Ecology Ch. 9

Pheromones are chemical substances produced by organisms to communicate with other members of their species

Which of the following are considered to be characteristics of populations? Growth rate; density; spacing

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

Match the distribution pattern to its description.

Random – individuals have equal chance of being found anywhere

Regular – individuals occur at equally spaced intervals

Clumped – individuals have a greater chance of being found at specific locations

Using the maps, rank the following three species of Encelia from the most “hairy” to the least “hairy”. Encelia farinose; Encelia actoni; Encelia californica

A population is defined as members of a species living in a defined area

To an ecologist, niche summarizes the environmental characteristics that influence the growth, reproduction, survival of a species

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

When talking about the distributions of organisms, “large scale” versus “small scale” refers to environmental change relative to the size of the organism

Which of the following would be areas where population biology would inform decision making? Pest control; wildlife management; response to epidemics

The three factors used for Rabinowitz’s rarity classification system for species includes: geographic range; local population size; habitat tolerance

Which of the following, non-demographic characteristics, would best describe the general characteristics of population presented in this chapter? Spatial

Match the kangaroo species to its biome.

Eastern Grey – temperate and tropical forests

Western Grey – Mediterranean wood and shrubland

Red – savannah and desert

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

Patterns of distribution are driven by a combination of environmental and social interactions

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

Rabinowitz’s rarity classification system is designed to evaluate whether a population is at risk for extinction

The number of individuals per unit area is known as: density

The presence of tiger beetles on southern mountain tops can be explained by climate change associated with global warming; glacial retreat

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

Through which of the following factors may climate be indirectly influencing the distributions of kangaroo species? Habitat; water supply; food production

Peregrine falcons had extensive geographic range and broad habitat tolerance but low population density, resulting in an increased risk of extinction

Competition between creosote bushes was thought to be the cause of their pattern of distribution

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? Poikilothermic vertebrates; invertebrates; birds

Hubbell and Johnson observed that aggressive bees tended to forage in groups and nonaggressive bees foraged singly or in small groups

In studying the relationship between population density and body size, Damuth analyzed data from herbivorous mammals

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

Areas of high density for a species are referred to as hot spots

The climatic factor that is most important in determining the distribution of large kangaroos in Australia is precipitation

Like peregrine falcons, tigers had broad habitat tolerance and extensive geographic range but low population density, resulting in an increased risk of extinction

Of the 171 bird species known to have become extinct since 1600, most are species restricted to islands

On a mountain slope, where environmental change is steep, a “small scale process” would be a smaller land area than an area where environmental change was more gradual

Brown et al. looked at bird distribution when they were in their breeding grounds

The climate found at higher elevation is most similar to that of boreal forests

In response to competitive interactions, the spatial distribution of Chthamalus can be considered to be a realized niche

During the course of their growth, Phillips and McMahon found that the distribution pattern of creosote bushes varied with time

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

One of the environmental factors thought to effect the relationship between range and population size is habitat tolerance

When swarms from different hives battled over a potential nest site, they engaged in ritualized combat

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

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

Whittaker and Neiring studied plants distributions along moisture and elevation gradients in the mountains of Arizona

Passenger pigeons went extinct as a result of which one of Rabinowitz’s risk factors? Narrow habitat tolerance

In trying to explain the distribution patterns of creosote bushes, Phillips and McMahon mapped sites that varied in temperature and precipitation but were similar in soil and slope

Based upon 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 critical resources in specific locations rather than social attraction

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

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

Continuous environmental gradients can produce clumped species distributions based upon favorable environment conditions occurring at specific locations

When studying the distribution patterns of bees, Hubbell and Johnson hypothesized that aggressive species would have regular patterns of nest distribution while nonaggressive species would be clumped or random

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

Areas of high density for a species are referred to as hot spots

In Hutchinson’s definition of niche, each environmental factor is an axis of an n-dimensional hypervolume. TRUE

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 smaller range as compared to a larger population

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

The germination of seeds at “safe sites” was part of the reason for the clumped distribution of young creosote bushes

When bees from different hives battled over an occupied nest site, they engaged in mortal combat

A proposed explanation for the distribution of creosote bushes is below ground competition

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

The concentration of fish crows near coastal locations is an example of a clumped distribution

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

Organisms living in a continental area can also be considered “island species” when they live in extremely restricted locations

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 fundamental to realized niches