Animal Behavior Terminology/Definitions

Basic Unit of Behavior

Firing of the neurons, common to all organisms

What is Behavior

• a response to stimulation

• Any externally visible activity

• A complex phenotype

• what an animal does

Phenotype

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Tinbergen’s 4 methods to study behavior

• Mechanisms

• Development

• Evolution

• Adaptive Value

Questions to study Mechanisms

How do changes in the environmental signals trigger physiological signals

Questions to study Development

Why did the behavior come to be

Questions to study Evolution

How did the Behavior evolve

Questions to study Adaptive Value

What is the reason for a behavior / why is it beneficial

Development and Mechanisms

Timbergen’s approximate ways of studying animal behavior

Evolution and Adaptive Value

Timbergen’s ultimate ways of studying animal behavior

Ontogeny

the development and change of an individual’s behavior over their lifetime

Example of Ontogeny

Play behavior in kittens

Environment and Genes

What causes behavior

Language

What is a trait that is affected by both environment and genes

The effect of environment on language

The development of an accent or picking up specific dialects

The effect of genetics on language

The ability to speak and vocalized verbal communications

Time

Some constraints placed on environmental effects of development

Example of time restraints

Song birds can only learn a song between a specific time window of early adolescents

Development

a process of gene-environment interactions

Epigenesis

• At any point of ontogeny, genes within an organism can be modified to change the development of behavior

• Gene expression is modified without altering the DNA

DNA methylation

A specific change in gene expression in which a gene is silenced

Nervous System, Endocrine System, Morphology

Behavioral changes during development are caused by

Morphology

study of form, characteristics, or structure of living organisms, internally and externally

Puberty

sexual maturation and onset of sexual and reproductive behavior

Changes in Hormonal State

Alteration in Behavioral Development

Example of Changes in Hormonal State

European Starlings have the ability to turn puberty “on”/ “off”

Example of Change in Morphology

Paddlefish are born without gills but develop them later to feed indiscriminately

Example of Change in Hormonal State in Bees

The amount of Juvenile Hormone in a bee alters the development in foraging behavior

Effects of Social Environment on Development

In some animals, the social surrounding can alter the production of juvenile hormone

Learning

• Adaptation within an individual’s life

• A process by which animals benefit from experience — thus modify behavior

• Variations result from natural selection

• A process that manifests itself by adaptive changes in individual behavior as a result of experience

Vincent B Wigglesworth

discovered the juvenile hormone by studying Kissing Bugs

Maturation

individuals can improve their behavior overtime

Problem of performance vs knowledge

Sometimes an animal has the capabilities to perform, but lacks the motivation to do so

Imprinting

a specialized form of early learning that includes an early sensitive phase and relatively permanent effects

Heinroth

discovered imprinting behavior in ducklings and goslings when they realized the birds would only follow the humans that ‘raised’ them

Lorenz

expanded upon knowledge of imprinting by identifying innate/learned components, critical period, and irreversible affects

Filial Imprinting

when animals imprinting upon a parent like creature; usually occurs at a very early age

Precocial Species

animals that shortly after birth/hatching are relatively mobile and independent

Altricial Species

animals that shortly after birth/hatching are in an underdeveloped, helpless state, and require extensive parental care for an extended period of time

Filial Imprinting in Precocial Species

imprint on moving objects

Sexual Imprinting

Mate preference in adulthood is influenced by exposure to certain species during the early sensitive phase

Early learning

During development some processes limited to critical periods; Critical period for learning and imprinting

Examples of Early Learning

Chicks are able to differentiate between quantity and color after limited exposure

Sensitive Phase

Early time period at which stimuli can be imprinted on and is driven by an internal developmental cycle

Fixed Action Patterns

A highly stereotyped and innate (not learned) behavior

Example of Fixed Pattern Behavior

Stickle back fish attack any stimuli with a red belly 

• Stimuli - red belly 

• Fixed pattern behavior - attack behavior

Sign Stimulus

An external sensory stimulus (releaser) which triggers a fixed action pattern

Supernormal Stimulus

exaggerated, artificial cues that trigger a non-adaptive response that simulate normal stimuli, but can lead to addiction or excessive use

The Song Control System

Comprised of the caudal motor pathway and anterior forebrain pathway this system is responsible for practice of bird song

