. Random - Regular - Clumped -

Answer 31

Individuals have equal chance of being found anywhere Individuals occur at equally spaced intervals Individuals have a greater chance of being found at specific locations

Question 32

Hubbell and Johnson observed that ______ bees tended to forage in groups and ______ bees foraged singly or in small groups.

Answer 32

aggressive; nonaggressive

Question 33

Within their study area, Hubbell and Johnson found that potential bee nest trees were located in a ______ pattern.

Answer 33

random

Question 34

Pheromones are ______ produced by organisms to communicate with other members of their species.

Answer 34

chemical substances

Question 35

When swarms from different hives battled over a POTENTIAL nest site, they engaged in ______ combat.

Answer 35

ritualized

Question 36

Patterns of distribution are driven by a combination of | ______ and ______ interactions.

Answer 36

environmental / biotic social / abiotic

Question 37

What happened between creosote bushes that was thought to be the cause of their pattern of distribution?

Answer 37

competition

Question 38

Pheromones are chemicals used by organisms to ______ other organisms.

Answer 38

communicate with

Question 39

When bees from different hives battled over an OCCUPIED nest site, they engaged in ______ combat.

Answer 39

mortal

Question 40

In trying to explain the distribution patterns of creosote bushes, Phillips and MacMahon mapped sites that varied in ______ and ______ but were similar in ______ and ______.

Answer 40

temperature; precipitation; soil; slope

Question 41

Large creosote bushes appear to have a(n) ______ distribution.

Answer 41

regular

Question 42

During the course of their growth, Phillips and McMahon found that the distribution pattern of creosote bushes ______.

Answer 42

changes as they grow (small, young) clumped, (medium) random, (large) regular

Question 43

A proposed explanation for the distribution of creosote bushes is ______ competition.

Answer 43

below ground

Question 44

In support of their hypothesis, Brisson and Reynolds found that the overlap of roots between adjacent plants was ______ the expected overlap if the plants simply had a circular pattern of root growth.

Answer 44

less than

Question 45

Research prior to Phillips and MacMahon indicated that creosote bush distribution was driven by ______.

Answer 45

moisture

Question 46

The germination of seeds at "safe sites" was part of the reason for the ______ distribution of young creosote bushes.

Answer 46

clumped

Question 47

Regardless of species, Root's analysis of the Christmas Bird Count data showed that birds have ______ distributions at continental scales.

Answer 47

clumped

Question 48

Brisson and Reynolds hypothesized that the distribution of creosote bushes would reflect ______ overlap of roots from nearby individuals.

Answer 48

reduced

Question 49

The change in distribution of creosote bushes from clumped to regular as they grow larger can also be thought of as a change in distribution reflecting the change from ______ to ______ niches.

Answer 49

fundamental; realized

Question 50

True or false: From its name, you would expect fish crows to have hot spots near coastal locations.

Answer 50

true

Question 51

Areas of high density for a species identified in the annual Christmas Bird Count are referred to as ______.

Answer 51

hot spots

Question 52

One of the criticisms of Root's analysis of bird distributions was that it only looked at data from a time when the birds were on their ______ grounds.

Answer 52

wintering

Question 53

Based on the role of social attraction to promote clumped distributions, you could understand why populations were clumped during breeding seasons. However, clumped wintering distributions are most likely due to the presence of ______ in specific locations rather than social attraction.

Answer 53

critical resources

Question 54

Whittaker and Neiring studied plant distributions along ______ and ______ gradients in the mountains of Arizona.

Answer 54

moisture; elevation

Question 55

In both Arizona and Great Smoky Mountains, particular tree species occurred ______ along the continuous environmental gradients from valleys to mountain tops.

Answer 55

at specific locations

Question 56

In general, population densities ______ body size.

Answer 56

decrease with

Question 57

Brown et al. looked at bird distributions when they were in their ______ grounds.

Answer 57

breeding

Question 58

Root et al. found that over half the bird populations occurred in less than 25% of the sites sampled. This would indicate that the birds had a ______ distribution.

Answer 58

clumped

Question 59

True or false: In their study, Whittaker and Neiring found Saguaro cacti growing in higher mountain locations.

Answer 59

false Saguaro cacti grow in the hotter and dried lower elevation deserts.

Question 60

In a biodiversity survey of the Great Plains, you would expect to find ______ numbers of field mice compared to bison in a defined sample area.

Answer 60

greater

Question 61

In Damuth's study, population densities and body sizes spanned _______ orders of magnitude.

Answer 61

5

Question 62

Peters and Wassenberg expanded upon Damuth's research on density and body size by looking at which of the following in addition to herbivorous mammals?

Answer 62

birds invertebrates poikilothermic vertebrates

Question 63

The three factors used for Rabinowitz's rarity classification system for species include ______.

Answer 63

geographic range habitat tolerance local population size

Question 64

Aquatic invertebrates tend to have ______ densities given their body's size compared to other organisms in the study.

Answer 64

higher

Question 65

For many organisms, there is a positive relationship between population size and range. This means that you would expect a small population to have a ______ range as compared to a larger population.

Answer 65

smaller

Question 66

Unlike animals, plant population densities decrease as individual plants grow older. This process is known as ______.

Answer 66

self-thinning

Question 67

Peregrine falcons had ______ and ______ but low population density, resulting in an increased risk of extinction.

Answer 67

broad habitat tolerance extensive geographic range

Question 68

Rabinowitz's rarity classification system is designed to evaluate whether a population is at risk for ______.

Answer 68

extinction

Question 69

Tigers are at risk of extinction because of which one of Rabinowitz's risk factors?

Answer 69

small population size

Question 70

Passenger pigeons went extinct as a result of which one of Rabinowitz's risk factors?

Answer 70

narrow habitat tolerance

Question 71

One of the environmental factors thought to affect the relationship between range and population size is ______.

Answer 71

habitat tolerance

Question 72

Island species are at extremely high risk for extinction due to which of Rabinowitz's risk factors?

Answer 72

small population size narrow habitat tolerance restricted range

Question 73

Peregrine falcons are at risk of extinction because of which one of Rabinowitz's risk factors?

Answer 73

small population size

Question 74

Like peregrine falcons, tigers had ______ and ______ but low population density, resulting in an increased risk of extinction.

Answer 74

extensive geographic range broad habitat tolerance

Question 75

The harelip sucker went extinct as a result of which one of Rabinowitz's risk factors?

Answer 75

narrow habitat tolerance

Question 76

Organisms living in a continental area can also be considered "island species" when they ______.

Answer 76

live in extremely isolated locations