Lecture 5, part 5- Foraging (what to eat)- Generalists versus specialists. Flashcards
Give an example of an animal which is a dietary specialist.
Give an example of an animal which is a dietary generalist.
What does this make them?
How do they do this?
What would humans be considered?
Koala- eat eucalyptus leaves.
Rats- learn what is good and bad to eat- eat different types of food.
Successful.
Conditioning- conditioned taste aversion.
Generalist- eat anything.
Rats- Conditioned taste aversion:
What are rats well prepared to learn?
What can they associate with each other?
What will this make them do?
What can they not learn?
What is used to induce nausea in rats?
Was this studied experimentally?
What foods are good + not good to eat.
The feeling of nausea with a particular food- even if it occurs hours later.
Avoid that food.
Cant associate sounds with nausea + not put off foods due to foot shocks.
Radiation.
Yes.
What do rats also exhibit?
What does that mean?
Where has this been studied?
What can rats do?
Social learning of food preferences.
Can learn which foods are good to eat.
In a lab- using flavours like cinnamon and cocoa.
Transfer info with each other about which foods are good to eat.
Social learning of food preference:
Explains what happens in 3 steps.
Is this the paradigm usually used to investigate this?
1) Demonstrator rat eat foods with a particular odour.
2) Observer rat is allowed to interact with the demonstrator rat- can smell them.
3) Observer subsequently has a preference for the food ate by the demonstrator.
Yes.
Continuation from social learning of food preference:
What did data from the experiment show?
When the demonstrated diet was cocoa based- observers ate more cocoa flavoured food- this is the same for when their diet was cinnamon based (ate less cocoa then).
Continuation from social learning of food preference:
When does social learning of food preference occur?
Due to social learning, what don’t some rats need to do?
When:
1) Offspring- of wild rats- brought into lab.
2) Food deprived + non-food deprived rats.
3) Unfamiliar + familiar demonstrator-observer pairs.
4) Young + adult rats.
5) Rats choosing fluids + solids.
Go out and experience the consequences of eating bad things- can learn from other rats.
Continuation from social learning of food preference:
What is the proximate mechanism?
What happens when rats experience a particular smell of food combined with that?
When can this effect also be produced without?
What is the ultimate causation?
Compound found in rats breath- carbon disulfide.
They will have increased preference for that food.
Without a demonstrator rat- as long as carbon disulfide (in their breath).
Learn to consume nutritionally balanced diet + avoid toxins.
Dietary specialism versus generalism:
What might the ability to form conditioned taste aversions be?
If this is true, then what should happen?
Would this be the case for dietary specialists?
An adaptation.
Other mammals- which are generalists- should form conditioned taste aversions.
No.
Give an example of an animal which is a dietary generalist.
What do big brown rats eat?
Name a bat which is a specialist.
What do they eat?
Bats like big brown ones.
Variety of insects.
Vampire bats.
Blood of other animals- like birds and mammals.
Specialist and generalist bats- comparing them based on their ability to form taste aversions:
In an experimental lab study, what was each species provided with?
What happened after after feeding?
When could it have happened?
Food or blood flavored with citric acid.
Experimental group- injections of LiCl- induces nausea.
Control group- received IP saline- does nothing.
Immediately after or delayed.
Continuation from specialist and generalist bats- comparing them based on their ability to form taste aversions:
What did the results from the study show?
Who continued to eat it?
Saline injection + other injection later- still keen on eating flavoured food. Other injection (toxin)- immediately or shortly after eating- had a strong conditioned taste aversion for the food- did not eat it after.
Vampire bats- did not form taste aversions- in the wild they do not need to do this (learn what is good or bad)- only feed on blood.
What can researchers use?
PCR tool- shows DNA in poo of bat- can see which animal they get blood from.
What dont vampire bats have?
Why?
What is not important to them?
Give an example of mammal which does not need to tell the difference between food- has lost it.
Sweet taste receptor gene.
Extremely narrow diet- only blood- stopped ability to taste less important food.
Tasting and having a preference for different foods as they only feed on blood.
Pandas- specialist- eat bamboo only.
Food identification for vampire bats:
What do vampire bats use to locate prey?
What do they use to detect warm blood flow close to the skin?
Olfactory cues (smell).
Infrared sensors.
