Editing Thermoregulation (section)

==Classification of animals by thermal characteristics==
===Endothermy vs. ectothermy===
Thermoregulation in organisms runs along a spectrum from [[endotherm]]y to [[ectotherm]]y. Endotherms create most of their heat via metabolic processes and are colloquially referred to as [[warm-blooded]]. When the surrounding temperatures are cold, endotherms increase metabolic heat production to keep their body temperature constant, thus making the internal body temperature of an endotherm more or less independent of the temperature of the environment.<ref name="Khan Academy">{{Cite web|url=https://www.khanacademy.org/science/biology/principles-of-physiology/metabolism-and-thermoregulation/a/endotherms-ectotherms|title=Khan Academy|website=Khan Academy|language=en|access-date=2017-04-03}}</ref> Endotherms possess a larger number of mitochondria per cell than ectotherms, enabling them to generate more heat by increasing the rate at which they metabolize fats and sugars.<ref name="Boundless">{{Cite journal|last=Boundless|date=2016-09-20|title=Homeostasis: Thermoregulation|url=https://www.boundless.com/biology/textbooks/boundless-biology-textbook/the-animal-body-basic-form-and-function-33/homeostasis-194/homeostasis-thermoregulation-743-11974/|journal=Boundless|language=en|access-date=3 April 2017|archive-date=4 April 2017|archive-url=https://web.archive.org/web/20170404045811/https://www.boundless.com/biology/textbooks/boundless-biology-textbook/the-animal-body-basic-form-and-function-33/homeostasis-194/homeostasis-thermoregulation-743-11974/}}</ref> Ectotherms use external sources of temperature to regulate their body temperatures. They are colloquially referred to as cold-blooded despite the fact that body temperatures often stay within the same temperature ranges as warm-blooded animals. Ectotherms are the opposite of endotherms when it comes to regulating internal temperatures. In ectotherms, the internal physiological sources of heat are of negligible importance; the biggest factor that enables them to maintain adequate body temperatures is due to environmental influences. Living in areas that maintain a constant temperature throughout the year, like the tropics or the ocean, has enabled ectotherms to develop behavioral mechanisms that respond to external temperatures, such as sun-bathing to increase body temperature, or seeking the cover of shade to lower body temperature.<ref name="Boundless"/><ref name="Khan Academy"/>

===Ectotherms===
{{Main|Ectotherm}}

[[File:BFAL SOTE shade.JPG|thumb|upright=1.1|Seeking shade is one method of cooling. Here [[sooty tern]] chicks are using a [[black-footed albatross]] chick for shade.]]

===Ectothermic cooling===
* Vaporization:
** [[Evaporation]] of sweat and other bodily fluids.
* Convection:
** Increasing blood flow to body surfaces to maximize heat transfer across the advective gradient.
* Conduction:
** Losing heat by being in contact with a colder surface. For instance:
*** Lying on cool ground.
*** Staying wet in a river, lake or sea.
*** Covering in cool mud.
* Radiation:
** Releasing heat by radiating it away from the body.

===Ectothermic heating (or minimizing heat loss)===
[[File:Lizard Thermoregulation.svg|thumb|The red line represents the air temperature.<br />
The purple line represents the body temperature of the lizard.<br />
The green line represents the base temperature of the burrow.<br />
Lizards are ectotherms and use behavioral adaptations to control their temperature. They regulate their behavior based on the temperature outside, if it is warm they will go outside up to a point and return to their burrow as necessary.]]
* Convection:
** Climbing to higher ground up trees, ridges, rocks.
** Entering a warm water or air current.
** Building an insulated nest or burrow.
* Conduction:
** Lying on a hot surface.
* Radiation:
** Lying in the sun (heating this way is affected by the body's angle in relation to the sun).
** Folding skin to reduce exposure.
** Concealing wing surfaces.
** Exposing wing surfaces.
* Insulation:
** Changing shape to alter surface/volume ratio.
** Inflating the body.
[[File:wiki stranglesnake.jpg|thumb|[[Thermographic]] image of a snake around an arm]]
To cope with low temperatures, some [[fish]] have developed the ability to remain functional even when the water temperature is below freezing; some use natural [[antifreeze]] or [[antifreeze proteins]] to resist ice crystal formation in their tissues.<ref name=":1">{{Cite journal|last1=Crevel|first1=R.W.R|last2=Fedyk|first2=J.K|last3=Spurgeon|first3=M.J|date=July 2002|title=Antifreeze proteins: characteristics, occurrence and human exposure|url=https://linkinghub.elsevier.com/retrieve/pii/S027869150200042X|journal=Food and Chemical Toxicology|language=en|volume=40|issue=7|pages=899–903|doi=10.1016/S0278-6915(02)00042-X|pmid=12065210}}</ref> [[Amphibian]]s and [[reptile]]s cope with heat gain by evaporative cooling and behavioral adaptations. An example of behavioral adaptation is that of a lizard lying in the sun on a hot rock in order to heat through radiation and conduction.{{cn|date=March 2025}}

