Deck 11: Population Distributions

Question 1

The orange-breasted sunbird (Anthobaphes violacea) lives only in the fynbos region in the Western Cape of South Africa. This is an example of a(n)

A) extinct species.
B) endemic species.
C) cosmopolitan species.
D) localized species.

Answer 1

B

Question 2

Species with very large geographic ranges that can span several continents are called

A) abundant.
B) endemic.
C) cosmopolitan.
D) dispersed.

Answer 2

C

Question 3

A species of tree is found from the Canadian border down to the southeast United States. This is called the species'

A) fundamental niche.
B) realized niche.
C) geographic niche.
D) geographic range.

Answer 3

D

Question 4

Which dispersion should be favored among plants that compete intraspecifically by casting shade?

A) clumped
B) evenly spaced
C) random
D) clustered

Question 5

When a species is in danger of becoming extinct, scientists use ecological niche modeling to assess where the species might have the highest probability of successful reintroductions. What does ecological niche modeling determine?

A) geographic range
B) fundamental niche
C) realized niche
D) ecological envelope

Question 6

Why are endemic species more at risk for becoming rare or endangered than cosmopolitan species?

Question 7

Compare and contrast the terms dispersion and dispersal.

Question 8

When there are direct interactions among individuals in a population, _____ dispersion is favored.

A) random
B) clustered
C) clumped
D) evenly spaced

Question 9

What is the difference between a species' realized niche and its ecological envelope?

A) The ecological envelope is the range of conditions under which a species lives, whereas the realized niche is a prediction of the range of conditions under which a species can live.
B) The realized niche is the range of conditions under which a species lives, whereas the ecological envelope predicts the range of conditions under which a species can live.
C) The realized niche is the range of conditions under which a species lives, whereas the ecological envelope is a measure of the total area in which a population lives.
D) The realized niche and the ecological envelope are essentially the same.

Question 10

What was the main factor that led to declines in collared lizard (Crotaphytus collaris) populations in the Ozark Mountains of Missouri?

A) Increased forest fires killed collared lizards and their preferred insect prey species.
B) Suppression of forest fires decreased the open habitat that collared lizards require.
C) Increased forest fires removed the cool, closed-canopy habitat that collared lizards require.
D) Suppression of forest fires led to an increase in the populations of collared lizard predators.

Question 11

The pattern of density and spacing of individuals in a population is called the

A) niche.
B) ecological envelope.
C) spatial structure.
D) geographic range.

Question 12

Determining the suitable habitat conditions for a species is called _____ modeling.

A) fundamental niche
B) ecological niche
C) geographic niche
D) spatial structure

Question 13

The range of abiotic conditions under which a species can persist is called its

A) fundamental niche.
B) geographic niche.
C) realized niche.
D) geographic range.

Question 14

How do dispersal and migration differ?

A) Dispersal is seasonal, and migration is usually permanent.
B) Dispersal is usually permanent, and migration is seasonal.
C) Dispersal is back-and forth-movement between two areas, and migration is unidirectional.
D) Migration is movement to colonize a new habitat, and dispersal is seasonal movement.

Question 15

An endangered frog species lives in only a few forest patches found throughout the Pacific Northwest of the United States. The Pacific Northwest is its _____, and the forest patches are its _____.

A) realized niche; geographic range
B) fundamental niche; realized niche
C) geographic range; realized niche
D) geographic range; fundamental niche

Question 16

The number of individuals _____ best defines abundance.

A) per unit area or volume
B) in a defined area
C) in a geographic range
D) in a species

Question 17

Sugar maple (Acer saccharum) is a tree species that is found throughout the northeastern United States in higher-elevation sites without sandy soils. What can you conclude about the distribution of sugar maples in terms of their geographic range and realized niche?

Question 18

What type of dispersion do many agricultural crops exhibit?

A) random
B) clustered
C) even
D) clumped

Question 19

Researchers examined data collected between 1985 and 2006 on diversity of fish in the North Sea, average bottom temperatures, and how species diversity was affected by temperature. According to the figure, what did they find? What did they conclude about the cause of the change in fish diversity?

Question 20

Populations whose individuals _____ favor clustered dispersion.

A) live in social groups
B) directly interact with each other
C) aggressively defend resources
D) do not interact with each other

Question 21

Ants should live in _____ populations, and rhinoceroses should live in _____ populations.

