Chapter 53 Flashcards
The interaction between animals and the animal prey they consume
predation
The process in which herbivores consume plants
herbivory
A set of mathematical models that predict the diet choices of animals as they encounter a range of potential food items
optimal foraging theory
coloration that allows an organism to match its background and hence become less vulnerable to predation or recognition by prey
cryptic coloration
Bright, contrasting patterns that advertise the unpalatability of poisonous or repellant species
aposematic coloration
A form of defense in which one species evolves an appearance resembling that of another
mimicry
The evolution of genetically based, reciprocal adaptations in 2 or more species that interact closely in the same ecological setting
coevolution
The form of defense in which a palatable or harmless species resembles an unpalatable or poisonous one
Batesian mimicry
The species in Batesian mimicry that is resembled by the mimic
model
A form of defense in which 2 or more unpalatable species share a similar appearance
Mullerian mimicry
The competition for resources between species
interspecific competition
Form of competition in which individuals fight over resources or otherwise harm each other directly
interference competition
Form of competition in which 2 or more individuals or populations use the same limiting resources
exploitative competition
The ecological principle stating that populations of 2 or more species cannot coexist indefinitely they rely on the same limiting resources and exploit them in the same way
competitive exclusion principle
The resources a population uses and the environmental conditions it requires over its lifetime
ecological niche
The range of conditions and resources that a population can possibly tolerate and use
fundamental niche
The range of resources and environmental conditions actually used by a population in nature
realized niche
The use of different resources or the use of resources in different ways by species living in the same place
resource partitioning
The phenomenon in which allopatric populations are morphologically similar and use similar resources, but sympatric populations are morphologically different and use different resources; may also apply to characters influencing mate choice
character displacement
An interspecific interaction in which the ecological relations of 2 or more species are intimately tied together
symbiosis
A symbiotic interaction in which one species benefits and the other is unaffected
commensalism
A symbiotic interaction between species in which both partners benefit
mutualism
A symbiotic interaction in which one species, the parasite, uses another, the host, in a way that is harmful to the host
Parasitism
An organism that feeds on the tissue of or otherwise exploits its host
parasite
A species that is fed on by a parasite
host
A parasite that lives in the internal organs of its host organism
endoparasites
A parasite that lives on the exterior of its host organism
ectoparasites
An insect species in which a female lays eggs in the larva or pupa of another insect species, and her young consume the tissues of the living host
parasitoids
How might natural selection favor a carnivore that spends more ime and energy capturing large prey than small prey?
Some carnivores spend more time and energy capturing large prey than small prey because large prey provide a larger return on their investment of time and energy in the hunt
What are the differences between cryptic coloration, aposematic coloration, and mimicry? Can a mimic ever have aposematic coloration?
Cryptic coloration makes an organism inconspicuous, allowing it to blend in with its surroundings. Aposematic coloration makes an organism highly conspicuous, advertising it unpalatability. Mimicry allows one organism, the mimic, to resemble another species, the model; models are usually unpalatable or poisonous. A mimic will have aposematic coloration if it resembles an aposematic model
How can field experiments demonstrate conclusively that 2 species compete for limiting resources?
Field experiments can demonstrate that 2 species are competing for limiting resources if removal of 1 species increases population size or density in the other or if the addition of a potential competitor decreases the population size or density of the other
The particular combination of species that occupy a site
species composition
A wide transition zone between adjacent communities
ecotones
Which view of communities suggests that they are just chance assemblages of species that happen to be adapted to similar abiotic environmental conditions?
Gleason’s individualistic view of communities suggests that they are just chance assemblages of species that happen to be adapted to similar abiotic environmental conditions
Why would you often find more species living in an ecotone than you would in the communities on either side of it?
Ecologists find more species living in an ecotone than in the communities on either side of it because ecotones contain species form both neighboring communities as well as species that are adapted to transitional environmental conditions
A species that defines the nature of a community by creating locally stable environmental conditions
foundation species
The number of species that live within an ecological community
species richness
The relative commonness of populations within a community
relative abundance
The species that is represented by a large proportion of the individuals present in an ecological community
dominant species
A community characteristic defined by species richness and the relative abundance of species
species diversity
A position in a food chain or web that defines the feeding habits of organisms
trophic levels
An autotroph usually a photosynthetic organism, a member of the first trophic level
primary producers
An organism that produces its own food using CO2 and other simple inorganic compounds form its environment and energy form the sun or from oxidation of inorganic substances
autotrophs
An organism that consumes other organisms in a community or ecosystem
consumers
An herbivore a member of the second trophic level
primary consumers
A carnivore that feeds on herbivores a member of the third trophic level
secondary consumers
A carnivore that feeds on other carnivores, a member of the fourth trophic level
tertiary consumers
An animal that feeds at several trophic levels, consuming plants, animals, and other sources of organic matter
omnivores
An organism that extracts energy from the organic detritus (refuse) produced at other trophic levels
detrivores
A small organism, such as a bacterium or fungus, that feeds on the remains of dead organisms, breaking down complex biological molecules or structures into simpler raw materials
decomposers
A depiction of the trophic structure of a community; a portrait of who eats whom
food chain
A set of interconnected food chains with multiple links
food web
The ability of a community to maintain its specie composition and relative abundances when environmental disturbances eliminate some species from the community
stability
What plant growth forms are common in tropical forests?
