Chapters 1 - 5: Intoduction to Animal Behavior Flashcards
What are the four major questions to ask about behavior? Who postulated them?
What is the proximate (immediate) cause of the behavior - “how does physiology cause behavior + what is the immediate stimuli”
How does the animal’s development change the behavior - “does behavior occur at all ages + does animal use sensory and motor abilities to modulate the behavioral pattern”
How does the behavior change reproductive success - “does the behavior affect its survival and reproduction + are there tradeoffs b/w the two areas”
How does the behavior reflect evolutionary history - “how does one species behavior relate to another closely related species + how did it originate + how has the behavior changed”
A.) They were postulated by Nikolaas Tinbergen.
What are the steps to studying animal behavior?
- Develop a working hypothesis
- Predict a likely outcome of an experiment or natural observation
- Collect data
- Determine whether prediction is correct or false
- Accept or reject hypothesis
What is the Darwinian theory?
Critical examination of how the behavior has been shaped over evolutionary time and how the individual’s behavior affects its reproductive success/survival rate.
What is Group Selection Theory?
Analyzes how a given behavior helps as group survive and how the group’s behavior impacts overall survival/reproductive success.
Why are prairie voles monogamous as opposed to their polygynous kin?
- Vasopressin (hormone) is released during copulation
- Male prairie voles have more brain receptors for vasopressin than other vole species
- Vasopressin appears to stimulate a reward center in the brain
- Vasopressin strengthens pair bond with female
- Have a genetic difference in the vasopressin receptor molecule (V1aR) - makes these voles more sensitive to vasopressin
What happens to polygynous species when their vasopressin receptor gene is modified to match prairie voles?
They become pair-bonded/form pair-bonds.
What is the ultimate determinant of the behavior? What is its evolutionary cause?
In the past, prairie vole males that formed close pair bonds produced more surviving offspring than males that were polygamous.
What are proximate causes of behavior?
- Short-term effects; occur over one individual’s lifespan
- Genetic/Developmental mechanisms (e.g., Development of sensory-motor systems + Gene/environment interactions)
- Sensory/motor mechanisms (e.g, Nervous systems for detecting stimuli + Hormone systems for coordinating responses + Muscular-skeletal systems for responding)
What are ultimate causes of behavior?
- Long-term effects; occur over evolutionary history
- History of behavior + selection shaping history of behavior
- Past and present usefulness of behavior in promoting lifetime reproductive success
How does the Darwinian theory interpret ultimate causation?
Individuals of a species are variable
Variation is heritable
Some individuals survive and reproduce better than others due to their traits
What does this Darwinian interpretation imply?
That individual reproductive success is the deciding factor in how traits are passed on over time, and that these successes throughout a species history is what shapes its genetics.
What are the three possible hypotheses for Langur infanticide as an ultimate behavior?
- Infanticide is an abnormal behavior caused by overcrowding (pathological behavior; not adaptive)
- Infanticide causes females to stop lactating, so they become reproductively receptive more quickly (adaptive)
- Male langurs kill infants to regulate the population size (less competition for resources) and benefit the group (group selection)
How do hormones impact proximate causation?
Endocrine glands can secrete more than one hormone, may have multiple and different effects on target cells, and different hormones can interact/influence each other.
What parts constitute the endocrine system?
Adrenal Pituitary Hypothalamus Thyroid Pancreas Gonads (testes/ovaries)
What do hormones affect?
Growth Metabolism Reactions to environmental stressors Aggression Reproductive behavior
What are hormones capable of doing, changing, or influencing in the body?
- Affect the chance that a specific sensory input will result in a specific response
- Prime an animal for a behavior
- Trigger onset of a behavior
- Modify expression of an ongoing behavior
- Organize behavior systems during early development (e.g., brain organization)
How is the ZENK gene in birds a demonstration of how genes code for specific traits?
In the zebra finch and in parrots, the ZENK gene is associated w/ bird song. Depending on how the song is being vocalized, the bird uses different parts of the brain to process either vocalizing the song or hearing it, as well as the familiarity of the w/ the song being sung.
What is neuroethology concerned with?
How behavior plays out as a result of the physical organization of the brain. (e.g., gender differences in brain organization)
What is an example of this?
Uni-hemispheric sleep in birds and marine animals, or when only one half of the brain is asleep and the other is awake.