A) high-density; high-density
B) low-density; low-density
C) high-density; low-density
D) low-density; high-density

Question 22

What factors drive the relationship between population density and adult body size?

A) resources and predation
B) space and predation
C) availability of mates and predation
D) space and resources

Question 23

A researcher who counts the number of individuals of a tree species between two fixed points is making a(n) _____ survey.

A) area-based
B) volume-based
C) line-transect
D) mark-recapture

Question 24

The best way to quantify organisms that are well camouflaged is a(n) _____ survey.

A) line-transect
B) mark-recapture
C) volume-based
D) area-based

Question 25

What is the relationship between population density and adult body size?

A) Population density is positively correlated to adult body size.
B) Population density is negatively correlated to adult body size.
C) Populations with high density generally have large-bodied species.
D) Populations with low density generally have small-bodied species.

Question 26

Dispersal limitation occurs when

A) there has not been sufficient time for a species to disperse into suitable habitat.
B) there is a barrier to dispersal into suitable habitat.
C) the new habitat is unsuitable for the species.
D) the new habitat is already occupied by a competing species.

Question 27

During the annual Christmas bird count conducted by the Audubon Society, volunteers count the number of individuals of every bird species they can see or hear along a predetermined path within a 24-kilometer circle. This is an example of a(n) _____ survey.

A) volume-based
B) area-based
C) mark-recapture
D) line-transect

Question 28

If the geographic range of a population is decreased, it is generally considered that the

A) size of the population will decrease.
B) size of the population will increase.
C) population will go extinct.
D) size of the population will stay the same.

Question 29

You conduct a mark-recapture survey of eastern fence lizards (Sceloporus undulates) in a 2-hectare plot in eastern Arizona. You mark 250 lizards and are able to recapture 75, of which 24 are marked. What is the estimated size of the population of fence lizards in this plot? Calculate the estimated population size for the plot and the estimated lizard density per hectare and per square meter. Use the following formula: where M is the number of initially marked individuals, N is the population size, R is the number of recaptured marked individuals, and C is the total number of individuals recaptured.

Question 30

Which of the following populations would be best estimated by an area-based survey?

A) flowers in a field
B) rodents in a grassland
C) fish on a coral reef
D) migratory birds on a pond

Question 31

Why does reduction of a population lead to decreased geographic range?

A) Fewer individuals need fewer resources.
B) Populations will clump tightly when populations reduce.
C) Smaller populations use fewer resources per capita.
D) Marginal habitats will receive fewer dispersing individuals.

Question 32

Measuring the lifetime dispersal distance of a species helps scientists to estimate how rapidly a growing population can increase its

A) geographic range.
B) fundamental range.
C) realized niche.
D) fundamental niche.

Question 33

Populations with high abundance tend to have a _____ range.

A) small geographic
B) small fundamental
C) large geographic
D) large fundamental

Question 34

For a mark-recapture survey, the ratio of the number of marked individuals to the total population is equal to the ratio of the

A) number of marked individuals recaptured to the total number of individuals in the second capture.
B) total number of individuals in the second capture to the number of marked individuals recaptured.
C) total number of individuals in the first capture to the number of marked individuals recaptured.
D) number of individuals in the second capture to the number of individuals marked in the first capture.

Question 35

Methods such as area-based, volume-based, and line-transect surveys would be best for estimations of _____ populations.

A) clustered
B) random
C) evenly spaced
D) mobile

Question 36

The relationship between population density and adult body size is demonstrated in many organisms. Would you expect this relationship to hold true for body size averaged across all developmental stages (juveniles to adults)? Why or why not?

Question 37

A researcher who wants to know how many tree seedlings are in a 1-hectare site counts the number of seedlings within five 2-square-meter subplots and then calculates the average. This method of determining the number of individuals in an area is known as a

A) census.
B) survey.
C) tally.
D) count.

Question 38

Imagine that you are conducting a mark-recapture survey of common pill bugs (Armadillidium vulgare), a terrestrial isopod, in a field. Unbeknownst to you, the majority of the pill bugs molt between marking and recapturing. How does this affect your estimate of the population size? How could you have foreseen this? How could you prevent this in the future?

Question 39

Based on the relationship between geographic range and population, what would you expect to happen if a large portion of a species' habitat is converted to agriculture?