Caudal Motor Pathway

pathway for song production

HVC

a specialized region of the brain that contains specialized neurons with a premotor nucleus that controls timing and sequence of bird song (production of bird song)

Anterior Forebrain Pathway

pathway for song learning 

Region X

receives input from the HVC and is critical for learning song learning

Bird Song

have a complex structure and are used for copulation solicitation, aggression/territory defense, auditory cue, differentiation, and sexual preference 

Bird Call

have simple structure, used to convey more specific information

Example of bird without song

Pigeons

Close-ended learners

birds with short time frame (critical period) for learning song

Open-ended learners

birds with an indefinite time window for song learning

The bird will use its innate song template and create a variation bird song

What happens if a bird is never exposed to a tutor?

Syrinx

the vocal organ responsible for producing bird song

Two bronchi

What allows birds to produce two notes at once?

Sexual dimorphism

hormones affect physical appearance, brain, and behavior

Region X does not exist

Why can’t many female birds produce song?

Seasonal changes in the production of neurons/neural pathways due to hormonal changes

How do seasonal changes affect bird song?

Adaptive advantage of changes in brain growth

the brain requires a high metabolic demand which are only advantageous during mating season

Auditory Cue

to communicate to other birds of the same species

Individual Species Recognition

song birds can differentiate between their own song, the song of a neighbor, and the song of a stranger

Neuron

a specialized cell that transmits nerve impulses

Interneuron

neurons that are a simple component of a neural pathway 

Dendrite

branched structure that accumulates knowledge for the cell body

Axon

surrounded by the myelin sheath, this part of a neuron is where electrical impulses travel when the neuron fires

Nodes of Ranvier

gaps in the myelin sheath that allow electrical impulses to jump between the nodes

Synapse

the gap between the terminal of one neuron and the dendrite 

Neurotransmitters

Synaptic vesicles that are released when action potentials is released

Action potential

an all or nothing response in which the neuron fires

Cause of Action Potential

Iron flow/iron pumps into the neuron

Myelination

the process of forming the myelin sheath around the axon

Increase the diameter of the axon (like squid) or Myelination

2 ways to increase action potential

Refractory Period

the recovery period in which a neuron cannot fire

Saltatory Conduction

The rapid jumping of nerve impulses along a myelinated axon, skipping from on Node of Ranvier to another

Inhibitory Response

When the firing of one neuron purposefully doesn’t set off another neuron

Exclamatory Response

When the firing of one neuron sets of the response of another

Electrical Synapse

an electrical signal that travels very quickly and causes an excitatory response

Hebbian Learning

The concept that neurons strengthen their connection when they are active at the same time (principle of neural plasticity)

Mechanisms of Escape Behavior in Moths

Two specific neurons are sensitive to specific frequencies of sound and connect to motor neurons to signal flight

A1 is 10X more sensitive to sound thus if the predator is far away, A1 send a signal for the wings to fly away

What is the purpose of neuron A1 in Moths?

A2 causes uncoordinated flight and then just fall out of the sky (attempted escape behavior)

What is the purpose of neuron A2 in Moths?

Central pattern generators

a bunch of neurons hooked up together and when one fires, it sets off a chain reaction. 

• If hooked up differently, it can cause very different outcomes

Stimulus Filtering

a process by which the body regulates which stimulus to respond to

Stage 1 Stimulus Filtering

• Stimuli filtered out at the level of sensory receptors (ex. Primate eye lens filter UV radiation). 

• Stopping the stimulus from getting into the brain / central nervous system

Stage 2 Stimulus Filtering

• Sensory Bias

• Getting the central nervous system to pay attention to one stimulus over the others

Example of Stage 1 filtering

Female Ormia ochracea (flies) detect crickets to lay their eggs on by tuning into the frequency of a cricket

Example of Stage 2 Filtering

Star-nosed Mole has more brain tissue that prioritizes the 11th appendage on its nose to receive stimuli from that region

Sensory Bias

some parts of the body are viewed as “critically” more important than others

Neural Plasticity

the ability of the brain to adapt its structure, function, and connections in response to stimuli

Phantom Limb Phenomenon

after losing a limb, one can still feel the limb present because there are neuron pathways still connected to that region within the brain

Temporal Organization of Behavior

how organisms arrange and sequence actions overtime driven by an endogenous clock

Nocturnal

Active during night

Diurnal

Active during the day

Crepuscular

Active during dawn/dusk