The plant growth forms found in tropical forests include a canopy of tall trees, an understory of shorter trees and shrubs, an herb layer, vinelike lianas, and epiphytes
What is the difference between species richness and relative abundance?
The species richness of a community is the number of species it contains. Relative abundance refers to the commonness or rarity of species in the community
Peregrine falcons are predatory birds that have been introduced into many North American cities, where they feed primarily on pigeons. The pigeons eat mostly vegetable matter. To what trophic level do pigeons and peregrine falcons belong?
Pigeons which eat grain and other vegetables matter are included in the second trophic level, primary consumer. Peregrine falcons which feed on pigeons and other birds are in the third trophic level secondary consumers
A species that has a greater effect on community structure than its number might suggest
keystone species
what are keystone species and how do they influence species richness in communities?
Keystone species are those that have a substantial effect on community structure even if their populations are not very dense. Keystone species may either increase or decrease species richness in the communities they occupy
How is the scientific literature on interspecific competition biased?
on the one hand, the ecological literature may overestimate the importance of competition because ecologists are more likely to study and publish papers on interactions in which competition is important than on interactions in which it is not. On the other hand, the literature may underestimate the importance of competition because if strong competition between species cannot persist for long periods of time, we are unlikely to find populations competing strongly in nature
Hypothesis proposing that species richness is greatest in communities that experience fairly frequent disturbances of moderate intensity
intermediate disturbance hypothesis
How might disturbances from storms allow coral reefs to be rejuvenated by the recruitment of young individuals?
Strong storms allow coral communities to be rejuvenated through the recruitment of new individuals because they scour the seafloor, removing existing coral colonies from the community. These openings provide spaces where coral larvae may settle and initiate the growth of new colonies
How do moderately severe and moderately frequent disturbances influence a community’s species richness?
Moderately severe and moderately frequent disturbances increase a community’s species richness by creating opportunities for r-selected species to colonize the habitat while allowing populations of K-selectd species to persist
A somewhat predictable series of changes in the species composition of a community over time
ecological succession
Predictable change in species composition of an ecological community that develops on bare ground
primary succession
a relatively stable, late successional stage in which the dominant vegetation replaces itself and persists until an environmental disturbance eliminates it, allowing other species to invade
climax community
Predictable changes in species composition in an ecological community that develops after existing vegetation is destroyed or disrupted by an environmental disturbance
secondary succession
a process in which debris from rivers and runoff accumulates in a body of fresh water causing it to fill in at the margins
aquatic succession
A hypothesis that explains ecological succession suggesting that species modify the local environment in ways that make it less suitable for themselves but more suitable for colonization by species typical of the next successional stage
facilitation hypothesis
A hypothesis suggesting that new species are prevented from occupying a community by whatever species are already present
inhibition hypothesis
hypothesis asserting that ecological succession proceeds because competitively superior species replace competitively inferior ones
tolerance hypothesis
an ecological community in which regular disturbance inhibits successional change
disclimax community
What is the difference between primary succession and secondary succession?
Primary succession occurs in places without soil; secondary succession occurs after a disturbance has destroyed vegetation
How does a climax community differ form early successional stages?
A climax community differs from earlier successional stages in having taller, longer-lived vegetation, generally higher species richness and a buffered physical environment under the vegetation
How do the 3 hypotheses about the cause of ecological succession view the role of population interactions in the successional process?
3 hypotheses about the underlying causes of succession differ in ow they view the role of population interactions. The facilitation hypothesis specifies no particular role for population interactions. The inhibition hypothesis suggests that as environmental conditions within the community change during succession, only species that can compete strongly under the changing conditions will persist
A hypothesis suggesting that the number of species on an island is governed by a given and take between the immigration of new species to the island and the extinction of species already there
equilibrium theory of island biogeography
What factors may foster the maintenance of high species richness in tropical communities?
Some explanations of the high species richness in the tropics suggest that the benign climate and historically low levels of severe disturbance have fostered more rapid rates of speciation. Other explanations suggest that the year-round availability of food resources and complex food webs allow more species to coexist in tropical regions
according to the equilibrium theory of island biogeography what are the effects of an island’s size and its distance from the mainland on the number of species that can occupy it?
According to the equilibrium theory of island biogeography large islands will harbor more species than small islands that are close to the mainland will harbor more species than those that are farther away
