Chapter 9 Population Distribution & Abundance Flashcards
Mountain tops and river basins are considered to be _________ boundaries, while countries and parks are considered to be _________ boundaries to populations.
natural
artificial
Which of the following would be areas where population biology would inform decision making?
response to epidemics
pest control
wildlife management
Which of the following are considered to be characteristics of populations?
density
spacing
growth rate
There are limits to how much organisms can compensate for ______ variation.
environmental
The environmental limits of a species are considered to be the species’ ______.
niche
A population is defined as ______.
members of a species living in a defined area
The difference between the realized and the fundamental niche is the additional requirement of
________ factors as part of the definition of the
________ niche.
biotic
realized niche
The greatest threat to biological diversity and integrity of the biosphere is the growth of ______ populations.
human population
The number of individuals per unit area is known as ______.
density
Behavioral, physiological, and anatomical characteristics interact with the ______ to influence the geographical distribution of populations.
environment
To an ecologist, niche summarizes the environmental characteristics that influence the ______, ______, and ______ of a species.
growth
survival
reproduction
Through which of the following factors may climate be indirectly influencing the distributions of kangaroo species?
water supply
food production
habitat
The difference between Grinnel’s niche concept and that of Elton was the inclusion of ______ factors in Elton’s definition.
abiotic
Match the kangaroo species to its biome. This match will reflect the factors that control their distribution.
Eastern Grey -
Western Grey -
Red -
Temperate and tropical forests
Mediterranean wood- and shrub land
Savannah and desert
The presence of tiger beetles on southern mountain tops can be explained by climate change associated with ______. (Select all that apply.)
glacial retreat
global warming
Schultz found that measurements of water loss, metabolic rates and temperature preferences _________ between the populations of C. longilabris.
were similar
Precipitation may be ______ influencing the distribution of kangaroos through other factors such as food production, habitat, and even pathogens or parasites.
indirectly
The climate found at higher elevations is most similar to that of ______.
boreal forests
Even though they have a similar distribution, locally, E. frutescens and E. farinosa differ in the ______ they are found in.
microclimates
The movement of tiger beetles northward and to higher elevations as a result of climatic warming is supported by evidence from ____________.
the fossil record
The larvae of Balanus are found at ______ levels of the intertidal zone compared to Chthamalus.
similar
Schultz found that for the tiger beetle C. longilabris, metabolic rates were ______ and preferred temperatures ______ than for other species of tiger beetles.
higher; lower
Variation in leaf pubescence (“hairiness”) of Encelia species varied in relationship to ______ along the gradient that Ehleringer and Clark studied.
moisture
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.
realized niche
The difference in pubescence between E. farinosa and E. frutescens results in ______ by E. frutescens in order to prevent overheating.
greater transpiration
When talking about the distributions of organisms, “large-scale” versus “small-scale” refers to ______ change relative to the size of the organism.
environmental
Connell found that the upper limits to the distributions of the intertidal barnacles are determined by susceptibility to ______.
dessication
Animals living near watering holes would be an example of a ______ distribution.
clumped
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.
smaller
Attraction between individuals would produce a more ______ distribution.
clumped
Match the distribution pattern to its description.
Random -
Regular -
Clumped -
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
Hubbell and Johnson observed that ______ bees tended to forage in groups and ______ bees foraged singly or in small groups.
aggressive; nonaggressive
Within their study area, Hubbell and Johnson found that potential bee nest trees were located in a ______ pattern.
random
Pheromones are ______ produced by organisms to communicate with other members of their species.
chemical substances
When swarms from different hives battled over a POTENTIAL nest site, they engaged in ______ combat.
ritualized
Patterns of distribution are driven by a combination of
______ and ______ interactions.
environmental / biotic
social / abiotic
What happened between creosote bushes that was thought to be the cause of their pattern of distribution?
competition
Pheromones are chemicals used by organisms to ______ other organisms.
communicate with
When bees from different hives battled over an OCCUPIED nest site, they engaged in ______ combat.
mortal
In trying to explain the distribution patterns of creosote bushes, Phillips and MacMahon mapped sites that varied in ______ and ______ but were similar in ______ and ______.
temperature; precipitation; soil; slope
Large creosote bushes appear to have a(n) ______ distribution.
regular
During the course of their growth, Phillips and McMahon found that the distribution pattern of creosote bushes ______.
changes as they grow
(small, young) clumped, (medium) random, (large) regular
A proposed explanation for the distribution of creosote bushes is ______ competition.
below ground
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.
less than
Research prior to Phillips and MacMahon indicated that creosote bush distribution was driven by ______.
moisture
The germination of seeds at “safe sites” was part of the reason for the ______ distribution of young creosote bushes.
clumped
Regardless of species, Root’s analysis of the Christmas Bird Count data showed that birds have ______ distributions at continental scales.
clumped
Brisson and Reynolds hypothesized that the distribution of creosote bushes would reflect ______ overlap of roots from nearby individuals.
reduced
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.
fundamental; realized
True or false: From its name, you would expect fish crows to have hot spots near coastal locations.
true
Areas of high density for a species identified in the annual Christmas Bird Count are referred to as ______.
hot spots
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.
wintering
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.
critical resources
Whittaker and Neiring studied plant distributions along ______ and ______ gradients in the mountains of Arizona.
moisture; elevation
In both Arizona and Great Smoky Mountains, particular tree species occurred ______ along the continuous environmental gradients from valleys to mountain tops.
at specific locations
In general, population densities ______ body size.
decrease with
Brown et al. looked at bird distributions when they were in their ______ grounds.
breeding
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.
clumped
True or false: In their study, Whittaker and Neiring found Saguaro cacti growing in higher mountain locations.
false
Saguaro cacti grow in the hotter and dried lower elevation deserts.
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.
greater
In Damuth’s study, population densities and body sizes spanned _______ orders of magnitude.
5
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?
birds
invertebrates
poikilothermic vertebrates
The three factors used for Rabinowitz’s rarity classification system for species include ______.
geographic range
habitat tolerance
local population size
Aquatic invertebrates tend to have ______ densities given their body’s size compared to other organisms in the study.
higher
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.
smaller
Unlike animals, plant population densities decrease as individual plants grow older. This process is known as ______.
self-thinning
Peregrine falcons had ______ and ______ but low population density, resulting in an increased risk of extinction.
broad habitat tolerance
extensive geographic range
Rabinowitz’s rarity classification system is designed to evaluate whether a population is at risk for ______.
extinction
Tigers are at risk of extinction because of which one of Rabinowitz’s risk factors?
small population size
Passenger pigeons went extinct as a result of which one of Rabinowitz’s risk factors?
narrow habitat tolerance
One of the environmental factors thought to affect the relationship between range and population size is ______.
habitat tolerance
Island species are at extremely high risk for extinction due to which of Rabinowitz’s risk factors?
small population size
narrow habitat tolerance
restricted range
Peregrine falcons are at risk of extinction because of which one of Rabinowitz’s risk factors?
small population size
Like peregrine falcons, tigers had ______ and ______ but low population density, resulting in an increased risk of extinction.
extensive geographic range
broad habitat tolerance
The harelip sucker went extinct as a result of which one of Rabinowitz’s risk factors?
narrow habitat tolerance
Organisms living in a continental area can also be considered “island species” when they ______.
live in extremely isolated locations
