unit 8: ecology

Types of animal communication

Innate (instinctive) & learned

Types of instinctive signaling

Behavioral, visual, tactile, chemical, auditory, electrical, and olfactory

Behavioral signaling

Behavioral signals that increase reproductive fitness, survival, & warn others -> step-by-step process

Fixed action pattern

A sequence of unlearned acts that is essentially unchangeable and usually carried to completion.

Visual signals

Used for recognition of warning signs, mating signs, etc.

Tactile signaling

Communication through the use of touch

Chemical signaling - pheromones

Chemicals signals emitted to comm mating, warning, and other signals -> skunk stench

Auditory signaling

Comms based on sound, such as sounds/cries for mating or warning that need to be performed or recognized

Olfactory signaling

Communication based on smell -> smelling of predators or family

Learned behaviors

Behaviors modified based on specific experiences

Circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

What causes circadian rhythm?

Light and dark in humans & animals; temperature in animals only

Imprinting

the process by which certain animals form attachments w/ first figure they see during a sensitive period very early in life

Spatial learning

Acquiring a mental representation of an environment to facilitate navigation and memory of locations and relationships between objects -> creation of boundaries

Cognitive mapping

Internal territorial recognition w/ out physical markers

Associative learning

Learning from experience -> the summation & association of experiences together leading to specific, learned behaviors

Cooperative behavior

Behavior that tends to increase the fitness of the individual and the survival of the population

What is the relationship between natural selection and the fitness of learned/innated behaviors?

Natural selection favors innate and learned behaviors that increase fitness

Endotherms

Use thermal energy energy generated by metabolism to maintain homeostatic body temps

Ectotherms

Lack efficient ways to maintain body temps, but may regulate their temps behaviorally by moving into the sun or shade

What is the relationship between metabolic rate per unit body mass and the size of multicellular organisms?

The smaller the organism, the higher the metabolic rate

What are the results of net gains/losses in energy?

Energy storage or growth of an organism vs. loss of mass & death of an organism

Autotrophs

Organisms that make their own food using energy captured from physical or chemical sources in their environment

Types of autotrophs

photoautotrophs and chemoautotrophs

Heterotrophs

An organism that obtains organic food molecules by eating other organisms or their by-products.

Heterotroph function

May metabolize carbs, lipids, and proteins as sources of energy by hydrolysis

How do changes in energy disrupt ecosystems?

A change in energy resources affects the size & # of trophic levels. A change in the producer level can affect the # and size of other trophic levels

Population growth formula

Birth rate minus death rate

What does reproduction in a population without constraints result in?

Exponential growth of a population

Density independent factors

limiting factor that affects all populations in similar ways, regardless of population size -

Density dependent factors

factor that limits a population more as population density increases

Carrying capacity

Largest number of individuals of a population that a environment can support

What happens when density factors are present in a population?

These limits causes a logistic growth model to ensue

K-selected population

Stable, reaches/hovers around K, few reproductive events & offspring, low juvenile mortality

R-selected population

"Boom or bust" size, unstable, many reproductive events & offspring, high juvenile/pre-natal death rates

Niche

The role of an organism within a community

Examples of niches

Habitat occupation, energy usage/production, interactions w/ other members of the community

Fundamental niche

The niche species could potentially occupy.

Realized niche

The niche species actually occupies

Interspecific competition

competition between members of different species

Competition

Benefits neither party (-/-), forces a change in realized niche

Competitive exclusion

When organisms are removed/eliminated from a community due to competition -> invasive species w/ out predators

Resource partitioning

the differentiation of niches/shared resources that enables similar species to coexist in a community by avoiding comp

Predator/prey interactions

(+/-), death of the species that is harmed

Types of defensive tactics from predators

Cryptic coloration (camouflage), aposematic (warning) coloration, batesian mimicry, mullerian mimicry

Parasitism

Parasite attaches to a host (+/-), the - species is harmed but does not die -> some parasites can cause pathogens

Endoparasites

Parasites that live within the body of their host.

Ectoparasites

Parasites that feed on external surface of host.

Aposematic coloration

Bright warning colors in animals with a chemical defense.

Batesian mimicry

a harmless species mimics a harmful one

Mullerian mimicry

two or more unpalatable species resemble each other

Commensalism

One benefits, other is unaffected (+/0)

Mutualism

Both species benefit (+/+)

Symbiosis

A close relationship between two species that benefits at least one of the species.

Trophic cascade

The impact of a predator on its prey influences the populations and behavior of species at multiple trophic lvls/food webs

What is the relationship between diversity and resilience in ecosystems?

Ecosystems with fewer component & less diversity are often less resilient to environmental changes

10% rule

Only 10% of the total energy produced at each trophic level and is available to the next level/food chain

Keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed, the ecosystem would change drastically/collapse

Food webs

the interconnected feeding relationships in an ecosystem

Pioneer species

First species to populate an area during primary succession

Bottom-up control

when the abundances of trophic groups are determined by the amount of energy available from producers

Up-down control

When consumers control the dynamic of energy flow in lower trophic levels

Succession

The series of predictable changes that occur in a community over time

Primary succession

An ecological succession that begins in an area where no biotic community previously existed -> pioneer species

Secondary succession

Succession following a disturbance that destroys a community without destroying the soil/biotic factors

Simpson's Diversity Index

The closer D is to 1, or the greater D is, the more diverse the community

Effects of invasive species

They can exploit a new niche free of predators or competitors or to outcompete other organisms for resources - competitive exclusion model

How can humans impact changes at local and global levels?

The introduction of new diseases can devastate native species and human activity can change native animal habitats