Lecture 3 Flashcards
What is SMR?
The sum of all the metabolic processes that have been taken on by the animal
Why do we measure field metabolism?
. Energy fluxes between an animal and its environment
. To estimate the energy required for various behaviours (so if you want to look at different behavioural decisions then we need to have a metabolic component to it because these are costs
. To estimate the actual food consumption of individual animals (therefore what status is it in- negative/ positive state balance)
. To estimate the food requirements of populations (so an estimate of their impact within some ecosystems and environments, and when it comes to human-wildlife conflicts- whether there is any conflict
How do you measure a animals metabolism in the lab?
. Food intake (can’t that this into the field but it is difficult to measure any sort of accuracy)
. Calorimetry
. Respirometry (although we can take this into the field as well)
(We are not measuring metabolic rate in any of these techniques it is about estimating the metabolic rate)
How do you measure metabolism in animals in the wild?
. Time energy budget (is the simplest one)
. Doubly labelled water
. Heart rate
. Accelerometry
(We are not measuring metabolic rate in any of these techniques it is about estimating the metabolic rate)
What is time energy budget?
It is a method of measuring the energy expenditure of the animal just through observation
How does time energy budget work?
. You continuously record the behaviour of the animal
. measure how long the animal spent performing each behaviour
. Assign energy values to each behaviours (have to undertake some laboratory investigations to find out how much things cost (resting, running- different speeds) then can use these to translate the time budget into energy budgets. Can also use information from research literature
. Calculate the overall energy expenditure
What are the problems/ constraints of the time energy budget technique?
. MR of individual behaviours has to be known
. Difficult to use accurately as other factors will affect the MR
. Need to confirm to standard operative temperature (especially ectoderms)
. Labour intensive (to follow the animals to record the behaviours)
(. Is technically easy though)
What is probably the most used method within ecological studies when estimating the metabolic rate in free living animals (wildly used)? What
Doubly labelled water (DLW)
How does the doubly labelled water technique for estimating the metabolic rate in free living animals work?
Inject the animal with water that is labelled with heavy oxygen O18 (is an isotope of oxygen that has extra neutrons).
Can also inject them with heavy water that has the hydrogen labelled (has an extra proton).
Eventually these injected substances will mix with the overall water of the animal but over time that water is turned over.
What is good about using O18 in the technique of estimating the metabolic rate of an animal, doubly labelled water?
It is not radioactive, it is stable, just heavier and we can detect it
What is good about using water that has the hydrogen labelled in the estimating metabolic rate technique doubly labelled water?
It is invert
How is the heavy water that has the hydrogen labelled in the technique of measuring metabolic rate doubly labelled water lost?
Will eventually mix with the overall water of the animal but over time that water is turned over. It will only be lost as water
How does the injected water that is labelled with heavy oxygen O18 in the estimating metabolic rate technique doubly labelled water lost? How is this used?
It is lost as water but also as CO2
So you record differences in the rates of loss and equates to the rate in which CO2 is produced, so can estimate how much CO2 is produced
Give a brief overview of the case study for the technique of estimating the metabolic rate of animals using doubly labelled water. Case study is on squirrels
Catch the squirrel, weigh it, tag it, take a background sample, then inject it with doubly labelled water, take another blood sample, release and then hopefully 24h or 48h later you recapture the animal, can’t weigh at three days because will have gone back to background levels
What are the errors associated with using doubly labelled water on more energetic animals?
. When you start using more energetic animals the estimates become much higher, so can get some extremely high deviations from the estimate to the actual measured results
How does the heart rate technique of estimating the metabolic rate of animals work?
They can have their heart rate recorded constantly by something planted inside it and storing data every 30 seconds. Using these we can record the animals for anything up to about a month constantly. New ones can do it over about a year
Why do we use heart rate to estimate the metabolic rate of animals?
Because heart rate and oxygen consumption are intimately linked. They should change consistently together provided cardiac stroke volume and tissue oxygen extraction remain constant or change systematically if they do then this equation holds true.
So, one can predict the other, measure heart rate because it is relatively easy to record and then can estimate oxygen consumption
What is the optimal strategy tit for tat? What is good about it? What can sometimes happen?
Is doing what your opponent did in the last move.
So this is slightly more cooperative and slightly less aggressive as it encourages the more cooperative strategies to be optimal.
Sometimes you can have several optimal strategies but sometimes it can lead to cooperative strategies
What does a good memory encourage?
Encourages more cooperative strategies to be optimal
What is turn based play with memory?
If you put two individuals together that have adopted different strategies and you play it over and over again and then tot up the payoffs that each player gets. The players can each remember what the other player did in the last turn
What does adding spatial structure increase?
The viability for cooperative strategies
What is a non-continuous game?
Is a small game with a set number of strategies that is well defined, compact game
What is a continuous game?
Can have an infinite number of strategies, less well bound game. You get various optimal strategies but sometimes can lead to more cooperative strategies (there are various things that can encourage cooperative strategies)