===Endothermy===
{{Main|Endotherm}}

An endotherm is an animal that regulates its own body temperature, typically by keeping it at a constant level. To regulate body temperature, an organism may need to prevent heat gains in arid environments. Evaporation of water, either across respiratory surfaces or across the skin in those animals possessing [[sweat glands]], helps in cooling body temperature to within the organism's tolerance range. Animals with a body covered by fur have limited ability to sweat, relying heavily on '''panting''' to increase evaporation of water across the moist surfaces of the lungs and the tongue and mouth. Mammals like cats, dogs and pigs, rely on panting or other means for thermal regulation and have sweat glands only in foot pads and snout. The sweat produced on pads of paws and on palms and soles mostly serves to increase friction and enhance grip. [[Bird]]s also counteract overheating by '''gular fluttering''', or rapid vibrations of the [[Gular skin|gular (throat) skin]].<ref>{{Cite book|last=Hill|first=Richard|title=Animal Physiology|publisher=Sinauer|year=2016|isbn=9781605354712|pages=270}}</ref> [[Down feathers]] trap warm air acting as excellent insulators just as hair in mammals acts as a good insulator. Mammalian skin is much thicker than that of birds and often has a continuous layer of insulating fat beneath the dermis. In marine mammals, such as whales, or animals that live in very cold regions, such as the polar bears, this is called [[blubber]]. Dense coats found in desert endotherms also aid in preventing heat gain such as in the case of the camels.{{cn|date=March 2024}}

A cold weather strategy is to temporarily decrease metabolic rate, decreasing the temperature difference between the animal and the air and thereby minimizing heat loss. Furthermore, having a lower metabolic rate is less energetically expensive. Many animals survive cold frosty nights through [[torpor]], a short-term temporary drop in body temperature. Organisms, when presented with the problem of regulating body temperature, have not only behavioural, physiological, and structural adaptations but also a feedback system to trigger these adaptations to regulate temperature accordingly. The main features of this system are ''stimulus, receptor, modulator, effector'' and then the feedback of the newly adjusted temperature to the ''stimulus.'' This cyclical process aids in homeostasis.{{cn|date=March 2024}}

===Homeothermy compared with poikilothermy===
[[Homeothermy]] and [[poikilothermy]] refer to how stable an organism's deep-body temperature is. Most endothermic organisms are homeothermic, like [[mammal]]s. However, animals with [[facultative endothermy]] are often poikilothermic, meaning their temperature can vary considerably. Most [[fish]] are ectotherms, as most of their heat comes from the surrounding water. However, almost all fish are poikilothermic.{{cn|date=March 2024}}

=== Beetles ===
The physiology of the [[Dendroctonus micans]] beetle encompasses a suite of adaptations crucial for its survival and reproduction. Flight capabilities enable them to disperse and locate new host trees, while sensory organs aid in detecting environmental cues and food sources. Of particular importance is their ability to thermoregulate, ensuring optimal body temperature in fluctuating forest conditions. This physiological mechanism, coupled with thermosensation, allows them to thrive across diverse environments. Overall, these adaptations underscore the beetle's remarkable resilience and highlight the significance of understanding their physiology for effective management and conservation efforts.<ref>{{Cite web |last=Benzel |first=Joseph |date=18 June 2015 |title=Great Spruce Bark Beetle Dendroctonus micans (Kugelann) |url=https://idtools.org/pdfs/low/Dendroctonus_micans_LoRes.pdf}}</ref>