Behavior: Behavioural Development

  1. Altricial young
    • Born relatively helpless, often with little or no fur or feathers generally incapable of locomotion or ingestion of solid food
    • E.g. Humans, song birds, mice, kittens, puppies
  2. Percocial young
    • Born more advanced, capable of locomotion and other behavior patterns, consume some solid food.
    • E.g. horses, cattle, giraffe, fish, etc
  3. Innate behaviors
    • Sign stimulus
    • Innate releasing mechanism (IRM)
    • Fixed action pattern (FAP)
  4. Sign stimulus
    A specific stimulus that results in a specific behavior pattern.  One example is the red bellied stipled back. If it has a red belly (regardless of what shape it is) the fish will attack
  5. Innate releasing mechanism (IRM)
    A neural process triggered by the sign stimulus that preprograms an animal for receiving the sign stimulus and mediates a specific behvarioural response.
  6. Fixed action pattern (FAP)
    An innate behavior pattern that is stereotyped, spontaneous and independent of immediate control, genetically encoded and independent of individual learning.
  7. Supernormal stimulus
    • A stimulus that produces more vigorous response than the normal stimulus.
    • E.g. the cow bird that is laid in another bird's nest but gets the most food because it is larger, looks older and talks the loudest...
  8. Sensitive period
    • Time in the life of an animal when a small amount of experience (or lack of experience) will have a large effect on later behavior (experience ranges from internal to external factors)
    • e.g. In mammals a brief hormone signal from the genitals induces sex-related changes int he brain that ultimately mediate sex-typical behavior, and manipulating embryo hormones outside this period has no effect on adult behavior
  9. Sensitive period and intrauterine position
    • Many affects of intrauterine hormone exposure
    • Rodents, swine, 0M females more 'attractive"
    • Rodents, 2M females more aggressive
    • Also occurs in animals which normally have 1 offspring, females with male twins show "masculination" effects. Females can be sterile.
  10. Hormones
    • Possible to observe effect of a particular hormone by studying behavior: in the absence of the hormone (if absence is not lethal); after the injection of known amounts of the hormone
    • Used to investigate influence of testosterone on male sexual behavior in the rat
  11. Ways Prenatal Stress Can Affect Offsprin
    • Production: birth weight, mortality, reproductive status
    • Behavior: fear & anxiety, memory & learning, maternal behavior, aggression
    • Physiology: Immune status, glucose metabolism, HPA axis
  12. Fetal programming
    • Conditions during pregnancy influence health in later life
    • Heart disease, diabetes higher in people with low birth weights
    • Poor nutrition, drug and alcohol use, poverty
    • Intergenerational effects
    • Maternal nutrient restriction affects properties of skeletal muscle in offspring
    • Maternal nutrient restriction alters gene expression in the ovine fetal heart
    • Influence of matternal undernutrtion and overfeeding on cardiac ciliary neurotrophic factor receptor and ventricular size in fetal sheep
  13. External factors after birth
    • Handled rat pups
    • open eyes sooner, heavier at later age
    • Less fearful in novel situation (open field test)
    • Mallard duck's strong response to mother's call depends on hearing the calls of other ducklings while they are still in the egg
    • Kittens vision needs to be primed with certain types of visual experiences (vertical and horizontal environments from 2wks-5 months)
  14. Pre-natal communication
    • Quail young emit clicking noises in the egg
    • 2 days prior to hatch chicks start to emit clicks (80-150/min)
    • If eggs are in contact chick hatch within a few minutes of each other
    • If eggs separated so they cannot communicate, hatching is spread over 2 days
    • Hens and chicks communicate through vocalizations prior to hatch
    • Communication may play a role in synchronizing the hatch
    • Commercial environments void of hen sounds
    • Influence choice by chicks, attracted to sounds heard during incubation
  15. Maternal effects and phenotypic plasticity
    • Mothers often play a role in determining the behavior of their offspring as adults
    • Phenotypic plasticity - genotype is flexibly expressed as different phenotypes, depending on the environment: Allows faster-than evolution adaptation to the environment.
  16. Adaptability of behavioral development
    • Harlow's "experiments" with Rhesus monkeys showed that rhesus monkeys entirely derived of contact with mothers and "reared" by artificial surrogates: gained weight, grew normally, behaviorally developed abnormally and were terrified of other monkeys if exposed
    • However, monkeys given even 15 min contact a day with other young monkeys developed essentially normally.
    • As adults: monkeys interacted normally unlike those individuals which had no social contacts as infants, which were withdrawn or very aggressive
  17. Maternal licking behavior
    • During first 2 postnatal weeks, rats do anogenital licking, males more than females.
    • This is important for brain development and behavior, including stress reactivity, emothionality, learning and memory, and sexual behavior.
    • It induces epigenetic changes after birth
    • DNA methylation patterns in the hippocampus cells of licked and non-licked varied
    • Mother's licking activity had the effect of removing dimmer switches on a gene that shapes stress receptors in the pup's growing brain
    • The well-licked rats had better developed hippocampi and released less of the stress hormone cortisol, making them calmer when startled
  18. Food preferences and mothers
    • Food choices by mother can influence offspring's food preference
    • Examples are mother's milk containing olfactory cue, breath, and observation
  19. Imprinting
    • Special form of learning
    • Precocial young form an attachment to and follow a large moving object in their environment
  20. Filial imprinting
    • Various behavioural changes whereby a young animal becomes attached to its mother (naturally) or another object
    • Occurs soon after birth or hatching
    • Birds and mammals
  21. Sexual Imprinting
    • Method by which animals learn to recognize speices for reproduction
    • Occurs later
    • ducks try to mate with Lorenz
  22. Sensitive period:
    • Time when animals can develop an attachment
    • eg. Puppies 3-13 weeks for forming normal social contacts
    • Rats: first week of life
    • Pigs: birth to 3 weeks
    • Young ruminants, first days
  23. Critical period
    • Part of sensitive period when the attachment response performance and reinforcement is greatest
    • E.g. Goats, the 1st hour after parturition, mother must smell and lick offsping
Card Set
Behavior: Behavioural Development
L:2 Behavioral Development