What two developmental factors are responsible for differences in bird song?
Innate variations (e.g., song is different at birth) versus environment exposure (e.g., hearing the song, social cues, etc.)
Can bird calls change over time? What happens?
Yes, it can. In male white-crowned sparrows, the dialect of their call changes slightly over time; the accent shifts and became normalized the more time passed. Females prefer the new version over previous versions.
What are the two hypotheses for why bird call has variation?
- Genetic differences cause differences in neural patterns
2. Environmental experiences early in life differ and result in different adult songs
How did scientists test variation in learning bird song?
They transplanted baby sparrow eggs. Sparrows raised in isolation do learn to sing, but do not develop a normal call. On the other side of the coin: if sparrows are still raised in isolation but exposed to adult calls, they do develop a normal call/dialect.
What does this mean?
Some environmental component is necessary to properly vocalize the song. Song production is innate, but proper vocalization is learned.
What happens to bird call if the sparrow is deafened?
Baby sparrows exposed to adult calls but deafened before they start to sing don’t develop normal calls. If raised in isolation w/o any exposure, they still do not develop normal calls. In short, deaf sparrows never develop a normal call.
What happens if they are exposed to the calls of another species?
Baby sparrows exposed only to the calls of a different species don’t develop a normal call.
What does this mean about how baby sparrows develop a “normal” call?
White-crowned sparrow must be exposed to their own species’ call early in life (i.e., there is a critical period). They must be able to hear their own call and practice in order to develop the proper call.
What is a critical period?
Period of early development when exposure to a stimulus is required for proper development; after this time period, learning the behavior may be impossible.
What also plays a role in developing the call? Why is this aspect important?
A.) Social interaction.
B.) Birds raised in captivity that can see and hear other species develop the call of that other species instead of their own call.
What happens to Galah hatchlings when their nests are stolen by pink cockatoos?
Hatchling galahs develop appropriate galah begging and alarm calls. However, they develop pink cockatoo contact (social) calls.
What are the key underlying mechanisms of song development in birds?
- Brain involvement in birdsong
- Storage of song (memory)
- Sound production
- Comparison of early song to song memories
How does testosterone development affect bird song?
Males and females are genetically different (ZZ vs ZW chromosome). If there is elevated testosterone, then there is more singing behavior. Finally, testosterone affects brain development, and male and female birds have different neural circuitry.
What is an example of female-male differences in w-c sparrows?
Male w-c sparrows produce estrogen in their brain cells, and estrogen is involved in development of neural pathways related to control/integration of birdsong. If the experimenter adds estrogen to female chicks, then they have a masculinized brain and singing behavior.
How do genes impact birdsong?
- Gene activity differs at different stages of development
- More/less of certain substances produced at different stages
- Timing of chromosome/gene/hormonal interactions affects development of brain structures
- Environmental feedback affects brain/gene activity
What brain areas are implicated when the ZENK gene is active in birds at different levels of singing behavior?
A.) Quiet room; no singing -> no activity
B.) Hearing & singing -> HVC, IMAN, Area X
C.) Hearing Only -> HVC, shelf, CHV, LI, IMAN, L3, Area X
D.) Singing Only -> HVC, IMAN, Area X
What does the ZENK gene seem to imply about the evolutionary development of bird song?
- ZENK activity during song production causes a measurable increase in a protein
- All 3 lineages with learned birdsong show ZENK activity in similar parts of the brainThis suggests that this trait did not evolve independently three different times; each time it evolved was likely related to prior evolution within birds as a whole.
What are the ultimate causes of variation in bird song?
- Species identification (identity announcement)
- Singing males gain by warning off males of their own species
- Distinctive call attracts females
What are the reproductive benefits of bird song that might cause it to develop?
- Fine-tuning of call appropriate to acoustic environment (different habitats cause different sound degradation)
- Ability to match song with appropriate social environment demonstrates health, condition, competitive ability
What are the three main components of the development of behavior?
- Hormones
- Sensory signals from other individuals
- Neural activity stimulated by environment
What is interactive theory of development?
Development requires both genetic information and environmental inputs (e.g., with worker bee development, as a bee’s behavioral phenotype changes from nurse to forager during her life, there must be changes in the interplay between genes and some aspect of the individual’s environment)
