Responses to the Environment and Ecology

Flashcards covering key vocabulary from the lecture notes.

Behavioral ecology

The study of how behaviors arise due to ecology and evolution.

Behavior

An animal's response to a stimulus (internal or external).

Proximate cause

How a behavior occurs or how it is modified.

Ultimate cause

Why a behavior occurs (in context of natural selection).

Innate behaviors

Developmentally fixed behaviors that are hereditary and do not require learning.

Learned behaviors

Behaviors that depend on environmental influence and experiences.

Fixed action patterns (FAPs)

A sequence of unlearned acts directly linked to a stimulus; actions are unchangeable and carried out to completion

Sign stimulus

External cue that triggers a fixed action pattern.

Migration

A regular, long-distance change in location.

Signal

A stimulus generated and transmitted from one animal to another; animal communication.

Pheromones

Chemicals emitted by members of a species that can affect other members of the same species.

Stimulus response chains

When a response to a stimulus serves as the next stimulus for a behavior; seen in animal courtships.

Kinesis

Random movement in response to a stimulus; non directional.

Taxis

Directional movement towards (positive) or away from (negative) a stimulus.

Phototaxis

Movement in response to light.

Chemotaxis

Movement in response to chemical signals.

Geotaxis

Movement in response to gravity.

Learning

The modification of behavior based on specific experiences.

Imprinting

A long-lasting behavioral response to an individual that happens during a sensitive period of development.

Spatial learning

Establishing memories based upon the spatial structure of the animal's surroundings.

Associative learning

The ability to associate one environmental feature with another.

Social learning

Learning through observations and imitations of the observed behaviors.

Foraging

Food obtaining behavior; searching for, recognizing, and capturing food items.

Altruism

Selfless behavior that reduces the individual's fitness but increases the fitness of the rest of the population.

Phototropism

A directional response that allows plants to grow towards (and in some cases away from) a source of light.

Photoperiodism

Allows plants to develop in response to day length; plants flower only at certain times of the year.

Ecosystem

The sum of all the organisms living in a given area and the abiotic factors they interact with.

Biotic factors

Living, or once living, components of an environment.

Abiotic factors

Nonliving (physical and chemical properties of the environment).

Metabolic rate

The total amount of energy an animal uses in a unit of time.

Endotherms

Use thermal energy from metabolism to maintain body temperatures.

Ectotherms

Use external sources (ie sun/shade or other organisms) to regulate their body temperature

Trophic levels

Species can be grouped into these based upon their mains source of nutrition and energy.

Primary producers (autotrophs)

Use light energy to synthesize organic compounds.

Heterotrophs

Rely on autotrophs because they cannot make their own food.

Primary consumers

Herbivores.

Secondary consumers

Carnivores that eat herbivores.

Tertiary consumers

Carnivores that eat other carnivores.

Decomposers

Get energy from detritus (nonliving organic material; leaves, wood, dead organisms).

Food chain

The transfer of food energy up the trophic levels.

Food webs

Linked food chains.

Primary production

The amount of light energy that is converted to chemical energy.

Gross primary production (GPP)

Total primary production in an ecosystem.

Net primary production (NPP)

The GPP minus the energy used by the primary producers for respiration (R₂).

Secondary production

The amount of chemical energy in a consumer's food that is converted to new biomass.

Biogeochemical cycles

Nutrient cycles that contain both biotic and abiotic factors.

Population

A group of individuals of the same species living in an area.

Population ecology

Analyzes the factors that affect population size and how and why it changes over time.

Density

The number of individuals per unit area.

Dispersion

The pattern of spacing among individuals within a population.

Demography

The study of the vital statistics of populations and how they change over time.

Life table

An age-specific summary of the survival pattern of a population.

Exponential growth model

A population living under ideal conditions (ie easy access to food, abundant food, free to reproduce, etc).

Logistic growth model

The per capita rate of increase approaches zero as the population size nears its carrying capacity.

Life history

The traits that affect an organism's schedule of reproduction and survival.

K-selection (density-dependent selection)

Selection for life history traits that are sensitive to population density; seen in high density populations that are close to carrying capacity (K).

R-selection (density independent selection)

Selection for life history traits that maximize reproductive success; seen in low density populations with little competition.

Density-dependent regulation

As a population increases, factors can slow or stop growth by decreasing birth rate and increasing death rate.

Density-independent regulation

Factors that exert their influence on population size, but the birth/death rate of a population does not change.

Community

A group of populations of different species living closely and capable of interacting.

Habitat

A place or part of an ecosystem occupied by an organism.

Ecological niche

The role and position a species has in its environment.

Fundamental niche

The niche potentially occupied by the species if there were no limiting factors (predators, competitors, etc).

Realized niche

The portion of the fundamental niche the species actually occupies.

Interspecific interactions

Interactions of individuals from one species with individuals of another species.

Competition

-/- relationship where individuals of different species compete for limited resources.

Competitive exclusion principle

Two species competing for the same resource cannot coexist permanently.

Niche partitioning

Natural selection drives competing species into different patterns of resource use, or different niches.

Predation

+/- relationship where one species (predator) kills and eats the other species (prey).

Cryptic coloration

Camouflage.

Batesian mimicry

Harmless species mimics a harmful one.

Mullerian mimicry

Two or more bad-tasting species resemble each other.

Herbivory

+/- relationship where one organism eats part of a plant or algal.

Symbiosis

When 2 or more species live in direct contact with one another.

Parasitism

(+/-) when one organism (parasite) derives nourishment from another (host).

Mutualism

(+/+) when both organisms benefit from the relationship.

Commensalism

(+/0) when one organism benefits and the other is neither harmed nor benefited.

Facilitation

(+/+ or 0/+) when one species has a positive effect on the survival and reproduction of another without intimate association of symbiosis.

Species diversity (biodiversity)

The variety of different organisms within a community.

Species richness

The number of different species.

Relative abundance

The proportion each species represents of all the individuals in the community.

Simpson's diversity index

Calculate diversity based on species richness and relative abundance.

Invasive species

Organisms that become established outside of their native range/ecosystem, usually by human activity.

Keystone species

Not usually abundant, but other species in an ecosystem rely on them because of their important ecological niches.

Disturbance

An event that changes a community by removing organisms from it or altering resource availability.

Ecological succession

The gradual process by which the species composition of a community changes and develops over time after a disturbance.

Primary succession

A series of changes on an entirely new (previously lifeless) habitat that has not been colonized.

Secondary succession

A series of changes that clears an existing community, but leaves the soil intact.

Biogeographical factors

Large scale factors that contribute to a range of diversity observed.

Pathogens

Disease causing organisms and viruses.