Question 40

Scientists commonly use _____ dispersal distance to quantify an organism's dispersal.

A) average
B) maximum
C) lifetime
D) median

Question 41

When a larger population is broken up into smaller groups that live in isolated patches, the smaller groups are called

A) subpopulations.
B) copopulations.
C) side populations.
D) sink populations.

Question 42

Researchers used an experimental design in which they cleared large patches of pine forest in five areas. The central cleared area served as the source of dispersers. The four remaining cleared patches were (1) a rectangular unconnected patch, (2) a rectangular patch connected to the central patch by a cleared path that served as a corridor, and (3) two rectangular patches with wings (patches with corridors that did not connect to other patches). The researchers were interested in the importance of habitat corridors to the movement of seeds, pollen, and butterflies between central and peripheral habitat patches. What was the purpose of the unconnected winged patches?

Question 43

In some parts of the United States, pathways for wildlife are built over or under highways to allow animals to cross safely. This is an example of a(n)

A) dispersal limitation.
B) habitat corridor.
C) ecological envelope.
D) ecological passage.

Question 44

Using the landscape metapopulation model, explain how the quality of the matrix between suitable habitat patches can limit the ability of a species to exhibit an ideal free distribution among suitable habitat patches.

Question 45

A southern European songbird, the blue tit (Parus caeruleus), breeds in two habitats that differ greatly in quality: downy oak forest and holm oak forest. In downy oak habitats, there are six times as many breeding pairs of blue tits and they produce 60 percent more total offspring per year than the holm oak blue tit populations. The downy oak blue tit populations have the potential to grow at the rate of 9 percent annually. In holm oak habitats, blue tits perform poorly and populations have the potential to decline 13 percent annually. Given the differences in the two habitats, why do blue tits persist in both? Be sure to include a discussion of the relevant metapopulation model in your answer.

Question 46

Which model specifically addresses the situation in which subpopulations in poor-quality habitats are maintained by immigration of individuals from other subpopulations that produce surplus individuals?

A) the basic metapopulation model
B) the source-sink metapopulation model
C) the landscape metapopulation model
D) the habitat metapopulation model

Question 47

The emerald ash borer (Agrilus planipennis) is an insect from eastern Asia that has invaded North America. The larvae of the emerald ash borer consume the cambium and phloem under the bark of American ash trees and eventually kill the trees. How can biologists predict the spread of this invasive pest? What might explain why the emerald ash borer is more of a problem in North America than in its native range?

Question 48

Although there is suitable habitat for sugar maple (Acer saccharum) in Europe and Asia, it is limited to North America because of lack of

A) habitat corridors to Europe and Asia.
B) dispersal mechanisms.
C) pollinators in Europe and Asia.
D) sufficient soil nutrients in Europe and Asia.

Question 49

Which of the following is NOT a characteristic of a source subpopulation?

A) high-quality habitat
B) high emigration rate
C) high level of resources
D) high immigration rate

Question 50

Researchers used an experimental design in which they cleared large patches of pine forest from five areas. The central cleared area served as the source of dispersers. The four remaining cleared patches were (1) a rectangular unconnected patch, (2) a rectangular patch connected to the central patch with a cleared path that served as a corridor, and (3) two rectangular patches with wings (patches with corridors that did not connect to other patches). The researchers were interested in the importance of habitat corridors to the movement of seeds, pollen, and butterflies between central and peripheral habitat patches. What was the purpose of planting male winterberry plants in central patches and female winterberry plants in peripheral patches? Based on the results, what would you conclude about the importance of habitat corridors?

Question 51

When individuals have perfect knowledge of habitat variation and distribute themselves in a way that allows all of them to have the same per capita benefit, they display a(n) _____ free distribution.

A) optimum
B) ideal
C) perfect
D) best

Question 52

In populations that fit a source-sink metapopulation model, organisms in _____ subpopulations disperse into _____ subpopulations.

A) higher-quality sink; lower-quality source
B) lower-quality sink; higher-quality source subpopulations
C) lower-quality source; higher-quality sink subpopulations
D) higher-quality source; lower-quality sink subpopulations

Question 53

Per capita benefit is the amount of resources

A) per individual.
B) for the total population.
C) per group of individuals.
D) per species.

