CBH4024 Exam 1

Reasons for studying behavior

-Practical applications: conservation

-Insight into behavioral mechanisms

-interest about learning about the natural world

Natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

How does variation contribute to natural selection?

Individuals with the most favorable variations are more likely to survive

Behavior

a way that animals can solve problems in their environment

ethology

study of animal behavior

Founders of Ethology

Niko Tinbergen, Karl von Frisch, Konrad Lorenz; won Nobel in 1973 in physiology and medicine for organization and elicitation of individual and social behavior patterns

Trait

A characteristic that an organism can pass on to its offspring through its genes.

Fitness

ability to survive and reproduce

Phenotype

An organism's physical appearance, or visible traits.

Genotype

genetic makeup of an organism

Adaptation

inherited characteristic that increases an organism's chance of survival

Genes

DNA segments that serve as the key functional units in hereditary transmission.

alleles

alternative versions of a gene

Behavior is

•A phenotype (Traits of an individual resulting from the interaction of its genotype with the environment.)

•Heritable•

Situationally flexible

Tinbergen 4 questions

-What is the immediate causation of the behavior? Physical/physiological mechanisms that underlie behavior

-How does the behavior develop? Ontogeny

-What is the evolutionary history of the behavior? When did the behavior emerge? Shared among relatives?

-What is the adaptive function of the behavior?

-How does it increase an individual's survival or reproductive success?

proximate explanations

a causal explanation of behavior that focuses on immediate situational , physiological, neurobiological, anatomical, or developmental mechanisms

ultimate explanations

- functional explanations at evolutionary level. statements of the role that behavior plays in the animals survival and reproduction

How is behavior studied?

Observations, experiments and comparative approaches

costs and benefits

The bad and good things related to making a decision

Purpose of seagull mobbing behavior?

To protect their eggs and chicks

-the fitness of the trait outweighs the costs

Predator distraction hypothesis

Mobbing potential predators distracts them from the nest

Gulls mobbing behavior and location

Gulls that nest on cliffs have fewer predators (like the kittiwake gull).•Mobbing behavior is not observed in the kittiwake gull.

Immediate causation ( proximate) of behavior - bird song

-Bird song is controlled by nuclei in the brain. Particularly the high vocal center nucleus or HVC

- The HVC connects to the RA, and both of these nuclei control singing in birds

-Song control nuclei made up of specialized neurons allow birds to learn song from adult birds and produce those songs as adults

Bird song

A complex pattern of notes used to mark territory and to attract mates or repel rivals

Example of a song dialect

-Chaffinches sing somewhat different versions of the standard species' song

How would you expect the song dialect of white crowned sparrows in different areas of California to differ?

Males from different areas in California have their own song dialects

What is the ontogeny of song dialects? ( What developmental factors are responsible?

Song is a learned behavior. Young songbirds hear the songs of adult males early in development and then practice matching their singing to their memories of song. Hearing a particular dialect will result in a young songbird copying that dialect in its adult song.

Song learning hypothesis

-White-crowned sparrows have a sensitive period 10 to 50 days after hatching.

-The bird matches his plastic song withhis memory of the tutor's song.

Social interaction hypothesis

-Researchers have heard wild white-crowned sparrows singing the songs of other bird species (a heterospecific song).

-Social interactions between birds and their tutors might affect song learning.

Ultimate or evolutionary history of song behavior

Possible explanation: An ancestor to the orders between hummingbirds and parrots and songbirds was a song learner. Vocal learning was continued in some lineages and not in others.

