Development of Behavior – Flashcards

-Different working behaviors in bees depending on age. -Youngest=Nursing bees (clean cells, feed larvae and nest mates. -Middle aged=pack/storage of pollen -Oldest=pollen foragers Genetic: -greater amounts of "for" gene expression in foragers vs nurses. Hormonal: -Juvenile Hormone (JH) affects Nurse-Forager transition -Normally JH is low in Nurse bees, high in Foragers -Experiment: --Add JH to young bees, become young foragers (not as good as old foragers). --Remove JH producing glad, N-F transition is very delayed if at all. --Can add JH after removal and restore normal N-F transition timing. --We can see that JH has a control on transition, but is it spontaneous? Social Interaction: -Is N-F transition affected by social interaction between bees of different or similar ages? -Experiment: --Created a colony of all young bees. --Added old foragers --Allowed colony to settle down then checked back --No young bees had transitioned to foragers -Experiment: --Created colony of all young bees again --Added different young bees so all were young --Found that a high percent of the original young bees had transitioned to foragers but added young bees didn't. -Results: -If there are no bees foraging, then young bees can transition to fill in the need, but if there are old foragers, then no young bees will transition. Physiological: -Older bees that are foraging will add a compound to the food when they regurgitate it for other bees. -Ethyl Oleate is involved with preventing JH from increasing, which slows the N-F transition.

Phenotypic Plasticity: can have the same genetic background, but their bodies and behavior change depending on their environment. Multiple females lay eggs in large ponds in spring. First eggs to hatch start eating insects first and grow fastest and largest. If there are lots of smaller salamanders around then you can see a cannibal niche form. If the smaller cannibals are related to the larger ones, you won't see cannibals, but if they are unrelated then you will see cannibal behavior. Possibly due to chemical sense but we aren't sure. Just know that the behavior only occurs if the environment is right. Phenotypic plasticity: differential gene expression based on different environmental conditions.

Birds will store seeds for later (caching). Will make a cache of seeds that they will come back to later. The trick is that they will be able to find it later. It turns out that the experience of having to hide and re-find food can make you better at doing both. Spacial learning study: -Gave birds access to bird feeders with whole seeds and some with powdered seeds. (Unlimited food). -Powdered seeds cannot be cached. -Birds with access only to whole seeds, ate a few seeds and then hid some for the future. -Birds that only had access to powdered seeds could only eat there and not hide them. -The whole seed group learned several locations where to hide seeds while powdered didn't. -Saw that those that could hide seeds grew a larger hippocampus (involved with special learning). -Saw that the brain/nervous system changed structure in response to experience.

Testing Hippocampus growth in London taxi drivers attempting to learn knowledge of entire city. -Apprentices trying to qualify for license. -Cab drivers who memorized 25,000 locations had larger posterior hippocampus areas compared to control groups and individuals who dropped out -Looked at MRI before and after training to determine that it was the act of learning that increased hippocampus size.

-During embryogenesis estrogen masculinizes the male brain by triggering growth in the song areas (HVC region). -Males have a MUCH larger song area than females -Males produce estrogen in the egg so no experiments can be performed on them, but females produce it later and can be experimented on Experiment with females: -Add estrogen pellets to food or insert implant under the skin of female nestling -Shows same growth in song areas as males do -As an adult they will often produce "male-like" songs when testosterone is later injected as a trigger.

-Singing behavior is innate, knowing what song to sing is learned -Nestlings sit in nest and hear father sing (days 10-50) -First have period of "subsong" where they are singing but it doesn't sound right b/c they are still learning and practicing. Brain is growing/developing. (days 150-200) -Then are able to produce full song. (after day 200) Experiment for developing song learning hypothesis: -Young males grown in isolation will never produce true song, even as adults. Raises questions about environmental factors that are missing. - Raised more males in isolation but played recorded songs by the same species. -Adults were able to sing their species specific song. -They have to hear the song within their critical period (this species is 10-50 days but varies by species) in order to learn it. -This occurs because during the critical period neural connections are being made when the bird memorizes the song he is supposed to sing.

