31.1: Key Terms

age structure

proportion of population members at specific age ranges

aggressive display

visual display by a species member to discourage other members of the same species or different species

aposematic coloration

warning coloration used as a defensive mechanism against predation

Batesian mimicry

type of mimicry where a non-harmful species takes on the warning colorations of a harmful one

behavior

change in an organism’s activities in response to a stimulus

behavioral biology

study of the biology and evolution of behavior

biotic potential (r_max)

maximal potential growth rate of a species

birth rate (B)

number of births within a population at a specific point in time

camouflage

avoid detection by blending in with the background

carrying capacity (K)

number of individuals of a species that can be supported by the limited resources of a habitat

classical conditioning

association of a specific stimulus and response through conditioning

climax community

final stage of succession, where a stable community is formed by a characteristic assortment of plant and animal species

cognitive learning

knowledge and skills acquired by the manipulation of information in the mind

commensalism

relationship between species wherein one species benefits from the close, prolonged interaction, while the other species neither benefits nor is harmed

competitive exclusion principle

no two species within a habitat can coexist when they compete for the same resources at the same place and time

conditioned behavior

behavior that becomes associated with a specific stimulus through conditioning

courtship display

visual display used to attract a mate

death rate (D)

number of deaths within a population at a specific point in time

demographic-based population model

modern model of population dynamics incorporating many features of the r- and K-selection theory

demography

statistical study of changes in populations over time

density-dependent regulation

regulation of population that is influenced by population density, such as crowding effects; usually involves biotic factors

density-independent regulation

regulation of populations by factors that operate independent of population density, such as forest fires and volcanic eruptions; usually involves abiotic factors

distraction display

visual display used to distract predators away from a nesting site

Emsleyan/Mertensian mimicry

type of mimicry where a harmful species resembles a less harmful one

energy budget

allocation of energy resources for body maintenance, reproduction, and parental care

environmental disturbance

change in the environment caused by natural disasters or human activities

ethology

biological study of animal behavior

exponential growth

accelerating growth pattern seen in species under conditions where resources are not limiting

fecundity

potential reproductive capacity of an individual

fixed action pattern

series of instinctual behaviors that, once initiated, always goes to completion regardless of changes in the environment

foraging

behaviors species use to find food

foundation species

species which often forms the major structural portion of the habitat

habituation

ability of a species to ignore repeated stimuli that have no consequence

host

organism a parasite lives on

imprinting

identification of parents by newborns as the first organism they see after birth

innate behavior

instinctual behavior that is not altered by changes in the environment

intersexual selection

selection of a desirable mate of the opposite sex

interspecific competition

competition between species for resources in a shared habitat or environment

intrasexual selection

competition between members of the same sex for a mate

intraspecific competition

competition between members of the same species

island biogeography

study of life on island chains and how their geography interacts with the diversity of species found there

iteroparity

life history strategy characterized by multiple reproductive events during the lifetime of a species

J-shaped growth curve

shape of an exponential growth curve

K-selected species

species suited to stable environments that produce a few, relatively large offspring and provide parental care

keystone species

species whose presence is key to maintaining biodiversity in an ecosystem and to upholding an ecological community’s structure

kin selection

sacrificing one’s own life so that one’s genes will be passed on to future generations by relatives

kinesis

undirected movement of an organism in response to a stimulus

learned behavior

behavior that responds to changes in the environment

life history

inherited pattern of resource allocation under the influence of natural selection and other evolutionary forces

life table

table showing the life expectancy of a population member based on its age

logistic growth

leveling off of exponential growth due to limiting resources

mark and recapture

technique used to determine population size in mobile organisms

migration

long-range seasonal movement of animal species

monogamy

mating system whereby one male and one female remain coupled for at least one mating season

mortality rate

proportion of population surviving to the beginning of an age interval that die during the age interval

Müllerian mimicry

type of mimicry where species share warning coloration and all are harmful to predators

mutualism

symbiotic relationship between two species where both species benefit

one-child policy

China’s policy to limit population growth by limiting urban couples to have only one child or face the penalty of a fine

operant conditioning

learned behaviors in response to positive and/or negative reinforcement

parasite

organism that uses resources from another species, the host

pioneer species

first species to appear in primary and secondary succession

polyandry

mating system where one female mates with many males

polygyny

mating system where one male mates with many females

population density

number of population members divided by the area or volume being measured

population growth rate

number of organisms added in each reproductive generation

population size (N)

number of population members in a habitat at the same time

primary succession

succession on land that previously has had no life

quadrat

square made of various materials used to determine population size and density in slow moving or stationary organisms

r-selected species

species suited to changing environments that produce many offspring and provide little or no parental care

reflex action

action in response to direct physical stimulation of a nerve

relative species abundance

absolute population size of a particular species relative to the population sizes of other species within the community

S-shaped growth curve

shape of a logistic growth curve

secondary succession

succession in response to environmental disturbances that move a community away from its equilibrium

semelparity

life history strategy characterized by a single reproductive event followed by death

signal

method of communication between animals including those obtained by the senses of smell, hearing, sight, or touch

species dispersion pattern

(also, species distribution pattern) spatial location of individuals of a given species within a habitat at a particular point in time

species richness

number of different species in a community

survivorship curve

graph of the number of surviving population members versus the relative age of the member

symbiosis

close interaction between individuals of different species over an extended period of time that impacts the abundance and distribution of the associating populations

taxis

directed movement in response to a stimulus

zero population growth

steady population size where birth rates and death rates are equal