What orders of birds can learn songs

Of the 23 orders only 3 can. Parrots, hummingbirds, and songbirds

Main difference between birds that can sing and those who cannot

Other birds can have complex vocalization, but this is not a learned behavior

Difference between birds that can sing

Song learning works similarly in parrots and songbirds and differs from song learning in hummingbirds

What does the phylogeny show about song learning birds

song learning evolved twice in the ancestor of songbirds and parrots, and independently in hummingbirds

What is ZENK?

a protein caused by gene ZENK. The protein is expressed inn areas of the brain when a bird hears the song of a bird of the same species (conspecifics)

Adaptive function

adaptive value of a behavioral trait as affected by the process of evolution by natural selection

Adaptive function of song learning - environment

Learning allows males the ability to match songs to local environment

-If forests are dense, birds sing at lower frequencies.

-Different dialects allows bird song to travel farther based on the acoustic environment.

Adaptive function of song learning - social environment

Learning allows males ability to match songs to social environment

-Birds need to recognize neighbors or specific individuals

Bird song and rivalry

Birds that match songs of its neighbor may be seen as a rival

Bird song and groups

- groups may be made up of related and unrelated birds

- small groups with only related birds have group identity calls vs individual calls

Why do birds sing?

Reproductive Functions:

-advertise sex of singer

-attract mates

-advertise territory

-indicate health

-synchronize mating behaviors

-strengthen pair bonds

Social Functions:

-"password" for individual recognition

-rally individuals for a collective action (mobbing)

-hold flock together

-convey information about food

Do female birds sing?

Yes some do. Some use it to compete with other females. Females have preferences on males to mate with, indicated by their calls. Song learning gives males the ability to match songs (adaptive function )

Song learning sensitive period

in the white-crowned sparrow between about 10 and 50 days after hatching, the tutored song is stored within the brain

Relationship of genes to behavior

-DNA is transcribed into RNA

-RNA is translated into a protein

-Differences in gene expression may lead to behavioral differences.

What is an epigenetic change?

an inherited change that does not alter the DNA base sequence.

Behavior and environment can cause how genes work

Main difference between genetic and epigenetic changes

Unlike genetic changes, epigenetic changes are reversible and do not change your DNA sequence, but they can change how your body reads a DNA sequence

Examples of epigenetic change

-DNA methylation: addition of a methyl group to genome regions with adjacent G and C nucleotides, affecting the way genes are expressed

-Histone modification: changes to histone or its tails

True or false. Epigenetic changes only lasts for one generation

False. It may last for multiple generations, despite there being no changes to DNA sequence

Examples of how genetic differences affect behavior

-Different pops of blackcap warblers migrate in different directions

-Western garter snake (inland and costal habitats) have food preferences because of genetics. Inland snake ate fish and frogs, costal snakes eat banana and slugs

How can genetics affect foraging?

The gene responsible for foraging behavior affects fruit flies and honey bees in different ways

-in fruit fly the gene determines the activity level of foraging

-in honeybees the gene helps bees transition from staying in the hive to leaving the hive to collect food

supergene

a suite of tightly linked genes that are inherited together because of close gene linkage affecting behavioral phenotype

Supergenes in male ruffs

Supergenes in ruffs cause hormonal and feather color differences, resulting in the different appearance and behavior in different males in the same species

- The satellite male ruff forms temporary alliances, is smaller in size and has lighter plumage, and is semi-cooperative. ( has supergene )

- independent male ruffs are territorial, have a larger body size and darker plumage, and is more aggressive.

Imprinting

the ability to learn occurring at a particular age or life stage

Polyphenism (developmental plasticity)

Discrete phenotypes arise from a single genotype as a result of differing environmental conditions

How is the social environment important in imprinting?

Many species depend on imprinting for normal development

brood parasitism

When a bird of one species lays its eggs in the nest of a bird of another species.

If brown headed cowbirds are raised by other species, how do they learn the cowbird song?

The password hypothesis: species specific vocalizations may be important for the ontogeny of species recognition.

-6 day old brown-headed cowbirds chicks react to calls of the same species, even though they are raised by another species.