Matching=that the bird is listening to the sounds it makes and matching them to the song that is encoded in the neural template Experiment: -Father with two children -Deafened one child AFTER the listening phase. -Even though the deaf child had heard its father sing, it couldn't hear himself sing, so it couldn't alter his song and tell if he was producing the right sound. Couldn't sing, could only chirp. -Showed they actually have to hear the sounds and hear their song to compare and determine if they have the right song

This gene is involved in re-wiring the brain for production of certain songs. By the time the bird has learned and developed a song similar to its tutor, the ZENK gene expression has tapered off. Expression deceases as the bird more closely matches his song to his tutor.

Involved in helping birds correctly memorize the song and in the right order. Expressed during the "listening phase". Experiment with zebra finches: -Used "knockdown technique" to disable the FoxP2 gene by inserting short segments of RNA into the gene to reduce expression. -Adult male tutors and young males were housed together. -Some young males had active FoxP2 some had disabled FoxP2. -The active ones showed accurate song learning while disabled ones showed big differences. -Determined FoxP2 is required for normal song development.

Idea that species are biased to learning their own species specific songs. Saw during song learning experiments that even when nestlings hear both conspecific and heterospecific songs at the same time during their critical period, when they grow up and hear themselves sing, they will produce the conspecific song. Found that sometimes birds would take one or two notes from another species and put it in their own song. They weren't completely ignoring other species, but were biased toward their own. Experiment: -Raised White-crowned sparrows in lab in isolation. Played recording for their species and two other species, found the males would learn WCS song and not others. -But if bird grows up with male of different species, will ignore the recorded song of their own species and learn song of male they live with. Idea that birds can pick up on social cues and over-ride their species bias, learning the song of the male they are raised near. Social interaction over-riding species bias.

-Different dialects within species depending on where they live. -Can switch dialect when they arrive at a new place based on what neighbor sounds like. -Main reason for switching dialects is for mate acquisition since it makes it easier for females to compare males if they sing the same song. Switching allows new arrivals to not be disadvantaged compared to natives.

1.) For males to attract females -Males establish territory and sing to attract females. -Researcher allowed them to set up territories. -Had a set of studies where some males had mates and some didn't. -Compared singing frequency: --Males with mates didn't sing while those without them did. --Captured mates and the males then sang again. --Releasing females into territory and males who acquired females shut up. --Found a HUGE amount of singing in areas where they removed female mates. -WCS females have been observed to be attracted to songs of male WCS and not songs of other species -Playback Experiment showed that females went to where their own species' song was playing. 2.) Indicate territory to other males

Experiment: -Had a speaker playing a recorded song next to a perch. -Recorded how long females spent on the perch near the speaker. -Found females preferred songs with longer bursts over shorter bursts. -Shows sexual selection for more complex songs.

Yep, singing indicates territory. Experiment: -allowed males to set up territory -removed a male from a territory to make an empty territory -In experimental groups they had a playback of a bird song of the same species and recorded how often males intruded on the territory. -Control group was left empty -Many intrusions in empty territory, few intrusions in territory with recorded song.

-Allows greater complexity of song (sexually selected) -Can demonstrate ability to sing better than the guy next door - so attracts more females -Allows flexibility of song - can match dialects which may improve ability to dominate the neighbor guy -Allows flexibility of song - Can tailor song to females

Most song birds. Individuals must hear a tutor sing its conspecific song shortly after hatching (critical period) in order to learn the song correctly.

Rarer. Ex: Canaries Individuals can acquire new song elements throughout life.

Ex: Brown-headed cowbird Doesn't set up a territory or build a nest. Females lay their eggs in nest of different species. Egg will hatch and be grown by the other species b/c birds think if the egg is in their nest, then it must be there's. It turns out that if you raise a baby cowbird in isolation, never hearing a song, it will grow up and still sing a cowbird song. -They DO NOT learn their song, it is INNATE. This allows them to grow up in a different species nest and still grow up to attract cowbird mates.

