movement in diff temps

effect of temp

optimal range in middel

thermodynamics if too called reaction rates decrease, capacity limitations

if too hot damage, proteins membranes, critical T death

marine animals thermal regulation

have very limited scope for thermoregulation as the enviornemnt is fairly homogenous. you don’t have warm or cool spots animals can exploit so their body more or less follows the water temp. may change seasonally or with major weather events.

• Adjust internal biochemical raes - regulate cellular and biochemical capacities (acclimation) so they adjust the thermal sensitivity of their biochemistry

• optima differ in different environments

regulating body temperature

• physiologically : internal heat production

• coevolution: biochemical processes are optimised at that T(little b)

• endothems are not independent from external enviornremtns

Changing blood flow

• chanign the bloodflow to the periphery to dump as much heat as possible

• in winter opposite, you get cold hands because your perfusion to your hands is reduced heat transfer with the enviornement

• cardiovascular changes

• changes in blood flow

• control rates of heat transfer

• endotherms and ectotherms both engage in behavioural

Behaviourally

• high heterogeneity in environment

• Microhabitat selection, pick thermal enviornements

heat transfer types

• radiation

• conduction

• convection

radiation

• short wave solar radiation

• long wave thermal radiation - any object of any temperature that will radiate electromagnetic or thermal electromagnetic waves. that will differ on the temp of the object relative to it’s enviornement

  • example - your sitting in front of a fire that is several 100 degress and your’re at 36 so you gain a lot of thermal regulation from the fire

  • assumption that most animals are similar temp to their enviornements so thermal radiation is relativley uninimportatn

• different surfaces absorb different rates, different colours, how exposed you are

• wave energy changes with wave length

• low wavelengths have a lot less energy

• animals can exploit the energy coming onto the earths surface all the time

conduction

• heat exchange within a solid

• between two solids

• temperature differential within solid

• molecules have different energetic state

• exchange of energy over time

• conductivity: rate at which energy is exchanged

• thickness and area of the material

• lots more heat exchange the bigger the temperature differential

• many animals will lie flat on the ground to exchange heat with their surroundings

particles with warmer energy carry higher levels of energy. eventually will equiblirate as particles bump into each other and exchange energy each time. the way they bump into each other depends on the amterial

convection

• heat exchange between a fluid and a solid, simply wind or water with surface

• temperature differential between fluid and solid

• boundary layer depends on flow

• heat exchnage will begreatest at the surface of the animal and decreases as you get further away

• convection coefficient: rate at which energy is exchanged within boundary layer

• there is a certain parameter that determines how much heat is exchanged between a particular fluid and an animal’s surface.

• much higher in water as water has high heat capacity

operative temp

• consider all heat exchange at (animal) surface

• single temperature describing thermal enviornement

• conceptually it is an ‘average’ surface temperature

• calculated from heat transfer equations

• energy balance at the surface

behaviour or random?

reptile experiment,

• take a Tb measurement from individuals

• plot a frequency of observation s

• compare means, variations

someone then did same experiment with beer can and showed that if you placed it in any random thermoreguoations you can get a random frequency distribution anyways

1. observe thermoregulatory behaviour directly

2. use a control

   1. null-model: tb of an animal that moves/behaves randomly

   2. compare measured Tb of real animal to null-model

• crockidles move between water and sun

• behaviour predictable and correlated with Tb

• relativley stable Tb during the day

• radiotransmitter inserted and it beeps at a certain frequency

• no experimental control

• cannot assess regulation

• compare T(little b) to theoretical animal that is not thermoregulating

• random operative temperature distribtuions

• provides control

• you can use random operative temperature controls or like the beer cans make like copper models (like lizards)

Effectiveness of thermoregulation

1. determine “selected” t(little b)

   1. ideal Tb with no constraints

   2. thermal gradient in lab

2. Measure Tb of animals in the field

3. measure null-distributions

   1. random distrubtion of operative temperatures

4. determine

If they thermoregulate actual body temperatures should be closer to selected temperatures than random temperature

species distrubtion

effort animals have to put into thermoregulate, eg. the behavioral functions of iguanas and the crocs.

of high efficiency of thermoregulation it may be a high cost, if low efficiency it may be the animal has no control over it’s body temp.

species range

• does theermoregulation limit distributions

• thermoregulate to the same Tb

• Is the same thermoregulatory efficiency required

• mean tb differens between sites (latitudes)

• thermoregulatory efficiency differs between latitudes

• different thermoregulatory efforts

• species distribtuion tied to thermoregulatory ability

important to look towards conservation areas in the future and thermoregulatory ares

conservation physiology

• Understanding thermoregulatory behavior and efficiency is crucial for conservation because:

  • Climate change alters thermal environments, potentially making current habitats unsuitable for some species.

  • Thermoregulatory refuges (microhabitats providing optimal temperature conditions) become critical for species survival.

  • Protecting areas with diverse thermal landscapes allows animals to behaviorally thermoregulate effectively.

  • Conservation planning must consider how species’ thermoregulatory limits influence their range shifts in response to warming climates.

  • Failure to preserve thermally suitable habitats may reduce species distributions and increase vulnerability to extinction.