Brood parasite example

The brown headed cowbirds is a brood parasite. The female lays eggs in the nests of other species, which then rear the parasitic young.

spatial memory

the ability to recall where objects are in relationship to each other in space

Spatial memory benefits in birds

- can help birds spot food they hid, a learned behavior that is gene dependent

- helps brood parasites navigate nests

Why do some male and female birds differ in caching(storing away food for later use) behavior?

Males provide the female and the offspring with food so it is beneficial for the male to have better memory for where the food is.

Stimuli

a thing or event that evokes a specific functional reaction

neurons

Individual cells in the nervous system that receive, integrate, and transmit information.

action potential

a neural impulse; a brief electrical charge that travels down an axon

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Fixed Action Pattern (FAP)

A sequence of behavioral acts that is essentially unchangeable and usually carried to completion once initiated.

innate releasing mechanism

a mechanism in the animal's nervous system that connects sign stimuli with the correct FAPs

Chick begging behavior summarized

The innate releasing mechanism in the chick processes the simple stimulus (the red dot on the parent's bill) which activates the fixed action pattern (begging behavior).

sign stimulus

a simple stimulus/cue that activates a behavior

How do bats find insects like moth?

Through producing high frequency sounds or echoes that are reflected back from objects (echoes)

How moths avoid bats

-A1 receptors detect ultrasound generating action potentials

-Based on the action potentials from A1, moths can tell how close a bat is and what direction the bat is coming from.

UV light and monarch butterfly migration

UV is important in the migration of monarch butterflies using it to navigate. The butterflies migrate during the day using the sun as a compass

Polarized light and monarch butterflies

=Polarized light is available even when the sun is behind clouds.

-when butterflies cannot see the sun, but can see the sky, they still fly in the right direction.

polarized light

scattered light waves that are perpendicular to rays from the sun

Why does one paper wasp species recognize faces, but another wasp species does not?

-Paper wasps are very sociable where individuals compete for dominance, thus the right to reproduce.

-Knowing the identity of others helps females know when to compete for higher status and when to accept a position subordinate to particular rivals

-Other species like P. metricus are solitary with little aggression among females

Tool use in animals

Mostly seen in wild animals as a way to forage for food

social brain hypothesis

the theory that cognitive demands inherent in social living led to the evolution of large primate brains

problems with social brain hypothesis

Does not explain the high cognitive abilities of animals with smaller brains, or why some large brained species live in simple societies, thus it may be better to look at the problem solving abilities of animals

Hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues coordinating physiology and behavior

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle independent of environmental changes

circannual rhythm

A annual cycle of behavior that expresses itself independent of environmental changes.

Environmental cues resetting circadian and circannual clocks

Environmental cues are important in resetting these clocks, some cues : sunrise/sunset, rainy seasons, the tide, and lunar cycles.

Environmental cues examples

-Galapagos marine iguana feed on intertidal algae at low tide and on underwater algae at high tide

- Banner tailed kangaroo rats stay in their burrow when there is moonlight since there are nocturnal predators that would benefit from moonlight.

- lions are more likely to search for food during the day

photosensitivity hypothesis

The circadian clock changes daily based on light.

photoperiod changes may indicate

food availability (think of the seasons)

Organizational effects

irreversible effects on early development causing permanent changes in physiology and behavior occurring during a specific critical period

Activational effects

an immediate/temporary regulatory effect. Occurring in adulthood, reversible, and only occurring when the hormone is present. These effects of hormones allow for flexibility of behavior

stress hormones

hormones that trigger the body's physiological response to stress;

Effect of a stressor

When there is a stressor, the hypothalamus makes corticotropin-releasing hormone, this causes the release of adrenocorticotropic hormone from the anterior pituitary gland. Glucocorticoids are then produced.

adaptive stress

Glucocorticoids are released causing a direct and rapid effect on behavior. In a fearful or stress-causing situation, we can run away and save our lives ex: in the presence of danger like a storm or predator.

Non-adaptive stress

Elevated glucocorticoids have negative effects. Result of chronic stressors like food availability or conflict with other animals