Cowbirds used as example. They live in large flocks and sing in the spring. The strength of their song is dependent on their social rank in the flock, which is determined by age (older=better). -Birds grown in isolation and released into flock will try to sing dominate songs and then get attacked until they learn that they are low in rank and shouldn't sing dominantly. Experiment: -They reared male cowbirds in the lab with different social situations. -Some grown in isolation -Some grown next to adult male unable to see him but can hear him -Some grown next to adult male unable to see or hear him -Some grown with full contact with adult male Results: -Females preferred males grown in isolation or males unable to see adult male but able to hear him. -Determined to be due to the fact that males grown with little to no contact with adults were never taught to not be dominate and would sing dominate song, which females were more attracted to. -If grown up in sight of male or in full contact they didn't sing a very nice song, kept it very low dominance.

Experiments involved raising males with females of other species. Results: males are born knowing their species-specific song but they alter it to please their audience --Males couldn't learn dialect b/c females don't sing. But can alter song when he hears one she likes. Will settle on one dialect based on what female prefers.

Imprinting is a type of learning which has -a critical period -Is triggered by specific stimuli -Is more-or-less permanent (thought might be modifiable slightly)

Konrad Lorenz was a classical ethologist who studied filial imprinting in geese. His basic protocol: divide clutch of eggs into two groups. One group remained in nest with the mother goose. The other he placed in an incubator and tended to himself. Noticed behavior indicative of imprinting: Following Behavior. Found two things that really mattered for imprinting to occur. --Movement --Sounding like a goose. Depending on circumstances there is more flexibility in imprinting than Lorenz previously thought.

Used mechanical tracks to imprint duckling to follow objects around in a circle. Could use various objects as long as they moved and played sound. Found in some experiments with sound that there is some species specificity in ducklings preferring sounds of their own species. To determine if preference for sound is innate or learned they ran a few experiments: -Isolated clutch of eggs from mother, both control and experimental groups preferred mallard sounds. Likely due to eggs imprinting each other right before hatching -Isolated individual eggs, but still showed preference for mallard sound. Likely due to imprinting itself while chirping in the egg -Isolated eggs, cut vocal cord while in egg so it was mute and never heard any bird sound. It was shown to not have any preference for one sound over another. Determined that ducklings actually learn what their mother should sound like by listening to itself.

Developed method to determine how imprinted chicks were. Ex: imprinted chicks to red box, their running rate toward the box (while on a wheel) is related to their level of imprinting. Compared to control that weren't imprinted on box. Wanted to find the active brain regions when chick sees imprinted object. One region, IMHV, was active while looking at the imprinted stimulus and was specific to that stimulus (presented different shapes and colors and only the Red Box from previously triggered the release). Wanted to determine what neurotransmitters are involved in visual imprinting in chicks. Found that trained chicks released more glutamate when they saw a stimulus than untrained chicks seeing the same stimulus. Additionally, they saw synaptic plasticity which is a sign of learning GABA and Glutamate are neurotransmitters involved in imprinting.

Took knowledge of imprinting behavior and applied it to a conservation problem. Very few numbers to start with, went practically extinct in 1900s when feathers and plumes were very popular, hunted for their feathers. Had about 38 left, were able to be brought back to almost 500. This was done by taking away eggs from females once they were laid, this would trigger her to lay an egg almost immediately (females only rear one egg). So one raised in wild and the removed one was raised in captivity and then released. The released ones did not know where to migrate to. Found that behavior to migrate was innate but where to go was learned. Often the route taken by the birds is not learned from parents but by natural selection. Birds who fly with their parents and find a route good or bad will adjust their flight path when they grow up. Solved migration problem by imprinting birds on small flying craft (Ultralight) then flew the route they would normally take in the wild. The imprinted cranes followed the craft. They got a large enough population that knew the path, but eventually stopped the operation because these birds didn't have good parenting skills. They knew the route but not how to raise their offspring, so the infant survival rate wasn't as high as they would like.