Question 54

According to an ideal free distribution, individual organisms would be expected to move into low-quality habitat when

A) the quality of the low-quality habitat increases to equal the high-quality habitat.
B) the per capita benefit of the low-quality habitat equals the per capita benefit of the high-quality habitat.
C) habitat corridors open up between the two habitats.
D) the per capita benefit of the high-quality habitat is greater than the per capita benefit of the low-quality habitat.

Question 55

As part of a scientific study, you are quantifying the reproductive success of individuals in a wildflower population in an isolated area. The total geographical range of this wildflower is only a few square kilometers, and you know from a previous ecological modeling study that this population occupies its entire ecological envelope. On average, an individual member of this species disperses its seeds an intermediate distance (about 100 meters) in a random direction via wind. You quantify reproductive success as the proportion of seeds released by a parent plant that successfully germinate. Considering only the abiotic environment, in which parts of the wildflower's geographic range would you predict average individual reproductive success to be the highest and the lowest? Explain why.

Question 56

Which model specifically addresses the situation where the patches differ in quality and regions of the surrounding matrix also differ in quality (leading to differences in dispersal potential)?

A) the landscape metapopulation model
B) the basic subpopulation model
C) the basic metapopulation model
D) the source-sink metapopulation model

Question 57

Which of the following is an example of dispersal limitation?

A) A species of bird is not aware of the habitat.
B) The preferred prey of a species of lizard is absent.
C) All mice that try to cross the highway to reach the new habitat are killed.
D) The soil moisture in the habitat is too low for a species of tree.

Question 58

Which of the following does NOT explain why an ideal free distribution might not be achieved in nature?

A) Individuals may not be aware that other habitats exist.
B) An individual's fitness is not solely determined by maximizing its resources.
C) Presence of predators or territoriality may preclude free movement between habitats.
D) Individuals may not be able to differentiate between high- and low-quality habitat.

Question 59

In the experiment in which stickleback fish (Gasterosteus aculeatus) were presented with high- and low-quality habitats, why would fish disperse from the high-food side of the aquarium to the low-food side?

A) The low-food side increased in quality.
B) The high-food side decreased in quality.
C) The low-food side per capita benefit equaled that of the high-food side.
D) The low-food side per capita benefit was less than the high-food side.

Question 60

Which population model applies to the situation in which patches of suitable habitat are embedded within a matrix of unsuitable habitat?

A) the basic metapopulation model
B) the basic subpopulation model
C) the source-sink metapopulation model
D) the landscape metapopulation model

Question 61

If one were looking at the characteristic related to how an individual in a population interacts with others of its species in a given area, one would likely be looking at what?

A) abundance
B) density
C) geographic range
D) dispersion

Question 62

In the example of the Ozark Mountain collard lizard, what would the glades be considered?

A) high-quality patches
B) low-quality patches
C) high-quality matrix
D) low-quality matrix

Question 63

What is true about habitat corridors??

A) They always connect two low-quality habitat patches.
B) They always connect two high-quality habitat patches.
C) They are a natural feature of the landscape.
D) They are the same habitat type as the patches connected.

Question 64

What is not true about a species' geographic range?

A) The geographic area is always contiguous.
B) The geographic range may span more than a single biome.
C) Individuals may be absent from some regions of a species' geographic range.
D) The geographic range may have variable vegetation types, soil types, and topography within its border.

Question 65

Individuals of a species will disperse themselves among different quality habitats such that they all have the same per capita benefit. What is that model called?

A) geographic range model
B) ideal free distribution model
C) realized niche model
D) source-sink metapopulation model

Question 66

Describe the difference between the source-sink metapopulation model and the landscape metapopulation model.

Question 67

Explain the difference between a species' fundamental and realized niche. What might cause a species to have a smaller (in terms of area) realized niche?

Question 68

Plants that grow by vegetative reproduction likely will have what type of dispersion pattern?

A) random
B) clustered
C) evenly spaced
D) ideal free

Question 69

Which of the following is NOT a reason we might see differences in density of a species within its geographic range?

A) seasonal migration patterns
B) habitat quality differences
C) Patches and matrix are of the same habitat type and quality.
D) Populations are larger in the center versus the edge of the geographic range.

Question 70

Explain how a conservation biologist/ecologist might employ ecological niche modeling when considering the probability of an invasive species spreading into a new habitat in the future.