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
Born more advanced, capable of locomotion and other behavior patterns, consume some solid food.
E.g. horses, cattle, giraffe, fish, etc
Innate releasing mechanism (IRM)
Fixed action pattern (FAP)
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
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.
Fixed action pattern (FAP)
An innate behavior pattern that is stereotyped, spontaneous and independent of immediate control, genetically encoded and independent of individual learning.
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...
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
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.
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
Ways Prenatal Stress Can Affect Offsprin
Production: birth weight, mortality, reproductive status
Behavior: fear & anxiety, memory & learning, maternal behavior, aggression
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
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
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)
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
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.
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
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
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
Special form of learning
Precocial young form an attachment to and follow a large moving object in their environment
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
Method by which animals learn to recognize speices for reproduction
ducks try to mate with Lorenz
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
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